Great world mysteries. Unsolved mysteries of science
From the very appearance of an interested consciousness, a person began to explore the world around him, constantly expanding his horizons. But it turns out that no matter how much you expand these horizons, even more distant horizons are found behind them, to which you have to reach for a long time. So what? We get real pleasure from learning something new. We are ready to gnaw on granite to get to the bottom of things. But there are some mysteries of science that we can't solve.
Did the universe start with the Big Bang?
The Big Bang theory has long been considered the most reliable, explaining the beginning of the universe. But is it really one hundred percent correct and the only answer?
The "Big Bang" theory was called one of its most cruel opponents, Fred Hoyle. He thought that the universe was static and eternal - but his hypothesis quickly died. In 1929, Edwin Hubble proved that the universe is expanding. This was followed by new evidence in favor of the Big Bang theory: in 1965 it was the existence of radiation from the microwave background, the afterglow of the Big Bang.
But there is one but. Hubble measurements made in 1929 were refuted in 1990. In fact, the universe expanded 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, this is impossible to prove. Maybe we need a new way to determine the beginning of the universe?
How to predict an earthquake?
Our understanding of the movements of the Earth began to take shape relatively recently. It was not until 1912 that Alfred Wegener came to the conclusion that the continents are in constant motion. In the 1960s, the US Navy noticed that the seabed was not as smooth as had been assumed until that point - it was made up of mountain ranges.
The scientists concluded that the seafloor 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. Now we know that earthquakes are born when two plates push against 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 occur. For example, scientists can predict that an earthquake is about to hit Los Angeles. It could mean any moment from tomorrow to the next 30 years.
What causes ice ages?
We still don't know what causes ice ages. Milutin Milankovitch proposed a solution in 1920. He stated that the earth is 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 right, because ice ages really came every 100,000 years.
But Milankovitch's theory fails to explain some of the major disturbances in this pattern - 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 fluctuations in carbon dioxide when there were no people yet? Scientists are scratching their heads, 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 human vault and an ape jaw on the Piltdown Common near Lewes 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 British Museum zoologist named Hinton. What for? Such was his revenge.
Hinton began working at the museum as a volunteer. When he asked for a salary, curator of paleontology Arthur Smith Woodward turned him down. So Hinton forged the skull to undermine Woodward's authority as a scientist. However, the plan didn't work.
In 1956, William Strauss proposed that the Neanderthal was our immediate ancestor. However, new fossil dating methods have shown that humans and Neanderthals lived at the same time and maintained contact. The position is still open.
Why did the abstract system of communication appear so late?
The earliest examples of art date back to 35,000 years ago. However, written language developed only 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 system of communication? Most likely, the first to change is our brain. But how? The brain is such a complex structure that it may 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 the 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 greet black holes in 1938. But Sir Arthur Eddington can also be understood, because the behavior of black holes is counterintuitive. Nobody knows what happens inside a black hole. In the 1990s, scientists discovered the existence of supermassive black holes the size of a billion suns. They tend to be located at the center of elliptical galaxies. Did they participate in the creation of these galaxies? We don't really know. And the black holes themselves are a real mystery to us, because we can neither see nor touch them, nor can we visit them.
How old is the universe?
Nobody knows for sure. Answers range from 8 to 20 billion years, but that's a pretty big spread. The strangest thing about this problem is that the universe may be younger than its oldest stars. Studies conducted 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 taken in 1999 disproved previous studies.
But their triumph was short-lived. Another study carried out with modern technologies, showed that the universe was 15% smaller, and therefore 15% younger. According to this study, there are stars older than the universe itself. What are we doing wrong? Perhaps we do not understand the fundamental laws of physics?
Are there multiple universes?
Science fiction writer Jack Williamson was the first to propose the concept of multiple universes in 1952. What inspired the physicist Hugh Everett. In 1957, he wrote a doctoral work on the topic of multiple universes. According to his model, each event creates a series of universes in which each takes place. possible result this event.
John Wheeler, Everett's manager, offered 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, apparently, does not have enough matter to collapse.
