Great world riddles. Unsolved mysteries of science
From the very beginning of the concerned consciousness, man began to explore the world around him, constantly expanding his horizons. But it turns out that no matter how you expand these horizons, behind them even more distant horizons are discovered, to which you have to stretch for a long time. So what? We get genuine pleasure learning something new. We are ready to gnaw on granite to get to the bottom of things. But we cannot solve some of the mysteries of science.
Did the Universe begin with the Big Bang?
The Big Bang theory has been considered the most reliable one for explaining the beginning of the universe for many years. But is she really one hundred percent correct and the only answer?
The theory was called the "Big Bang" by one of its fiercest opponents, Fred Hoyle. He thought the universe was static and eternal - but his hypothesis quickly died. In 1929, Edwin Hubble proved that the universe was expanding. Then came new evidence in favor of the Big Bang theory: in 1965 it was the existence of microwave background radiation, the afterglow of the Big Bang.
But there is one but. Hubble's measurements in 1929 were disproved in 1990. In fact, the universe was expanding more slowly than the Big Bang theory predicted. In response, Alan Guth made some adjustments to the Big Bang theory. He stated that the universe expanded rapidly at first and then slowly.
But as critics of the Big Bang theory point out, it's impossible to prove it. Maybe we need a new way to define the beginning of the universe?
How to predict an earthquake?
Our understanding of the movements of the Earth began to take shape relatively recently. Only in 1912 did Alfred Wegener come to the idea that continents are in constant motion. In the 1960s, the US Navy noticed that the seabed was not as smooth as previously thought - it consisted of mountain ranges.
Scientists concluded that the seabed was also affected by volcanoes and earthquakes. This discovery led to the theory of plate tectonics, which explains the large-scale movements of the Earth's lithosphere. We now know that earthquakes are born when two plates creep on top of each other.
We were able to localize places that are more prone to tectonic activity than others. But we still don't know exactly when the earthquake will happen. For example, scientists can predict that an earthquake will soon occur in Los Angeles. This could mean any moment from tomorrow to the next 30 years.
What Causes Ice Ages?
We still don't know what triggers the ice ages. Milutin Milankovich proposed a solution in 1920. He stated that the Earth receives different amount solar energy at different times due to the way our planet moves. This leads to the appearance of ice ages at regular intervals. At first, Milankovitch's idea seemed correct, because ice ages did occur every 100,000 years.
But Milankovitch's theory cannot explain some of the major disturbances in this scheme - for example, a period of 200 million years without a single ice age. New theories have focused on the greenhouse effect, but this raises more questions than it answers. What caused carbon dioxide fluctuations when there were no humans yet? Scientists are racking their brains, but no one knows the truth yet.
Is there a missing link?
The missing link is a hypothetical evolutionary link between primates and humans. In 1912, Charles Dawson found a skull with a vaulted human and ape jaw at Piltdown Common near Lewis in England. For 41 years, the scientific community believed we had found the missing link.
However, this unusual find turned out to be a fake, created by a zoologist at the British Museum named Hinton. What for? That was his revenge.
Hinton volunteered for the museum. When he asked for a salary, paleontology curator Arthur Smith Woodward turned him down. Therefore, Hinton forged the skull to undermine Woodward's credibility as a scientist. However, the plan did not work.
In 1956, William Strauss suggested that the Neanderthal was our direct ancestor. However, new methods of dating the fossils have shown that humans and Neanderthals lived simultaneously and maintained contact. The vacancy is still open.
Why did the abstract communication system appear so late?
The earliest examples of art date from 35,000 years ago. However, the written language only developed 7,000 years ago, and mathematics took another 2,000 years.
Why was there such a big gap between the first abstract drawings and the first communication system? Most likely, our brain should change first. But how? The brain is such a complex structure that it can take several centuries before we fully understand how it works.
What are black holes?
The concept of black holes was initially met with disbelief. When physicist Sir Arthur Eddington first heard about them, he exclaimed: "I think there must be a law of nature that does not allow a star to behave in such a strange way!"
Oppenheimer was the first to welcome black holes in 1938. But Sir Arthur Eddington is understandable because the behavior of black holes is counterintuitive. Nobody knows what is going on inside the black hole. In the 1990s, scientists discovered the existence of supermassive black holes the size of a billion suns. They are usually located at the center of elliptical galaxies. Did they take part in the creation of these galaxies? We don't really know. And the black holes themselves are a real mystery for us, because we can neither see nor touch them, as well as visit.
How old is the universe?
Nobody knows for sure. Answers range from 8 to 20 billion years, but this is quite a wide spread. The strangest thing about this problem is that the universe may be younger than its oldest stars. Research carried out in 1994 showed that the universe is 8 billion years old, which means that the oldest star in the Milky Way is older than the universe itself. Fortunately, measurements made in 1999 contradicted previous studies.
But their triumph was short-lived. Another study done with modern technologies, showed that the universe was 15% smaller, and hence 15% younger. According to this study, there are stars older than the universe itself. What are we doing wrong? Perhaps we don't understand the fundamental laws of physics?
Are there multiple universes?
The first concept of multiple universes was proposed by science fiction writer Jack Williamson in 1952. What inspired the physicist Hugh Everett. In 1957, he wrote his doctoral work on the topic of multiple universes. According to his model, each event creates a series of universes in which each possible outcome this event.
