Physicists have set the record for breaking reality. Physicists looked into the "complete void" and proved that there is something in it Quantum physics the latest

Another year is coming to an end, and it's time to sit down again, fold your arms, take a deep breath, and look at some of the headlines of scientific articles that we may not have paid attention to before. Scientists are constantly creating new developments in various fields, such as nanotechnology, gene therapy or quantum physics, and this always opens up new horizons.

The titles of scientific articles are increasingly reminiscent of the titles of stories from science fiction magazines. Considering what 2017 brought us, we can only look forward to what the new 2018 will bring.

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Source: muz4in.net

Scientists have created temporal crystals for which the laws of time symmetry do not apply

According to the first law of thermodynamics, it is impossible to create a perpetual motion machine that will work without an additional source of energy. However, earlier this year, physicists succeeded in creating structures called temporal crystals that cast doubt on this thesis.

Temporal crystals act as the first real examples of a new state of matter called "nonequilibrium", in which atoms have a variable temperature and are never in thermal equilibrium with each other. Temporal crystals have an atomic structure that repeats not only in space, but also in time, which allows them to maintain constant vibrations without receiving energy. This happens even in a stationary state, which is the lowest energy state, when movement is theoretically impossible, since it requires energy.

So do time crystals violate the laws of physics? Strictly speaking, no. The law of conservation of energy only works in systems with symmetry in time, which implies that the laws of physics are the same everywhere and always. However, temporal crystals violate the laws of symmetry of time and space. And not only them. Magnets are also sometimes considered natural asymmetric objects because they have north and south poles.

Another reason why temporal crystals do not violate the laws of thermodynamics is that they are not completely isolated. Sometimes they need to be "pushed" - that is, to give an external impulse, after receiving which they will already begin to change their states again and again. It is possible that in the future these crystals will find wide application in the field of information transfer and storage in quantum systems. They can play a pivotal role in quantum computing.

"Living" wings of a dragonfly

The Merriam-Webster Encyclopedia says that a wing is a movable appendage of feathers or membrane used by birds, insects, and bats to fly. It shouldn't be alive, but entomologists at the University of Keele in Germany have made some startling discoveries that suggest otherwise - at least for some dragonflies.

Insects breathe through the tracheal system. Air enters the body through openings called spiracles. It then travels through a complex network of tracheas that carry air to all cells in the body. However, the wings themselves are composed almost entirely of dead tissue, which dries up and becomes translucent or becomes covered with colored patterns. Areas of dead tissue are permeated by veins, and these are the only wing components that are part of the respiratory system.

However, when entomologist Rainer Guillermo Ferreira looked at the wing of a male dragonfly Zenithoptera through an electron microscope, he saw tiny branching tracheal tubes. This was the first time that something like this was seen in an insect's wing. Much research will be required to determine if this physiological feature is unique to this species, or perhaps also occurs in other dragonflies or even other insects. It is even possible that this is a single mutation. The abundant supply of oxygen may explain the bright, complex blue patterns in the wings of the dragonfly Zenithoptera, which do not contain blue pigment.

Ancient tick with dinosaur blood inside

Of course, this made people think immediately of the scenario from Jurassic Park and the possibility of using blood to recreate dinosaurs. Unfortunately, this will not happen in the near future, because it is impossible to extract DNA samples from the found pieces of amber. Discussions about how long a DNA molecule can hold out is still not over, but even according to the most optimistic estimates and under the most optimal conditions, their lifespan is no more than a few million years.

But, although the tick, named Deinocrotondraculi ("Terrible Dracula"), did not help restore the dinosaurs, it is still a highly unusual find. Now we know not only that ancient ticks were found among feathered dinosaurs, but also that they even infected dinosaur nests.

Modification of the genes of an adult

Today, the pinnacle of gene therapy is “clustered regularly interspaced short palindromic repeats,” or CRISPR. The family of DNA sequences that currently form the basis of CRISPR-Cas9 technology could theoretically change human DNA forever.

In 2017, genetic engineering took a decisive leap forward after a team at the Proteomic Research Center in Beijing announced that it had successfully used CRISPR-Cas9 to eliminate disease-causing mutations in viable human embryos. Another team, from the Francis Crick Institute in London, went the opposite way and used this technology for the first time to deliberately create mutations in human embryos. In particular, they "turned off" a gene that promotes the development of embryos into blastocysts.

Research has shown that CRISPR-Cas9 technology works - and quite successfully. However, this has sparked intense ethical debate about how far this technology can be used. In theory, this could lead to "designer children" who can have intellectual, athletic and physical characteristics in accordance with the characteristics specified by the parents.

