Below is a list unsolved problems modern physics ... Some of these problems are theoretical. It means that existing theories are unable to explain certain observed phenomena or experimental results. Other problems are experimental, which means that there are difficulties in creating an experiment to test the proposed theory or to study in more detail any phenomenon. The following problems are either fundamental theoretical problems or theoretical ideas for which experimental data are lacking. Some of these issues are closely related. For example, extra dimensions or supersymmetry can solve the hierarchy problem. It is believed that the full theory of quantum gravity is capable of answering most of the listed questions (except for the problem of the island of stability).

• 1. Quantum gravity. Can quantum mechanics and general relativity be combined into a single self-consistent theory (perhaps this is quantum field theory)? Is spacetime continuous or discrete? Will a self-consistent theory use a hypothetical graviton, or will it be entirely a product of the discrete structure of spacetime (as in loop quantum gravity)? Are there deviations from the predictions of general relativity for very small or very large scales or in other extraordinary circumstances that follow from the theory of quantum gravity?
• 2. Black holes, disappearance of information in a black hole, Hawking radiation. Do black holes produce thermal radiation as predicted by theory? Does this radiation contain information about their internal structure, as implied by gravity-gauge invariance duality, or not, as follows from Hawking's original calculation? If not, and black holes can continuously evaporate, then what happens to the information stored in them (quantum mechanics does not provide for the destruction of information)? Or will the radiation stop at some point, when little is left of the black hole? Is there any other way to investigate their internal structure, if such a structure exists at all? Does the law of conservation of baryon charge hold inside a black hole? There is no known proof of the principle of cosmic censorship, as well as the exact formulation of the conditions under which it is fulfilled. There is no complete and complete theory of the magnetosphere of black holes. There is no known exact formula for calculating the number of different states of a system, the collapse of which leads to the appearance of a black hole with a given mass, angular momentum and charge. There is no known proof in the general case of the "no hair theorem" for a black hole.
• 3. Dimension of space-time. Are there additional dimensions of space-time in nature, in addition to the four known to us? If so, how many are there? Is the dimension "3 + 1" (or higher) an a priori property of the Universe, or is it the result of other physical processes, as suggested, for example, by the theory of causal dynamic triangulation? Can we experimentally "observe" higher spatial dimensions? Is the holographic principle true, according to which the physics of our "3 + 1" -dimensional space-time is equivalent to physics on the hypersurface with the dimension "2 + 1"?
• 4. Inflationary model of the Universe. Is the theory correct cosmic inflation, and if so, what are the details of this stage? What is the hypothetical inflaton field responsible for the rise in inflation? If inflation occurred at one point, is this the beginning of a self-sustaining process due to inflation of quantum-mechanical oscillations, which will continue in a completely different place, far from this point?
• 5. Multiverse. Are there physical reasons for the existence of other universes that are fundamentally unobservable? For example: are there quantum mechanical "alternate histories" or "many worlds"? Are there "other" universes with physical laws arising from alternative ways violations of the apparent symmetry of physical forces at high energies, located perhaps incredibly far away due to cosmic inflation? Could other universes have influenced ours, causing, for example, anomalies in the temperature distribution of the relic radiation? Is it justified to use the anthropic principle to solve global cosmological dilemmas?
• 6. The principle of cosmic censorship and the hypothesis of the protection of chronology. Could singularities, not lurking beyond the event horizon, known as “naked singularities”, arise from realistic initial conditions, or could we prove some version of Roger Penrose's “cosmic censorship hypothesis” that assumes that this is not possible? Recently, facts have appeared in favor of the inconsistency of the hypothesis of cosmic censorship, which means that naked singularities should be encountered much more often than just as extreme solutions of the Kerr - Newman equations; nevertheless, no conclusive evidence of this has yet been presented. Likewise, there will be closed timelike curves that arise in some solutions to the equations of general relativity (and which suggest the possibility of time travel in reverse direction) are excluded by the theory of quantum gravity, which combines general relativity with quantum mechanics, as Stephen Hawking's "chronology defense hypothesis" suggests?
• 7. Time axis. What can they tell us about the nature of time by phenomena that differ from each other by walking in time forward and backward? How is time different from space? Why are CP violations observed only in some weak interactions and nowhere else? Are CP violations a consequence of the second law of thermodynamics, or are they a separate time axis? Are there any exceptions to the principle of causality? Is the past the only possible one? Is the present moment physically different from the past and the future, or is it just a result of the peculiarities of consciousness? How have people learned to negotiate what is the present moment? (See also Entropy (time axis) below).
• 8. Locality. Are there non-local phenomena in quantum physics? If they exist, do they not have restrictions in the transmission of information, or: can energy and matter also move along a non-local path? Under what conditions are nonlocal phenomena observed? What does the presence or absence of non-local phenomena entail for the fundamental structure of space-time? How does this relate to quantum entanglement? How to interpret this from the standpoint correct interpretation fundamental nature of quantum physics?
• 9. The future of the universe. Is the Universe heading towards the Big Freeze, Big Rip, Big Compression, or Big Rebound? Is our universe part of an infinitely repeating cyclical pattern?