John Wheeler, Everett's boss, suggested a different version. In his opinion, the universe periodically expanded and then contracted to the size of an atom. But some scientists have noted that the universe does not seem to have enough matter to collapse.
Stephen Hawking developed the theory that there are an infinite number of universes with every possible future.
The only problem is that we cannot test these theories in practice.
What will be the end of the universe?
Some theories suggest that the universe will begin to shrink at some point until it reaches the size of an atom. Then there will be another big bang and the universe will be reborn.
But there is another possibility. The universe can expand indefinitely, pushing galaxies farther and farther apart. Eventually, the stars will burn out all their fuel and there will be nothing left.
Oct 23, 2017 Gennady
You reduce the pain with morphine until the last day of the experiment, and then replace the morphine with saline. And guess what's going on? Saline relieves pain.
This is the placebo effect: somehow a composition made of nothing can have a very powerful effect. Doctors have known about the placebo effect for a long time. But apart from the fact that, apparently, it has a biochemical nature, we do not know anything. One thing is clear: the mind can influence the biochemistry of the body.
2. The problem of the horizon
Our Universe turns out to be inexplicably united. Look at space from one edge of the visible universe to the other, and you will see that the background of microwave radiation in space is at the same temperature throughout. This doesn't seem surprising until you remember that these two edges are 28 billion light years apart, and our universe is only 14 billion years old.
Nothing can move faster than the speed of light, so it is impossible for thermal radiation to travel between the two horizons and balance the hot and cold zones formed during the Big Bang, establishing the thermal equilibrium that we see now.
Scientifically, the same background temperature is an anomaly. It could be explained by the recognition that the speed of light is not constant. But even in this case, we are still powerless before the question: why?
3. Ultra-energetic cosmic rays
For more than a decade, physicists in Japan have been observing cosmic rays that should not exist. Cosmic rays are particles that travel in the Universe at speeds close to the speed of light. Some cosmic rays come to Earth as a result of violent events such as a supernova explosion. But we know nothing about the origin of the high-energy particles observed in nature. And even this is not a real secret yet.
When cosmic ray particles move through space, they lose energy when colliding with photons low level energy, for example, from cosmic microwave background radiation. However, the University of Tokyo discovered very high energy cosmic rays. Theoretically, they could only appear from our galaxy, but astronomers cannot find the source of these cosmic rays in our galaxy.
4. The phenomenon of homeopathy
Madeleine Ennis, a pharmacologist at Queen's University Belfast, is a disaster for homeopathy. She opposed claims by homeopaths that chemical agent can be diluted to such an extent that the sample contains practically nothing but water, and at the same time has healing power. Ennis set out to prove once and for all that homeopathy is just chatter.
In her latest work, she describes how her group in four different laboratories investigated the effects of ultra-dilute histamine solutions on white blood cells involved in inflammation. To the surprise of the scientists, it turned out that homeopathic solutions (diluted to such an extent that, apparently, did not contain even one molecule of histamine) worked in the same way as histamine.
Prior to these experiments, no homeopathic remedy had ever worked in clinical trials. But the Belfast study suggests something is going on. "We," says Ennis, "cannot explain our findings and report them to encourage others to investigate this phenomenon."
If the results turn out to be real, she believes, the consequences could be very significant: we may have to rewrite physics and chemistry.
5. Dark matter
Take our best knowledge of gravity, apply it to the rotation of galaxies, and you will immediately find the problem: according to our knowledge, galaxies should disintegrate. Galactic matter revolves around a central point as its gravitational pull creates centripetal forces. But there is not enough mass in galaxies to create the observed rotation.
Vera Rubin, an astronomer at the Department of Terrestrial Magnetism at the Carnegie Institution in Washington, noticed this anomaly in the late 1970s. The best answer physicists could give was to assume that there is more matter in the universe than we can observe. The problem was that no one could explain what this "dark matter" is.
Scientists still cannot explain it, and this is an unpleasant gap in our understanding. Astronomical observations suggest that dark matter must account for roughly 90% of the mass of the universe, and yet we are strikingly clueless as to what that 90% is.
6. Life on Mars
July 20, 1976 Gilbert Levin sits on the very edge of his chair. At a distance of millions of kilometers away, on Mars, the Viking lander took soil samples. Levin's apparatus mixed them with a substance containing carbon-14. Scientists participating in the experiment believe that if methane emissions containing carbon-14 are found in the soil, then there should be life on Mars.
Viking's analyzers give a positive result. Something consumes nutrients, converts them and then gives off a gas containing carbon-14. But why is there no holiday?
Because another analyzer designed to detect organic molecules, which are essential signs of life, found nothing. Scientists were cautious and declared the Viking's discoveries false positive. But is it?
The results, transmitted from the last NASA spacecraft, show that in the past, the surface of Mars almost certainly contained water and was therefore favorable for life. There is other evidence as well. “Every flight to Mars,” says Gilbert Levin, “provides data to support my conclusion. None of them contradicts it.”
Levin is no longer defending his views alone. Joe Miller, a microbiologist at the University of Southern California at Los Angeles, has reanalyzed the data and believes the emissions show signs of a circadian cycle. And this, with a high degree of probability, implies the presence of life. Whether these scientists are right is still unknown.