Ethics aside, research went further this November when CRISPR-Cas9 was first tested on an adult. Brad Maddu, 44, from California, suffers from Hunter Syndrome, an incurable disease that could eventually lead him to a wheelchair. He was injected with billions of copies of the correcting gene. It will take several months before it can be determined whether the procedure has been successful.

What came before - sponge or comb jelly?

A new scientific report, which was published in 2017, should end the longstanding debate about the origins of animals once and for all. According to the study, sponges are the "sisters" of all animals in the world. This is due to the fact that sponges were the first group that separated during evolution from the primitive common ancestor of all animals. This happened about 750 million years ago.

Previously, there was a heated debate that boiled down to two main candidates: the aforementioned sponges and the marine invertebrate called ctenophores. While sponges are the simplest creatures that sit on the ocean floor and feed by passing and filtering water through their bodies, comb jellies are more complex. They resemble a jellyfish, are able to move in water, can create light patterns and have a simple nervous system. The question of which one was the first is the question of what our common ancestor looked like. This is considered the most important moment in tracking the history of our evolution.

While the results of the study boldly proclaim that the issue has been resolved, just a few months earlier, another study had been published, which stated that our evolutionary "sisters" were ctenophores. Therefore, it is too early to say that the latest results can be considered reliable enough to suppress any doubts.

Raccoons passed an ancient intelligence test

In the sixth century BC, the ancient Greek writer Aesop wrote or collected many fables that are now known as "Aesop's Fables". Among them was a fable called "The Crow and the Jug", which describes how a thirsty crow threw pebbles into a jug to raise the water level and finally get drunk.

Several thousand years later, scientists realized that this fable described a good way to test the intelligence of animals. Experiments showed that the experimental animals understood cause and effect. The ravens, like their relatives, rooks and jays, confirmed the truth of the fable. Monkeys also passed this test, and raccoons were added to the list this year.

During the Aesop fable test, eight raccoons received containers of water, on the surface of which marshmallows floated. The water level was too low to be reached. Two of the subjects successfully threw stones into the container to raise the water level and get what they wanted.

Other test subjects found their own creative solutions that the researchers had never expected. One of the raccoons, instead of throwing stones into the container, climbed onto the container and began to swing from side to side on it until it knocked over. In another test, using floating and sinking balls instead of stones, experts hoped that raccoons would use sinking balls and discard the floating ones. Instead, some animals began to repeatedly dip the floating ball into the water, until the rising wave nailed the marshmallow pieces to the side, making them easier to retrieve.

Physicists create the first topological laser

Physicists at the University of California at San Diego claim that they have created a new type of laser - "topological", the beam of which can take any complex shape without light scattering. The device works on the basis of the concept of topological insulators (materials that are dielectrics inside their volume, but conduct current along the surface), which received the Nobel Prize in Physics in 2016.

Usually, ring resonators are used to amplify light in lasers. They are more efficient than sharp corner resonators. However, this time, the research team created a topological cavity using a photonic crystal as a mirror. In particular, two photonic crystals with different topologies were used, one of which was a star-shaped cell in a square lattice, and the other was a triangular lattice with cylindrical air holes. Team member Boubacar Kante likened them to a bagel and pretzel: although both are bread with holes, the different number of holes makes them different.

Once the crystals are in the right place, the beam takes on the desired shape. This system is controlled by a magnetic field. It allows you to change the direction in which light is emitted, thereby creating a luminous flux. Direct practical application of this is able to increase the speed of optical communication. However, in the future, this is seen as a step forward in the creation of optical computers.

Scientists have discovered excitonium

Physicists around the world were enthusiastic about the discovery of a new form of matter called excitonium. This form is a condensate of quasiparticles, excitons, which are a bound state of a free electron and an electron hole, which is formed as a result of the fact that the molecule has lost an electron. Moreover, Harvard theoretical physicist Bert Halperin predicted the existence of excitonium back in the 1960s, and since then scientists have tried to prove it was right (or wrong).

Like many major scientific discoveries, there was a fair amount of coincidence in this discovery. The University of Illinois research team that discovered the excitonium was actually mastering a new technology called electron beam energy loss spectroscopy (M-EELS) - designed specifically to identify excitons. However, the discovery came when the researchers only performed calibration tests. One team member entered the room while everyone else was looking at the screens. They said they had detected a "light plasmon," the precursor to exciton condensation.

Study leader Professor Peter Abbamont compared this discovery to the Higgs boson - it will not have direct use in real life, but shows that our current understanding of quantum mechanics is on the right track.