• 10. Hierarchy problem. Why is gravity such a weak force? It becomes large only on the Planck scale, for particles with energies of the order of 10 19 GeV, which is much higher than the electroweak scale (in low-energy physics, the dominant energy is 100 GeV). Why are these scales so different from each other? What is preventing electroweak-scale quantities such as the Higgs boson mass from obtaining quantum corrections on scales of the order of the Planck ones? Are supersymmetry, extra dimensions, or just anthropic fine-tuning the solution to this problem?
• 11. Magnetic monopole. Were there particles - carriers of "magnetic charge" in any past epochs with higher energies? If so, are there any today? (Paul Dirac showed that the presence of some types of magnetic monopoles could explain the quantization of charge.)
• 12. Decay of the proton and the Great Unification. How can three different quantum mechanical fundamental interactions be combined quantum theory fields? Why is the lightest baryon, which is a proton, absolutely stable? If the proton is unstable, what is its half-life?
• 13. Supersymmetry. Is supersymmetry of space realized in nature? If so, what is the mechanism of supersymmetry breaking? Does supersymmetry stabilize the electroweak scale by preventing high quantum corrections? Is it dark matter from light supersymmetric particles?
• 14. Generations of matter. Are there more than three generations of quarks and leptons? Is the number of generations related to the dimension of space? Why do generations exist at all? Is there a theory that could explain the presence of mass in some quarks and leptons in certain generations on the basis of first principles (Yukawa theory of interaction)?
• 15. Fundamental symmetry and neutrinos. What is the nature of neutrinos, what is their mass, and how did they shape the evolution of the universe? Why is there more matter found in the Universe now than antimatter? What invisible forces were present at the dawn of the Universe, but disappeared from sight during the development of the Universe?
• 16. Quantum field theory. Are the principles of relativistic local quantum field theory compatible with the existence of a nontrivial scattering matrix?
• 17. Massless particles. Why massless particles without spin do not exist in nature?
• 18. Quantum chromodynamics. What are the phase states of strongly interacting matter and what role do they play in space? What is internal organization nucleons? What properties of strongly interacting matter does QCD predict? What governs the transition of quarks and gluons to pi-mesons and nucleons? What is the role of gluons and gluon interactions in nucleons and nuclei? What determines key features QCD and what is their relationship to the nature of gravity and space-time?
• 19. Atomic nucleus and nuclear astrophysics. What is the nature of nuclear forces that bind protons and neutrons into stable nuclei and rare isotopes? What is the reason for the combination of simple particles into complex nuclei? What is the nature of neutron stars and dense nuclear matter? What is the origin of the elements in space? What are the nuclear reactions that drive stars and cause them to explode?
• 20. The island of stability. What is the heaviest stable or metastable nucleus that can exist?
• 21. Quantum mechanics and the correspondence principle (sometimes called quantum chaos). Are there any preferred interpretations of quantum mechanics? How does a quantum description of reality, which includes elements such as quantum superposition of states and wavefunction collapse or quantum decoherence, lead to the reality we see? The same can be formulated using the measurement problem: what is the “dimension” that makes the wave function fall into a certain state?
• 22. Physical information. Are there physical phenomena, such as black holes or wave function collapse, that irrevocably destroy information about their previous states?
• 23. The theory of everything ("Theories of the Grand Unification"). Is there a theory that explains the meanings of all fundamental physical constants? Is there a theory that explains why the standard model's gauge invariance is as it is, why the observed spacetime has 3 + 1 dimensions, and why the laws of physics are as they are? Do “fundamental physical constants” change over time? Are any particles in the standard model of physics elementary particles actually composed of other particles, bound so strongly that they cannot be observed at current experimental energies? Are there fundamental particles that have not yet been observed, and if so, what are they and what are their properties? Are there unobservable fundamental forces that the theory suggests that explain other unsolved problems in physics?
• 24. Gauge invariance. Are there really non-Abelian gauge theories with a gap in the mass spectrum?
• 25. CP symmetry. Why isn't CP-symmetry preserved? Why does it persist in most of the observed processes?
• 26. Semiconductor physics. The quantum theory of semiconductors cannot accurately calculate a single semiconductor constant.
• 27. The quantum physics. The exact solution of the Schrödinger equation for many-electron atoms is unknown.
• 28. When solving the problem of the scattering of two beams by one obstacle, the scattering cross section turns out to be infinitely large.
• 29. Feynmanium: What will happen to a chemical element with an atomic number higher than 137, as a result of which the 1s 1 electron will have to move at a speed exceeding the speed of light (according to the Bohr atom model)? Is Feynmanium the last chemical to exist physically? The problem can manifest itself at about element 137, where the expansion of the nuclear charge distribution reaches its final point. See the Extended Periodic Table of Elements article and the Relativistic effects section.
• 30. Statistical physics. There is no systematic theory of irreversible processes that makes it possible to carry out quantitative calculations for any given physical process.
• 31. Quantum electrodynamics. Are there gravitational effects caused by zero-point oscillations of the electromagnetic field? It is not known how, when calculating quantum electrodynamics in the high-frequency region, simultaneously fulfill the conditions for the finiteness of the result, relativistic invariance, and the sum of all alternative probabilities equal to unity.
• 32. Biophysics. There is no quantitative theory for the kinetics of conformational relaxation of protein macromolecules and their complexes. There is no complete theory of electron transfer in biological structures.
• 33. Superconductivity. It is impossible to predict theoretically, knowing the structure and composition of a substance, whether it will go into a superconducting state with decreasing temperature.

