"Dark Matter and Dinosaurs". Chapter from a book. Harvard physicist has a radical new theory of human existence

Recent research on this mysterious substance suggests a scenario in which it could be "guilty" of the extinction of the dinosaurs, or at least the fact that comets hit our planet.

Although the sequence of events linking dark matter to dinosaurs or comets is still rather fuzzy, the speculation itself is intriguing because it involves two important astronomical questions: the nature of dark matter And change in flight directions of space objects. The idea of ​​unknown dark matter was born at the moment when scientists discovered that there is some inexplicable gravitational force in the Universe that makes galaxies move. And last year, Lisa Randall and Matthew Reece of Harvard University, along with their colleagues, developed a model that suggests that dark matter is some kind of invisible thin disks lurking in galaxies, or located at a certain angle along the towards them.

Oort cloud is a hypothetical spherical region solar system, serving as a source of long-period comets. Instrumentally, the existence of the Oort cloud has not been confirmed, but many indirect facts point to its existence.

Just as the solar system revolves around the center of our Milky Way galaxy, so does the galaxy move up and down about every 70 million years. This means that approximately every 35 million years a disk of dark matter must cross the galaxy.

Randall and Rees note that this cycle correlates with the timing of comet impacts on Earth.

This is what made the researchers wonder if there is a connection between the falls of celestial objects and the passage of the solar system through dark matter. In their opinion, when this happens, first, the disk exerts a stronger gravitational pull on the solar system. Such a force could disrupt the Oort Cloud, thereby tearing out a number of comets from it and sending them into our system.

So, for example, last year it was from the Oort Cloud that it flew to us. Second, when researchers looked at craters on Earth larger than 20 kilometers that were created in the last 250 million years, they noticed that the frequency and depth of these craters increase precisely in the 35-million cycles when the solar system should have shifted. However, the comet impact crater, formed about 66 million years ago, doesn't exactly match the proposed model, but Randall says it's pretty close.

Another complicating point for analysis is that craters on Earth remain from both comet impacts and asteroid impacts. But only comets from the Oort Cloud are initially far enough away to be attributed to the influence of dark matter.

Scientists hope that in the future they will be able to distinguish and analyze in more detail different types of impacts on the earth's surface. Luigi Foschini of the Astronomical Observatory in Milan says such theories are essential to science.

astronomer, observatory in Milan I think it's always worth putting forward as many hypotheses as possible.

However, in his opinion, there is still too little evidence of a connection between the frequency of comet impacts and the theory of a dark matter disk.

We cannot see or feel it. But Lisa Randall believes that dark matter can explain a lot about our universe - including the death of dinosaurs. But every astronomy buff knows that dark matter is a very elusive thing. We do not see it, we do not hear it, we do not feel it, we do not know what it tastes and smells like. Even with the most ingenious scientific equipment in the world, we have not yet been able to obtain evidence that this long-specified form of matter exists at all - although the universe is believed to be full of dark matter.

But if its existence is no longer in doubt, there are still many questions about dark matter - including the type of particles of which it is composed. And, along with other leading scientists, Harvard physicist Lisa Randall is trying to answer these questions.

Not so long ago, the senior science editor of the Huffington Post spoke with Randall, and as a result, an interesting interview was born, which we will share with you. It is always interesting to hear the opinion of a specialist on his topic, and even in an accessible language.

What is dark matter?

It is an elusive form of matter that interacts through gravity like ordinary matter, but does not emit or absorb light. Dark matter seems to exist everywhere in the universe. But we do not perceive it directly: only through its gravitational influence, since it interacts so weakly with the ordinary matter that we are used to.

Is dark matter made of atoms?

No. It does not consist of atoms or even elementary particles familiar to us like protons and electrons, which are charged and therefore interact with light. However, it is possible that dark matter consists of particles whose mass is comparable to those that we know. If this is the case, and if these particles are moving at the speed we can imagine, billions of dark matter particles are penetrating each of us every second. But no one notices.

If it's invisible, why do we call it "dark"?

Perhaps dark matter would be better with the name "transparent matter". What we usually call "dark" is something that, like your black shirt or jacket, absorbs light. But in the case of dark matter, light simply passes through it.

How do we know that dark matter exists?

We know it exists because we see its effects on stars and galaxies. With telescopes and other instruments, we can see that something other than the gravity of the stars and galaxies we observe is affecting the motion of those stars and galaxies.

Dark matter affects the expansion of the universe, the path that light rays take to reach us from distant objects, and many other measurable phenomena that convince us of the existence of dark matter. We know about dark matter - and its unconditional existence - by measuring gravitational effects.

The dark matter hypothesis was first put forward many decades ago. Tell us about it.

Dark matter was first proposed in 1933 by Fritz Zwicky, a Swiss astronomer at the California Institute of Technology. He came up with this idea after observing the speeds of stars in a giant group of gravitationally bound galaxies known as the Coma Cluster. It takes a certain amount of gravity to keep the fast-moving stars in a cluster from drifting apart. And based on calculations of the speed of stars, Zwicky calculated that the amount of mass that a cluster must have in order to have the necessary gravitational pull was 400 times greater than the contribution of the measured luminous mass - that is, the matter that emits light. To account for all this extra matter, Zwicky proposed the existence of what he called, dunkle materie, which is German for "dark matter".

Despite these early observations, dark matter was essentially ignored for a long time (and his estimate of the missing matter was actually too large). But in the 1970s, the idea was revived when astronomers observed the movement of satellite galaxies - small galaxies in the vicinity of larger ones - that could only be explained by the presence of additional invisible matter. These and other observations have brought dark matter into the realm of serious research.

But its status was greatly enhanced in the 1970s by the work of Vera Rubin, an astronomer at the Carnegie Institution in Washington. Rubin and her colleague Kent Ford found that the rotation rates of stars were pretty much the same at any distance from the galactic center. That is, the stars rotated at a constant speed even far beyond the region containing luminous matter. The only possible explanation was the presence of some unaccounted for matter that helped keep distant stars moving faster than expected.

The remarkable conclusion of these researchers was that ordinary matter accounted for only one-sixth of the mass needed to keep stars in orbit. Their observations were the most convincing evidence of dark matter at that time.

What is the current state of knowledge about dark matter?

Scientists have made great progress in understanding dark matter, but big questions remain. For a researcher like me, this is the optimal situation. Perhaps one could say that the physicists who study the "dark" participate in the Copernican revolution in a more abstract form. Not only is the Earth not physically the center of the universe, but our physical state is far from being central to most of matter.

Revealing the most basic elements of ordinary matter was difficult, but its study was much more straightforward than the study of the dark matter that surrounds us. Despite the weakness of its interactions, in the next ten years, scientists have a real chance to identify and determine the nature of dark matter. And as dark matter accumulates in galaxies and other structures, future observations of the galaxy and the universe allow physicists and astronomers to study it in new ways.

What can new discoveries about dark matter tell us about the origin of the universe?

No one knows how the universe began, and understanding dark matter will not necessarily bring us new ideas. But the existence of dark matter helps us understand how the universe evolved and how structures like galaxies formed. If dark matter has special properties, these could be reflected in galaxy sizes and distribution.

What about the existence of multiple universes - the so-called multiverse?

Dark matter and multiple universes are not really related in any way. We know about dark matter from its effects on the expansion of the universe, among other things. Other universes may be even darker matter in the sense that they are so far away from us that they won't affect us gravitationally even once in the lifetime of the universe. But that also means we can't study them by observation. I prefer to study the "multiverse", which is here and now.

What is the connection between dark matter and dinosaurs that you wrote about in your book?

My colleagues and I believe that dark matter may have ultimately (and indirectly) been responsible for the extinction of the dinosaurs. We know that 66 million years ago, an object at least 10 kilometers wide fell to Earth from space and destroyed land dinosaurs, as well as three-quarters of the other species on Earth. This object could be a comet from the Oort belt, a hypothetical region of comets and other bodies outside the orbit of Neptune. But why this comet was knocked out of its stable orbit in the Oort belt, no one really knows.

Our guess is that during the passage of the solar system through the middle plane of the Milky Way galaxy, it collided with a disk of dark matter that knocked out this distant object, resulting in a catastrophic collision. In our galactic neighborhood, the bulk of dark matter surrounds us in an incredibly smooth and diffuse spherical halo.

The illustration shows the movement of the Sun through the galactic plane.

The type of dark matter that triggered the demise of the dinosaurs was distributed very differently from most of the dark matter in the universe. This additional type of dark matter should have left the halo untouched, but its excellent interaction caused it to condense into a disk - right in the center of the Milky Way's plane. This thin region became so dense that as it passed through and the Sun oscillated up and down as it moved through our galaxy, the gravitational influence of this disk was incredibly strong.

Its gravitational pull was powerful enough to knock out comets at the outer edge of the solar system, where the Sun's opposing pull was too weak to bring them back into place. The escaped comets were ejected from the solar system or - instantly - redirected to the inner solar system, where they could potentially hit the Earth.

If dark matter can explain the demise of the dinosaurs, can it also explain how life on Earth began?

Material falling to the Earth, like comets and asteroids, almost certainly played a role in determining the Earth's composition and could also play a role in starting key life processes. Most of these theories remain speculative, but fit well with the picture of the world and are worth the effort expended on them.

And if dark matter can send dangerous comets or asteroids in our direction, should we worry?

Of course, sometimes asteroids come pretty close. Collisions will undoubtedly occur, but their expected frequency and magnitude remain a matter of debate. Whether something will hit us, whether it will damage us over time and whether we should worry about it, these are still unresolved questions. Personally, I do not consider this the greatest danger to humanity.

Should we be worried? It depends on the scale, the cost, the threshold of our concern, the decisions society makes, and whether we can deal with the threat. Such threats rarely cause a stir, even if there is potential damage. And although they can indeed strike and destroy a large population center, the chances that this will happen in the foreseeable future are negligible.

Your view of space as a physics is different from the view of people who are far from science. What wrong conclusions do such people draw about the universe?

There are many, but let me focus on the dark matter itself. Given that they have never seen it (not felt its warmth or smell), many people I talk to are surprised to learn about the existence of dark matter and find it very mysterious - or even ask if there is any errors. People ask how it is even possible that most of the matter - five times the amount of ordinary matter - could not be detected with modern telescopes.

Personally, I would expect something the opposite (although not everyone thinks so). It would be a much greater mystery to me if all the matter that we see with our own eyes were the only matter that exists. Why would we have perfect sense organs that almost everyone can feel? big lesson that physicists have gotten over the centuries is how much is hidden from our view. From this point of view, the question should sound different: why should everything we know converge with the energy density that it has?

Do you feel some greatness in the Universe? Or does your scientific knowledge put everything in its place?

When I began to focus on the ideas behind my book, I was amazed and fascinated not only by our current knowledge of the environment—local, solar, galactic, and universal—but by how much we hope to understand everything on our tiny island at all. here on Earth. I was also struck by the many connections between phenomena that allow us to exist at all.