Scientists have created nanorobots that kill cancer

Researchers at the University of Durham claim to have created nanorobots that are capable of detecting cancer cells and killing them in just 60 seconds. In a successful university trial, it took the tiny robots one to three minutes to penetrate the outer membrane into a cancerous prostate cell and immediately destroy it.

Nanorobots are 50,000 times smaller than the diameter of a human hair. They are activated by light and rotate at a speed of two to three million revolutions per second in order to be able to penetrate the cell membrane. When they achieve their goal, they can either destroy it or inject a useful therapeutic agent into it.

Until now, nanorobots have only been tested on individual cells, but encouraging results have prompted scientists to move on to experiments on microorganisms and small fish. The further goal is to move on to rodents, and then to people.

An interstellar asteroid could be an alien spacecraft

It has only been a couple of months since astronomers happily announced the discovery of the first interstellar object to fly through the solar system, an asteroid called Oumuamua. Since then, they have observed many strange things happening to this celestial body. Sometimes it behaved so unusual that scientists believe that the object may be an alien spacecraft.

First of all, its form is alarming. Oumuamua has the shape of a cigar with a length to diameter ratio of ten to one, which has never been seen in any of the observed asteroids. At first, scientists thought it was a comet, but then realized that it was not, because the object did not leave a tail behind it as it approached the Sun. Moreover, some experts argue that the object's rotation speed should have destroyed any normal asteroid. One gets the impression that it was specially created for interstellar travel.

But if it was created artificially, then what could it be? Some say that this is an alien probe, others believe that it may be a spacecraft, the engines of which have malfunctioned, and now it is sailing through space. In any case, participants in programs such as SETI and BreakthroughListen believe that Oumuamua requires further investigation, so they aim their telescopes at him and listen for any radio signals.

While the alien hypothesis has not been confirmed in any way, the initial SETI observations have led nowhere. Many researchers are still pessimistic about the chances that the object could be created by aliens, but in any case, research will continue.

According to Einstein's special theory of relativity, the speed of light is unchanged - and is equal to approximately 300,000,000 meters per second, regardless of the observer. This in itself is incredible, given that nothing can travel faster than light, but still purely theoretical. There is an interesting part about special relativity called "time dilation," which says that the faster you move, the slower time moves for you, as opposed to the environment. Driving for an hour will make you a little less old than if you were just sitting at your computer at home. Additional nanoseconds are unlikely to significantly change your life, but the fact remains.

It turns out that if you move at the speed of light, time will freeze in place? This is true. But before you try to become immortal, keep in mind that it is impossible to move at the speed of light if you are unlucky enough to be born with light. Technically speaking, moving at the speed of light would require an infinite amount of energy.

We have just come to the conclusion that nothing can move faster than the speed of light. Well ... yes and no. While this remains technically true, there is a loophole in theory that has been found in the most incredible branch of physics, quantum mechanics.

Quantum mechanics is essentially the study of physics on a microscopic scale, such as the behavior of subatomic particles. These types of particles are incredibly small, but extremely important because they form the building blocks of everything in the universe. You can think of them as tiny spinning electrically charged balls. No unnecessary complications.

So we have two electrons (subatomic particles with a negative charge). is a special process that binds these particles in such a way that they become identical (have the same spin and charge). When this happens, from that moment on, the electrons become identical. This means that if you change one of them - say, change the spin - the other will react immediately. No matter where he is. Even if you don't touch it. The impact of this process is amazing - you understand that in theory this information (in this case, the direction of the spin) can be teleported anywhere in the universe.

Gravity affects light

Let's go back to light and talk about general relativity (also by Einstein). This theory includes a concept known as light deflection - the path of light may not always be straight.

As strange as it sounds, it has been proven many times. Although light has no mass, its path depends on things that have mass, like the sun. Therefore, if light from a distant star passes close enough to another star, it will go around it. How does this concern us? It's simple: perhaps the stars that we see are in completely different places. Remember the next time you look at the stars: it could all be just a play of light.

Thanks to some of the theories we've already discussed, physicists have fairly accurate ways to measure the total mass present in the universe. They also have fairly accurate ways of measuring the total mass that we can observe - but bad luck, these two numbers do not match.

In fact, the volume of the total mass in the universe is significantly greater than the total mass that we can calculate. Physicists had to find an explanation for this, and the result was a theory that included dark matter - a mysterious substance that does not emit light and takes up about 95% of the mass in the universe. Although the existence of dark matter has not been formally proven (because we cannot observe it), there is a lot of evidence in favor of dark matter, and it must exist in one form or another.