Stephen Hawking developed a theory that says 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 contract 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 pain with morphine until the last day of the experiment, and then replace the morphine with saline. And guess what happens? Saline solution relieves pain.
It's the placebo effect: somehow a compound out 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. Horizon problem
Our Universe turns out to be inexplicably united. Look at space from one end of the visible universe to the other, and you will see that the microwave background in space has 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 travel faster than the speed of light, so it is impossible for thermal radiation to travel between two horizons and balance the hot and cold zones that formed during the Big Bang, establishing the thermal equilibrium that we see now.
From a scientific point of view, the same temperature of the background radiation 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 shouldn't exist. Cosmic rays are particles that travel through the universe at a speed close to the speed of light. Some cosmic rays come to Earth as a result of violent events such as supernova explosions. But we know nothing about the origin of the high-energy particles observed in nature. And even that isn't really a secret.
As cosmic ray particles travel through space, they lose energy when they collide with photons. low level energy, for example, from the cosmic microwave background radiation. However, the University of Tokyo discovered cosmic rays with very high energy. Theoretically, they could only come from our galaxy, but astronomers cannot find the source of these cosmic rays in our galaxy.
4. Phenomenon of homeopathy
Madeleine Ennis, a pharmacologist at Queen's University Belfast, is a disaster for homeopathy. She opposed the claims of 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 a healing power. Ennis is determined to prove once and for all that homeopathy is just talk.
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 scientists, it turned out that homeopathic solutions (diluted to such an extent that they apparently did not contain even a single 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 that 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 must decay. Galactic matter revolves around a central point as its gravitational pull creates centripetal forces. But there is not enough mass to create the observed rotation in galaxies.
Vera Rubin, an astronomer in the department of terrestrial magnetism at the Carnegie Institution in Washington, noticed this anomaly in the late 1970s. The best answer that 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 should make up roughly 90% of the mass of the universe, and yet we are remarkably ignorant of what that 90% is.
6. Life on Mars
July 20, 1976 Gilbert Levin sits on the very edge of his chair. Millions of kilometers away, on Mars, the Viking lander took soil samples. Levin's equipment mixed them with a substance containing carbon-14. Scientists involved in the experiment believe that if methane emissions containing carbon-14 are found in the soil, then there should be life on Mars.
Analyzers "Viking" give a positive result. Something is consuming nutrients, converts them, and then emits a gas containing carbon-14. But why is there no holiday?
Because another analyzer, designed to determine the organic molecules that are necessary signs of life, found nothing. Scientists were cautious and declared the findings of the Viking false positive. But is it?
The results, transmitted from NASA's latest spacecraft, show that in the past, the surface of Mars almost certainly contained water and was therefore favorable for life. There are other proofs as well. "Every flight to Mars," says Gilbert Levin, "provides data to back up my conclusion. None of it contradicts it."
Levin is no longer defending his views alone. Joe Miller, a microbiologist at the University of Southern California in Los Angeles, reanalyzed the data and believes the outliers show signs of a circadian cycle. And this with a high degree of probability suggests the existence 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 Caen team led by Francisco Miguel Marquès fired beryllium nuclei at a small carbon target and analyzed their trajectories with detectors. Scientists expected to see four different neutrons hit different detectors. Instead, they found only one flash of light in one detector.
The energy of this flash 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 this is ridiculously unlikely.
At the same time, such behavior is not improbable 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 holding them together is such that it cannot even hold two single neutrons, let alone four.
Marquez and his group were so stunned by the results that they "buried" these data in a scientific work, which spoke of a certain probability of discovering tetraneutrons in the future. After all, if you start to change the laws of physics to justify the connection of four neutrons, chaos will arise.
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 observing. And, even worse, the formed elements become too heavy for space. "Probably the universe would 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 number of bound neutrons, which means that when the neutrons gather into masses, forces that are still inexplicable 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 plate 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 devices should have already been in deep space. However, in an unusual way, their trajectories strongly deviated from the calculated ones.