Just so you understand, my point of view is not religious. I see no need to endow everything with purpose or meaning. Yet I helplessly feel what we tend to call religious emotions as I try to grasp the immensity of the universe, our past, and how it all fits together. You begin to look at stupid everyday life in a different way. This new research has allowed me to take a different look at the world and at the many pieces of the universe that created the Earth - and us.

Not so long ago, during spring break at Harvard, I decided to visit friends in Colorado, do some work there and go skiing. The Rocky Mountains are an excellent place for solitude and reflection, where the nights are as magnificent as the days. On clear nights, flashes of light from "shooting stars" - those tiny ancient meteoroids that are collapsing in the sky - illuminate the sky. One night, my friend and I stood at the house, mesmerized by the abundance of luminous objects tracing the dark sky. A couple of times quite noticeable meteors turned out to be in my field of vision, and then we saw a really large meteor, the trace of which did not disappear for several seconds.

Although I am a physicist, such spectacles often put me in a state of peace, and I simply enjoy them. This time, however, I thought about what kind of object it is and what its trajectory might mean. The meteor is the end of a 4.5 billion year story - a one-second flash indicating that the meteoric body traveled 50–100 km through the atmosphere before evaporating and disappearing. Most likely, it passed over our heads at an altitude of 50–100 km, which is why we see its trail as a large arc in the sky. That, in general, is all - a beautiful sight and something that we can at least partially explain. When I said that this wonderful picture in the sky was the result of the combustion in the atmosphere of a particle of cosmic dust or an object the size of a small pebble, my friend, who was not a scientist, was very surprised and declared that, in his opinion, it was an object no less kilometers across.

Our conversation quickly moved from the beauty of the night sky to the scale of the catastrophe that could be caused by a kilometer-sized object falling to Earth. The probability of an object of such a significant size colliding with the Earth is small, and the probability of any large object falling in a densely populated area is even less. Nevertheless, the appearance of the surface of the Moon (there are too few craters preserved on Earth to draw any conclusions from them) suggests that millions of large objects ranging in size from one to 1000 km across have collided with it during the existence of the Earth. However, most of these collisions took place billions of years ago during the Late Heavy Bombardment, which, despite its name, was observed shortly after the formation of the solar system, even before it became more or less stable.

Fortunately for life on Earth, the frequency of large meteoroid impacts has greatly decreased since the bombardment. Even a meteorite that recently fell in Siberia, filmed by video recorders and with the help of mobile phones, - The Chelyabinsk meteorite, which left a bright trail in the sky and on YouTube, was only about 20 m across. The only recent collision of an object of this magnitude, which my friend spoke of, was the fall of fragments of Comet Shoemaker-Levy on Jupiter in 1994. the object was larger and possibly several kilometers across before it broke apart. Evidence of the consequences that kilometer-sized fragments can lead to was a dark cloud the size of the Earth above the surface of Jupiter. Twenty meters across is a large object, but a kilometer across is a completely different matter.

However, one should not forget that the history of meteorites is connected not only with destruction. Meteor bodies and micrometeoroids, constantly falling on the Earth, also bring something good. Meteorites - fragments of meteoroids that have reached the surface of the Earth, could well be sources of amino acids, fundamentally important for the emergence of life, as well as water - another key component of life in the form in which we know it. Without a doubt, most of the metals we extract from the bowels of the earth also have extraterrestrial origin. It can also be argued that humans would not have come into being without the rapid rise of mammals that occurred after the meteorite impact of the Earth (see Chapter 12 for details) that wiped out the dinosaurs.

It's a giant mass extinction species, which happened 66 million years ago, is just one of many stories linking life on Earth with the evolution of the solar system. This book, about such a seemingly abstract substance as dark matter, which I am studying, is actually devoted to the relationship of the Earth with its cosmic environment. I now turn to the story of what we know about the asteroids and comets that hit the Earth, and the scars they left behind. I will also touch on the question of what may collide with our planet in the future and whether the visits of these destructive and unwanted guests can be avoided.

A bolt from the blue

Such an unusual phenomenon as the fall of space objects to Earth seems so incredible that official science initially simply did not accept most reports of such cases as reliable. Although people in antiquity believed that objects from outer space could reach the surface of the Earth, and peasants in more recent times believed so, the more enlightened classes were suspicious of such an idea until the 19th century. Uneducated shepherds who watched objects fall from the sky knew what it was, but their testimonies did not inspire confidence, since many of them told about imaginary events. Even the scientists who eventually accepted the fact that objects were falling on our planet did not initially believe that these rocks were of cosmic origin. They preferred to look for their source on Earth, in particular, they saw it in volcanoes.

The cosmic origin of meteorites did not become part of the generally accepted notion until June 1794, after an accidental fall of stones on the territory of the Academy in Siena, where the event was observed by many educated Italians and British tourists. It all started with a high dark cloud, from where, following the stones that fell like rain on the ground, smoke went, sparks fell and a slowly moving red lightning appeared. Abbot Ambrogio Soldani in Siena found the fallen material interesting enough to collect eyewitness accounts and send a sample to the Naples-based chemist Guglielmo Thomson - under this pseudonym was William Thomson, who had to leave Oxford as a result of a scandal because of his relationship with a servant boy. Careful examination of the sample indicated an extraterrestrial origin for the object. It was a more sensible explanation than the far-fetched assumptions of a lunar circulation or lightning striking dust. It also made more sense than the seemingly reasonable alternative suggestion of a volcanic origin for these stones from then-active Vesuvius. The idea of ​​a volcanic source was quite understandable, since, by pure chance, the eruption of Vesuvius had occurred only 18 hours before. However, Vesuvius was 320 km away and not at all in that direction, so the volcanic theory was rejected.

The question of the origin of meteoroids was finally resolved by the chemist Edward Howard, with the assistance of the French aristocrat and scientist Jacques Louis, comte de Bournon, who fled to London during the French Revolution in 1800. Howard and the Count made an analysis of a meteorite that fell near Benaris in India. As it turned out, the nickel content in its composition was much higher than the concentration of this metal, which is characteristic of the Earth's surface, as well as for stony rocks fused under high pressure. The chemical analysis performed by Thomson, Howard, and the Comte de Bournon was exactly what the German scientist Ernst Florence Friedrich Chladny lacked to support his own hypothesis that the speed of such objects falling to Earth was too fast to accept other than cosmic explanations. Curiously, the fall of a celestial object in Siena occurred just two months after the publication of Chladni's On the Origin of Ironmasses, which received - alas! - unfavorable reviews and negative ratings until a Berlin newspaper two years later bothered to write about the fall of Siena.

In England, more popular small book Edward King, F.R.S., published the same year. King's book dealt with the Siena event and contained many references to Chladni's work. In England, arguments in favor of the cosmic origin of meteorites appeared even earlier, on December 13, 1795, after the fall of a stone weighing more than 25 kg in Wold Cottage, Yorkshire. Given the growing confidence in the methods of chemistry, which has recently ceased to be confused with alchemy, and the testimony of many eyewitnesses in the 19th century. meteorites are finally recognized for what they really are. Since that time, many objects of undoubtedly extraterrestrial origin have fallen on our planet.

Events closer to our time

Headlines mentioning meteoroids and meteorites are guaranteed to attract everyone's interest. However, despite the keen interest in these bright phenomena, it should not be forgotten that the Earth today is generally in balance with the solar system, and dramatic events do not happen often. Almost all meteoroids are not large enough to penetrate past the upper atmosphere, where most of their solid material evaporates. Larger objects arrive only occasionally. Small particles, however, constantly bombard the Earth. Most micrometeoroids entering the atmosphere are so small that they don't even burn up. Objects the size of a millimeter also fall quite often - perhaps every 30 seconds - and burn without any consequences. Objects larger than 2-3 cm partially burn up in the atmosphere, and their fragments may well reach the earth's surface, but they are too small to notice them.

Once every few thousand years, a large object can explode in the lower atmosphere. The largest such event that we know of took place in 1908 in the region of Podkamennaya Tunguska, Russia. Even without a collision with the surface, the explosion of such an object in the atmosphere can leave a noticeable mark on the Earth. We do not know what exactly exploded in the sky near the Podkamennaya Tunguska River in the Siberian taiga - an asteroid or a comet. The strength of the explosion of this approximately 50-meter bolide- a space object that is destroyed in the atmosphere - was equal to 10–15 Mt in TNT equivalent, which is 1000 times more atomic explosion in Hiroshima, but smaller than the most powerful nuclear weapon ever tested. The explosion destroyed a forest over an area of ​​2000 km 2, and the strength of its shock wave is estimated at about 5 points on the Richter scale. It is noteworthy that in the place where the epicenter of the explosion was supposedly located, the trees remained standing, but in the district the forest was completely felled. Zone size standing trees and the absence of a crater indicate that the body collapsed at an altitude of 6 to 10 km.

Estimates of the risk of recurrence of such an event vary to a certain extent due to the ambiguity of estimates of the size of the Tunguska object, which range from 30 to 70 m. Objects with sizes in this interval can fall to the Earth with a frequency from once every several hundred years to once every 2000 years. One way or another, most meteoroids fall to Earth in relatively uninhabited places, since densely populated areas are quite scattered.

The Tunguska meteoroid is no exception in this sense. It exploded over an uninhabited region of Siberia, 70 km from the nearest trading post and even further from the nearest village - the village of Nizhnekarelinskoye. The explosion, however, was strong enough to knock out all the windows in this not too close village and knock down passers-by. The villagers had to turn away from the blindingly bright flash in the sky. Two decades after the explosion, scientists visiting the area were told that local shepherds heard deafening thunder, and two even died from the shock wave. The consequences for the animal world were terrible - almost 1000 deer died from the fire that started as a result of the explosion.

The consequences of the explosion were felt and significantly greater territory. The roar was heard by people at a distance equal to the width of France, and atmospheric pressure changed throughout the globe. The shock wave circled the globe three times. In fact, many of the devastating effects of the larger and better-studied Chicxulub meteorite that wiped out the dinosaurs, which we’ll talk about later, were observed after the fall of the Tunguska meteorite - strong winds, fires, climate change and the disappearance of almost half of the ozone in the atmosphere.

However, since the meteor exploded in a remote and uninhabited area, and the media were not developed at that time, most people knew almost nothing about this giant explosion for several decades, until the true extent of the devastation was established as a result of research. Not only did the Tunguska event take place in remote places, the First World War, and then the revolution in Russia, prevented the spread of information about it. If this explosion happened an hour earlier or later, it could have occurred in a densely populated region, where atmospheric effects or a tsunami in the ocean would have killed thousands of people. In this case, the trace would have remained not only on the surface of the Earth, but also in the history of the 20th century. and, most likely, would have strongly influenced the subsequent policy and development of science.