Our universe is expanding rapidly

The concepts get more complicated, and to understand why, we need to go back to the Big Bang theory. Before becoming a popular TV show, the Big Bang theory was an important explanation for the origin of our universe. To put it simply: our universe began with an explosion. Debris (planets, stars, etc.) spread in all directions, driven by the tremendous energy of the explosion. Since the debris is heavy enough, we expected this explosive spread to slow down over time.

But that did not happen. In fact, our universe is expanding faster and faster over time. And this is weird. This means that space is constantly growing. The only possible way to explain this is dark matter, or rather dark energy, which causes this constant acceleration. What is dark energy? To you .

Any matter is energy

Matter and energy are just two sides of the same coin. In fact, you've always known this if you've ever seen the formula E = mc 2. E is energy and m is mass. The amount of energy contained in a given amount of mass is determined by multiplying the mass by the square of the speed of light.

The explanation for this phenomenon is very exciting and is associated with the fact that the mass of an object increases as it approaches the speed of light (even if time slows down). The proof is pretty complicated, so you can just take the word for it. Look at atomic bombs, which convert fairly small amounts of matter into powerful bursts of energy.

Wave-corpuscle dualism

Some things are not as straightforward as they seem. At first glance, particles (like an electron) and waves (like light) appear to be completely different. The former are solid lumps of matter, the latter are beams of radiated energy, or something like that. Like apples and oranges. It turns out that things like light and electrons are not limited to just one state - they can be both particles and waves at the same time, depending on who is looking at them.

Seriously. It sounds funny, but there is concrete evidence that light is a wave and light is a particle. Light is both. Simultaneously. Not some kind of mediator between two states, but both. We are back in the field of quantum mechanics, and in quantum mechanics, the universe loves this way and not otherwise.

All objects fall at the same speed

It may seem to many that heavy objects fall faster than light objects - this sounds healthy. Surely a bowling ball falls faster than a feather. This is true, but not because of gravity - the only reason it happens is because the earth's atmosphere provides resistance. Even 400 years ago, Galileo first realized that gravity works the same on all objects, regardless of their masses. If you were with a bowling ball and a feather on the moon (which has no atmosphere), they would fall at the same time.

That's all. At this point, you can get started with the mind.

You think that space itself is empty. This assumption is quite reasonable - that's why it is space, space. But the Universe does not tolerate emptiness, therefore, particles are constantly being born and destroyed in space, in space, in emptiness. They are called virtual, but in fact they are real, and this has been proven. They exist for a fraction of a second, but that's long enough to break some of the fundamental laws of physics. Scientists call this phenomenon "quantum foam" because it is terribly similar to gas bubbles in a soft drink.

Double slit experiment

We noted above that everything can be both a particle and a wave at the same time. But here's the catch: if an apple is in the hand, we know exactly what shape it is. This is an apple, not some apple wave. What determines the state of a particle? The answer is we.

The double slit experiment is just an incredibly simple and mysterious experiment. This is what it is about. Scientists place a screen with two slits against the wall and shoot a beam of light through the slit so we can see where it will hit the wall. Since light is a wave, it will create a certain diffraction pattern and you will see streaks of light scattered all over the wall. Although there were two slits.

But the particles should react differently - flying through two slits, they should leave two stripes on the wall exactly opposite the slits. And if light is a particle, why doesn't it exhibit this behavior? The answer is that the light will exhibit this behavior - but only if we want to. As a wave, light flies through both slits at the same time, but as a particle, it will only pass through one. All we need to do to turn light into a particle is to measure every particle of light (photon) that passes through the slit. Imagine a camera taking pictures of every photon that passes through the slit. The same photon cannot fly through another slit without being a wave. The interference pattern on the wall will be simple: two streaks of light. We physically change the outcome of an event by simply measuring it, observing it.

This is called the "observer effect". While this is a good way to end this article, it hasn't even scratched the surface of the incredible stuff that physicists find. There are tons of variations on the double slit experiment that are even crazier and more interesting. You can look for them only if you are not afraid that quantum mechanics will suck you in.

The end of the year is a high time to take stock and talk about future directions of development. We invite you to take a quick glance at what 2017 brought in elementary particle physics, what results were heard and what trends are outlined. This collection, of course, will be subjective, but it will illuminate the current state of fundamental physics of the microworld from one widely popular angle of view - through the search for New Physics.