7. Tetraneutrons
Four years ago, six particles were discovered that should not have existed. They were called tetraneutrons - four neutrons that are in a bond that defies the laws of physics.
A team from Caen, led by Francisco Miguel Marquès, fired beryllium nuclei at a small carbon target and analyzed their trajectories using detectors. Scientists expected to see four different neutrons hitting different detectors. Instead, they found only one flash of light in one detector.
The energy of this burst showed that all four neutrons hit the same detector. Perhaps it's just a coincidence that four neutrons accidentally hit the same place at the same time. But that's ridiculously unlikely.
However, this behavior is not unlikely for tetraneutrons. True, some may argue that, according to the standard model of particle physics, tetraneutrons simply cannot exist. Indeed, according to the Pauli principle, in one system there are not even two protons or neutrons that could have the same quantum properties. The nuclear force that holds them together is such that it cannot even hold two single neutrons, let alone four.
Marquez and his group were so overwhelmed by the results that they "buried" this data in a scientific work, which said about a certain probability of the discovery of tetraneutrons in the future. After all, if you start changing the laws of physics in order to substantiate the connection of four neutrons, chaos will arise.
The recognition of the existence of tetraneutrons would mean that the combination of elements formed after the Big Bang is not consistent with what we are now seeing. And even worse, the formed elements become too heavy for space. "The universe would probably have collapsed before it began to expand," says Natalia Timofeyuk, a theorist at the University of Surrey in Guildford, UK.
At the same time, there is other evidence that speaks in favor of the fact that matter can consist of numerous neutrons. These are neutron stars. They contain a huge amount of bound neutrons, which means that when the neutrons gather into masses, forces still unexplained to us come into play.
8. Pioneer anomaly
In 1972, the Americans launched the Pioneer-10 spacecraft. On board was a message to extraterrestrial civilizations - a tablet with images of a man, a woman and a diagram of the location of the Earth in space. A year later, Pioneer-11 followed him. By now, both vehicles should have already been in deep space. However, in an unusual way, their trajectories strongly deviated from the calculated ones.
Something started to pull (or push) them, causing them to move with acceleration. It was tiny - less than a nanometer per second, equivalent to one ten-billionth of the gravity on the Earth's surface. But that was enough to push the Pioneer-10 off its trajectory by 400,000 kilometers.
With Pioneer-11, NASA lost contact in 1995, but until then, it deviated from the trajectory in the same way as its predecessor. What caused this? Nobody knows.
Some of the possible explanations have already been rejected, including programming bugs, solar wind, and fuel leaks. If the cause was some gravitational effect, then we know nothing about it. Physicists are simply at a loss.
9. Dark energy
This is one of the most famous and most intractable problems in physics. In 1998, astronomers discovered that the universe was expanding at an ever faster rate. Prior to that, it was believed that after the Big Bang, the expansion of the universe slows down.
Scientists have not yet found a reasonable explanation for this discovery. One of the assumptions is that some property of empty space is responsible for this phenomenon. Cosmologists have called it dark energy. But all attempts to identify her have failed.
10. Tenth planet
If you take a trip to the very edge Solar system, into the cold zone of space beyond Pluto, you will see something strange. After passing the Kuiper Belt - an area of \u200b\u200bspace teeming with icy cliffs - you suddenly see empty space.
Astronomers call this boundary the Kuiper Rock, since after it the density of the cosmic rock belt decreases sharply. What is the reason? The only answer to this may be the presence of a tenth planet in our solar system. Moreover, in order to clear space of debris in this way, it must be as massive as Earth or Mars.
But, although calculations show that such a body could have caused the existence of the Kuiper belt, no one has ever seen this legendary tenth planet.
11. Space signal WOW
It lasted 37 seconds and came from space. On August 15, 1977, on a printout of a radio telescope in Delaware, the recorders drew: WOW. And twenty-eight years later, no one knows what caused this signal.
The pulses came from the constellation Sagittarius at a frequency of about 1420 MHz. Transmissions in this range are prohibited by international agreement. Natural sources radiations, such as thermal emissions from planets, cover a much wider frequency range. What caused the emission of these pulses? There is still no answer.
The closest star in this direction is 220 light years away. If the signal came from there, then it must be either a huge astronomical event, or an advanced extraterrestrial civilization with an amazingly powerful transmitter.
All subsequent observations in the same area of \u200b\u200bthe sky did not lead to anything. A signal like this WOW is no longer registered.
12. Such fickle constant
In 1997, astronomer John Webb and his team at the University of New South Wales in Sydney analyzed the light coming to Earth from distant quasars. On its 12 billion year journey, light travels through interstellar clouds made of metals such as iron, nickel and chromium. The researchers found that these atoms absorb photons of the quasar's light, but not at all as expected.
The only more or less reasonable explanation for this phenomenon is that the physical constant, called the fine structure constant, or alpha, has a different value when light passes through the clouds.
But this is heresy! Alpha is an extremely important constant that determines how light interacts with matter, and it shouldn't change! Its value, among other things, depends on the charge of the electron, the speed of light and Planck's constant. Is it possible for any of these parameters to actually change ?!
None of the physicists wanted to believe that the measurements were correct. Webb and his group have tried to find errors in their results for years. But they still have not succeeded.
Webb's results are not the only evidence that something is wrong with our understanding of alpha. A recent analysis of the only known natural nuclear reactor that operated nearly 2 billion years ago where Oklo is now in Gabon also suggests that something has changed in the interaction of light with matter.