Something began to pull (or push) them, as a result of which they began to move with acceleration. It was tiny - less than a nanometer per second, which is equivalent to one ten-billionth of gravity on the Earth's surface. But this was enough to move the Pioneer-10 from its trajectory by 400,000 kilometers.
NASA lost contact with Pioneer 11 in 1995, but until that moment it deviated from the trajectory in the same way as its predecessor. What caused it? Nobody knows.
Some of the possible explanations have already been rejected, including software 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 is expanding at an ever-increasing rate. Before 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 through the Kuiper belt - a region of space teeming with ice rocks - you suddenly see empty space.
Astronomers call this boundary the Kuiper rock, because after it the density of the cosmic rock belt decreases sharply. What is the reason? The only answer to this could be the presence of a tenth planet in our solar system. Moreover, in order to clear the space of debris in this way, it must be as massive as the Earth or Mars.
But, although calculations show that such a body could cause 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 outer space. 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 springs Emissions such as thermal emissions from planets cover a much wider range of frequencies. What caused the emission of these pulses? There is still no answer.
The nearest star to us 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 a surprisingly powerful transmitter.
All subsequent observations in the same part of the sky led to nothing. A signal like WOW is no longer registered.
12. Such fickle constants
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 passes through interstellar clouds made up of metals such as iron, nickel and chromium. The researchers found that these atoms absorb photons of quasar light, but not at all what was expected.
The only more or less reasonable explanation for this phenomenon is that a physical constant called the fine structure constant, or alpha, has a different value when light passes through 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 some of these parameters to actually change?!
None of the physicists wanted to believe in the correctness of the measurements. Webb and his group spent many years trying to find errors in their results. But they still haven't succeeded.
Webb's results are not the only ones that confirm that there is something wrong with our understanding of alpha. A recent analysis of the only known natural nuclear reactor operating almost 2 billion years ago in what is now Oklo 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 the fission products preserved in the Oklo soil makes it possible to determine the value of the constant at the time of their formation.
Using this method, Steve Lamoreaux and colleagues at Los Alamos National Laboratory in New Mexico estimated that alpha has decreased by more than 4% since the Oklo action. And this means that our ideas about constants may turn out to be wrong.
13. Low temperature nuclear fusion (LTF)
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 whether nuclear reactions can room temperature generate more energy than it consumes (it is believed that this is only possible inside stars).
Controlled nuclear fusion would solve many of the world's energy problems. No wonder the US Department of Energy is so interested in it. Last December, after a lengthy review of all the evidence, it said it was open to proposals for new NTS experiments.
It's a pretty cool twist. Fifteen years ago, this same ministry concluded that the initial NTS results obtained by Martin Fleischmann and Stanley Pons of the University of Utah and solemnly presented at a press conference in 1989 could not be confirmed, 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 accepted scientific theories hold that nuclear fusion is impossible at room temperature.
It would seem that our world has been studied up and down and science will certainly have an answer to any question that interests us. However, no matter how. Until now, there are many mysterious things and phenomena that have no rational explanation.
cat purr
Everyone knows that cats always purr when they feel good. However, no one knows how they do it. There is no special organ in the throat of cats to make such sounds. It is interesting that during the purring it is impossible to listen to the heart or lungs of cats, and the purring itself is continuous, on inhalation and exhalation.
Scientists believe that cats use their vocal cords to make vibrating sounds that we hear as purrs. Also, in the course of research, it turned out that the frequency of purring is in the range necessary to accelerate regeneration and wound healing. Therefore, your cat is probably an excellent doctor.
Appearance of views out of nowhere
Scientists have been struggling with this riddle for many years. The fact is that many species of animals and plants on our planet simply appeared out of nowhere. They had no ancestors from which they could evolve, and this baffles science.
So it was, for example, with amphibians: the stage at which the 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 various kinds. Then, after the alleged cataclysm (about 65 million years ago), which led to the extinction of dinosaurs, several various groups mammals.