Actual problems mean important for a given time. Once upon a time the urgency of the problems of physics was completely different. Questions such as "why it gets dark at night", "why the wind blows" or "why the water is wet" were resolved. Let's see what scientists are puzzling over these days.

Despite the fact that we can explain more and more fully the world, more and more questions over time. Scientists direct their thoughts and devices into the depths of the Universe and the jungle of atoms, finding there such things that cannot yet be explained.

Unsolved problems of physics

Some of the topical and unsolved problems of modern physics are purely theoretical. Some problems in theoretical physics are simply impossible to verify experimentally. Another part is questions related to experiments.

For example, the experiment is inconsistent with a previously developed theory. There are also applied tasks. Example: environmental problems of physics associated with the search for new sources of energy. Finally, the fourth group - purely philosophical problems of modern science, looking for an answer to "the main question of the meaning of life, the Universe and all that."

Dark energy and the future of the universe

According to today's concepts, the Universe is expanding. Moreover, according to the analysis of relict radiation and supernova radiation, it expands with acceleration. The expansion is due to dark energy. Dark energy Is an undefined form of energy that was introduced into the model of the universe to explain accelerated expansion. Dark energy does not interact with matter in the ways we know, and its nature is a great mystery. There are two ideas about dark energy:

• According to the first, it fills the Universe uniformly, that is, it is a cosmological constant and has a constant energy density.
• According to the second, the dynamic density of dark energy changes in space and time.

Depending on which of the ideas about dark energy is correct, one can assume the future fate of the Universe. If the density of dark energy grows, then we are waiting for Big gap in which all matter falls apart.

Another option is Big compression when gravitational forces prevail, expansion will stop and be replaced by contraction. In this scenario, everything that was in the Universe first collapses into separate black holes, and then collapses into one common singularity.

Many unresolved issues are related to black holes and their radiation. Read a separate article about these mysterious objects.

Matter and antimatter

Everything that we observe around us is matter composed of particles. Antimatter Is a substance composed of antiparticles. An antiparticle is a twin of a particle. The only difference between a particle and an antiparticle is charge. For example, the charge of an electron is negative, while its counterpart from the world of antiparticles, the positron, has the same positive charge. Antiparticles can be obtained in particle accelerators, but no one has met them in nature.

When interacting (colliding), matter and antimatter annihilate, resulting in the formation of photons. Why it is matter that predominates in the Universe is a big question of modern physics. It is assumed that this asymmetry arose in the first fractions of a second after the Big Bang.

After all, if matter and antimatter were equal, all particles would annihilate, leaving only photons as a result. There are suggestions that the distant and completely unexplored regions of the Universe are filled with antimatter. But whether this is so remains to be seen with a lot of brain work.

By the way! For our readers, there is now a 10% discount on

The theory of everything

Is there a theory that can explain absolutely everything physical phenomena at an elementary level? Maybe there is. Another question is whether we can think of it. The theory of everything, or The Grand Unification Theory is a theory that explains the meanings of all known physical constants and unites 5 fundamental interactions:

• strong interaction;
• weak interaction;
• electromagnetic interaction;
• gravitational interaction;
• Higgs field.

By the way, you can read about what it is and why it is so important in our blog.

Of the many theories proposed, none have been experimentally tested. One of the most promising directions in this matter is the unification of quantum mechanics and general relativity in theory of quantum gravity... However, these theories have different areas applications, and so far all attempts to combine them lead to a divergence that cannot be removed.

How many dimensions are there?

We are used to a three-dimensional world. We can move in the three dimensions known to us back and forth, up and down, feeling comfortable. However, there is M-theory, according to which there is already 11 measurements, only 3 of which are available to us.

It is quite difficult to imagine, if not impossible. True, for such cases there is a mathematical apparatus that helps to cope with the problem. In order not to blow up the brain for yourself and you, we will not cite mathematical calculations from M-theory. Better to quote the physicist Stephen Hawking:

We are just evolved descendants of monkeys on a small planet with an unremarkable star. But we have a chance to comprehend the Universe. This is what makes us special.

What can we say about distant space when we do not know everything about our home. For example, there is still no clear explanation for the origin and periodic inversion of its poles.

There are a lot of riddles and tasks. The same unsolved problems exist in chemistry, astronomy, biology, mathematics, philosophy. Solving one secret, we get two in return. This is the joy of learning. Let us remind you that you will be helped to cope with any task, no matter how difficult it is. The problems of teaching physics, like any other science, are much easier to solve than fundamental scientific questions.

Where you can, among other things, join the project and take part in its discussion.

List This page on the scale of grading of articles of the Project: Physics has list level.

High

The importance of this page for the Physics project: high

March 27-30, 2011 information from the article " Unsolved problems of modern physics"Appeared on the title page in the column" Did you know". The column presented the text: “There is an opinion that the number unsolved problems of modern physics decreased by four points over the past decades ". The full issue of the column is available in the Do You Know Archive.

The article is a translation of the corresponding English version... Lev Dubovoy 09:51, 10 March 2011 (UTC)

Pioneer effect[edit source]

Found an explanation for the Pioneer effect. Is it worth removing it from the list now? Russians are coming! 20:55, 28 August 2012 (UTC)

There are many explanations for the effect, none of them is on this moment generally accepted. IMHO let it hang for now :) Evatutin 19:35, 13 September 2012 (UTC) Yes, but, as I understand it, this is the first explanation that is consistent with the observed deviation in speed. Although I agree that we have to wait. Russians are coming! 05:26 14 September 2012 (UTC)

particle physics[edit source]

Generations of matter:

Why three generations of particles are needed is still unclear. The hierarchy of coupling constants and masses of these particles is not clear. It is not clear if there are other generations other than these three. It is not known if there are other particles that we do not know about. It is not clear why the Higgs boson, just discovered at the Large Hadron Collider, is so light. There are other important questions that the Standard Model does not answer.

Higgs particle [edit source]

The Higgs particle has already been found. --195.248.94.136 10:51 6 September 2012 (UTC)

While physicists are careful with their conclusions, maybe he is not alone there, different decay channels are being investigated - IMHO let it hang for now ... Evatutin 19:33, 13 September 2012 (UTC) Only solved problems that were on the list are moved to the section Unsolved problems of modern physics # Issues resolved in recent decades - Arbnos 10:26, 1st December 2012 (UTC)

Neutrino mass[edit source]

It has been known for a long time. But the section is called Problems Solved in the Last Decades - it seems that the problem was solved not so long ago, after the portals on the list .-- Arbnos 14:15, 2 July 2013 (UTC)

Horizon problem[edit source]

You call this "the same temperature": http://img818.imageshack.us/img818/1583/img606x341spaceplanck21.jpg ??? This is the same as saying "Problem 2 + 2 = 5". This is not a problem at all, since this is a fundamentally wrong statement.