The proportion of certain radioactive isotopes produced in such a reactor depends on alpha, and therefore analysis of fission products retained in Oklo soil makes it possible to determine the value of a constant during their formation.
Using this method, Steve Lamoreaux and colleagues at Los Alamos National Laboratory in New Mexico have estimated that alpha has decreased by more than 4% since the operation in Oklo. And this means that our ideas about constants may turn out to be wrong.
13. Low-temperature nuclear fusion (LTS)
After a sixteen-year absence, he returned. Although, in fact, the NTS never disappeared. Since 1989, the US Navy laboratories have conducted more than 200 experiments designed to find out if nuclear reactions can occur when room temperature generate more energy than consume (it is believed that this is possible only inside the stars).
Controlled nuclear fusion would solve many of the world's energy problems. Unsurprisingly, the US Department of Energy is so interested in him. Last December, after a lengthy review of all the evidence, it said it was open to suggestions for new NTS experiments.
This is a pretty sharp turn. Fifteen years ago, this same ministry concluded that the initial STC results obtained by Martin Fleischmann and Stanley Pons of the University of Utah and inaugurated at a press conference in 1989 could not be verified, and thus they are probably false.
The basic principle of NTS is that immersing palladium electrodes in heavy water (in which oxygen is combined with an isotope of heavy hydrogen) can release a large amount of energy. The catch is that all generally accepted scientific theories believe that nuclear fusion at room temperature is impossible.
It would seem that our world has been studied up and down and science certainly has an answer to any question that interests us. However, it’s not so. Until now, there are many mysterious things and phenomena that do not have a rational explanation.
Cat purr
Everyone knows that cats always purr when they feel good. However, how they do it, no one knows. There is no special organ in the throat of cats to make such sounds. Interestingly, while purring, you cannot listen to the heart or lungs of cats, and the purr itself is continuous, on inhalation and exhalation.
Scientists believe that cats use their vocal cords to make vibrating sounds that we hear like purrs. Also, in the course of research, it turned out that the frequency of purr is in the range necessary to accelerate regeneration and wound healing. Therefore, your cat is probably a great doctor.
Species coming out of nowhere
Scientists have been fighting this mystery for many years. The fact is that many species of animals and plants on our planet simply appeared out of nowhere. They did not have ancestors from which they could evolve, and this confuses science.
This was the case, for example, with amphibians: the stage at which fish gave birth to amphibians is not exactly known. And the very first land animals appeared already with developed limbs and a well-defined head. And dozens of different types... Then, after the alleged cataclysm (about 65 million years ago), which led to the extinction of the dinosaurs, several different groups mammals.
Magnetic compass in cows
You probably haven't even thought about it. In general, no one thought about it before the advent of Google Earth. It was this service that made it possible to study thousands of images of grazing cows (don't ask why) and discover one strange pattern. About 70% of cows, when eating or drinking, turn their heads strictly north or south. Moreover, this is observed on all continents, regardless of the terrain, weather and other factors.
What is dark matter made of?
About 27% of the entire universe is dark matter. It is such a thing that does not emit electromagnetic radiation and does not directly interact with it. That is, dark matter does not emit light at all. This property makes its direct observation impossible.
The first theories about dark matter appeared about 60 years ago, but scientists still cannot provide direct evidence of its existence, although everything indicates that it exists.
How many planets are in our solar system?
Since scientists officially excluded Pluto from the club of planets, it is believed that there are 8 of them left in our solar system. But no matter how it is. Most of our solar system is still unexplored. The region between Mercury and the Sun is too bright, and the region beyond Uranus is too dark.
By the way, right on the outskirts of our solar system, beyond Pluto, is the so-called Kuiper belt, which consists of icy objects. There, scientists every day discover hundreds of thousands of objects the same size as Pluto, or even larger.
By the way, they noticed a large gap in the Kuiper belt. This suggests that there is another planet the size of Earth or Mars, which has attracted all these stones around it. So scientists will have to rewrite textbooks many times to explain how many planets are in our solar system.
Why are people divided into left-handers and right-handers?
Scientists have studied well why most people use right hand more often than the left. However, they still cannot understand what mechanisms are working in this case.
It is believed that the majority (70 to 95%) are right-handed, the minority (5 to 30%) are left-handed. And there is also the percentage of ambidextrous people in whom both arms are equally developed. Although scientists here differ in opinion.
Genes have been shown to influence left-handedness and right-handedness, but the exact "left-handed gene" has not yet been identified. There is also evidence that the environment can also influence the choice of the dominant hand. For example, teachers retrained children to use their right rather than their left hand.
Extinction of megafauna
The common name for the giant animals that once walked the Earth is megafauna. The megafauna disappeared about 10 thousand years ago. And scientists have not been able to figure out why.
Some believe that the megafauna became extinct due to climate change, but there is little hard evidence for this. Another theory is that they simply did not have enough food. However, not everything is so simple here either. Scientists in Alaska sometimes find perfectly preserved mammoths with undigested greens in their stomachs and even in their mouths. This suggests that the animals died literally for dining table, and all at once. Why this happened, scientists do not know.
Why do we dream
Some people believe that dreams are just random images and brain impulses, while others believe that they carry deep meaning, these are subconscious desires, problems and experiences. But one way or another, no one will give you an exact answer.