Magnetic compass in cows
You probably didn't even think about it. In general, no one thought before the advent of Google Earth. It was this service that allowed us to study thousands of pictures of grazing cows (don't ask why) and discover one strange pattern. About 70% of cows, when eating or drinking, turn their heads due 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. This 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 it impossible to directly observe it.
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 is.
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. 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 in the outskirts of our solar system, beyond Pluto, is the so-called Kuiper belt, which consists of icy objects. There, scientists discover hundreds of thousands of objects every day, the size of Pluto, and even more.
By the way, they noticed a big 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. So scientists will have to rewrite textbooks many times to explain how many planets there 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 work in this case.
It is believed that the majority (from 70 to 95%) are right-handed, a minority (from 5 to 30%) are left-handed. And there is also a percentage of ambidexters in which both hands are equally developed. Although scientists disagree here.
It has been proven that left-handedness and right-handedness are influenced by genes, but the exact “left-handed gene” has not yet been identified. There is also evidence that environment can also influence dominant hand selection. So, for example, teachers retrained children to use their right hand more often than their left hand.
Extinction of the megafauna
The common name for giant animals that once walked the Earth is megafauna. Megafauna disappeared about 10 thousand years ago. And scientists haven't 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, everything is not 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 the same time. 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 are sure 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 fail to provide an answer. The study of dreams is a special science - 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.
space roar
In 2006, while trying to study young stars, scientists ran into a problem: an incomprehensible, mysterious noise that interfered with the study. Researchers never figured out what creates it. Sure, sound can't travel through space, but radio waves can, but from where? What publishes them? They managed to find out only 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 types, but no less questions still remain unanswered. For example, we still have no idea why they are different and why this is necessary from the point of view of evolution.
Blood groups are distinguished by antigens in blood cells, these antigens are antibody signals 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 diseases and immunity. For example, it turned out that people with a third blood type are more susceptible to E. coli, and with a zero one they have almost complete immunity to one form of malaria.
Why is there more visible matter than antimatter?
Most of the discussion takes place around b-mesons, short-lived subatomic particles consisting of one quark and one antiquark. The decay of B-mesons is slower than the decay of anti-B-mesons, due to which there could be enough B-mesons 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, take on a normal state, which is quite possible, since there are still more ordinary particles than antiparticles.
Where did lithium disappear from the universe
In the early universe, when the temperature was incredibly high, the isotopes of hydrogen, helium, and lithium formed in large quantities, but over time, only a third of the isotopes of lithium-7 remained. Various theories including, and hypothetical, based on hypothetical bosons called axions, attempt to shed light on the cause of the change. Theories have also been proposed to explain the disappearance of lithium by the fact that it was absorbed by the cores of stars that cannot be detected by modern telescopes. Be that as it may, a single and accurate version explaining this phenomenon does not yet exist.
Why do people sleep
Although we know that the human body is regulated by the so-called circadian clock - the biological instrument responsible for sleep and wakefulness - the essence of this phenomenon has not yet been explained. During sleep, tissue, cell regeneration and many other processes take place in the human body. There are organisms that do not need sleep at all, so why do people need it? Several suggestions have been made regarding this issue, but none of them is exhaustive. While scientists do not know exactly why we sleep, they have already figured out how important sleep is for the body and how much it affects processes such as mental work and flexibility of thinking.
How Gravity Works
We all know that the moon's gravity causes the tides to ebb and flow, the earth's gravity keeps us on the earth's surface, the sun's gravity 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, while not having sufficient explanations for what reason it exists. Why are atoms mostly made up of empty space? Why is the force that holds atoms together different from gravity? Is gravity made up of particles? These questions cannot be answered with the current understanding of physics.
Where is everyone
The diameter of the observable universe is 92 billion light years, filled with billions of galaxies with stars and planets, however, visible traces of life are present only 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 until now?
This puzzle is known as the Fermi Paradox. Many explanations for this paradox have been proposed, some of them quite plausible. We can talk forever about some possible 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 frustrating scenario - Earth is indeed the only habitable planet in the universe.
What is dark matter made of?