In the century that has passed since the Tunguska explosion, several smaller, but still noteworthy, celestial objects have fallen to Earth. The fireball that exploded in the atmosphere in the Amazon region of Brazil in 1930 was perhaps one of the largest, although this event is poorly documented. The strength of its explosion was less than in the Tunguska taiga, and, according to estimates, ranged from 1/100 to 1/2 of the Tunguska fireball. Nevertheless, the mass of the meteoric body exceeded 1000 tons and, it is possible that it reached 25,000 tons, and the released energy approached 100 kt in TNT equivalent. Risk assessments vary, but objects ranging in size from 10 to 30 m can fall to Earth at a frequency ranging from once every decade to once every several hundred centuries. The calculated frequency is highly dependent on the size of the object. When varying the body size by a factor of two, the estimates differ by a factor of 10.

A bolide, similar in size to the Amazonian, exploded at an altitude of 15 km over Spain two years later, releasing approximately 200 kilotons of TNT energy. Over the next half century, explosions occurred several more times, but none of them can be compared with the event in Brazil, so I will not list them. Only the so-called Vela incident, which took place in 1979 between the South Atlantic and the Indian Ocean, deserves attention. It got its name from the name of the American reconnaissance satellite Vela, which spotted the flash. Although it was originally thought to be caused by a meteor, many now view the event as a ground-based test of a nuclear weapon.

Of course, surveillance equipment also detects real fireballs. US Department of Defense infrared sensors and US Department of Energy sensors operating in the visible part of the spectrum registered on February 1, 1994 an explosion of a meteor body ranging in size from 5 to 15 m above Pacific Ocean in the Marshall Islands area. It was also seen by two fishermen off the coast of Korae Island, Micronesia, several hundred kilometers from where it occurred. Another explosion of a 10-meter object with a capacity of 25 kt of TNT occurred in 2002 over the Mediterranean Sea between Greece and Libya. A more recent event was observed on October 8, 2009 near the city of Bon, Indonesia. Perhaps this was the result of an explosion of an object about 10 m in diameter with a power of 50 kt.

Wandering comets or asteroids can also be the source of meteoroids. The trajectories of distant comets are difficult to predict, but large enough asteroids can be detected long before they approach the Earth. The asteroid that hit Sudan in 2008 was a significant one. That year, on October 6, scientists determined that the asteroid they had discovered should collide with the Earth the next morning. And it happened. The collision was not large, and no one lived near the crash site. However, this case showed that the fall celestial bodies in some cases it is possible to predict, although how soon we know this depends on the sensitivity of our equipment, the size of the object and its speed.

The most recent notable event was the fall of the Chelyabinsk meteorite, it happened on February 15, 2013 and remained not only in photographs, but also in people's memories. This fireball exploded at an altitude of 20-50 km above the southern part of the Ural region of Russia. The force of the explosion was 500 kt in TNT equivalent, its main part dissipated in the atmosphere, but the blast wave still reached the Earth's surface in a few minutes. The culprit of the event was an asteroid 15-20 m in diameter and weighing about 13,000 tons, which was moving, according to calculations, at a speed of 18 km / s - about 60 times faster than sound. The observers not only saw the explosion, but also felt the heat released as a result of the deceleration of the object in the atmosphere.

Some 1,500 people were injured in the blast, but mostly due to secondary effects such as broken window panes. The number of victims turned out to be so large due to the fact that many rushed to the windows to look at the rapidly flying source of blinding light - an unusual sight. Like in a horror movie, a light in the sky made people approach the most dangerous place at the very moment when shock wave and did the most damage.

In addition to the hype that rose in the media, just at the time of the impact of the meteor body, there were reports that another asteroid was approaching the Earth. If the Chelyabinsk meteorite approached unnoticed, then this other 30-meter object, which made its closest approach to Earth about 16 hours later, never entered the atmosphere. A lot of people have expressed the idea of ​​​​a common origin for both asteroids, but subsequent research has shown that this is most likely not the case.

Near ground objects

In addition to the asteroid predicted in February 2013, many other objects approached the Earth, which, although they did not enter the atmosphere, invariably attracted great attention. The same objects that did collide with the Earth, for the most part, were harmless. One way or another, past collisions have had a real impact on the geological structure and biology of our planet, and there are no guarantees that this will not happen again in the future. As our knowledge of asteroids deepens, and the (perhaps exaggerated) awareness of their potential danger, the search for objects that can cross the Earth's orbit intensifies.

The most frequent collisions (although not necessarily the largest) occur with the so-called near-Earth objects, which are quite close to the Earth and approach the Sun at a distance no more than 30% greater than the distance between the Earth and the Sun. This criterion is met by about 10,000 near-Earth asteroids and a slightly smaller number of comets, as well as some large meteoroids and even, from a formal point of view, spacecraft orbiting the Sun.

Near-Earth asteroids are divided into several categories (Fig. 16). Bodies that enter near-Earth space and approach the Earth without crossing its orbit are called cupids by the name of an asteroid discovered in 1932, which approached the Earth at 16 million km, or 0.11 AU. e. Although they do not currently intersect our trajectory, there are fears that perturbations caused by Jupiter or Mars could increase the eccentricity of their orbits and lead to an intersection with the Earth's orbit. Apollos- their name is also associated with a specific asteroid - currently cross the earth's orbit in a radial direction, although due to the fact that their orbits are above or below the ecliptic plane (the apparent path of the Sun in the sky that determines the plane of the earth's orbit), in practice they do not collide with the earth. Their trajectories, however, can change over time and deviate in a dangerous direction. The second category of Earth-crossing asteroids, which differ from the Apollos in the location of their orbits, which are smaller than the Earth's orbit, is called Atons. The Aton family also bears the name of one of the asteroids of this type. The last category of near-Earth asteroids are Athyra- the orbits of these bodies are completely within the orbit of the Earth. They are difficult to detect, so we know of only a few such asteroids.

Near-Earth asteroids do not live that long by geological and cosmological standards. They stay in the near-Earth region for no more than a few million years before leaving the solar system or colliding with the Sun or some planet. This means that in order to maintain a population in a region close to the Earth's orbit, new asteroids must constantly come into it. Perhaps this is facilitated by the perturbing effects of Jupiter on the asteroid belt.

Most near-Earth asteroids are stony bodies, in addition to them there are quite a few carbonaceous asteroids containing carbon. Only the Cupids, which currently do not cross our trajectory, have dimensions of more than 10 km in diameter. Among the Apollos, however, there are quite a few objects larger than 5 km across - enough to cause significant destruction if they were in the path of the Earth. The largest near-Earth asteroid with a diameter of 32 km is Ganymede, named after the son of the Trojan king. One of the moons of Jupiter is also called Ganymede, but this is a completely different object. It is also the largest, but among the satellites in the solar system.

Near-Earth asteroids have become another area of ​​intense research in the last 50 years. Before that, no one took seriously the idea of ​​the possibility of their collision with the Earth. Now, all over the world, work is underway to catalog and track near-Earth asteroids. The last time I was in the Canary Islands and visited an observatory in Tenerife, its director and a dozen students were doing data analysis in search of asteroids. The telescope there is not large and modern, but I was impressed by the interest of the students and the knowledge of the search methods.

More modern telescopes to search for asteroids use charge-coupled devices, that is, semiconductor arrays that convert photons into an electrical charge and identify where the photons fall. Automatic reading systems also increase the frequency of asteroid detection. The Minor Planet Center of the Harvard-Smithsonian Center for Astrophysics MAC website (http://www.minorplanetcenter.net/) publishes the latest numbers of discovered minor planets, comets, and approaching objects.

For obvious reasons, most attention is paid to orbits close to the Earth's orbit. The US and the European Union are collaborating to find such objects as part of the Spaceguard initiative, named after Arthur C. Clarke's sci-fi novel Rendezvous with Rama. The goal of the first Spaceguard program was defined in a 1992 review report to the US Congress, on the basis of which it was decided to identify most near-Earth objects larger than a kilometer within a decade. A kilometer is a significant size, it is larger than the size of the smallest object capable of causing damage, however, we stopped at this value because kilometer objects are easier to detect and can lead to global destruction. Fortunately, the kilometer objects known to us are mostly in orbits between Mars and Jupiter in the asteroid belt. Until they change their orbits and turn into near-Earth objects, there is no danger in them.

Active observations, orbit predictions and computer simulations enabled astronomers to reach the Spaceguard initiative's goal of identifying the most kilometer-long near-Earth objects in 2009, almost on schedule. The latest data puts the number of kilometer-long and larger near-Earth asteroids close to 940. A panel set up by the US National Academy of Sciences determined that even with all the uncertainties, this number is fairly accurate, and total amount such objects does not exceed 1100. Active search has also helped to identify about 100,000 asteroids and about 10,000 near-Earth asteroids less than a kilometer in size.

Most of the large near-Earth asteroids targeted by the Spaceguard initiative are aliens from the inner and central regions of the asteroid belt. The Commission of the National Academy of Sciences found that about 20% of their orbits are within 0.05 AU. e. from the Earth. Such asteroids are called "potentially hazardous near-Earth objects." According to the Academy's conclusion, none of these objects poses a threat in the current century, which, of course, cannot but rejoice. However, such a conclusion is not at all surprising, given that the expected frequency of collisions of kilometers-long objects with the Earth does not exceed one time in several hundred thousand years.

In fact, only one near-Earth object is known with a significant probability of a collision with the Earth in the near future. However, the probability of its approach is only 0.3%, and even then not earlier than 2880. We are practically not threatened by anything, at least at the present time, even taking into account all the uncertainties. Some astronomers initially expressed concern about another asteroid, the demonic 300-meter Apophis, which, according to calculations, should be closest to the Earth in 2029 and pass by, and then return in 2036 or 2037 and possibly collide with it. . According to assumptions, the asteroid's trajectory will pass through the so-called "gravitational corridor", which can send it to Earth. However, further calculations showed that this was a false alarm. Neither Apophis nor any other object known to us should collide with the Earth in the foreseeable future.

At this place, one could breathe a sigh of relief, if not for the smaller objects that cannot be discounted. Although they are less than a kilometer in size and cannot cause damage of the same magnitude, the frequency of their approach to the Earth and falling is much higher. Therefore, the goal of the Spaceguard initiative was revised in 2005 to include the detection, cataloging and characterization of at least 90% of potentially dangerous near-Earth objects larger than 140 m. This work is unlikely to result in the discovery of anything really catastrophic, but cataloging is a good thing.

Risk assessment

It is clear that asteroids from time to time are very close to the Earth. Collisions do occur, but their expected frequency and severity remain a matter of debate. To say whether something will collide with the Earth or not and whether it will cause damage in the foreseeable future, we cannot definitively and definitely.

Should we be worried? It all depends on the scale, the costs, the feeling of fear, the determination of countries to take the necessary measures and our perceptions of the control of events. The physical aspects considered in this book concern mainly processes occurring over millions and even billions of years. The model I worked on (we will talk about it in the next part of the book) is associated with periodic, with a frequency of 30-35 million years, collisions with large (several kilometers across) meteor objects. None of this, on a time scale, can present an urgent problem for mankind. People have far more pressing concerns.