Even techniques such as hypnosis and lucid dreaming do not provide an answer. A special science is engaged in the study of dreams - oneirology. Scientists in this field are unanimous that dreams symbolize something hidden deep in the psyche of people, although what exactly - no one can say.
Cosmic roar
In 2006, while trying to study young stars, scientists were faced with a problem: an incomprehensible, mysterious noise that interfered with the study. Researchers have never understood what creates it. Of course, sound cannot travel through space, but radio waves can, but from where? What publishes them? We only managed to find out that these waves do not belong to stars or other cosmic formations and phenomena known to man.
Why do we have different blood types?
Yes, science knows a lot about blood groups, but no fewer questions still remain unanswered. For example, we still have no idea why they are different and why this is needed from the point of view of evolution.
Blood groups differ in the antigens in the blood cells; these antigens are signals from antibodies that destroy foreign cells in the body. Scientists don't know why these antigens are different.
There is speculation that they have something to do with disease and immunity. For example, it turned out that people with the third blood group are more susceptible to E. coli, and with zero they have almost complete immunity to one of the forms of malaria.
Why is there more visible matter than antimatter
Most of the discussion is around b-mesons, short-lived subatomic particles made up of one quark and one antiquark. The decay of B-mesons is slower than the decay of anti-B-mesons, due to which enough B-mesons could appear to form everything in the Universe. We add that the existing B-, D- and K-mesons can change and become antiparticles, and turn into particles again. According to one hypothesis, mesons, in all likelihood, assume an ordinary state, which is quite possible, since there are still more ordinary particles than antiparticles.
Where did lithium go from the universe?
In the early universe, when temperatures were incredibly high, isotopes of hydrogen, helium and lithium were formed in large quantities, but over time, only a third of the isotopes of lithium-7 remained. Various theories, including hypothetical ones based on hypothetical bosons called axions, attempt to shed light on the cause of the change. Theories are also proposed explaining the disappearance of lithium by the fact that it was absorbed by the cores of stars, which cannot be detected by modern telescopes. Be that as it may, a unified and accurate version explaining this phenomenon does not yet exist.
Why do people need sleep
Although we know that the human body is regulated by the so-called circadian clock - a biological instrument responsible for sleep and wakefulness - the essence of this phenomenon has not yet been explained. During sleep, tissues, cells and many other processes are regenerated in the human body. There are organisms that don't need sleep at all, so why do humans need it? Several assumptions have been made regarding this issue, but none of them are exhaustive. While scientists do not know exactly why we sleep, they have already figured out how important sleep is for the body and how strongly it affects processes such as mental work and mental flexibility.
How gravity works
We all know that the gravity of the Moon causes the ebb and flow, the gravity of the Earth keeps us on the earth's surface, the gravity of the Sun keeps our planet in orbit, but how deep is our understanding of these phenomena? This force affects the fact that large objects have the ability to attract smaller ones to themselves. Scientists are still delving into the essence of the action of gravity, without having sufficient explanations for what reason it exists. Why are atoms mostly empty space? Why is the force that holds atoms together different from gravity? Is gravity made of any kind of particles? The answers to these questions cannot be obtained with the help of modern understanding of physics.
Where is everyone
The observable universe is 92 billion light-years in diameter, filled with billions of galaxies with stars and planets, yet visible traces of life are only present on Earth. Statistically, the chance that we are the only form of life in the Universe is impossibly small, but why haven't we contacted anyone so far?
This puzzle is known as the Fermi Paradox. Many explanations for this paradox have been proposed, some of which are quite plausible. We can always speculate about some probable scenarios: missed signals, about the fact that they are already here, and we do not know about it, they cannot or do not want to contact us. Or - here's the most disappointing scenario - Earth is truly the only habitable planet in the universe.
What dark matter is made of
About 80% of the matter in the universe is dark matter. Dark matter is a kind of substance that does not emit electromagnetic radiation at all and does not interact with it. Despite the fact that the first theories about dark matter appeared about 70 years ago, no direct evidence has been found to support its existence. Many scientists believe that dark matter is formed from weakly interacting massive particles that can be hundreds of times more massive than protons, but their interaction cannot be easily detected using existing instruments.
How life began
Proponents of the "Primordial Soup" theory believe that the fertile early Earth independently formed the ever-increasing complex molecules that gave rise to life on Earth. This could happen at the bottom of the ocean, and in the craters of volcanoes and in the ice. Taking into account that DNA is the dominant basis of life on the planet, RNA could be one of the root causes of the origin of life on our planet. Other theories consider electromagnetic and volcanic activity to be the most important aspects for nascent life. Some believe in panspermia, the hypothesis that life was brought to Earth with meteorites or comets in the form of microbes.
How tectonic activity occurs
The theory of lithospheric plates, moving, redistributing continents and causing earthquakes and volcanic eruptions, has spread relatively recently.
Despite the fact that the first postulates at the beginning of the 1500 century said that all the current continents could be a single continent (which is not a particular exaggeration, you just need to look at the map of the world), this idea did not become widespread until the 1960s, when a well-founded physical evidence is the theory of ocean floor spreading, according to which the blocks of the lithosphere of the oceanic crust move apart and the released space is filled with magma generated in the Earth's mantle.