About 80% of the matter in the universe is made up of dark matter. Dark matter is such a peculiar 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, direct evidence confirming its existence has not been found. Many scientists believe that dark matter is made up of weakly interacting massive particles that can be hundreds of times more massive than protons, but their interaction cannot be easily detected with current instruments.
How life began
Proponents of the "Original 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 layers of ice. Considering that DNA is the dominant basis of life on the planet, RNA could be one of the primary 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 by meteorites or comets in the form of microbes.
How does tectonic activity occur
The theory of lithospheric plates moving, redistributing continents and causing earthquakes and volcanic eruptions, has become widespread relatively recently.
Despite the fact that the first postulates in the early 1500 century said that all the current continents could be a single continent (which is not much of an exaggeration, just look at a map of the world), this idea did not become very popular until the 1960s, when a reasonable physical evidence of the ocean floor spreading theory, 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 causes 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 temperature changes and diminishing vital resources. Migration can take thousands of miles in just one direction, so how do animals repeat this way back and forth year after year? Each view uses different navigational tools, including those that allow you to use the features magnetic field Earth. For animals, they serve as a kind of internal compass. Scientists still do not know how this 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 discussed earlier, makes 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 a theory. So far, it is known only that it has a low density, is very evenly distributed, and, presumably, does not interact with ordinary matter through 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 the galaxies and the atoms that make up matter. We have built machines that can calculate and solve problems that humans cannot solve. We decided the age-old math problems and created theories that gave mathematics new problems. This article is not about those achievements. This article is about the problems in science that still keep scientists searching and scratching their heads thoughtfully in the hope that someday these questions will lead to the 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. Flight turbulence, technically called "clear air turbulence", occurs when two air bodies moving at different speeds meet. Physicists, however, have difficulty explaining this phenomenon of turbulence in liquids. Mathematicians have nightmares about her.
Turbulence in liquids is all around us. The jet flowing out of a faucet completely breaks up into chaotic fluid particles, different from the single stream that we get when we open a faucet. This is one of classic examples turbulence, which is used to explain the phenomenon to schoolchildren and students. Turbulence is common in nature, it can be found in various geophysical and oceanic flows. It is also important to engineers, as it is often generated in the airflow over turbine blades, flaps, and other elements. Turbulence is characterized by random fluctuations in variables such as speed and pressure.
Although many experiments have been done on the topic of turbulence and a lot of empirical data has been obtained, we are still far from a convincing theory of what exactly causes turbulence in a liquid, how it is controlled, and what exactly orders this chaos. The solution of the problem is further complicated by the fact that the equations that determine the motion of a fluid - the Navier-Stokes equations - are very difficult to analyze. Scientists resort to high-performance computational 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 the quantum physicist Werner Heisenberg was asked if he could stand before God and be given 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 talk to Prof. Roddam Narasimha and this is what he said:
“Today, we are not able to predict the simplest turbulent flows without referring to experimental data on the flow itself. For example, it is currently impossible to predict the pressure loss in a turbulent flow pipe, but thanks to the clever use of data obtained in experiments, it is becoming known. The main problem is that the problems of turbulent flows that are of interest to us are almost always in the highest degree are non-linear, and there seems to be no mathematics that can handle such highly non-linear problems. Among many physicists for a long time it was widely believed that when their topic pops up new problem, somehow, as if by magic, the math needed to solve it suddenly turns out to be already invented. The problem of turbulence demonstrates an exception to this rule. The laws governing the problem are well known and for simple non-pressurized fluids under normal conditions are contained 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 given rise to a new generation of computational techniques. A solution, however approximate, to the theory of turbulence will enable science to make better weather forecasts, design energy-efficient cars and aircraft, and better understand various natural phenomena.
Origin of life
We have always been obsessed with studying the possibility of life on other planets, but there is one question that worries scientists more: how did life appear on Earth? Although the answer to this question will not be of much practical use, the path to the answer may lead to a number of interesting discoveries in fields ranging from microbiology to astrophysics.