Collider cases

The main source of news from the world of elementary particles remains the Large Hadron Collider. Actually, it was created in order to expand our knowledge of the fundamental properties of the microworld and to dig into the unknown. The collider is now running Run 2 for many years. The CERN-approved schedule for the collider extends to the mid-2030s, and it won't have direct competitors for at least another decade. His scientific program includes problems from a wide variety of areas of particle physics, so that even if results are delayed in one direction, this is offset by news from others.

There remains the widest scope for high-profile discoveries. The fact is that all these LHCb data were obtained on the basis of the Run 1 statistics collected in 2010-2012. A thorough analysis of the data and comparison with modeling takes a very long time, and the processing of data for 2016, and even more so for 2017, has not yet been completed. Unlike ATLAS and CMS, the LHCb statistics do not show such a huge leap in the transition from Run 1 to Run 2, but physicists still expect a significant update of the situation with the riddles of B-mesons. But there is still Run 3 ahead, and then - LHC at increased luminosity, and who knows what else the next decade will bring.

In addition, the upgraded SuperKEKB B-factory with the Belle II detector will be commissioned next year. In the coming years, it will become a full-fledged hunter of deviations, and by 2024 it will have accumulated a completely exorbitant luminosity of 50 ab −1 (that is, 50,000 fb −1), see Fig. 5. As a result, if, say, the violation of lepton universality found in decays of B mesons into D mesons and leptons is real, then the Belle II detector will be able to confirm it at a statistical significance level of as much as 14σ (now it reaches only 4σ).

Rare B-meson decays are a hot topic for theorists as well. Loud statements that the experiment significantly diverges from the predictions of the Standard Model are possible only if we reliably calculate these very predictions. But they cannot be simply taken and calculated. Everything rests on the internal dynamics of hadrons, a headache for theorists that has to be estimated on the basis of assumptions. As a result, several theoretical groups give significantly different estimates of how serious the discrepancy between experiment and the Standard Model is: some claim that it is greater than 5σ, others that it does not exceed 3σ. This state of uncertainty, alas, is characteristic of current interpretations of B-meson anomalies.

Low energies

However, apart from the search for hints of New physics at high energies, there are many other problems in particle physics. They may make headlines less often, but for physicists themselves they are also very important.

One active area of ​​research concerns hadron spectroscopy and, in particular, multiquark hadrons. A number of discoveries have been made at the LHC in recent years (most notably the discovery of a pentaquark with hidden charm), but 2017 also brought in several new particles. We talked about five new particles from the family of Ω c -baryons at once, opened in a single stroke, and about the first twice charmed baryon. An indirect demonstration of how much this topic has captured physicists can serve in Nature about energy release in hadronic mergers; publication in this journal, and even a theoretical article, is a completely extraordinary situation for particle physics.

To deal with it, a new experiment Muon g-2 is launched at Fermilab this year to measure the ill-fated magnetic moment of the muon with an accuracy several times higher than the 2001 result (see the recent report of the collaboration). The first serious results should be expected already in 2018, the final ones after 2019. If the deviation remains at the same level, it will become a serious application for a sensation. Meanwhile, in anticipation of a verdict from Fermilab, theoretical calculations are also being refined. The catch here is that the hadronic contribution to the anomalous magnetic moment of the muon cannot be calculated "at the tip of the pen." This calculation is also inevitably based on experiments, but of a completely different kind - for example, on the production of hadrons in low-energy electron-positron collisions. And just two weeks ago, a new measurement appeared from the CLEO-c detector in the CESR accelerator at Cornell University. It clarifies the theoretical calculation and, as it turned out, aggravates discrepancy: the theory and experiment of 2001 now differ by all 4σ. Well, the more interesting it will be to know the results of the Muon g-2 experiment.

There are also purely instrumental problems in particle physics, for example, when different measurements of the same quantity strongly diverge from each other. We will not focus on measurements of the gravitational constant - this blatantly unsatisfactory situation goes beyond particle physics. But the problem with the neutron lifetime - it is described in full detail in our 2013 newsletter - is worth mentioning. If until the mid-2000s all measurements of the neutron lifetime yielded approximately the same results, then the new experiment in 2005 carried out by A.P. Serebrov's group was in sharp contrast to them. The design of the experiments was fundamentally different: in one, the radioactivity of a passing neutron beam was measured, and in the other, the survival of ultracold neutrons in a gravitational trap. The sources of bias in these two types of experiments are completely different, and each group criticized the "competitor", insisting that they had taken into account their errors properly. And now, it seems, the scientific dispute is nearing its resolution. This year, two new measurements appeared (first, second), carried out according to different methods. They both give close values ​​and support the 2005 result (Fig. 7). The final point can be put by a new Japanese beam experiment described in a recent report.