Scientists are not entirely sure what is causing these very shifts and how the boundaries of tectonic plates were designated. There are countless different theories, but none of them fully explains all aspects of tectonic activity.
How animals migrate
Many species of animals and insects migrate throughout the year, escaping seasonal changes in temperature and decreasing vital resources. Migration can take thousands of kilometers in one direction alone, so how do animals repeat this journey back and forth year after year? Each species employs a variety of navigation tools, including those that allow the use of capabilities magnetic field Earth. They serve as a kind of internal compass for animals. Scientists still do not know how such an ability can be developed or how animals determine the exact direction from year to year.
What is dark energy
Of all the unsolved mysteries, this is the main one. Dark matter, which was mentioned earlier, accounts for up to 80% of all matter in the observable Universe, dark energy, a hypothetical form of energy, according to scientists, can occupy up to 70% of the Universe. It is called one of the reasons for the expansion of the universe, although it is this moment nothing more than theory. So far, all that is known about it is that it has a low density, is very evenly distributed, and, presumably, does not interact with ordinary matter through the known fundamental types of interaction.
Over the past two centuries, science has answered many questions about nature and the laws that govern it. We were able to explore galaxies and atoms that make up matter. We have built machines that can count and solve problems that cannot be solved by humans. We decided the age-old math problems and created theories that gave mathematics new problems. This article is not about these achievements. This article is about the problems in science that still cause scientists to search and scratch their heads thoughtfully in the hope that someday these questions will lead to an exclamation of "Eureka!"
Turbulence
Turbulence is not a new word. You know it as a word for sudden shaking during flight. However, turbulence in fluid mechanics is a completely different matter. Airborne turbulence, technically referred to as “clear air turbulence,” occurs when two bodies of air meet at different speeds. Physicists, however, have difficulty in explaining this phenomenon of turbulence in fluids. Mathematicians have nightmares about her.
Turbulence in fluids surrounds us everywhere. The jet flowing out of the tap completely disintegrates into chaotic particles of liquid, different from the single flow that we receive when we open the tap. This is one of classic examples turbulence, which is used to explain the phenomenon to schoolchildren and students. Turbulence is common in nature and can be found in various geophysical and oceanic streams. It is also important for engineers, as it is often generated in flows over turbine blades, flaps and other elements. Turbulence is characterized by random fluctuations in variables such as speed and pressure.
Although there have been many experiments and empirical data on turbulence, we are still far from a convincing theory of what exactly causes turbulence in a fluid, how it is controlled, and what exactly is ordering this chaos. The solution to the problem is further complicated by the fact that the equations governing the motion of a fluid - the Navier-Stokes equations - are very difficult to analyze. Scientists resort to high-performance computing techniques, along with experiments and theoretical simplifications in the process of studying the phenomenon, but there is no complete theory of turbulence. Thus, fluid turbulence remains one of the most important unsolved problems in physics today. Nobel laureate Richard Feynman called it "the most important unsolved problem in classical physics." When quantum physicist Werner Heisenberg was asked if he would appear before God and get the opportunity to ask him for anything, whatever it was, the physicist replied: “I would ask him two questions. Why relativity? And why turbulence? I think he will definitely have an answer to the first question. "
Digit.in got a chance to speak with Professor Roddam Narasimha and this is what he replied:
“Today we are not able to predict the simplest turbulent flows without referring to experimental data on the flow itself. For example, it is not currently possible to predict the pressure loss in a turbulent pipe, but through clever use of experimental data it is becoming known. The main problem is that the problems of turbulent flows of interest to us are almost always in the highest degree are nonlinear, and there seems to be no mathematics that can handle such highly nonlinear problems. Among many physicists for a long time it was widely believed that when a topic pops up new problem, somehow, as if by magic, the mathematics necessary for the solution suddenly turns out to be invented. The turbulence problem demonstrates an exception to this rule. The laws governing the problem are well known and for simple non-pressurized fluids under normal conditions are enclosed in the Navier-Stokes equations. But the solutions remain unknown. Current mathematics is ineffective in solving the problem of turbulence. As Richard Feynman said, turbulence remains the greatest unsolved problem in classical physics. "
The importance of turbulence studies has spawned a new generation of computational techniques. A solution, at least roughly, to the theory of turbulence will enable science to make better weather forecasts, design energy-efficient cars and airplanes, and better understand various natural phenomena.
Origin of life
We have always been obsessed with exploring the possibility of life on other planets, but there is one question that worries scientists more: how did life appear on Earth? While there is little practical benefit to answering this question, the path to the answer could lead to a number of interesting discoveries in fields from microbiology to astrophysics.
Scientists believe that the key to understanding the origin of life may be in figuring out how two characteristics of life - reproduction and genetic transmission - emerged as processes in molecules that gained the ability to replicate. This led to the formation of the so-called theory of "primary soup", according to which a mixture appeared on the young Earth in an incomprehensible way, a kind of a soup of molecules, which was saturated with the energy of the sun and lightning. Over time, these molecules had to form into more complex organic structures that make up life. This theory received partial support during the famous Miller-Urie experiment, when two scientists created an amino acid by passing electrical charges through a mixture. simple elements from methane, ammonia, water and hydrogen. However, the discovery of DNA and RNA tempered the initial delight, since it seems impossible that such an elegant structure as DNA could develop from a primitive soup of chemicals.