Scientists believe the key to understanding the origin of life may lie in understanding how the two hallmarks 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 "primordial soup" theory, according to which a mixture appeared on the young Earth in an incomprehensible way, a kind of soup of molecules, which was saturated with the energy of the sun and lightning. Over a long time, these molecules should have folded into the more complex organic structures that make up life. This theory received partial support during the famous Miller-Ury 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 has tempered the initial enthusiasm, because 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 to 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 elements that could form nucleotides, the building blocks of RNA molecules. The fact is that nucleotides are extremely difficult to produce, even in the laboratory. The primordial soup seems incapable of producing these molecules. This conclusion has led to another school of thought, which believes that the organic molecules present in primitive life are of extraterrestrial origin and were brought to Earth from space on meteorites, leading to the development of the theory of panspermia. Another possible explanation comes down to the "iron-sulfur world" theory, which claims that life on Earth formed deep under water, emerged from chemical reactions that take place in hot water under 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.
Protein folding
A trip to the halls of memory will take us to the school chemistry or physics lessons that we all loved so much (well, almost everyone), where they explained to us that proteins are extremely important molecules and the building blocks of life. Protein molecules are made up of sequences of amino acids that influence their structure and, in turn, determine the specific activity of the protein. How a protein folds and takes on a unique native spatial structure remains an old mystery in science. Science magazine once named protein folding as one of the biggest unsolved problems in science. The problem, at its core, 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 its amino acid sequence? 3) considering big number possible conformations, how does a protein fold so quickly? Significant progress has been made on all three fronts over the past few decades, yet scientists still have not fully deciphered the underlying 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 lowest possible energy state, which gives it stability. Due to the great complexity of the structure and the large number of force fields involved, it is quite difficult to understand the exact physics of the folding process of small proteins. The problem of structure prediction was tried to be solved 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 multidomain proteins from their amino acid sequence.
To understand the process, imagine that you are at the crossroads of a thousand roads that lead in the same direction, and you need to choose the path that will lead you to your goal in the shortest time. Exactly the same, only on a larger scale, the problem lies in the kinetic mechanism of protein folding into a certain state of the possible. It has been found that random thermal motions play a large role in the fast nature of folding and that the protein "flies" through conformations locally avoiding unfavorable structures, but the physical pathway remains an open question - and its resolution could lead to faster protein structure prediction algorithms.
The problem of 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 polymer 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, protein misfolding 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 ceased to be the same is to say nothing. Then came Albert Einstein with his general theory of 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 brilliantly 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 unify quantum mechanics and relativity, two of the most successful theories of the 20th century, remains the greatest research challenge in science.
This problem has given rise to new and interesting fields 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 various forms. Each string can vibrate in a certain way, which gives it a certain mass and spin. String theory is incredibly complex and is mathematically structured in ten dimensions of space-time - six more than we used to count. This theory successfully explains many of the oddities in the marriage between gravity and quantum mechanics, and was at one time a strong candidate for the "theory of everything" position.
Another theory that formulates quantum gravity is called loop quantum gravity. The PCG is relatively less ambitious and tries to be, first of all, a confident theory of gravity without aiming for a grand unification. PCG represents space-time as a web of tiny loops, hence the name. Unlike string theory, PCG does not add extra dimensions.
Although both theories have their pros and cons, the theory of quantum gravity remains an unresolved issue because neither theory has been proven experimentally. Experimental verification and confirmation of any of the above theories remains a gigantic problem in experimental physics.
The theory of quantum gravity is unlikely to have a significant effect in our Everyday life, however, once discovered and proven, it will be powerful evidence that we are far advanced in science and can move further towards the physics of black holes, time travel and wormholes.
Riemann hypothesis
In an interview, renowned number theorist Terence Tao called prime numbers the atomic elements of number theory, a pretty weighty characterization. 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 unstable and do not fit into patterns. Large numbers (the product of two prime numbers) are used to encrypt millions of secure online transactions. A simple factorization of such a number would take forever. However, if we somehow comprehend the seemingly random nature of prime numbers 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 would have profound implications for banking, commercial structures, and security.