Apparently, another mystery that tormented physicists for seven years - the problem of the proton radius - is also close to being solved. This fundamental characteristic of the key building block of matter has, of course, been measured in numerous experiments, and they all also gave roughly the same results. However, in 2010, studying the spectroscopy of not ordinary, but muonic hydrogen, the CREMA collaboration found that, according to these data, the proton radius is 4% less than the generally accepted value. The discrepancy was very serious - at 7σ. In addition, in the past year the problem has been exacerbated by similar measurements with muonic deuterium. In general, it became completely incomprehensible what the catch was: in calculations, in experiments (and then in which ones), in data processing, or in nature itself (yes, some theorists tried to see manifestations of New Physics here too). For a detailed popular description of this problem, see the large materials. Muonic deuterium spectroscopy has exacerbated the problem with the proton radius and the Slit in armor; a brief overview of the current situation as of August this year is given in the publication The proton radius puzzle.

And in October this year in the magazine Science came out with the results of new experiments in which the radius of the proton was measured in ordinary hydrogen. And - surprise: the new result strongly diverged in the previous, all respected hydrogen data, but agreed with the new muon data (Fig. 8). It seems that the reason for the discrepancy was hidden in the intricacies of measuring the frequencies of atomic transitions, and not in the properties of the proton itself. If other groups confirm this measurement, then the problem with the radius of the proton can be considered closed.

But another low-energy mystery - an anomaly in the nuclear transitions of metastable beryllium-8 - has not yet received an explanation (Fig. 9). Appearing out of nowhere two years ago, it attracted the attention of many theorists looking for manifestations of New Physics, since it resembled the process of birth and decay of a new light particle with a mass of 17 MeV. Several dozen articles have already been published on this topic, but no generally accepted explanation has yet been found (see a review of the situation as of July this year in a recent report). Now the verification of this anomaly is included as a separate item of the scientific program in future experiments to search for new light particles, and we can only wait for their results.

Signals from space

Elementary particles can be searched for and studied not only at colliders, but also in space. The most direct way is to catch particles of cosmic rays and, by their spectrum, composition, and angular distribution, find out where these particles came from. Of course, the vast majority of space aliens were dispersed to high energies by various astrophysical objects. But it may be that some of them arose as a result of the annihilation or decay of dark matter particles. If such a connection is confirmed, it will be a long-awaited indication of specific particles of dark matter, so necessary for cosmology, but so elusive in direct experiments.

Over the past decade, several unexpected features have been discovered in the spectra of cosmic particles of various kinds; the two most curious ones concern the fraction of cosmic positrons and high-energy antiprotons. However, in both cases, there are also purely astrophysical options for explaining why there is so much antimatter in cosmic rays.

And just recently, a new sensation was thrown to physicists by the first results of the DAMPE satellite observatory: in its spectrum of cosmic electrons, a high narrow burst at an energy of 1.4 TeV "appeared" (see a detailed description in the news, "Elements", 12/13/2017). Of course, many perceived it as a direct signal from the annihilation or decay of dark matter particles (Fig. 10) - in the very first days after the publication of the DAMPE results, more than a dozen articles on this topic were published (see the material Kinks and Bursts of Deep Space). Now the tide has slackened; it is clear that the next step is for new observational data, and they, fortunately, will come in a year or two.

But another recent result applies to completely different scales, cosmological, and to other particles - neutrinos. In the article arXiv: 1711.05210, which appeared in November, it is reported that, based on the spatial distribution of galaxy clusters, for the first time it was possible to measure the sum of the masses of all types of neutrinos: 0.11 ± 0.03 eV. Neutrinos are the most mysterious fundamental particles known. They are discouragingly light, so light that most physicists are convinced that it is not the Higgs mechanism that is responsible for their mass, but some kind of New Physics. In addition, they oscillate, spontaneously transform into each other on the fly - and for the proof of this fact, the Nobel Prize in Physics for 2015 was awarded. Thanks to oscillations, we know that the three types of neutrinos have different masses, but we do not know them. common scale. If we had this one and only number, the sum of the masses of all neutrinos, we would be able to sharply limit the fantasies of theorists as to where the neutrino masses come from at all.

The general scale of neutrino masses can, in principle, be measured in the laboratory (experiments are underway, but so far they only give an upper limit), or can be extracted from space observations. The fact is that there have always been a lot of neutrinos in space, and in the early Universe they influenced the formation of a large-scale structure - the embryos of future galaxies and their clusters (Fig. 11). Depending on what their mass is, this influence differs. Therefore, having studied the statistical distribution of galaxies and their clusters, it is possible to extract the total mass of all types of neutrinos.