Be that as it may, even if this is a slight digression, a book on meteor impacts cannot be good without laying out the scientific understanding of their potential impact on our world. This topic appears so often in the news and conversations that it would not be superfluous to quote some current assessments. Forecasts are also used by governments when it comes to discussing how to detect asteroids and prevent them from colliding with the Earth.

In accordance with the Consolidated Appropriations Act of 2008, NASA invited the National Science Council of the US National Academy of Sciences to conduct a study of near-Earth objects. The goal was not to solve theoretical problems collisions, but in assessing the risk of collision with rogue asteroids and the possibility of reducing this risk.

Attention was focused on the study of small near-Earth objects that collide with the Earth much more often and that can potentially be moved away from the Earth. Comets in short period orbits are similar in their trajectories to asteroids, so they can be detected in the same way. Long-period comets are almost impossible to detect in advance. In addition, they come from all directions and are less likely to be in the equatorial plane of the Earth's orbit, which makes it difficult to find. Either way, while some of the recent events may well have been comet-related, comets appear in the Earth's vicinity much less frequently. And, finally, there is practically no possibility of detecting long-period comets with such a lead in order to have time to do something, even if technical capabilities allowed us to deflect asteroids. Thus, since it is currently not possible to catalog dangerous long-period comets, current research is limited to asteroids and short-period comets.

However, long-period comets - or at least comets coming from the outer solar system - will be the focus of attention later. Objects from the outer solar system are much less bound, so it is easier for perturbations - gravitational and others - to push them out of orbit and send them into the solar system or out of it. Despite the fact that they are not among the objects covered by the study of the Academy of Sciences, the interest of scientists in them does not disappear.

Scientists' conclusions

In 2010, the US National Academy of Sciences presented its data on asteroids and associated hazards in a paper titled Protecting Planet Earth: A Report on Near-Earth Object Tracking and Collision Mitigation Strategies. Below I will present the most interesting conclusions from this paper and provide some tables and graphs along with comments explaining their content.

When interpreting the numbers, remember to take into account the relative low density of densely populated urban areas, which the Global Urban Mapping Project estimates account for approximately 3% of the Earth's land area. Although the devastation of any area will not cause delight, the biggest fears are associated with urban areas. The low density of cities on the Earth's surface leads to the fact that the frequency of causing significant damage by relatively small extraterrestrial objects is approximately 30 times lower than the frequency of their impact. So, if, according to forecasts, an object with a size of 5 to 10 m will collide with the Earth once a century, then hitting such an object in Big City should be expected no more than once every three millennia.

One should also take into account the large uncertainty of almost all forecasts, which is estimated at best as tenfold. One of the reasons for the abundance of stories in the media about the danger of distant objects approaching us, which in the end turn out to be empty, is that even a small error in determining the trajectory greatly changes the calculated probability of a collision. In addition, we cannot fully estimate the magnitude of the impact and damage that even known large objects can cause. However, even with all the uncertainties, the results of the National Academy of Sciences study are quite reliable and useful. So, taking into account the existing uncertainty, let's move on to the consideration of relatively recent (related to 2010) statistics.

My favorite table is shown in fig. 17. It shows that asteroid impacts kill an average of 91 people a year. Although the effects of asteroid impacts do not compare with the most serious causes of death - those that are comparable in scale to wheelchair fatalities (not shown), - the number 91 in the table against asteroids is a little surprising and seems alarmingly high. It also looks absurdly accurate given the uncertainties we've been talking about. Of course, not every year exactly 91 people die as a result of an asteroid impact. In fact, only a few such cases have been documented throughout history. Such a high number is misleading, since it takes into account the consequences of grandiose collisions, which, as said, happen very rarely. The diagram in fig. 18 explains this.

From this diagram it follows that the vast majority of the number of fatal outcomes given in the table is associated with large objects, collisions with which are extremely rare. This is indicated by a peak at a diameter of several kilometers. Such events are extremely rare, they are a kind of "black swans" of collisions with asteroids. If we confine ourselves to objects less than 10 m in size, then the number of fatal outcomes per year drops to several units, and this is the upper limit. So what frequency of falling objects of different sizes should we realistically expect? Another diagram helps to find the answer to this question (Fig. 19). It's more complex, but take it with understanding. In fact, this is the quintessence of our current ideas.

Although it is more difficult to understand what this diagram is talking about, it contains a lot of information. It uses a logarithmic scale. This means that as the size changes, the frequency (time) of collisions changes much more than it might seem. For example, if a 10-meter object can collide with the Earth once a decade, then a 25-meter object can collide with the Earth once every 200 years. It also means that small changes in the measured parameters can have a very large impact on the predictions.

The upper axis shows how much energy, in megatons, an object of a given size releases if it moves at a speed of 20 km/s. For example, a 25-meter object releases energy equivalent to the energy of an explosion of one megaton of TNT. The diagram also shows the expected number of objects depending on the size and their probable brightness, which characterizes the ability to detect and track the object. Small asteroids, although their number is significant, are more difficult to detect due to the diminutiveness of such objects and, as a result, their lower brightness.

The estimated frequency of collisions, for example, with a 500-meter object is once every 100,000 years, with a kilometer-long object once every 500,000 years, and with a 5-km object once every about 200 million years. It also follows from the diagram that a collision with a 10-kilometer body, i.e., such a body that led to the extinction of dinosaurs, should be expected once every 10-100 million years.

If you are only interested in the frequency of collisions, then it is better to use the simpler graph in Fig. 20. Note that the top of the vertical axis has smaller values ​​and the bottom has larger ones, so large collisions are much less common than small ones. Also note that the numbers on the vertical axis are in exponential notation, in other words, they show how many times the number 10 should be multiplied by itself. For example, 10 1 is 10, 10 2 is 100, and 10 0 is one.

Finally, to give an idea of ​​the degree of danger of objects of different sizes, I will give another table compiled on the basis of the results of a study by the National Academy of Sciences (Fig. 21). It follows from this that a collision with an object several kilometers in diameter will have a global effect. Collisions with large meteoroids are much rarer than other natural disasters, so they do not pose an immediate threat. However, if they do occur, the consequences are catastrophic. The table also shows that, for example, an object 300 m in size can collide with the Earth once every 100,000 years. The result could be an increase in the concentration of sulfur in the atmosphere to a level comparable to the level after the explosion of the Krakatoa volcano, and damage to life, or at least agriculture over most of the planet. And this table, like the previous diagrams, suggests that an atmospheric explosion comparable to the Tunguska one can occur once every thousand years. The details of any such catastrophic scenario will, of course, depend on the size of the object and the specific location in which it will fall.

What to do

What is the conclusion from this? First of all, it's wonderful that so many objects orbit with us in space. We think of the Earth as special, but in reality, if you look more broadly, it is just one of the inner planets of the solar system, orbiting a particular star. One way or another, although we recognize the proximity of our space neighbors, the second conclusion that follows from what has been said is that asteroids are not the biggest threat to human existence. Collisions may occur and may even cause damage, but they do not pose an imminent danger to humans, at least not in the foreseeable future.

But even if this is the case, the question of what to do in the event of something dangerous should still arise. It would be a shame to watch some object on a dangerous trajectory for the Earth for several years and not be able to change your fate. The absence of a serious danger does not mean that we should not do anything to protect ourselves from the destruction of a meteoroid or think about avoiding a collision.

Not surprisingly, many are working on solving the problem and there are many proposals for protection against dangerous space objects, although the matter has not yet come to the creation of real means. The two main defense strategies are destruction of objects or their deflection. Destruction itself is not best idea. Breaking something threatening the Earth into many fragments hurtling in the same direction would likely increase the chances of a collision. Although the damage from a single fragment will be less, the cumulative effect of a collision with many fragments is unlikely to inspire anyone.

So deviating seems like a more reasonable approach. Most effective deflection strategies involve increasing or decreasing the speed of an approaching object, rather than a lateral push. The Earth is quite small and moves relatively quickly around the Sun (at a speed of about 30 km/s). Depending on the direction in which the object is approaching, changing its trajectory so that it arrives only seven minutes earlier or later (during which time the Earth has time to travel a distance equal to its radius) can turn the collision into an impressive but safe flyby. This does not require a radical change in the orbit. If the object is detected in advance, for example, several years before the collision, then even a small speed adjustment will be sufficient.

None of the proposals for deflection or destruction will save us from an object larger than a few kilometers in size, capable of causing a global catastrophe. Fortunately, such a collision is unlikely to be expected in the next million years. In the case of smaller objects up to a kilometer in size, from which we can, in principle, protect ourselves, the most effective means of deflection is a nuclear explosion. However, international law prohibits the use of nuclear weapons in outer space, at least for the time being, so this technology is not being developed. It is also possible, although much less efficient, to use a ramming object, which will transfer its kinetic energy, i.e. the energy of its movement, to the approaching asteroid. When there is sufficient time, especially if there is the possibility of several collisions, such a strategy can be effective for asteroids up to several hundred kilometers in size. Other deflection technology proposals include solar panels, spacecraft that act as gravity tugs, and jet engines - basically anything that can generate enough force. Such methods are fully operational in the case of objects up to hundreds of meters in size, but only if danger is detected for several decades. All this (like the asteroids themselves) requires further study, so it is too early to say what exactly will work.

Such proposals, while interesting and worthy of consideration, are at present no more than a glimpse into the future. None of these technologies currently exist. At the same time, one project, Asteroid Impact and Deflection Assessment, designed to test the feasibility of the idea of ​​a kinetic ram, is already being worked out quite seriously. Work is also underway on another project, the Asteroid Redirect Mission, which involves transferring an asteroid or part of it into a lunar orbit and, possibly, organizing a landing of people on it later. One way or another, the actual creation of any structures for these projects has not yet begun.

Some object to the creation of anti-asteroid technologies on the grounds that they may be dangerous in a broader sense. There are fears, for example, that they will be used for military purposes, and not to save the Earth, although, in my opinion, this is very unlikely, given the preemption that is necessary for the effective use of such means. Considerations have also been made regarding the psychological and sociological danger of finding an asteroid in an Earth impact trajectory when it is too late or technically impossible to change anything, but in my opinion this is nothing more than a delaying solution tactic that can be used against any constructive offers.

Even if these dubious fears are discounted, we still have the question of whether we should somehow prepare for asteroid impacts and, if so, when. In reality, it is a matter of money and resources. The International Academy of Astronautics organizes meetings to discuss such issues and decide on the best strategy. A colleague of mine who attended a conference in Flagstaff, Arizona in 2013 on planetary defense against an asteroid-comet hazard, talked about how they practiced what to do in case of an asteroid approach and had to find best strategy organization of training alarm. They had to determine “what to do with the uncertainty of the size of the object and the change in orbit over time”, “when to proceed to action”, “at what point should the president be informed” (the conference was held in the USA, after all), “at what point it is necessary to start evacuating the population of the region” and “when it is necessary to launch a missile with a nuclear charge in order to prevent a potential tragedy.” These questions, although they seemed to me in some way intended to entertain guests, clearly demonstrated that even well-meaning and well-informed astronomers can have very different attitudes and reactions to an approaching space object.