There is a current that suggests that the young world was more of an RNA world than a DNA world. RNA, as it turned out, has the ability to speed up reactions while remaining unchanged and store genetic material along with the ability to reproduce. But to call RNA the original replicator of life instead of DNA, scientists must find evidence of the elements that could have formed nucleotides - the building blocks of RNA molecules. The fact is that nucleotides are extremely difficult to produce, even under laboratory conditions. The primordial soup seems incapable of producing these molecules. This conclusion led to another school of thought, which believes that organic molecules present in primitive life are of extraterrestrial origin and were brought to Earth from space on meteorites, which led to the development of the theory of panspermia. Another possible explanation comes down to the theory of the "iron-sulfur world", which claims that life on Earth was formed deep under water, came out of chemical reactionsthat take place in hot water high pressure found near hydrothermal vents.
It is quite remarkable that even after 200 years of industrialization, we still do not know how life appeared on Earth. However, interest in this problem always remains at a good temperature level.
Squirrel folding
A trip to the palaces of memory will lead us to school lessons in chemistry or physics, which we all loved so much (well, almost everyone), where they explained to us that proteins are extremely important molecules and building blocks of life. Protein molecules are made up of sequences of amino acids that affect their structure and, in turn, determine the specific activity of the protein. How a protein folds and adopts a unique native spatial structure remains an old mystery in science. The journal Science once named protein folding as one of the biggest unsolved problems in science. The problem, in essence, consists of three parts: 1) how exactly does a protein evolve into its final native structure? 2) can we derive a computational algorithm to predict the structure of a protein from the sequence of its amino acids? 3) considering big number possible conformations, how does the protein fold so quickly? Significant progress has been made on all three fronts over the past few decades, but scientists still have not fully deciphered the driving mechanisms and hidden principles of protein folding.
The folding process involves a large number of forces and interactions that allow the protein to reach the state of the lowest possible energy, which gives it stability. Due to the great complexity of the structure and the large number of force fields involved, it is rather difficult to understand the exact physics of the folding process of small proteins. They tried to solve the problem of predicting the structure in combination with physics and powerful computers. Although some success has been achieved with small and relatively simple proteins, scientists are still trying to accurately predict the folded shape of complex multi-domain proteins from their amino acid sequence.
To understand the process, imagine that you are at the crossroads of thousands of roads that lead in one direction, and you need to choose the path that will lead you to your goal in the least amount of time. Exactly the same, only a larger-scale problem lies in the kinetic mechanism of protein folding into a certain possible state. It was found that random heat movements play a large role in the rapid nature of folding and that the protein "flies" through the conformations locally, avoiding unfavorable structures, but the physical path remains an open question - and its solution may lead to the emergence of faster algorithms for predicting protein structure.
Protein folding remains a hot topic in modern biochemical and biophysical research. The physics and computational algorithms developed for protein folding have led to the development of new artificial polymeric materials... In addition to contributing to the growth of scientific computing, the problem has led to a better understanding of diseases like type II diabetes, Alzheimer's, Parkinson's and Huntington's - in these disorders, improper protein folding plays an important role. A better understanding of the physics of protein folding could not only lead to breakthroughs in materials science and biology, but also revolutionize medicine.
Quantum theory of gravity
We all know about the apple that fell on Newton's head and led to the discovery of gravity. To say that after that the world has ceased to be the same is to say nothing. Then came Albert Einstein with his theory of general relativity. He took a fresh look at gravity and the curvature of space-time, the fabric that makes up the universe. Imagine a heavy ball lying on the bed and a small ball lying nearby. The heavy ball presses on the sheet, bending it, and the small ball rolls towards the first ball. Einstein's theory of gravity works great and even explains the curvature of light. However, when it comes to subatomic particles, whose work is explained by the laws of quantum mechanics, general relativity produces rather strange results. Developing a theory of gravity that can combine quantum mechanics and the theory of relativity, the two most successful theories of the 20th century, remains science's biggest research challenge.
This problem has spawned new and interesting areas in physics and mathematics. The so-called string theory has attracted the most attention. String theory replaces the concept of particles with tiny vibrating strings that can receive various forms... Each string can vibrate in a certain way, which gives it a certain mass and spin. String theory is incredibly complex and mathematically arranged in ten dimensions of spacetime - six more than we are used to thinking. This theory successfully explains many of the oddities of the marriage of gravity to quantum mechanics and was at one time a stable candidate for the position of "theory of everything."
Another theory that formulates quantum gravity is called loop quantum gravity. The PKG is relatively less ambitious and tries to be, above all, a confident theory of gravity, not aiming at a grand unification. PCG represents space-time as a fabric formed by tiny loops, hence the name. Unlike string theory, PKG does not add extra dimensions.
Although both theories have their pros and cons, the theory of quantum gravity remains an unresolved issue as neither theory has been proven experimentally. Experimental verification and confirmation by any of the above theories remains a gigantic problem in experimental physics.
The theory of quantum gravity is unlikely to have a meaningful effect in our everyday lifehowever, once discovered and proven, it will be powerful evidence that we are far advanced in science and can move on, towards the physics of black holes, time travel and wormholes.