Of course, such attempts have been made before, but they all gave only a restriction from above. The most conservative of these is the result of the 2013 Planck collaboration: the sum of the masses is less than 0.25 eV. Separate groups of researchers then combined the Planck data with others and obtained stronger, but also more model-dependent upper limits, up to 0.14 eV. But this still remained precisely the limitations! And a new article, having analyzed the recently published catalog of galaxy clusters, was for the first time able to see the effect of non-zero mass and extract the number 0.11 ± 0.03 eV. This work continues further, so it can be expected that the situation will be fully determined in the coming years. In the meantime, we note that the astrophysical community was rather wary of this work: apparently, such an indirect statistical measurement requires careful rechecking.

And a little about theory

Theoretical particle physics in 2017, in general, continued the trend of previous years. There are separate, well-defined areas of work, and within them theorists systematically solve their rather technical problems. And there is a very wide community of phenomenological physicists who, using different methods, are trying to find New Physics. In this motley team, there is not even a close hint of coordinated movement in one direction. Rather, in the absence of clear experimental indications, there is a Brownian motion of theorist particles in a multidimensional and intricate space of mathematical possibilities. There is some benefit from this: the community is testing all possible options for the hypothetical structure of our world, either discarding them due to disagreement with the experiment, or, conversely, developing in depth. But theorists themselves admit that the overwhelming majority of the specific models that they are now proposing and studying will sooner or later be thrown away as unnecessary in the dustbin of history.

Of the entire endless sea of ​​developments, we will single out, perhaps, only one tendency, which has begun to intensify in the last year or two. Physicists gradually stop clinging to ideas that seemed natural to them - be they aesthetic considerations or naturalness in a computational sense, see a recent report on this, which explicitly emphasizes this idea. What this will eventually lead to is impossible to predict now, from 2017. Maybe theorists will find an elegant theory, the predictions of which will be confirmed. Or maybe long-awaited experimental results will come first, pointing to physics beyond the Standard Model, and theorists will use trial and error to find the keys to them. It may, of course, be the case that nothing essentially new will not be discovered in the coming decades - and then the whole approach to further study of the microworld will have to be revised. In short, we are now at a crossroads and in a state of uncertainty. But this should not be seen as reasons for despondency, but as a sign that changes await us.

December is the time to take stock. The editors of the project "Vesti.Nauka" (nauka.site) have selected for you ten of the most interesting news that physicists have delighted us with in the past year.

New state of matter

The technology makes the molecules assemble themselves into the desired structures.

The state of a substance called excitonium was theoretically predicted almost half a century ago, but it was possible to obtain it in an experiment only now.

This state is associated with the formation of a Bose condensate from exciton quasiparticles, which are a pair of an electron and a hole. We are what all these tricky words mean.

Polariton computer

The new computer uses quasiparticle polaritons.

This news came from Skolkovo. Skoltech scientists have implemented a fundamentally new scheme of computer operation. It can be compared to the following method for finding the lowest point of the surface: do not engage in cumbersome calculations, but overturn a glass of water over it. Only instead of the surface there was a field of the required configuration, and instead of water - quasiparticles of polaritons. Our stuff is in this quantum wisdom.

Earth-to-satellite quantum teleportation

For the first time, the quantum state of a photon was "sent" from the Earth to a satellite.

And here once again the Large Hadron Collider came to the aid of physicists. "Vesti.Nauka", what the researchers managed to achieve and what have lead atoms to do with it.

Interaction of photons at room temperature

The phenomenon was first observed at room temperature.

Photons have many different ways to interact with each other, and a science called nonlinear optics is studying them. And if the scattering of light by light was only recently observed, then the Kerr effect has long been familiar to experimenters.

However, in 2017, it was successfully reproduced for the first time for individual photons at room temperature. We are talking about this interesting phenomenon, which in some sense can also be called a "collision of light particles", and about the technological prospects that open up in connection with it.

Time crystal

The creation of experimenters demonstrates "crystalline" ordering not in space, but in time.

In empty space, no point is different from another. In a crystal, everything is different: there is a repeating structure called a crystal lattice. Are such structures possible, which, without energy expenditure, are repeated not in space, but in time?

"Stellar" thermonuclear reactions on Earth

Physicists have recreated the conditions in the bowels of stars in a thermonuclear reactor.

An industrial thermonuclear reactor is the cherished dream of mankind. But the experiments have been going on for more than half a century, and the longed-for practically free energy is gone.