I hope I've convinced you that such threats aren't all that relevant, even if they can cause damage. While it is possible that, under some unfortunate set of circumstances, an asteroid could collide with the Earth and destroy a large population center, the chances of such a scenario occurring in the foreseeable future are extremely small. As a scientist, I am in favor of taking into account and calculating the trajectories of as many space objects as possible. As an enthusiast, I advocate a spacecraft that could take a potentially dangerous near-Earth object into a safe orbit. However, in reality, no one knows for sure what is best to do.

Ultimately, society must understand that, as in the case of any scientific and technical program what it will cost us, what we will learn and what additional benefits we will get. Now that you know the basic facts, you have the opportunity to form an informed opinion if necessary. The current data helps, but it cannot be considered complete. Just as in many political decisions, we need to link scientific assumptions to practical considerations and moral imperatives. In my opinion, even in the absence of a threat, the science itself is interesting enough to merit a relatively small investment in the search for new asteroids and their study. However, only time will tell what society and private capital will ultimately choose.

The George E. Brown, Jr. Near-Earth Object Survey section of the NASA Authorization Act of 2005 (Public Law 109-155).

transcript

1 DARK MATTER AND DINOSAURS

2 Lisa Randall DARK MATTER AND THE DINOSAURS THE ASTOUNDING INTERCONNECTEDNESS OF THE UNIVERSE An Imprint of HarperCollinsPublishers

3 Lisa Randall DARK MATTER AND DINOSAURS AN AMAZING INTERRELATION OF EVENTS IN THE UNIVERSE Moscow 2017

4 UDC 524.8: BBC:28.01 P96 Translator Vyacheslav Ionov Scientific editors Elena Naimark, Dr. of Biol. sciences; Dmitry Gorbunov, Ph.D. Phys.-Math. P96 Randall L. Dark Matter and Dinosaurs: An Amazing Interconnection of Events in the Universe / Lisa Randall; Per. from English. Moscow: Alpina non-fiction, p. ISBN What do dark matter have in common with the dinosaurs that dominated the Earth for many millions of years and then suddenly died out? It is believed that the cause of their death was a collision with a comet, but no one knows why it left its usual orbit. In this masterpiece of popular science literature, renowned theoretical physicist Lisa Randall offers her explanation. It was dark matter, in her opinion, that could send a comet fatal to dinosaurs to Earth. The intricacies of astronomy and biology in the book read like a detective story, in which new ideas about dark matter help to uncover not only the mysteries of the five mass extinctions, but also the origins of our existence. UDC 524.8: LBC:28.01 This book was published as part of the Dmitry Zimin Book Projects program and continues the Dynasty Library series. Dmitry Borisovich Zimin is the founder of the Vimpelcom company (Beeline), the Dynasty Foundation for non-commercial programs and the Moscow Time Foundation. The Dmitry Zimin Book Projects program unites three projects that are well known to the readership: the publishing of popular science translated books Dynasty Library, the publishing direction of the Moscow Time Foundation, and the Enlightener prize in the field of Russian-language popular science literature. Detailed information about Dmitry Zimin's Book Projects can be found on the website ziminbookprojects.ru. All rights reserved. No part of this book may be reproduced in any form or by any means, including posting on the Internet and in corporate networks, as well as recording in computer memory for private or public use, without the written permission of the copyright owner. rights. For the organization of access to the publisher's electronic library, please contact ISBN (Russian) ISBN (English) Lisa Randall, 2015 Russian edition, translation, design. LLC "Alpina non-fiction", 2017

5 CONTENTS Introduction... 7 Part I: THE BEGINNING AND DEVELOPMENT OF THE UNIVERSE 1 The Secret Society of Dark Matter The Discovery of Dark Matter Big Questions Near the Beginning: A Very Good Starting Point The Birth of a Galaxy...85 Part II THE LIVING SOLAR SYSTEM 6 Meteor Bodies, Meteors and Meteorites The short but bright life of comets Edge of the solar system Life, full of danger Shock and awe Mass extinctions

6 12 The End of the Dinosaurs Living in the Habitable Zone What Will Be, Will Be Oort Cloud Comets Part III The Nature of Dark Matter 16 The Matter of the Invisible World How to See the Invisible Socially Connected Dark Matter The Speed ​​of Darkness Dark Disk Quests Dark Matter and Comet Collisions Conclusion: The Eternal Search Acknowledgments List of illustrations Additional reading About the author Index

7 INTRODUCTION The words "dark matter" and "dinosaurs" rarely go together, except perhaps in computer games, in a fantasy club, or in some Spielberg film that has not yet been released. Dark matter, the elusive substance of the Universe, participates in gravitational interaction like ordinary matter, but does not emit or absorb light. Astronomers register gravitational manifestations of dark matter, but in literally they don't see her. Well, dinosaurs do not think it is necessary to explain who they are. These vertebrates dominated the Earth millions of years ago. Although both dark matter and dinosaurs excite the imagination, you have every reason to believe that between invisible physical substance and legendary creatures there is nothing in common. It is quite possible that this is so. At the same time, the Universe is, by definition, a single whole, and, in principle, its components must interact. This book presents a hypothetical scenario based on the idea that dark matter could have been responsible (indirectly, of course) for the extinction of the dinosaurs. Paleontologists, geologists and physicists agree that 66 million years ago, a space object collided with the Earth,

8 8 DARK MATTER AND DINOSAURS, which had a diameter of at least 10 km, and destroyed the land dinosaurs, and with them another three-quarters of the biological species that existed on our planet. It could have been a comet from the periphery of the solar system, but no one knows why it left its loosely coupled but stable orbit. We assume that during the passage of the Sun through the middle plane of the Milky Way, a cluster of stars and light dust, visible in the clear night sky, a disk of dark matter appeared in the path of the Solar System, which pushed the distant object out of its orbit and thus provoked a cataclysm. In the vicinity of our Galaxy there is a huge mass of dark matter, it surrounds us and forms a homogeneous and scattered spherical halo. However, the reason for the extinction of the dinosaurs was a different type of dark matter, which is distributed completely differently than the vast majority of the elusive dark matter in the universe. This type of dark matter does not affect the halo in any way, but as a result of interactions of a different nature, it forms a disk right in the middle plane of the Milky Way. This thin region can be so dense that as the solar system passes through it as it moves along the galactic orbit, the gravitational influence of this disk is unusually strong. And then on the periphery of the solar system, where the attraction of the Sun is weakening, comets can leave their orbits, knocked down by the powerful attraction of the disk. Such comets fly out of the solar system or, more importantly for us, head towards its center, and then a collision with the Earth is possible. So, in principle, it could be. I want to say right away that I do not know if this idea is correct. After all, only a very unusual type of dark matter could have a tangible impact on living beings (which, strictly speaking, are no longer alive). Here is a story about our non-trivial assumption about the existence of a surprisingly "influential" dark matter.

10 10 DARK MATTER AND DINOSAURS finally understand, based on bits of knowledge gained here on Earth. I was also struck by the variety of interrelationships between the processes that led to the emergence of people. I emphasize that I am far from a religious worldview. I have no need to associate what is happening with a higher purpose or purpose. And yet, I cannot help feeling admiration, which is usually called religious, watching our approach to understanding the infinity of the universe, to understanding our past and their relationship. And when we try to overcome limitation Everyday life, this feeling is very encouraging. Latest Research literally made me look at the world and many elements of the Universe in a different way, the interaction of which led to the emergence of the Earth and man. I grew up in New York, in Queens, and the stone walls of the city are more familiar to me than natural landscapes. What little living thing could be admired was limited to parks and lawns that bore little resemblance to what existed before the advent of people. At the same time, we literally walk on the remains of living beings, or at least their shells. Chalk cliffs, which can be seen on the coast or outside the city, consist of the remains of creatures that lived millions of years ago. Mountains rise where tectonic plates converge, and these plates are driven by molten magma, which, in turn, is the result of the decay of radioactive materials near the Earth's core. Our fossil energy carriers are the result of nuclear processes occurring on the Sun, the energy of which is transformed and accumulated in various ways. Many of the minerals we use are heavy elements that hit the Earth's surface with asteroids and comets. Meteorites brought some amino acids to Earth, and maybe life itself or the seeds of life. But even before all this happened, dark matter began to form clumps that attracted ordinary matter to itself, which eventually turned into galaxies, clusters of galaxies.

12 12 DARK MATTER AND DINOSAURS in the course of earthly life, it was also disastrous. At least one such space object led to a devastating extinction of biological species 66 million years ago. At the same time, although he completely destroyed the dinosaurs, he provided the conditions for prosperity large mammals, including a person. The second equally striking aspect is the bounty of our time for scientific discoveries, which I am about to talk about. Such a statement can probably be made at any point in the history of human civilizations, but this does not deprive it of justice: we have made a huge leap in the development of our science in recent [here, insert the figure appropriate to the context] years. For the studies I review, this figure is less than 50 years. Both my own research and the work of other scientists make me constantly amazed at the novelty and audacity of recent discoveries. With ingenuity and perseverance, scientists are trying to link the prevailing ideas with the amazing, always interesting and sometimes frightening facts that are revealed to us about the world. The scientific knowledge presented in this book relates to the history of the universe, which has 13.8 billion years if you are interested in the Universe, or 4.6 billion years if your interest is in the solar system. But at the same time, the history of human interest in these scientific mysteries has less than a century. Dinosaurs died out 66 million years ago, but paleontologists and geologists have suggested the reason for their extinction only in the 1900s. At first it took decades of careful guesswork, only then did the scientific community fully appreciate them. These timings are not random. The association of dinosaur extinction with an extraterrestrial object only began to look more plausible when astronauts landed on the moon and saw these real evidences of the dynamic nature of the solar system near the craters. In the last 50 years, significant advances in particle physics and cosmology have made it possible to build a Stan-

13 INTRODUCTION 13 a gift model that describes the basic elements of matter as we understand them today. The amount of dark matter and dark energy in the universe became clear in recent decades 20th century Around the same period, our understanding of the solar system changed. And only in the 1990s. scientists have discovered Kuiper belt objects in the vicinity of Pluto, showing that Pluto does not orbit the Sun alone. The number of planets has decreased, but only because the science we studied at school has become richer and much more complex. The third aspect concerns the pace of change. Species adapt through natural selection if they have enough time to adapt. But adaptation does not happen immediately in a radical way. She is too slow. Dinosaurs weren't prepared for a 10-kilometer meteorite impact with Earth. They couldn't adjust. Those who lived on land, who could not burrow into the ground because of their size, had nowhere to go. With the advent of new ideas and technologies, disputes over the radicality and gradualness of change become very important. The key to understanding the majority latest discoveries both scientific and all others is the speed of the processes they describe. I often hear talk about how development in some areas, such as genetics and Internet technology, is unprecedentedly fast. However, this is not quite true. The understanding of the causes of disease or the principles of the circulatory system, gained centuries ago, has led to changes at least as profound as today's genetics promise. The advent of writing, and later the printing press, influenced the ways of acquiring knowledge and the worldview of people no less significantly than the advent of the Internet. All modern changes, if we are talking about their important features, are distinguished by really exceptional speed, and this applies not only to scientific processes,

14 14 DARK MATTER AND DINOSAURS but also to ecological and sociological changes. Although it is unlikely that we should now seriously fear death from a collision with a meteorite, the acceleration in the rate of environmental change and the extinction of species is a very real danger, and the consequences of this phenomenon can be compared in many respects to the consequences of a cosmic catastrophe. So the purpose of this book is quite clear to help us better understand the amazing story of how we got here and now, and wisely use the knowledge gained. There is a fourth important aspect - a wonderful science that describes the often hidden elements of our world and its development, as well as how deeply our knowledge can penetrate the Universe. Many people are fascinated by the idea of ​​a multiverse of many other universes that are inaccessible to us. However, no less interesting is the idea of ​​a set hidden worlds both biological and physical, for the study and knowledge of which we still have a chance. I hope to show in this book how exciting it can be to think about what we know and what we might learn in the future. The book begins by explaining the main points of the cosmology of the science of how the universe came to be in its current state. The Big Bang theory, the model of cosmological inflation and the formation of the Universe are considered first. This part also explains what dark matter is, how we know it exists, and why it fits into the structure of the universe. Dark matter accounts for 85% of the matter in the universe, while ordinary matter, that is, what stars, gas and people are made of, is only 15%. Despite this, people are mainly occupied with the existence and significance of ordinary matter, which, to be fair, interacts incomparably stronger.

