is a parallel universe.
To put it simply, every time and space is like an ultimate family.
It is also understandable that, like other scholars,
had the same appearance but lived a completely different life in another time and space.
In four-dimensional space (excluding time, which is a spatial dimension), a space that is independent of our three-dimensional space is like standing on the first floor of a three-dimensional space and another person standing on the second floor. In a four-dimensional space, you are in this three-dimensional space and he is in another three-dimensional space. Other three-dimensional spaces besides our three-dimensional space are called different dimensions.
This is also a theory of cosmic space. Generally speaking, we think that our world is a three-dimensional space. Einstein added time to have a four-dimensional space-time.
The theory of extra-dimensional space is that there are some places that are not in our 4-dimensional space and time, but coexist with our 4-dimensional space and time, and cannot be found in our space and time. This kind of place is an extra-dimensional space.
This idea expands the four-dimensional space-time of the universe to five or more dimensions. (String theory extends to more than ten dimensions. I’m not familiar with it, so I didn’t bring it out.)
Various theories are conceivable, but we haven’t been able to prove it yet!
The dimensions are reversed!
For example, our universe is mathematically a one-dimensional straight line that can extend infinitely to both ends. It can be said to be infinite.
However, when we jump out of one dimension and look at a two-dimensional plane, we will find that next to our original infinitely extending straight line, there are countless parallel straight lines that coexist with our straight line. This can be understood as a parallel universe.
Similarly, you can add dimensions to expand it into three dimensions. ....
To sum up, by expanding the dimensions, we can realize the phenomenon of "some places are not in our four-dimensional space and time but coexist with our four-dimensional space and time", just like we live in a two-dimensional In space, you will never feel the existence of three-dimensional space.
The definition of parallel universe
Is the other article you are reading exactly the same as this one? That guy is not himself, but lives in a misty mountain range, endless fields, noisy cities, and revolves around a star with eight other planets, and is also called "Earth"? His (her) life experience is the same as yours every second. However, maybe at this moment she is about to put the article down and you are about to read it.
This idea of ??"being in two places at the same time" sounds strange and unbelievable, but it seems that we have to accept it because it is supported by various astronomical observations. The most popular and simplest model of the universe now states that there is a galaxy exactly like our Milky Way about 10 (10 28) meters away from us, and there is a galaxy exactly like you inside. Although this distance is beyond people's imagination, it does not affect the authenticity of your "doppelg?nger". The idea originally stemmed from a very simple "natural possibility" rather than the assumptions of modern physics: the size of the universe is infinite (or at least large enough), and matter is evenly distributed, as astronomical observations indicate . In this case, according to statistical laws, it can be concluded that all events (no matter how similar or identical) will happen countless times: there will be countless planets that will give birth to human beings, and among them there will be people exactly like you - -Exactly the same appearance, name, memory and even the same actions and choices as you-and there will be more than one such person, to be exact, there are infinite ones.
The latest cosmological observations show that the concept of parallel universes is not a metaphor. Space seems infinite. If this is the case, everything that can happen must happen, no matter how absurd they may be. Beyond our astronomical observations, there is a universe exactly like ours. Astronomers have even calculated their average distance from Earth.
You may never see your "shadow". The farthest distance you can observe is the farthest distance that light has traveled since the Big Bang: approximately 654.38+0.4 billion light-years, which is 4X10^26 meters - a radius that just defines the size of our observable horizon The size of the sphere, or simply, the universe, is also called the Hubble volume. Similarly, the other universe you live in is also a sphere of the same size. The above is the most intuitive explanation of "parallel universe". Each universe is a small part of the larger "multiverse".
Parallel Universe Level
With such a definition of "universe", one might think that this is just a metaphysical approach. However, the difference between physics and metaphysics is whether the theory can be tested experimentally, not whether it looks weird or contains something difficult to detect. Over the years, the frontiers of physics have continued to expand, absorbing and incorporating many abstract (even metaphysical) concepts, such as a spherical Earth, invisible electromagnetic fields, the rapid and slow flow of time, quantum overlap, the curvature of space, black holes, and more. In recent years, the concept of the "multiverse" has been added to the above list, and it works with some previously tested theories, such as relativity and quantum mechanics, to achieve at least one basic criterion of an empirical scientific theory: making predictions. Of course, the conclusions drawn may also be wrong. So far, scientists have discussed as many as four types of independent parallel universes. What matters now is not the existence of multiverses, but how many levels they have.
The First Level: Beyond the Horizon
All parallel universes constitute the first multiverse. - This is the least controversial layer. Everyone accepts the fact that although we cannot see another self at the moment, we can observe it in another place, or simply wait in the same place for a long time. It's like observing a ship coming from above sea level - observing an object beyond the horizon is similar. As light travels, the radius of the observable universe expands by one light-year every year, and you just have to sit there and watch. Of course, you may not wait for the day when light from another universe reaches here, but in theory, if the theory of cosmic expansion holds true, your descendants might be able to see them with super telescopes.
How about it, the concept of the first layer of the multiverse sounds unremarkable? Isn't space infinite? Who could have imagined that there was a sign somewhere that said "Space ends, watch out for the ditch below"? If this is the case, everyone will instinctively question: What is "outside"? In fact, Einstein's gravitational field theory has turned our intuition into a problem. Space may not be infinite as long as it has a certain curvature or is not topological as we intuitively think of it (i.e. has an interconnected structure).