• I think the new "Space" video will be useful: http://video.euronews.com/flv/mag/130311_SESU_121A0_R.flv

What's most interesting is that WMAP showed exactly the same image 10 years ago. Who's color blind, raise your hand.

The laws of aerohydrodynamics[edit source]

I propose to add one more unsolved problem to the list - even one related to classical mechanics, which is usually considered completely studied and simple. The problem of a sharp discrepancy between the theoretical laws of aerohydrodynamics and experimental data. The results of simulations performed according to the Euler equations do not correspond to the results obtained in wind tunnels. As a result, there are currently no working systems of equations in aerohydrodynamics that could be used to make aerodynamic calculations. There are a number of empirical equations that describe experiments well only within the narrow framework of a number of conditions and there is no way to make calculations in the general case.

The situation is even absurd - in the 21st century, all developments in aerodynamics are carried out through tests in wind tunnels, while in all other areas of technology they have long managed only with accurate calculations, without later rechecking them experimentally. 62.165.40.146 10:28, 4 September 2013 (UTC) Valeev Rustam

No need, tasks for which there is not enough computing power, there are enough in other areas, in thermodynamics, for example. There are no fundamental difficulties, the models are simply extremely complex. --Renju player 15:28 Nov 1, 2013 (UTC)

Nonsense [edit source]

FIRST

Is spacetime fundamentally continuous or discrete?

The question is very poorly formulated. Space-time is either continuous or discrete. So far, modern physics cannot answer this question. This is the problem. But this formulation asks something completely different: here both options are taken as a whole " continuous or discrete"And asks:" Is space-time fundamentally continuous or discrete? ". The answer is yes, spacetime is continuous or discrete. And I have a question, why was there such a question? You can't formulate the question like that. Apparently, the author did a poor job of retelling Ginzburg. And what is meant by “ fundamentally"? >> Kron7 10:16, 10 September 2013 (UTC)

Can be reformulated as "Is space continuous or is it discrete?" This formulation seems to exclude the meaning of the question you have cited. Dair T "arg 15:45, 10 September 2013 (UTC) Yes, that's a completely different matter. Corrected. >> Kron7 07:18, 11 September 2013 (UTC)

Yes, space-time is discrete, since only absolutely empty space can be continuous, and space-time is far from empty

;SECOND

Inertial mass / gravitational mass ratio for elementary particles In accordance with the principle of equivalence of the general theory of relativity, the ratio of inertial to gravitational mass for all elementary particles is equal to unity. However, there is no experimental confirmation of this law for many particles.

In particular, we do not know what will be the weight a macroscopic piece of antimatter known masses .

How is this sentence to be understood? >> Kron7 14:19 10 September 2013 (UTC)

Weight, as you know, is the force with which a body acts on a support or suspension. Mass is measured in kilograms, weight in newtons. In zero gravity, a body weighing one kilogram will have zero weight. The question of what will be the weight of a piece of antimatter of a given mass is therefore not a tautology. --Renju player 11:42, 21 November 2013 (UTC)

Well, what is there incomprehensible? And we must remove the question: how does space differ from time? Yakov176.49.146.171 19:59, 23 November 2013 (UTC) And we need to remove the question about the time machine: this is anti-scientific nonsense. Yakov176.49.75.100 21:47, 24 November 2013 (UTC)

Hydrodynamics [edit source]

Hydrodynamics is one of the branches of modern physics, along with mechanics, field theory, quantum mechanics, etc. By the way, hydrodynamic methods are actively used in cosmology, when studying the problems of the universe, (Ryabina 14:43, November 2, 2013 (UTC))

You may be confusing the complexity of computational problems with fundamentally unsolved problems. So, the N-body problem has not yet been solved analytically, in a number of cases it presents significant difficulties with an approximate numerical solution, but it does not contain any fundamental riddles and secrets of the universe. There are no fundamental difficulties in hydrodynamics, there are only computational and model ones, but they are abundant. In general, let's be careful to separate warm and soft. --Renju player 07:19 5 November 2013 (UTC)

Computational problems are related to unsolved problems in mathematics, not physics. Yakov 176.49.185.224 07:08, 9 November 2013 (UTC)

Minus thing [edit source]

To the theoretical questions of physics, I would add the hypothesis of minus-matter. This hypothesis is purely mathematical: mass can have a negative value. Like any purely mathematical hypothesis, it is logically consistent. But, if we take the philosophy of physics, then this hypothesis contains a disguised rejection of determinism. Although, perhaps, there are still undiscovered laws of physics describing minus-matter. --Yakov 176.49.185.224 07:08, November 9, 2013 (UTC)

Sho tse take? (where did they get it?) --Tpyvvikky .. for mathematicians and the time can be negative .. and sho now

Superconductivity[edit source]

What are the problems with BCS, what does the article say about the absence of a "completely satisfactory microscopic theory of superconductivity"? At the same time, a link to the textbook published in 1963, a slightly outdated source for an article on modern problems of physics. I am taking this passage away for now. --Renju player 08:06, 21 August 2014 (UTC)

Cold fusion[edit source]

"What is the explanation for the controversial reports of excess heat, radiation and transmutation?" The explanation is that they are unreliable / incorrect / erroneous. In any case, by the standards of modern science. The links are dead. Removed. 95.106.188.102 09:59, 30 October 2014 (UTC)

Copy [edit source]