15 INTRODUCTION 15 One way or another, as in the case of mankind, there is no reason to lock in on a small fraction of those who have a disproportionate strong influence. The dominant 15% of matter that we can see and feel is just a fraction of existence. I will show the critical role of dark matter in the universe, both for the galaxies and clusters of galaxies that formed from the disordered cosmic plasma in the early universe, and for maintaining the stability of these structures today. The second part of the book deals with the solar system. Of course, the topic of the solar system is so immense that it is quite possible to devote a separate book to it, it will be enough even for an encyclopedia. Therefore, I limit myself to questions that may be related to dinosaurs, meteorites, asteroids and comets. This part describes objects that have collided with the Earth or collisions with which we can expect in the future, as well as a few but significant evidence of the extinction of species or meteorite falls that occur with enviable regularity at intervals of about 30 million years. It also discusses the origin and destruction of life, summarizing all that is known about the five largest mass extinction events, including the catastrophe that wiped out the dinosaurs. The third and final part of the book brings together the ideas of the first two parts and begins with a discussion of dark matter models. It explains the best-known ideas about what dark matter is, as well as the latest assumptions about the interactions of dark matter, which were mentioned above. At the moment, we only know that dark matter interacts with ordinary matter in a gravitational way. Gravitational effects in general are so negligible that we can only observe the influence of huge masses such as the Earth and the Sun, but even this is rather weak. After all, even a paper holder with a tiny

16 16 DARK MATTER AND DINOSAURS with a magnet successfully counteracts the attraction of the planet Earth. At the same time, other forces can also act in dark matter. Our new model challenges the common assumption and prejudice that matter familiar to us is unique in terms of the forces of electromagnetism, weak and strong nuclear forces through which it interacts. It is these forces that determine many of the amazing features of our world. What if there are also strong non-gravitational interactions in certain types of dark matter? If this is true, then the forces of dark matter could be an unexpected confirmation of connections between the microcosm and macroscopic phenomena, deeper than what we know now. Although everything in the universe can, in principle, interact, most of these interactions are too weak to be noticeable. We can only observe what affects us in a tangible way. If something causes a negligible effect, then it can be under our noses and go unnoticed. This is most likely why the dark matter particles that supposedly surround us have not yet been detected. The third part of the book shows how a broader view of dark matter, the question of why the dark universe should be so simple, when our universe is so complex, opens up previously unexplored possibilities for us. Maybe some of the effects of dark matter are due to the power of dark light, if you will. If we imagine the vast majority of dark matter as a relatively uninfluential 85% of the population, then the newly proposed type of dark matter can be viewed as a prosperous middle class, imitating ordinary matter in its interactions. Additional interactions will change the structure of the galaxy and allow this new part to influence the movement of stars and other objects from ordinary matter.

17 INTRODUCTION 17 In the next five years, satellite observations will determine the shape of our Galaxy, its composition and other characteristics much more accurately than ever, tell a lot about our galactic environment and show whether our assumption is correct or not. Such tangible perspectives make dark matter and our model a real avenue of research worth exploring, even if dark matter is not the building block that you and I are made of. The scope of research may include impacts with meteorites, one of which may well be the link between dark matter and the extinction of the dinosaurs. The premises and concepts connecting these phenomena give a capacious, three-dimensional picture of the Universe. I would like not only to present these ideas, but also to push you to explore and understand more deeply the amazing richness of our world.

19 PART I ORIGIN AND DEVELOPMENT OF THE UNIVERSE

21 1 THE SECRET SOCIETY OF DARK MATTER We often don't notice what we don't expect. Meteors flash and disappear in the sky on a moonless night, unfamiliar animals follow us on our heels in the forest, magnificent architectural forms surround us while walking around the city. But we do not see them, even if they are in the field of view. Our body serves as a haven for entire colonies of bacteria. The number of bacterial cells inside us is ten times greater than the number of our own cells. But we do not feel the presence of these microscopic creatures, we do not feel how they absorb nutrients and help our digestive system. It's only when bacteria misbehaves and causes distress that most of us catch on and even acknowledge their existence. To see something, you need to look, and besides, you also need to know how to look. Moreover, the phenomena I have just mentioned are observable in principle. Now imagine the difficulty of understanding something that you literally cannot see. This is exactly what dark matter is, the elusive substance of the universe, which

22 22 ORIGIN AND DEVELOPMENT OF THE UNIVERSE infinitely weakly interacts with the matter we understand. In the following chapters, I will introduce you to the various measurement methods that have enabled astronomers and physicists to prove the existence of dark matter. Here I will tell you about this elusive substance itself: what it is, why it seems incomprehensible and why, from the point of view of certain theories, it is not. INVISIBLE AMONG US Although the Internet is a giant network that connects billions of people in real time, most of those who communicate on social networks do not interact with each other directly and even indirectly. Participants add as friends those who have similar opinions and interests, subscribe to the pages of like-minded people and turn to news sources that reflect their own ideas about the world. With such limited interactions, the population of people connected online breaks down into distinct non-interacting groups, within which there is rarely alternative point vision. Even friends of friends usually don't cite the different opinions of other groups, so most Internet dwellers don't notice the existence of unfamiliar communities with different, incompatible ideas. We are not too isolated from worlds beyond our own. But with respect to dark matter, we are all smeared with the same world. Dark matter is simply not part of the social network of ordinary matter. She lives in an internet chat that we don't even know how to enter. It is in the same Universe and occupies the same regions of space as visible matter. However, dark matter particles interact very little with ordinary matter as we know it. As is the case with online communities that we are unaware of, to say the least.

23 THE SECRET SOCIETY OF DARK MATTER 23 every day about dark matter, then no one will know about its existence. Like the bacteria inside us, dark matter is one of many other "universes" right under our noses. And, like these microscopic creatures, it is all around us. Dark matter passes right through our bodies, it circles us in outer space 1. However, we do not notice any of its manifestations, because it interacts so weakly that it does not form a distinct community. This community is completely isolated from the matter that we know. It is nonetheless very important. If bacterial cells, despite their abundance, account for only 1 2% of our mass, then dark matter, although it makes up an insignificant part in our body, accounts for approximately 85% of the matter in the Universe. Every cubic centimeter of space around you contains dark matter, the mass of which is approximately the mass of a proton 2. Much or little depends on how you look at it. If dark matter consists of particles whose mass is comparable to the mass of particles known to us, and if these particles move at a speed that can be expected based on known laws, then billions of dark matter particles pass through each of us every second. Somehow, no one notices it. The impact of even billions of dark matter particles on us is vanishingly small. That is why we cannot sensually perceive dark matter. It does not interact with light, at least not in a way that humans can detect this interaction. Dark matter is a different substance, 1 Actually, we do not know this. There are models of dark matter in which it is not elementary particles, but compact macroscopic objects. large mass. There are not so many such objects in the surrounding space to expect regular "meetings" of the human body with them. Note. scientific ed. 2 It must be understood that this is an average, i.e. if we consider the mass of matter in a large region of space of the Universe, then the mass of dark matter is as if there is one proton in every cubic centimeter. Note. scientific ed.

24 24 ORIGIN AND DEVELOPMENT OF THE UNIVERSE than ordinary matter, it does not consist of atoms or other elementary particles familiar to us that interact with light, and such interaction is fundamental for everything that we see. What dark matter consists of is the riddle over which my colleagues and I are struggling with them. It is possible that these are particles of some new type. If so, what are their properties? Do they enter into any other interactions besides gravitational interactions? If the experiments now being carried out are successful, then negligible electromagnetic interactions can be found in dark matter particles, so small that they have not yet been able to register. Special space probes are looking for these interactions, how it happens, I will explain in the third part of the book. But for now, dark matter remains invisible. Its presence does not affect the detectors at the current level of sensitivity. However, when dark matter is concentrated in localized space, its net gravitational influence becomes significant and it has a noticeable effect on stars and nearby galaxies. Dark matter affects the expansion of the universe, the path of light coming from distant objects, the orbits of stars around the center of the galaxy, and many other measurable phenomena in such a way that it makes one believe in its existence. It is because of these measurable gravitational effects that we know about the existence of dark matter. In addition, despite its invisibility and intangibility, dark matter played a key role in shaping the structure of the universe. Dark matter can be compared to the underestimated ordinary members of society. Although they are not visible to the supreme arbiters of destinies, without an army of workers building pyramids, laying highways, assembling electronic equipment, the development of civilization is impossible. Like other inconspicuous groups of people in

25 THE SECRET SOCIETY OF DARK MATTER 25 In our society, dark matter is fundamentally important to our world. If there were no dark matter in the early Universe, now there would be no one even to talk about what was happening, not to mention the creation of a coherent picture of the evolution of the Universe. Without dark matter, there would be no time for the formation of the structure that we observe. Clots of dark matter became the embryos of the Milky Way, as well as other galaxies and clusters of galaxies. If galaxies had not formed, there would be no stars, no solar system, no life as we know it. Even today, the cumulative effect of dark matter keeps galaxies and galactic systems intact. Dark matter may even affect the trajectory of the solar system, if there is a dark disk mentioned in the introduction. Anyway, we don't observe dark matter directly. Scientists know many forms of matter, but those of which we know the composition are observed through one or another type of emitted light or, more generally, electromagnetic radiation 1. Electromagnetic radiation is perceived as light in the visible frequency range, and outside this narrow range it may be, for example, radio waves or ultraviolet radiation. The effects can be observed with a microscope, radar, or as optical images in a photograph. In this case, there is always an electromagnetic interaction. Not every interaction is the most direct way charged particles interact with light. However, the elements of the Standard Model in elementary particle physics are the most fundamental elements of matter that we know interact to such an extent that light 1 There are, however, neutrino elementary particles that participate only in weak interactions and are "observed" through the birth of electrically charged particles of electrons and their heavier analogs of muons and tau leptons. Note. scientific ed.