Riemann hypothesis
In an interview, the famous number theorist Terence Tao called prime numbers the atomic elements of number theory, a pretty weighty characteristic. Prime numbers have only two divisors, 1 and the number itself, and thus are the simplest elements in the world of numbers. Prime numbers are also extremely volatile and don't fit into patterns. Large numbers (the product of two primes) are used to encrypt millions of secure online transactions. Simple factorization of such a number will take forever. Nevertheless, if we somehow comprehend the random, at first glance, nature of the primes and better understand their work, we will get closer to something great and literally hack the Internet. Solving the Riemann hypothesis could take us ten steps closer to understanding prime numbers and will have serious implications for banking, business, and security.
As mentioned, primes are known for their tricky behavior. In 1859, Bernhard Riemann discovered that the number of primes not exceeding x — the prime distribution function denoted by pi (x) —can be expressed in terms of the distribution of the so-called "nontrivial zeros" of the zeta function. The Riemann solution is related to the zeta function and the associated distribution of points on the line of integers for which the function is equal to 0. The hypothesis is related to a certain set of these points, "nontrivial zeros", which are believed to lie on the critical line: all nontrivial zeros are zeta functions have a real part equal to ½. This hypothesis has confirmed more than a billion such zeros and may reveal the mystery shrouding the distribution of primes.
As any mathematician knows, the Riemann hypothesis remains one of the biggest unanswered mysteries. Its solution will not only affect science and society, but also guarantee the author of the solution a prize of a million dollars. This is one of the seven great mysteries of the millennium. There were a great many attempts to prove the Riemann hypothesis, but all of them were unsuccessful.
Survival mechanisms of tardigrades
Tardigrades are a class of microorganisms that are quite common in nature in all climatic zones and at any altitude of our seven continents. But these are not ordinary microorganisms: they have an extraordinary ability to survive. Take, for example, that these are the first living organisms that can survive the dangerous vacuum of space. A few tardigrades entered orbit with the Foton-M3 rocket, were exposed to all sorts of cosmic radiation, and returned virtually unharmed.
These organisms are not only able to survive in space, but can also withstand temperatures just above absolute zero and boiling water. They also tolerate the pressure of the Mariana Trench, an 11-kilometer rift in the Pacific Ocean.
Research has reduced some of the incredible abilities of tardigrades to cryptobiosis, anhydrobiosis (desiccation), a condition in which metabolic activity is extremely slowed down. Drying allows the creature to lose water and practically stop metabolism. Having gained access to water, the tardigrade restores its original state and continues to live as if nothing had happened. This ability helps her survive in the desert and during drought, but how does this "little water bear" manage to survive in space or in extreme temperatures?
In its dried form, the tardigrade activates several vital functions. The sugar molecule inhibits cellular expansion, and the antioxidants produced neutralize the threat posed by the oxygen-reactive molecules present in the radiation from outer space. Antioxidants help repair damaged DNA, and this ability also explains the tardigrade's ability to withstand extreme pressure. While all of these functions explain the superpowers of tardigrades, we know very little about their functions at the molecular level. The evolutionary history of little water bears also remains a mystery. Are their talents related to extraterrestrial origins?
Studying tardigrades can have interesting implications. If cryonics becomes possible, the applications will be incredible. Medicines and pills can be stored at room temperature, it will be possible to create supersuits for the development of other planets. Astrobiologists will fine-tune their instruments to search for life beyond Earth even more accurately. If a microorganism on Earth can survive in such incredible conditions, it is likely that such tardigrades are on the moons of Jupiter and sleep, waiting to be discovered.
Dark energy and dark matter
Exploring matter on Earth is like poking around in a sandbox. All matter known to us is only about 5% of the known universe. The rest of the universe is "dark" and is mostly composed of "dark matter" (27%) and "dark energy" (68%).
Any list of unsolved problems in science would be incomplete without mentioning the mysterious dark matter and dark energy. Dark energy acts as the proposed reason for the expansion of the universe. In 1998, when two independent teams of scientists confirmed that the expansion of the Universe was accelerating, this disproved the then popular belief that gravity was slowing the expansion of the Universe. Theorists are still racking their brains trying to explain this, and dark energy remains the most appropriate explanation. But what it really is - no one knows. There are suggestions that dark energy can be a property of space, a kind of energy of the cosmos, or fluids that penetrate space, which in an incomprehensible way lead to the acceleration of the expansion of the Universe, while "ordinary" energy is not capable of this.
Dark matter is a weird thing too. It practically does not interact with anything, even with light, making it much more difficult to detect. Dark matter has been discovered along with weirdness in the dynamics of some galaxies. The known mass of the galaxy cannot explain the discrepancy with the observed data, so scientists have concluded that there is some form of invisible matter whose gravitational pull holds the galaxies together. Dark matter has never been directly observed, but scientists have observed its effects using gravitational lensing (the curvature of light interacting gravitationally with invisible matter).
The composition of dark matter remains one of the greatest challenges in particle physics and cosmology. Scientists believe that dark matter is composed of exotic particles - wimps - that owe their existence to the theory of supersymmetry. Scientists also speculate that dark matter may be composed of baryons.
While both theories - dark matter and dark energy - stem from our inability to explain some of the observable features of the universe, they are essentially fundamental forces of the cosmos and attract funding for large experiments. Dark energy repels, and dark matter attracts. If one of the forces prevails, the fate of the Universe will be decided accordingly - whether it will expand or contract. But for now, both theories remain dark, as do the culprits of their appearance.