A copy of the article http://ensiklopedia.ru/wiki/%D0%9D%D0%B5%D1%80%D0%B5%D1%88%D1%91%D0%BD%D0%BD%D1%8B%D0 % B5_% D0% BF% D1% 80% D0% BE% D0% B1% D0% BB% D0% B5% D0% BC% D1% 8B_% D1% 81% D0% BE% D0% B2% D1% 80 % D0% B5% D0% BC% D0% B5% D0% BD% D0% BD% D0% BE% D0% B9_% D1% 84% D0% B8% D0% B7% D0% B8% D0% BA% D0 % B8 - Arbnos 00:06, 8 November 2015 (UTC)

Absolute time[edit source]

According to SRT, there is no absolute time, so the question of the age of the Universe (and of the future of the Universe as well) does not make sense. 37.215.42.23 00:24 19 March 2016 (UTC)

I'm afraid you are not in the subject. Soshenkov (obs.) 23:45, March 16, 2017 (UTC)

Hamiltonian formalism and Newton's differential paradigm[edit source]

1. Is the most fundamental problem of physics that amazing fact that (so far) all fundamental theories are expressed through the Hamiltonian formalism?

2. Is even more amazing and a completely inexplicable fact encrypted in the second anagram Newton's hypothesis that that the laws of nature are expressed in terms of the differential equations? Is this hypothesis exhaustive or does it allow for other mathematical generalizations?

3. The problem of biological evolution is a consequence of fundamental physical laws, or is it an independent phenomenon? Isn't the phenomenon of biological evolution a direct consequence of Newton's differential hypothesis? Soshenkov (obs.) 23:43, March 16, 2017 (UTC)

Space, time and mass[edit source]

What are "space" and "time"? How do massive bodies "bend" space and influence time? How does "curved" space interact with bodies, causing universal gravitation, and photons, changing their trajectory? And what does entropy have to do with it? (Explanation. General relativity gives formulas that can be used, for example, to calculate relativistic corrections for the clocks of the global navigation satellite system, but it does not even raise the listed questions. If we consider the analogy with gas thermodynamics, then general relativity corresponds to the level of gas thermodynamics at the level of macroscopic parameters (pressure , density, temperature), but here we need an analogue at the level of the molecular kinetic theory of gas. Maybe hypothetical theories of quantum gravity will explain what we are looking for ...) P36M AKrigel / obs 17:36, 31 December 2018 (UTC) It is interesting to know the reasons and see the link for discussion. That's why I asked here, a well-known unsolved problem, in society better known than most of the article (in my subjective opinion). Even children are told about it for educational purposes: in Moscow in the "Experimentarium" there is a separate stand with this effect. Dissent, please respond. Jukier (obs.) 06:33, 1 January 2019 (UTC)

• • Everything is simple here. "Serious" scientific journals are afraid to publish materials on controversial and unclear issues, so as not to lose their reputation. Nobody reads articles in other publications and the results published in them do not affect anything. Polemics are published in general in exceptional cases. Textbook authors try to avoid writing about things they don't understand. An encyclopedia is not a place for discussion. The IP rules require that the material of the articles be based on AI, and in disputes between the participants, a consensus is reached. Neither requirement can be achieved in case of publication of an article on unsolved problems of physics. Ranque tube only particular example big problem. In theoretical meteorology, the situation is more serious. The issue of thermal equilibrium in the atmosphere is basic, it is impossible to hush it up, but there is no theory. Without this, all other reasoning is devoid of scientific foundation. The professors do not tell students about this problem, as an unsolved one, and textbooks lie in different ways. This is primarily about the equilibrium temperature gradient]

    Synodic period and rotation around the axis of the terrestrial planets. Earth and Venus are turned on one side to each other while being on the same axis with the sun. So is the Earth with Mercury. Those. the period of rotation of Mercury is synchronized with the Earth, not the Sun (although it was believed for a very long time that it would be synchronized with the Sun as the Earth was synchronized with the Moon). speakus (obs.) 18:11, 9 March 2019 (UTC)

    • If you find a source that refers to this as an unsolved problem, then you can add it. - Alexey Kopylov 21:00, 15 March 2019 (UTC)
    
    

    Will it be possible to detect gravitational waves?

    Some observatories are looking for evidence of the existence of gravitational waves. If such waves can be found, these fluctuations of the space-time structure itself will indicate cataclysms occurring in the Universe, such as supernova explosions, collisions of black holes, and possibly still unknown events. For details, see the article by W. Waite Gibbs, "Space-Time Ripples."

    What is the lifetime of a proton?

    Some theories outside the Standard Model (see Chapter 2) predict proton decay, and several detectors have been built to detect this decay. Although the decay itself has not yet been observed, the lower limit of the half-life for a proton is estimated at 10 32 years (significantly exceeding the age of the Universe). With the advent of more sensitive sensors, it may be possible to detect the decay of a proton, or it will be necessary to move the lower limit of its half-life.

    Are superconductors possible at high temperatures?

    Superconductivity appears when a metal's electrical resistance drops to zero. Under such conditions, established in the conductor electricity flows without losses, which are inherent in ordinary current when passing through conductors like copper wire... The phenomenon of superconductivity was first observed at extremely low temperatures (just above absolute zero, - 273 ° C). In 1986, scientists succeeded in making superconducting materials at the boiling point of liquid nitrogen (-196 ° C), which already allowed the creation of industrial products. The mechanism of this phenomenon is not yet fully understood, but researchers are trying to achieve superconductivity at room temperature, which will reduce energy losses.

    Chemistry problems

    How does the composition of a molecule determine its appearance?

    Knowledge of the orbital structure of atoms in simple molecules makes it fairly easy to determine the appearance of the molecule. However, theoretical studies of the appearance of complex molecules, especially biologically important ones, have not yet been carried out. One aspect of this problem is protein folding, discussed in the List of Ideas, 8.

    What are chemical processes with cancer?