As already mentioned, prime numbers are known for their complex behavior. In 1859, Bernhard Riemann discovered that the number of primes not greater than x—the distribution function of primes, denoted pi(x)—is expressed in terms of the distribution of the so-called "non-trivial 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 0. The conjecture is related to a certain set of these points, "non-trivial zeros", which are thought to lie on the critical line: all non-trivial zeros of the zeta- functions have a real part equal to ½. This conjecture has confirmed over a billion such zeros and may reveal the mystery surrounding the distribution of prime numbers.
Any mathematician knows that 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 one 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.
Tardigrade survival mechanisms
Tardigrades are a class of microorganisms that are quite common in nature in all climatic zones and at all altitudes of our seven continents. But these are no ordinary microorganisms: they have extraordinary survival abilities. Take, for example, that these are the first living organisms that can survive the dangerous vacuum of space. Few tardigrades entered orbit on Foton-M3 rockets, were exposed to all sorts of cosmic radiation, and returned virtually unscathed.
These organisms are not only capable of surviving in space, but can also withstand temperatures just above absolute zero and boiling water. They also endure the pressure of the Mariana Trench, a 11-kilometer-long fissure in the Pacific Ocean.
Research has reduced some of the incredible abilities of tardigrades to cryptobiosis, anhydrobiosis (desiccation) - a state in which metabolic activity is extremely slowed down. Dehydration allows the creature to lose water and virtually 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 it survive in the desert and drought, but how does this "little water bear" manage to survive in space or extreme temperatures?
In its dried form, the tardigrade activates several vital functions. The sugar molecule inhibits cell expansion, and the produced antioxidants neutralize the threat posed by oxygen-reactive molecules present in space radiation. Antioxidants help repair damaged DNA, and this same ability explains the tardigrade's ability to survive extreme pressure. While all these functions explain the superpowers of tardigrades, we know very little about their functions at the molecular level. The evolutionary history of small water bears also remains a mystery. Are their talents connected with extraterrestrial origin?
Studying tardigrades can have interesting implications. If cryonics becomes possible, its applications will be incredible. Medicines and pills can be stored at room temperature, it will be possible to create supersuits for the exploration of other planets. Astrobiologists will tune their instruments to search for life beyond Earth even more precisely. If a microorganism on Earth can survive in such incredible conditions, chances are that there are such tardigrades on Jupiter's moons, sleeping, waiting to be discovered.
Dark energy and dark matter
The study of matter on Earth can be compared to picking in a sandbox. All the matter known to us makes up only about 5% of the known universe. The rest of the Universe is "dark" and mostly consists of "dark matter" (27%) and "dark energy" (68%).
Any list of unsolved problems in science would be incomplete without mentioning the enigmatic dark matter and dark energy. Dark energy is the proposed cause of the expansion of the universe. In 1998, when two independent teams of scientists confirmed that the expansion of the universe was accelerating, it disproved the then-popular notion that gravity was slowing the expansion of the universe. Theorists are still scratching their heads trying to explain this, and dark energy remains the most likely explanation. But what it really is - no one knows. There are suggestions that dark energy may be a property of space, a kind of cosmic energy, or fluids penetrating space, which inexplicably lead to an acceleration of the expansion of the Universe, while "ordinary" energy is not capable of this.
Dark matter is also a strange thing. It practically does not interact with anything, even with light, significantly complicating its detection. Dark matter has been discovered along with oddities in the dynamics of some galaxies. The known mass of a galaxy cannot explain the discrepancies 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 observed directly, but scientists have observed its effects through gravitational lensing (the bending of light interacting gravitationally with invisible matter).
The composition of dark matter remains one of the greatest problems in particle physics and cosmology. Scientists believe that dark matter is made up of exotic particles - WIMPs - which owe their existence to the theory of supersymmetry. Scientists also suggest 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 in fact the fundamental forces of the cosmos and attract funding for large experiments. Dark energy repels, while dark matter attracts. In the case of the prevalence of one of the forces, the fate of the Universe will be decided accordingly - whether it will expand or contract. But while both theories remain obscure, as well as the culprits of their appearance.