26 26 ORIGIN AND DEVELOPMENT OF THE UNIVERSE is, if not directly a friend, then at least a friend of a friend of all forms of matter visible to us. Not only visual, but also our other sensory perceptions, tactile, olfactory, gustatory and sound, are based on atomic interactions, which, in turn, are associated with the interactions of electrically charged particles. The sense of touch, too, although for more subtle reasons, is associated with electromagnetic vibrations and interactions. Since all human sensory perceptions without exception are based on electromagnetic interactions of one kind or another, we cannot directly perceive dark matter in the way we are accustomed to. Although dark matter is everywhere around us, we do not see or feel it. When light hits dark matter, nothing happens, it just passes through it. Considering that no one had ever seen (touched or smelled) it, many with whom I spoke were surprised at the existence of dark matter and considered it mysterious, if not even asking if it was a figment of the imagination. People ask how it is possible that the vast majority of matter about five times the mass of ordinary matter is not visible in traditional telescopes. Personally, I would expect the exact opposite (though I guess not everyone sees things that way). It would be more mysterious to me if our eyes could see all the matter that exists. Who said that we are endowed with ideal sense organs capable of directly perceiving everything that exists? The greatest thing that physics has given us over many centuries is the understanding of how much is hidden from our eyes. From this perspective, the question is why matter as we know it has such an energy density in the universe. Dark matter may seem like an extravagant idea to some, but the assumption of its existence is incomparably less recklessness than the revision of the laws of gravity.

27 SECRET SOCIETY OF DARK MATTER 27 which opponents would probably prefer to such extravagance. Dark matter, although completely unusual, most likely has a more or less traditional explanation that is fully consistent with all known laws of physics. After all, why on earth should all matter that obeys the known laws of gravity behave in exactly the same way as the matter we know? In short, why should all matter interact with light? Dark matter may simply be a substance that has a different fundamental charge or lacks a fundamental charge. Without an electrical charge or interactions with charged particles, it can neither absorb nor emit light. However, the problem with one of the aspects of dark matter still exists is its name. I don't mean the word "matter". This substance is indeed a form of matter in the sense that it forms clumps and exerts a gravitational influence, reacting to the force of gravity like any other kind of matter. It is this interaction that allows physicists and astronomers to detect its presence. The word “dark” is not entirely appropriate in the name, for the reason that we see dark things that absorb light, and also because such a label makes this substance in our perception more powerful and negative than it really is. Dark matter is not dark at all, it is transparent. Dark matter absorbs light. Transparent bodies are indifferent to it. Light can fall on dark matter, but neither this matter nor the light itself undergo any changes. Not so long ago, at an interdisciplinary conference, I met Massimo, a professional marketer specializing in branding. When I told him about my research, he looked at me incredulously and asked, “Why is it called dark matter?” It was not the scientific rationale that confused him, but the overly negative connotation of the name. Of course, not every brand acquires

28 28 ORIGIN AND DEVELOPMENT OF THE UNIVERSE negative coloring due to the presence of the word “dark”. "The Dark Knight" 1 was a great guy, well, maybe with a complex character. But compared to the word's role in the titles Dark Shadows 2, Dark Materials 3, Transformers: Dark of the Moon 4, Darth Vader's "Dark Side of the Force" 5, not to mention the "dark song" from Lego . Filma, "dark" in dark matter has a rather innocent meaning. Despite our apparent fascination with the dark side of things, dark matter does not really live up to the reputation of its name. Yet she has one common feature with evil forces: it is invisible to us. Dark matter is absolutely correctly named in the sense that no matter how you heat it, it does not emit any light. From this point of view, it is really dark, not because it is opaque, but because it is the opposite of everything light-emitting and even reflective. No one sees dark matter directly, either through a microscope or a telescope. As with evil spirits in movies and literature, invisibility serves as a protective cover for her. In Massimo's opinion, "transparent matter" would have sounded better, or at least not as intimidating. From a physics standpoint, however, I'm not sure he's right. Dark matter, even if I don't like it, attracts attention. One way or another, there is nothing sinister or powerful about dark matter, at least until it accumulates in huge quantities. It interacts with ordinary matter so weakly that it is extremely difficult to detect it. That is where the interest lies. 1 Dark Knight is the hero of a film thriller directed by Christopher Nolan. Note. per. 2 Dark Shadows is an adventure thriller with horror elements, in the Russian version of "Dark Shadows". Note. per. 3 His Dark Materials is a science fiction trilogy by British writer Philip Pullman. Note. per. 4 Transformers: Dark of the Moon is an American science fiction action movie. Note. per. 5 Darth Vader is the protagonist of the movie epic " star Wars". Note. per.

29 THE SECRET SOCIETY OF DARK MATTER 29 BLACK HOLES AND DARK ENERGY There are other misunderstandings associated with the name "dark matter" besides the ominous sound mentioned above. For example, many of those with whom I discussed my work did not see the difference between dark matter and black holes. To emphasize the difference, I'll take a brief look at the nature of black holes, which are objects that form when there is too much matter in a very small region of outer space. Nothing, including light, can escape their monstrous gravity field. Black holes and dark matter have no more in common than black ink and black comedy. Dark matter does not interact with light. Black holes absorb light like anything else that gets too close. Black holes are black because all the light that enters them stays inside. It does not radiate or reflect. Dark matter may well be involved in the formation of black holes 1, since any matter is capable of collapsing and turning into a black hole. However, black holes and dark matter are definitely not the same thing. Under no circumstances should they be mixed. Another misconception has to do with the unfortunate name of dark matter. Since dark energy still exists in the Universe, which is also an ambiguous name, it is often confused with dark matter. Although this is a departure from our main theme, I will note that dark energy occupies an important place in modern cosmology, and I will try to explain its essence in order to avoid confusion in the future. Dark energy is not matter, it's just energy. Dark energy exists even if there is not a single particle or substance in another form around. It is distributed throughout the universe, but does not form clumps, like ordinary matter. 1 More precisely, there is an assumption that black holes are possible sources of dark matter, a topic we will address later. At the same time, experimental limitations and theoretical calculations currently make such a scenario extremely unlikely. Note. ed.

30 30 ORIGIN AND DEVELOPMENT OF THE UNIVERSE dark energy is everywhere the same; its density in one region does not differ from the density in another region. Dark energy is very different from dark matter, which collects into objects and is denser in some places than in others. Dark matter behaves exactly like the familiar matter that forms objects like stars, galaxies, and clusters of galaxies. Dark energy is always distributed evenly. Dark energy also does not change over time. Unlike matter or radiation, dark energy does not become more diffuse as the universe expands. This is, in a certain sense, its defining property. The density of dark energy is energy that is not associated with particles or matter remains unchanged over time. For this reason, physicists often refer to this form of energy as the cosmological constant. At an early stage in the evolution of the universe, the vast majority of energy existed in the form of radiation. However, radiation scatters 1 faster than matter, so matter eventually became the most significant carrier of energy. Much later in the evolution of the Universe, the dominant position passed to dark energy, which never dissipates, unlike radiation and matter, and which now accounts for approximately 70% of the energy density of the Universe. Before Einstein proposed his theory of relativity, everyone was only interested in the relative energy, the difference between the energy of one state and the energy of another. However, Einstein's theory showed that the absolute amount of energy is significant in itself and determines the gravitational force that compresses or expands the universe. big riddle 1 The word "dissipates" here and below is used in the same ordinary sense as in the expression "the fog has dissipated". To clarify this usage, we note that in the expanding Universe, the density of all particles decreases, and for ultrarelativistic radiation particles, both momenta or frequency decrease (light turns red). As a result, the contribution of radiation to the energy density of the Universe falls faster than the contribution of matter (nonrelativistic particles, whose main contribution is determined by mass). Note. scientific ed.

Black holes and the information paradox Juan Maldacena Institute for Advanced Study, Princeton, USA Black holes in Newton's theory of gravity Theory of relativity: a special general curved space-time

I. V. Yakovlev Materials on physics MathUs.ru Stephen Hawking Brief history of time It brief summary books by Stephen Hawking, which I wrote once. On five pages I have tried to reflect the main

Are you able to believe in the existence of Allah? The word "iman" in translation means faith, confirmation and recognition. The ulema of the science of akydah (belief) give iyman the following definition: “Iyman recognition by the tongue

Ask Ethan 21: Why Does Life Exist? Tags: Life Abiogenesis Author: Ethan Siegel Translation: Vyacheslav Golovanov @SLY_G Published: Geektimes In a nutshell, I can formulate everything that I have learned about life:

1. Condition. It is known that the Moon is always turned to the Earth with one side, so it is impossible to observe the far side of the Moon from the Earth. From which planet in the solar system would it be convenient to observe the reverse side

I II III Laboratory work 18 Rutherford's experiment Purpose of the work Theoretical part 1 Introduction 2 Scattering of α-particles 3 Differential scattering cross section 4 Rutherford's formula Experimental part 1 Method

REDUCTION OF THE MASS OF STARS DUE TO ENERGY RADIATION1). G. Vogt. Not only the adherents of the theory of relativity, but also those scientists who stand on the grounds of classical physics, now believe that

2.Explanatory note. The program complies with the federal component state standard basic general education in physics (Order of the Ministry of Education of Russia dated 03/05/2004 1089 "On approval

63 L.A. Sergeeva Man and the Universe: a modern interpretation of the problem The problems of cosmology, their philosophical interpretation have acquired a new actual sound at the moment, although the problem of man and the environment

Presentation (in physics) Isaac Newton (01/04/1643 - 03/31/1727) Great Britain An outstanding English scientist who laid the foundations of modern natural science, the creator of classical physics, a member

WORKING PROGRAM IN PHYSICS GRADE 11 (basic level) 4 ELECTRODYNAMICS 35 hours 4.1 Elementary electric charge. 1 Know: 4.2 The law of conservation of electric charge Coulomb's law 1 concepts: electric

Secondary school with in-depth study foreign language at the Embassy of Russia in the UK AGREED at the meeting of the MS (Zubov S.Yu.) September 10, 2014 APPROVED by the school principal

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION educational institution higher vocational education"SAMARA STATE ECONOMIC UNIVERSITY"

Planck particles, as decay products of the N-particle, will have corresponding characteristics depending on the age of the Universe. These characteristics are the rest mass equal to the value of the elementary

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION MOSCOW STATE UNIVERSITY OF GEODESY AND CARTOGRAPHY (MIIGAIK) Annotation of the work program of the discipline Concepts of modern natural science

Change in the speed of light and Nobel prizes for interpretations. One of the methods for measuring distance in deep space is called the “standard candles” method, Figure 1. Sector areas illuminated by the same

Regional stage of the All-Russian Olympiad in Astronomy Year 6 Conditions of problems Grade 9 1. Can the constellation of the Southern Cross (declination about 6) be observed in the northern part of the sky? If yes, in what areas

V.Yu.Gankin, Yu.V.Gankin Gravity Any discovery of a new law is useful only when more can be extracted from it than what was invested in it R.Feynman From the preface to the Russian edition of the book

12.5.13. Physics Mechanical phenomena recognize mechanical phenomena and explain, on the basis of existing knowledge, the main properties or conditions for the occurrence of these phenomena: uniform and uniformly accelerated rectilinear

Municipal budgetary educational institution additional education children "Children's (teenage) center" of the administration of the municipality Kireevsky district SCENARIO "JOURNEY TO THE STARS" Teacher-organizer:

Conditions and solution of problems of the Open City Olympiad in Astronomy, Astrophysics and Space Physics named after V.I. Viktor Yuryevich Trakhtengerts February 01, 2015 8 9 grades Each task is worth 7 points 1.