    Biological factors like heredity and the environment are likely to play a large role in the development of cancer. Knowing what is happening in cancer cells chemical reactions may be able to create molecules to interrupt these reactions and make cells resistant to cancer.

    How do molecules communicate in living cells?

    Molecules of the desired shape are used to alert the cells when the message is transmitted through "fitting" in the form of complementarity. Protein molecules are the most important, so the way they are folded determines their shape [conformation]. Therefore, a deeper knowledge of the protein folding will help solve the problem with the connection.

    Where is cell aging set at the molecular level?

    Another biochemical problem of aging is possibly associated with DNA and proteins involved in the “repair” of DNA, which is cut off in the course of repeated replication (see: List of Ideas, 9. Genetic Technologies).

    Biology problems

    How is it developing whole organism from one fertilized egg?

    It seems that it will be possible to answer this question as soon as the main problem from Chap. 4: what is the structure and purpose of the proteome? Of course, each organism has its own peculiarities in the structure of proteins and their purpose, but it will certainly be possible to find a lot in common.

    What Causes Mass Extinctions?

    Over the past 500 million years, there has been a complete extinction of species five times. Science continues to search for the reasons for this. The last extinction, which happened 65 million years ago, at the turn of the Cretaceous and Tertiary periods, is associated with the extinction of dinosaurs. As David Rop puts the question in the book Extinction: Genes Pumped or Luck? (see: Sources for in-depth study), was the extinction of most organisms living at that time due to genetic factors or some kind of cataclysm? According to the hypothesis put forward by the father and son, Louis and Walter, Alvarez, 65 million years ago a huge meteorite (about 10 km across) fell to the Earth. The blow produced by him raised huge clouds of dust, which interfered with photosynthesis, which led to the death of many plants, and therefore, animals that make up the same food chain, up to huge, but vulnerable dinosaurs. Support for this hypothesis is a large meteorite crater discovered in the southern part of the Gulf of Mexico in 1993. Is it possible that previous extinctions were the result of similar collisions? Research and controversy continues.

    Dinosaurs were warm-blooded or cold-blooded animals?

    British anatomy professor Richard Owen coined the concept of "dinosaur" (which means "dire lizards") in 1841, when only three incomplete skeletons were found. The British animal painter and sculptor Benjamin Waterhouse Gaukins took up the re-creation of the appearance of extinct animals. Since the first specimens found had iguana-like teeth, the stuffed animals resembled huge iguanas, causing quite a stir among visitors.

    But lizards are cold-blooded reptiles, and therefore at first they decided that dinosaurs were such. Several scientists then suggested that at least some of the dinosaurs were warm-blooded animals. Proof was not until 2000, when a fossilized dinosaur heart was found in South Dakota. Having a four-chambered device, this heart confirms the assumption of warm-blooded dinosaurs, since there are only three chambers in the heart of lizards. However, more evidence is needed to convince the rest of the world that this assumption is true.

    What is the basis of human consciousness?

    Being a subject of study humanities, this question goes far beyond the scope of this book, but many of our scientific colleagues undertake to study it.

    As you might expect, there are several approaches to the interpretation of human consciousness. Proponents of reductionism argue that the brain is a huge set of interacting molecules and that eventually we will figure out the rules for their work (see the article by Crick and Koch "The Problem of Consciousness" [In the world of science. 1992. No. 11–12]).

    Another approach goes back to quantum mechanics... According to him, we are not able to comprehend the nonlinearity and unpredictability of the brain until we understand the connection between the atomic and macroscopic levels of the behavior of matter (see Roger Penrose's book The King's New Mind: On Computers, Thinking and the Laws of Physics [M., 2003]; a (See also Shadows of the Mind: In Search of the Science of Consciousness. [M., 2003]).

    In accordance with the old approach, the human mind has a mystical component that is inaccessible to scientific explanation, so that science is not at all capable of comprehending human consciousness.

    In connection with the recent work of Stephen Wolfram on creating ordered images by constantly applying the same simple rules(see Chapter 5) it is not surprising that this approach is used in relation to human consciousness; so another point of view will appear.

    Geology problems

    What is causing the big changes in the Earth's climate like widespread warming and ice ages?

    Ice ages, characteristic of the Earth for the last 35 million years, occurred approximately every 100 thousand years. Glaciers are advancing and receding throughout the northern temperate belt, leaving memorial signs in the form of rivers, lakes and seas. 30 million years ago, when dinosaurs roamed the Earth, the climate was much warmer than the current one, so trees grew even near the North Pole. As already mentioned in Ch. 5, the temperature of the earth's surface depends on the equilibrium state of the incoming and outgoing energies. Many factors affect this balance, including the energy emitted by the Sun, debris in space between which the Earth is wading, incident radiation, changes in the Earth's orbit, atmospheric changes, and fluctuations in the amount of energy emitted by the Earth (albedo).

    This is the direction in which research is being conducted, especially given the recent controversy over greenhouse effect... There are many theories, but there is still no true understanding of what is happening.

    Can volcanic eruptions or earthquakes be predicted?

    Some volcanic eruptions are predictable, such as the recent (1991) eruption of Mount Pinatubo in the Philippines, but others are unavailable for modern means, still catching volcanologists by surprise (for example, the eruption of Mount St. Helens, Washington, May 18, 1980). Many factors cause volcanic eruptions. There is no single theoretical approach that holds true for all volcanoes.

    Earthquakes are even more difficult to predict than volcanic eruptions. Some well-known geologists even doubt the possibility of making a reliable forecast (see: List of ideas, 13. Predicting earthquakes).

    What's going on in the earth's core?

