10 great undiscovered secrets of physics. Part 1
Toward bright spark; In 1900, Lord Kelvin announced that there was nothing new to discover in physics, only more accurate measurements. Three decades after this strange theory, quantum mechanics and Einstein’s theory of relativity were introduced. In this article and the next article, you will get acquainted with 10 questions of the greatest wonders of physics.
1-The nature of dark energy
Based on observations of space-time expansion, scientists estimate that more than 70% of the total forces in the universe make up this unknown energy; In fact, we know that the world is full of this energy; But we do not know how to look at it.
2-What is dark matter?
About 84% of the matter in the universe neither absorbs nor emits light, which is called dark matter. Dark matter is not visible even indirectly; But its existence can be proved by its effect on the gravitational force of visible matter, radiation, and the expansion structure of the universe.
3- Are there parallel universes?
Astrophysicists’ information shows that space-time may be curved instead of flat, which means that space-time will continue indefinitely in all directions. If so, then the region we can see and think of as the universe is only part of the infinity. But at the same time, quantum physics tells us that only a limited number of particle arrangements can exist in each piece of the universe, and with this limited number in infinite pieces of the universe, particles have to repeat their arrangements over and over again indefinitely. This means that cosmic fragments will exist just like our world (containing someone like you and me).
4- Why is there more matter than antimatter?
The answer to this question explains how our world came into being. According to the laws of physics, it is assumed that at the moment of the Big Bang there must have been an equal amount of matter and antimatter, but if that were the case, the universe would have been destroyed by now. Electrons in contact with positrons, neutrons in counter-neutrons And so the other particles had to be destroyed in the face of their counterparts, and in the end all that remains is a sea of photons in a matterless universe.
5- What will be the fate of the world?
The fate of the universe depends heavily on the unknown factor Ω. Ω represents the density of matter in relation to the energy scattered around the world and can have three states, less than one, more than one and equal to one.
If Ω is greater than one, it means that space-time is closed, like the surface of an extraordinarily large sphere that reaches the first position on each side. If we imagine the universe closed and do not consider dark energy, the fate of our universe will be such that the expansion of the universe will stop when the universe begins to contract, and this contraction will eventually compress the whole universe. This great compression is the opposite of the great explosion from which the universe was born.
But if we consider Ω less than one, then space-time will be open, imagine the level of a saddle! In this case, the ultimate destiny of the world will be first a great freeze and then a great disintegration. In this theory, the rate of expansion of the universe will reach a point where stars and galaxies are disintegrating and scattering in intergalactic space.
The third case is that Ω is equal to one. In this state, our world will be without curvature and smooth and will expand indefinitely in all directions. If there is no dark energy, this flat world will expand forever at a negative acceleration rate until this acceleration reaches zero and the universe remains stable, but if there is dark energy, the ultimate destiny of the universe will expand forever and eventually Great freezing and then great disintegration.