Planets of the Solar System Lesson of the world around us in grade 4 (Textbook by O. T. Poglazova “The world around us”, grade 4, part 3) Starunova Olga Eduardovna, primary school teacher, secondary school 427 of Kronstadt

Lecture 4 QUANTUM-FIELD AND MODERN SCIENTIFIC PICTURES OF THE WORLD Quantum-field NCM (beginning of the 20th century) was formed on the basis of the quantum hypothesis of M. Planck, wave mechanics of E. Schrödinger, quantum mechanics

DEPARTMENT OF EDUCATION AND SCIENCE OF THE LIPETSK REGION STATE REGIONAL AUTONOMOUS VOCATIONAL EDUCATIONAL INSTITUTION "LIPETSK METALLURGICAL COLLEGE" SET OF CONTROL AND MEASURING MATERIALS

ORIGIN AND DEVELOPMENT OF THE UNIVERSE In this article I would like to present a new approach to the emergence and development of the Universe. The need for a new approach is due to contradictions, which, from my point of view,

This file Satellites_Fedotovo_2016.pdf contains full information about all the outbursts of the Iridium satellites and all the flights of other bright satellites that can be observed during the eighth Karelian

EXPLANATORY NOTE The work program in physics is compiled on the basis of an exemplary program of secondary (complete) general education in basic level physics and corresponds to the federal state

Annotation to the textbook physics class (basic level) Gromov S.V. The work program is compiled on the basis of an exemplary program prepared and published in the collection "Programs of educational institutions:

4 ELECTROSTATIC FIELD IN THE PRESENCE OF CONDUCTORS Conductors of electricity are substances containing free charged particles. In conducting bodies, electric charges can move freely in space.

Municipal budgetary educational institution "School 41 "Harmony" with in-depth study of individual subjects" of the Samara city district WORKING PROGRAM Subject physics Class 9 Number of hours

Explanatory note When compiling the program, the following legal documents were used federal component of the state standard for secondary (complete) general education in physics, approved

Annotation to the work program in physics. Grades 7-9. The work program was developed on the basis of: 1. Exemplary program of secondary general education in physics. 2. Programs of basic general education in physics

Lecture 5 5. DOUBLE STARS AND STAR MASSES Very often, two stars can appear close to each other in the sky, although in reality they are at significantly different distances. Such random

Section 3. PHILOSOPHICAL PICTURE OF THE WORLD 1. The basis of being, existing as the cause of itself a) substance b) being c) form d) accident 2. Being is a) everything that exists around b) some kind of material formation

Municipal budgetary educational institution "School 13" of the city of Sarov CONSIDERED at a meeting of the school methodological association of teachers of the natural science cycle Minutes 1 of 08.29.2016 AGREED

2. Solutions to tasks of the Regional stage and the system of evaluation of each task. Grade 9 1. Condition. Some distant star simultaneously rose above the horizon in Moscow (latitude 55 45, longitude 37 37) and in

REFERENCE "Determination of the density of the planets of the terrestrial group" student 7 "B" class secondary school 167 Tepikin Victor Mercury. Mercury is the first planet from the Sun and the smallest of the terrestrial group. Its diameter

PHILOSOPHY Lecture Topic: PHILOSOPHY AND SCIENTIFIC PICTURE OF THE WORLD (2 hours) Objectives: - formation of ideas about the philosophical understanding of the world, being and matter - creation of conditions for the development of philosophical thinking;

PUSHKINSKY LYCEUM 1500 JV "Krasnoe Selo" Cognitive and creative project preparatory group about space. What is above the sky? Project author: Tamrazyan A.R. Moscow, 2015 Introduction Interest in space

LABORATORY WORK 4.8. SIMULATION OF THE TUNNELING EFFECT ON THE MICROWAVE Aims of the work: Familiarization with the main regularities of the tunneling effect on the microwave model. P r i b o r s a n d e d u s

Municipal Budgetary Educational Institution Secondary School 2 of the Urban Settlement "Working Village Vanino" of the Vanino Municipal District of the Khabarovsk Territory

Department of Experimental Physics SPbSPU, Work 3.6 MEASURING THE SPEED OF LIGHT INTRODUCTION M. Yu. Lipovskaya Yu. P. Yashin The speed of light is one of the main constants of our world and determines the limiting speed

Part I Peace in the movement The 5th Wave Trooping ïîòüüüüüüüüè öççààà ëëëëëëëëëëâââþþââââþâüüüüññüñññââñââââââââàâàññññññññññññè .èè.. In this part... This part is an introduction

Such different logic Program tutor: Kazangapova M.S. Authors of the project:- Vagner A.N., Gorbacheva V.V., Kozhakhmetova Z.M., Orynbaev B.N. William Shakespeare Explain the concept of "logic" from a scientific point of view

Appendix to the work program CALENDAR - THEMATIC PLANNING OF EDUCATIONAL MATERIAL for 2013-2014 academic year Subject: the world around them Class: 2d Teacher Vasilyeva I.N. Number of hours per year: 68h

SLOW ARCHITECTURE Maria Elkina Norwegian architect Reyulf Ramstad told ART1 about the reconstruction of the famous Troll Road, moving to the East and learning from landscapes. Maria Elkina: Tell us a little

L. G. Dzhakhaya (Tbilisi, Georgia) HUMAN IN THE MODERN SCIENTIFIC AND PHILOSOPHICAL CONCEPTS OF THE UNIVERSE Man and human society, their appearance and further progressive development can be correct,

Chapter 3 EVOLUTION OF THE UNIVERSE In the evenings the stars light up in the sky. In clear weather, with the naked eye, they can be counted in the sky up to three thousand. But this is only a very small part of those stars and other cosmic

FEBRUARY 38 365 Louise Hay Positive Attitudes Let's make February a month of good feelings! Every morning, proclaim out loud: “I choose the thoughts that create me good mood!" lying down

ALL-RUSSIAN OLYMPIAD FOR SCHOOLCHILDREN IN ASTRONOMY INFORMATION for the participant of the Regional stage of the All-Russian Olympiad for schoolchildren in astronomy 2012 Moscow 2011 1 Dear friend! Before you start to decide

Information for the Scientific Council of the ACC based on the materials of the report dated February 9, 2007 Dark matter (identification problem) were: a.g. Doroshkevich VN Lukash, ID Novikov Where is the matter? Luminous: * Stars Dark

Educational-methodical complex (EMC) Physics Annotation to the work program of the 7th grade A.V.Peryshkin. Physics grade 7. Moscow. Bustard.2012 A.V.Peryshkin. Collection of problems in physics 7-9. Moscow Exam.2015 Educational

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION FEDERAL STATE BUDGETARY INSTITUTION OF SCIENCE SPECIAL ASTROPHYSICAL OBSERVATORY OF THE RUSSIAN ACADEMY OF SCIENCES

Considered at a meeting of the Moscow Region Agreed Approved by teachers of mathematics and physics Deputy. Director for water resources management Director of MBOU secondary school with keys /Kamaltdinova Z.Z./ /Selyanina F.F./ /Selyanina Z.R/ 2011 2011 Order

XXIII St. Petersburg Astronomy Olympiad theoretical round, solutions 206 February 4, 9th grade

RUSSIAN ACADEMY OF EDUCATION Experimental materials for grade 5 students

8 Examples of problem solving Problem Absolutely black body heated from temperature to 3 C How many times has the total radiation power changed in this case? Given: T C373K; T 3 S573K; σ 5.67-3 W m K Find: N /N

Autonomous educational non-profit organization of higher education "Institute of Management, Marketing and Finance" Educational publication METHODOLOGICAL INSTRUCTIONS FOR STUDENTS FOR PRACTICAL STUDIES AND SELF

XXI St. Petersburg Astronomy Olympiad Correspondence qualifying round, decisions 2013 2014 December 5 January 15 Grades 5 6 1. Antares, Andromeda Nebula, Jupiter, Alpha Centauri, Sun. Arrange

Lisa Randall "Dark Matter and Dinosaurs"

Space detective with a spoiler on the cover. Version of one genocide from the author of "Knockin' on Heaven".

Lisa Randall, following the results of the investigation and lengthy operational-search activities, calls dark matter the killer of dinosaurs. Not a heavy piece of dark fabric, which can be killed if dropped from a sufficient height, but a hypothetical filler of the cosmic void invisible to observations and measurements. Scientists after calculation average speed The rotation of galaxies came to the conclusion that the entire mass of physical objects in the Universe is clearly not enough for everything to spin and spin like that. Something helps the galaxies to gain momentum, is heavy enough and creates a gravitational background that holds everything in the universe in a single system. It was by the gravitational influence of this something that scientists came to the conclusion that there is a certain form of matter that invisibly controls the movement of all cosmic bodies - from cosmic dust to huge star clusters. Dark matter is a master of disguise and has many faces. There are several versions of what such matter might be. Scientists have not yet felt it, but they are already dividing it into species.

One such species 66 million years ago changed the trajectory of one comet and sent it to Earth, where dinosaurs led a carefree life, eating grass and each other. Perhaps the unfortunate animals, unaware of their fate, were intelligent enough to organize religious processions and imprison for reposts, fight for territory and drown the alarm bells of the instinct of self-preservation in tar and oil pits. They had their own faith, but there was no future. A cosmic body of negligible dimensions by cosmic standards - about 10 km in diameter - put an end to their plans to get to the lush greenery and bite harder on the barrel of a gaping neighbor. Dinosaurs, as well as many people, cannot comprehend the amazing interconnection of large and small objects, energies and thoughts in an infinitely amazing Universe. Dark matter destroyed the dinosaurs, controlled (to some extent) the periods of flourishing and extinction of life on planet Earth, contributed to the emergence of intelligent life and the emergence of the dominant species of homo sapiens. Wait, then it turns out that dark matter is...

Lisa Randall is the first woman to hold a tenured position in the physics department at Princeton University, and the first woman to hold a tenured position as a theoretical physicist at MIT and at Harvard University.

Purchase: bookvoed.ru/book?id=7066932&utm_source=vkontakte&utm_medium=social&utm_campaign=vkontakte

This article was automatically added from the community