Science is a fickle thing. Several thousand years ago, people considered the Earth flat, a couple of centuries ago, they thought that diseases spread through unpleasant odors, and in the middle of the last century, no one could believe that every home would have a computer.
And the fact that science cannot yet explain speaks not of its weakness but of a lack of information. The time will come, and we will understand what is there, beyond the boundaries of the Universe. But there are still things that scientists still cannot explain.
Why time moves forward
We do not consider time to be something extraordinary, and we take it for granted: it just moves forward, and that’s it. The problem is that time itself is an abstract quantity. In addition, all objects in the Universe move at a certain speed; therefore, time also moves at a certain speed. But what its speed is is both an important and ridiculous question.
It is not clear how time can move at a certain speed because the speed changes with time. Okay, let’s leave this difficult question and move on to a simpler one – the motion vector. Everyone understands that time moves forward, and we cannot go to the past. But why exactly forward? There is still no understanding of why time flows in only one direction in physics.
Scientists associate time with entropy – the irreversible dissipation of energy. Since the Universe is moving towards increasing entropy, this is the flow of time forward as we perceive it. Simply put, it is much easier to break than to build, and therefore everything in the Universe tends to increase entropy, not to retain energy.
The problem is that the passage of time does not affect the laws of physics, and if time were associated with an increase in entropy as you move forward, it would only make sense if it increases as you move backward, which destroys this theory. So we still don’t know why time moves forward.
How magnetoreception works
Magnetoreception is a sense that enables the body to sense a magnetic field and allows it to determine the direction of movement, height, or location. Birds and many animals have this feeling, and it allows them to easily find their way south or north, depending on the time of migration.
With the help of magnetoreception, birds and animals travel thousands of kilometers and arrive at exactly the intended place without straying off course. Scientists still do not understand exactly how this works. Previously, it was believed that iron in the beak and other parts of the body was responsible for this. Still, later scientists deduced the theory that the protein in the eyes is responsible for orientation along the magnetic poles. Whichever theory turns out to be correct, it is still unclear how magnetoreception works.
What is glass
Any layman will say that glass is a solid matter like metal, only more fragile. But this is not the case, and in fact, glass is somewhere in the middle between a solid and a liquid state. Simply put, even though it seems completely rigid, it has the physical and mechanical properties of both a solid and a super viscous liquid and can go from a liquid to a glassy state. Moreover, even now, the glass located in the window next to you is a viscous substance, but its fluidity does not manifest itself in any way at room temperature for decades and even centuries.
This is where the problem lies – what to refer to glass. Proposals are already being put forward to classify glass as another state of matter because it cannot be completely attributed to either a liquid or a solid state.
Why is there an asymmetry between matter and antimatter in the Universe?
Antimatter is a substance consisting of antiparticles that are not observed in nature in a stable state and so far can only be created in laboratory conditions. Scientists know how to create antimatter, consisting of antiprotons and antineutrons with shells of positrons. In fact, these are the same protons and neutrons but with the opposite charge, and when they collide with ordinary matter, they annihilate each other, releasing photons and pairs of particles-antiparticles.
Scientists believe that when antimatter is created, ordinary matter is also created, so in theory, there should be an equal share of them in the Universe. The problem is that we do not observe a large accumulation of antimatter, which is why there is a debate about whether our Universe consists almost exclusively of matter or regions where antimatter prevails over matter. This gave rise to one of the main unsolved problems of physics, and it is believed that the asymmetry of matter and antimatter arose in the first fractions of a second after the Big Bang.
But what contributed to this? Why did matter prevail over antimatter? What interfered with this process? These questions still remain unanswered.
What is dark matter
Dark matter, like black holes, is one of the most popular terms in popular culture, found in many science fiction works. But what is dark matter itself – scientists still do not know. It would seem, well, okay, since it is unclear what it is all about, but no. The fact is that, according to research results, our Universe consists of ordinary matter by only 4.9%, dark matter accounts for 26.8%, and dark energy – 68.3%.
And if we can describe the properties of ordinary matter, then dark matter is a mystery in everything. Neither the composition nor the nature of this substance is known. It is believed that dark matter does not exist at all, but then what affects the acceleration of the expansion of galaxies and other laws of physics?
How many dimensions exist in the Universe
Three dimensions are familiar to us – width, height, and depth. We think that everyone, when asked about the number of dimensions in physics lessons, answered that there are only three of them, and he was wrong because there is one more thing – time. This is, albeit a conditional but still a measurement, because an object exists not only in space but also moves forward in time.
But physicists do not agree that we live in a universe where only space-time exists. According to String Theory and other theories, there are over 10 dimensions. In some theories, scientists suggest that there are even 26 dimensions. But where are they all and how do they look, what properties do they have? These questions remain unanswered so far.
What is the difficulty? Imagine yourself as the hero of a 2D game where there is only height and width. They tell you that you are wrong, and there is also such a thing as depth. But how to understand it if you have not encountered it? We only have to guess.
What is the size of the Universe, and what is outside of it
Going to any online encyclopedia, you can find out that the diameter of the Universe is about 92 billion light-years. But these values are just speculation based on mathematical calculations. To do this, scientists took the starting point, compared it with the age of the Universe and other parameters, and based on this, they derived the above figure.
The problem is that we don’t even come close to guessing the real size of the Universe, and we also don’t know for sure if it is infinite or has boundaries. Moreover, both theories simply blow up the mind because if the Universe is infinite, it is generally impossible to comprehend, and if it is finite, then what is beyond its boundaries?