    The two lower shells of the Earth, the outer and inner core, are inaccessible to us due to the deep bedding and high pressure, which excludes direct measurements. All information about earth cores geologists obtain from observations of the surface and total density, composition and magnetic properties, as well as studies using seismic waves. In addition, the study of iron meteorites helps in view of the similarity of the process of their formation with the terrestrial one. Recent results from seismic waves have revealed different wave velocities in the north-south and east-west directions, indicating a layered solid inner core.

    Astronomy problems

    Are we alone in the universe?

    Despite the absence of any experimental evidence for the existence of extraterrestrial life, there are plenty of theories on this score, as well as attempts to find news from distant civilizations.

    How do galaxies evolve?

    As already mentioned in Ch. 6, Edwin Hubble classified everything famous galaxies according to their appearance. Despite the thorough description of their current state, this approach does not allow understanding the evolution of galaxies. Several theories have been put forward to explain the formation of spiral, elliptical and irregular galaxies. These theories are based on the physics of gas clouds that predated galaxies. Supercomputer modeling has made it possible to clarify something, but has not yet led to a unified theory of the formation of galaxies. The creation of such a theory requires additional research.

    Are Earth-like planets common?

    Mathematical models predict the existence of Earth-like planets from a few to millions within the Milky Way. Powerful telescopes have found more than 70 planets outside the solar system, but most are Jupiter-sized or larger. As telescopes improve, it will be possible to find other planets, which will help determine which of the mathematical models is more consistent with reality.

    What is the source of the Y-ray bursts?

    The strongest γ-rays are observed about once a day, which often turns out to be more powerful than all others taken together (γ-rays are similar to visible light, but they have much higher frequency and energy). This phenomenon was first recorded in the late 1960s, but was not reported until the 1970s, as all sensors were used to monitor compliance with the nuclear test ban.

    At first, astronomers believed that the sources of these emissions were within the Milky Way. The high intensity of the radiation gave rise to the assumption of the proximity of its sources. But as data accumulated, it became apparent that these emissions were coming from everywhere, and were not concentrated in the plane of the Milky Way.

    The flare detected in 1997 by the Hubble Space Telescope indicated that it came from the periphery of a faintly luminous galaxy several billion light years away. Since the source was far from the center of the galaxy, it was unlikely to be a black hole. It is believed that these bursts of gamma radiation emanate from ordinary stars contained in the disk of the galaxy, possibly due to the collision of neutron stars or other celestial bodies still unknown to us.

    Why is Pluto so strikingly different from all other planets?

    The four inner planets - Mercury, Venus, Earth and Mars - are relatively small, rocky and close to the Sun. The four outer planets - Jupiter, Saturn, Uranus and Neptune - are large, gaseous, and distant from the Sun. Now about Pluto. Pluto is small (like the inner planets) and distant from the Sun (like the outer planets). In this sense, Pluto falls out of the general row. It orbits the Sun in the vicinity of an area called the Kuiper Belt, which contains many Pluto-like bodies (some astronomers call them Pluto).

    Recently, several museums have decided to strip Pluto of planetary status. Until more bodies from the Kuiper belt can be mapped, the controversy over Pluto's status will continue.

    How old is the universe?

    The age of the universe can be estimated in several ways. In one way, the age of the chemical elements in the composition of the Milky Way is estimated from the results radioactive decay elements with a known half-life based on the assumption that the elements are synthesized (inside supernovae of large stars) with constant speed... According to this method, the age of the Universe is determined to be 14.5 ± 3 billion years.

    Another method involves estimating the age of the star clusters based on some assumptions about cluster behavior and distance. The age of the most ancient clusters is estimated at 11.5 ± 1.3 billion years, and for the Universe - 11-14 billion years.

    The age of the Universe, determined by the rate of its expansion and the distance to the most distant objects, is 13-14 billion years. The recent discovery of the accelerated expansion of the Universe (see Chapter 6) makes this quantity more uncertain.

    Another method has recently been developed. The Hubble Space Telescope, working at its limit, measured the temperature of the oldest white dwarfs in globular cluster M4. (This method is similar to estimating the time elapsed after a fire burned out, based on the ash temperature.) It turned out that the age of the oldest white dwarfs is 12-13 billion years. If we assume that the first stars were formed no earlier than 1 billion years after the "big bang", the age of the Universe is 13-14 billion years, and the estimate serves as a check of the indicators obtained by other methods.

    In February 2003, data were obtained from the Wilkinson Microwave Anisotropy Probe (WMAP), which allowed the most accurate calculation of the age of the Universe: 13.7 ± 0.2 billion years.

    Are there multiple universes?

    According to one possible solution discussed in Ch. 6 of the problem of the accelerated expansion of the Universe, a multitude of universes inhabiting separate "branes" (multidimensional membranes) are obtained. For all its speculativeness, this idea gives a wide scope for all kinds of speculation. For more information on multiple universes, see Martin Rees's book Our Cosmic Abode.

    When is the next meeting with an asteroid for the Earth?

    Space fragments are constantly hitting the Earth. And that is why it is so important to know how large the celestial bodies fall on us and how often. Bodies with a diameter of 1 m enter the Earth's atmosphere several times a month. They often explode at high altitudes, releasing energy equal to a small explosion. atomic bomb... Approximately once a century, a body 100 m across flies to us, leaving behind a great memory (a tangible blow). After the explosion of a similar celestial body in 1908 over the Siberian taiga, in the basin of the Podkamennaya Tunguska River [Krasnoyarsk Territory], trees were felled on an area of ​​about 2 thousand km 2.

    The impact of a celestial body with a diameter of 1 km, occurring once every million years, can lead to enormous destruction and even cause climate change. Collision with celestial body the size of 10 km in diameter, probably led to the extinction of dinosaurs at the turn of the Cretaceous and Tertiary epochs 65 million years ago. Although a body of this size may appear only once every 100 million years, steps are already being taken on Earth to avoid being caught off guard. Near-Earth Objects (NEOs) and Near-Earth Asteroid Observing (NEAT) projects are being developed, according to which, by 2010, it will be possible to track 90% of asteroids with a diameter of more than 1 km, total number which, according to various estimates, is in the range of 500-1000. Another program, Spacewatch, by the University of Arizona, is to observe the sky looking for possible "candidates" for a collision with the Earth.