Yet in 2017, an important step was taken in this direction. Researchers for the first time almost exactly recreated the conditions prevailing in the bowels of the stars. how they did it.

Let's hope that 2018 will be just as rich in interesting experiments and unexpected discoveries. Follow the news. By the way, we also did a review of the outgoing year for you.

The year began with the discovery of the Holy Grail - physicists succeeded in turning hydrogen into metal. The experiment confirmed the theoretical developments of the first half of the last century. Researchers at Harvard University cooled the element to -267 degrees Celsius and subjected it to pressure of 495 gigapascals, which is more than at the center of the Earth.

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The experimenters themselves compared the receipt of the planet's first metallic hydrogen with the acquisition of the sacred cup - the main goal of the legendary knights. But the question remained open whether hydrogen will retain its properties when the pressure is released. Physicists hope not.

Time travel is possible

Revise the concept of time theorists from the University of Vienna and the Austrian Academy of Sciences. According to the laws of quantum mechanics, the more accurate a watch, the sooner it exposes the flow of time to the effect of quantum uncertainty. And this limits the ability of our measuring instruments, no matter how well made.

It is impossible to measure time. But you can travel in it using curvatures, a scientist from the University of British Columbia (Canada). True, so far this is only a theoretical tolerance. There are no necessary materials to create a real time machine.

On the other hand, quantum particles are capable of going back into the past, more precisely, to influence other particles in time. This theory was confirmed in 2017 by scientists from Chapman University (USA) and the Perimeter Institute for Theoretical Physics (Canada). Their theoretical research led to an interesting conclusion: either physical phenomena are capable of propagating into the past, or science has encountered an immaterial way of particle interaction.

Exactly two layers of graphene can stop a bullet

Dark energy doesn't exist. But it is not exactly

The debate about dark energy, a hypothetical constant that explains the expansion of the universe, has not stopped since the beginning of the millennium. This year, physicists came to the conclusion that dark energy does not exist after all.

Scientists from the University of Budapest and their colleagues from the United States that the error lies in the understanding of the structure of the universe. Proponents of the concept of dark energy proceeded from the fact that matter is uniform in density, which is not the case. The computer model showed that the Universe consists of bubbles, and this removes the contradictions. Dark energy is no longer needed to explain unexplained phenomena.

However, built on a supercomputer at the University of Durham (Britain) led astrophysicists to the exact opposite conclusions. And the data from the magnetic alpha spectrometer from the International Space Station that dark energy does exist. This was independently stated by two groups of researchers: from Germany and from China.

Most importantly, XENON1T, the world's most sensitive dark matter detector, produced the first. True, there are no positive results yet. But scientists are happy that the system works at all and demonstrates minimal errors.

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Technology

Gravity is the key to other dimensions

Physicists have long dreamed of building a theory of everything - a system that would comprehensively describe reality. One of the four fundamental interactions, gravity, does not allow. The particles that would carry the gravitational interaction have not been found. So, in accordance with the laws of quantum mechanics, there are no waves either.

An ingenious solution to the problem is scientists from the Max Planck Institute. In their opinion, the gravitational field arises exactly at the moment when the quantum wave becomes a particle.

Another obstacle to the construction of a theory of everything is the lack of action opposite to the force of attraction, this factor also breaks the symmetry of ideal formulas. However, scientists from the University of Washington in April 2017 a substance that behaves as if it has a negative mass. The effect has been achieved before, but the result has never been so precise and definite.

Interest in the study of gravity is increased by the theory that gravity is influenced from other dimensions. Physicists from the Max Planck Institute (Germany), using the most modern detectors of gravitational waves, confirm or deny the existence of other measurements in a year. At the end of 2018 or at the latest at the beginning of 2019.

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Quantum mechanics is doomed

It is easy to see that most of the discoveries of modern physics are associated with the study of quantum mechanics. However, scientists that the quantum theory in its modern form will not last long. And the key to understanding the world will be new mathematics.

In the light of such statements, it is not clear how to perceive the news that experimenters from the Niels Bohr Institute, for the first time in the history of science, make qubits rotate in the opposite direction. Or that the second law of thermodynamics is under certain circumstances in the quantum world, as physicists from MIPT claim. Perhaps all this should be taken as confirmation of the current theory. Perhaps - as a step towards a new physics that will describe reality even more accurately.

In the meantime, scientists continue to search for phenomena that will reconcile the worlds of Einstein and Newton. Perhaps a new form of matter will help in this. By the way, it turned out to be a condensate, although so far theorists have argued a lot about its nature.