A hundred years ago, scientists dared to assume that all the basic laws and riddles of physics were open and studied. But, on 14 December 1900 Max Planck presented his quantum hypothesis, which has changed the world of science.
Albert Einstein, Niels Bohr, and Erwin Schrödinger later used and developed his idea, thereby transferring mankind to an entirely new level of understanding of the surrounding space and time. Some discoveries gave rise to more questions than answers. Having solved them, we will approach the secrets of the Universe.
Dark Energy
The main acting force in the Universe is gravity, with its eternal desire to collect everything at one point. But then why the Universe is expanding and the speed of its expansion is continuously growing? (the expansion occurs at a speed of 74 km/sec for every 3.26 million light years). Obvious that there is an invisible "agent", which is waging war with gravity since the beginning of time.
Scientists call this "dark energy"- an inherent property of space itself, which has "negative pressure". The amount of dark energy increases with the growth of space. Another version says: dark energy is a dynamic field and its energy density varies in space and time. According to the growth of the Universe, dark energy is at least 70% of the total space, but we still have no idea where and how to look for it.
The Arrow of Time
Any process in the Universe obeys the law of entropy. The initial order seeks to the maximum chaos, the more ordered state passes to less ordered. There is no way to reverse the entropy process. If you mixed ketchup with fries, you will not be able to divide them. Thus we can say that time is always moving forward, that's an arrow extending from the past to the future.
The degree of entropy depends directly on the amount of energy of the process, but when it appeared at first time? At that moment of the birth of the Universe, a tremendous amount of energy was in a relatively small space. But we can’t explain why entropy had the lowest value (relative current), and time did not exist at that moment. The answer to this question will help us to understand what is time and how to "create" it.
Inaccurate perception of Reality
We can say that we perceive space through elementary particles, which obey the laws of quantum mechanics. According to these laws, the particles act not as “solid balls”, but as waves that propagate to huge areas. Each particle is described by a wave function that indicates its possible location, speed and other properties. But, at the time of particle measurement, all values of its properties are destroyed, and the obtained data cease to exist.
In fact, the data you received is no longer relevant. Imagine that this is a wave that formed in the heart of the ocean, and you could see it only on the shore, faced with the shore, the wave disappears. It is unknown why the measurement of particles leads to the destruction of their wave functions. Having solved the problem of measurement, we will approach the understanding of what is reality.
The existence of Parallel Universes
The data obtained by astrophysicists and a number of scientific phenomena suggest that the spacetime continuum can be "flat" and not "curved”, therefore, it tends to infinity. If so, then our Universe is only a part of the infinite Multiverse.
Thus, the question of "Fine-tuned Universe" is removed, and there are parallel worlds with their own physical laws. Everything is possible, any combination of all that you could and could not imagine. The coincidence of an infinite number of probabilities that have led to incredible results. According to some calculations right after the Big Bang were created 101010^7 universes. But we have no way to prove their existence or to detect at least one of them.
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Humanity made a huge number of incredible and amazing discoveries. In a sense, our knowledge is already ahead of our biological possibilities of understanding and perception of that knowledge. It is possible that we will never be able to find the answers to the above questions because they are beyond human thinking. Maybe this knowledge are not meant for us, we are not yet ready to know the answers...
sources: Dark energy, Arrow of time, Entropy, Wave function, Parallel Universes, Multiverse, Spacetime, Fine tuned Universe images from Google Search.