    For more information, refer to the World Wide Web sites: http: //neat.jpl. nasa. gov, http://neo.jpl.nasa.gov and http: //apacewatch.Ipl. arizona. edu /

    What happened before the "big bang"?

    Since time and space have been reporting from the “big bang”, the concept of “before” has no meaning. This is tantamount to asking what is north of the North Pole. Or, as the American writer Gertrude Stein would put it, there is no "then" then. But such difficulties do not stop theorists. Perhaps before the Big Bang, the time was imaginary; there probably was nothing at all, and the universe arose from fluctuations in the vacuum; or there was a collision with another "brane" (see the issue of multiple universes raised earlier). It is difficult to find experimental confirmation of such theories, since the enormous temperature of the original fireball prevented the creation of any atomic or subatomic formations that could have existed before the expansion of the universe.

    Notes:

    Occam's razor - the principle that everything should seek the simplest interpretation; most often this principle is formulated as follows: "Without necessity, much should not be asserted" (pluralitas non est ponenda sine necessitate) or: "What can be explained by less should not be expressed by more" (frustra fit per plura quod potest fieri per pauciora ). Usually, historians' formulation “Entities should not be multiplied unnecessarily” (entia non sunt multiplicandasine necessitate) is not found in Occam's writings (these are the words of Durand from Saint-Pursen, c. 1270-1334 - French theologian and Dominican monk; a very similar expression for the first time found in the French Franciscan monk Odo Rigaud, c. 1205-1275).

    The so-called topological tunnels. Other names for these hypothetical objects are the Einstein-Rosen bridges (1909-1995), Podolsky (1896-1966), Schwarzschild's throats (1873-1916). Tunnels can connect both separate, arbitrarily distant regions of the space of our Universe, and regions with different moments of the beginning of its inflation. Discussion continues on the feasibility of tunnels, their passability and evolution.

    Kuiper Gerard Peter (1905–1973) was a Dutch and American astronomer. Discovered the satellite of Uranus - Miranda (1948), the satellite of Neptune - Nereid (1949), carbon dioxide in the atmosphere of Mars, the atmosphere near the satellite of Saturn Titan. Compiled several detailed atlases of photographs of the Moon. Revealed many double stars and white dwarfs.

    The satellite named in memory of the initiator of this experiment - astrophysicist David T. Wilkinson. Weight 840 kg. Life was launched in June 2001 into a near-solar orbit, to the Lagrange point L2 (1.5 million km from the Earth), where the gravitational forces of the Earth and the Sun are equal to each other and the conditions for precision observations of the entire sky are most favorable. The receiving equipment is protected from the Sun, Earth and the Moon (the closest sources of thermal noise) by a large round screen, on the illuminated side of which there are solar batteries. This orientation is maintained throughout the flight. Two receiving mirrors with an area of ​​1.4x1.6 m, set back to back, scan the sky away from the orientation axis. As a result of the rotation of the station around its own axis, 30% of the celestial sphere is visible per day. The resolution of WMAP is 30 times that of the previous Cosmic Background Explorer (COBE) satellite launched by NASA in 1989. The size of the measured cell in the sky is 0.2x0.2 °, which immediately affected the accuracy of celestial maps. The sensitivity of the receiving equipment has also increased many times over. For example, a 4-year COBE dataset is collected in just 10 days in a new experiment.

    For a few seconds, a blinding, bright fireball was observed moving across the sky from southeast to northwest. On the path of the fireball, which was visible over the vast territory of Eastern Siberia (within a radius of up to 800 km), there was a powerful dust trail that remained for several hours. After the light phenomena, an explosion was heard at a distance of over 1000 km. In many villages, there was a shaking of the soil and buildings, like an earthquake, cracked window glass, household utensils fell from the shelves, hanging objects swayed, etc. Many people, as well as pets, were knocked down by the air wave. Seismographs in Irkutsk and in a number of places in Western Europe recorded a seismic wave. An air blast wave was recorded on barograms obtained at many Siberian meteorological stations, in St. Petersburg and a number of meteorological stations in Great Britain. These phenomena are most fully explained by the cometary hypothesis, according to which they were caused by the invasion of the earth's atmosphere by a small comet moving at cosmic speed. According to modern concepts, comets are composed of frozen water and various gases with impurities of inclusions of nickel iron and rocky matter. GI Petrov in 1975 determined that the "Tunguska body" was very loose and no more than 10 times higher than the air density at the Earth's surface. It was a loose snowball with a radius of 300 m and a density of less than 0.01 g / cm. At an altitude of about 10 km, the body turned into gas, dispersed in the atmosphere, which explains the unusually bright nights in Western Siberia and in Europe after this event. The shock wave that fell to the ground caused the forest to fall.

    Stein Gertrude (1874-1946) - American writer, literary theorist !. Modernist. Formally - experimental prose (The Making of Americans, 1906–1908, published 1925) in the mainstream of literature! "Stream of consciousness". Biographical book "Autobiography of Alice B. Toklas" (1933). Stein belongs to the expression "lost generation" (in Russian: Stein G. Autobiography of Alice B. Toklas. St. Petersburg, 2000; Stein G. Autobiography of Alice B. Toklas. Picasso. Lectures in America. Moscow, 2001).

    A hint of the words there is no there, there from chapter 4! from the 1936 novella (published 1937) A Biography of All, which is a sequel to her famous novel The Autobiography of Alice B. Toklas.