Another possibility is that space itself is infinite, but all matter is confined to a finite area around us - the once popular "island universe" model. What's different about this model is that the distribution of matter appears in fractal patterns on large scales and is constantly dissipating. In this case, almost every universe in the first multiverse would eventually become empty and fall into silence. However, recent observations of three-dimensional galaxy distribution and microwave backgrounds have shown that the organization of matter exhibits some fuzzy uniformity on large scales, and clear details cannot be observed on scales larger than 10 24 meters. Assuming this pattern continues, the space beyond the Hubble Volume will also be filled with planets, stars, and galaxies.
There is data to support the theory that space extends beyond the observable universe. The WMAP satellite recently measured fluctuations in the microwave background radiation (left). The strongest amplitude exceeds 0.5 kHz, implying that the space is very large, even infinite (middle picture). In addition, the WMAP and 2dF galaxy redshift detectors found that matter is evenly distributed in space at very large scales.
Observers living in different parallel universes of the first multiverse will perceive the same physical laws as us, but with different initial conditions. According to the current theory, matter was thrown out with a certain degree of randomness in the early stages of the Big Bang, and this process includes all possibilities for the distribution of matter, and each possibility is non-zero. Cosmologists assume that our universe, with its approximately uniform distribution of matter and initial wave state (one of 100,000 possibilities), is a fairly typical (at least typical of all parallel universes that have produced observers) individual . Then the nearest person who is exactly like you will be 10 (10 28) meters away; only 10 (10 92) meters away will there be an area with a radius of 100 light years, and everything in it will be exactly the same as the space we live in , that is to say, everything that happens in our world in the next 100 years will be completely reproduced in this area; at least 10 (10 118) meters away, the area will increase to the size of Hubble. In other words, it will There is a universe exactly like ours.
The average distance to another universe exactly like ours may not be as far away as theoretically calculated, but it may be much closer.
Because the organization of matter is also restricted by other physical laws. Given some laws such as planet formation processes and chemical equations, astronomers suspect that there are at least 10 20 inhabited planets in our Hubble volume alone. Some of them may be very similar to Earth.
The first multiverse framework is often used to evaluate modern cosmological theories, although this process is rarely articulated. For example, let's examine how our cosmologists try to map the geometry of the universe in "spherical space" through the microwave background. With the difference in the radius of curvature of space, the size of the "hot areas" and "cold areas" on the cosmic microwave background map will show some characteristics; the observation area shows that the curvature is too small to form a spherical closed space. However, it is important to maintain statistical rigor. The average size of these regions in each Hubble space is completely random. So it is possible that the universe is fooling us - it is not that the curvature of space is not enough to form a closed sphere, making the observed area very small, but just because the average area of ??our universe is naturally smaller than others. So when cosmologists swear that their spherical space model is 99.9% reliable, what they really mean is that our universe is so unsociable that only one in 1,000 Hubble volumes would be like that.
The point of this lesson is: even if we cannot observe other universes, the multiverse theory can still be verified in practice. The key is to predict the * * * of each parallel universe in the first multiverse and indicate its probability distribution - what mathematicians call a "measurement". Our universe should be one of those "most likely universes." Otherwise - and unfortunately we live in an unlikely universe - then the previously hypothesized theory would be in big trouble. As we will discuss next, how to solve this measurement problem becomes quite challenging.
The second level: the bubbles left after expansion.
If the concept of the first-level multiverse is not easy to digest, you can try to imagine the structure of an infinite group of the next first-level multiverse: the groups are independent of each other and even have different space-time dimensions and physical constants . These groups constitute the second multiverse—predicted by modern theory as "disorderly expansion."
As an inevitable extension of the Big Bang theory, "inflation" is closely related to many other corollaries of the theory. For example, why is our universe so large and regular, smooth and flat? The answer is that "space has undergone a rapid stretching process", which can not only explain the above problems, but also explain many other properties of the universe. See "The Inflating Universe" by Alan H. Guth and Paul J. Steinhard; Scientific American, May 1984; "The Inflation" by Andre Linder, "The Inflation" by Self-Propagating Expanding Universe, November 1994 The theory is not only stated by many elementary particle theories, but also confirmed by many observations. "Continued disorder" refers to behavior on the largest scale. The space as a whole is being stretched and will continue to do so forever. But certain areas stop pulling, creating individual "bubbles," like those inside puffed up toast. There are countless such bubbles. Each of them is the first multiverse: infinite in size and filled with matter precipitated by fluctuations in energy fields.
For the earth, the other bubble is infinitely far away, so far that you can never reach it even if you travel at the speed of light. Because the space between Earth and "the other bubble" stretches far faster than you can travel. If there was another you in another bubble, even your descendants would never think of observing him. For the same reason, that is, the expansion of space is accelerating, the observation results are frustrating: not even the other self in the first multi-space can be seen.
The second level of the multiverse is very different from the first level. Not only are the initial conditions different between bubbles, but their appearance is also different. The current mainstream view in physics is that the dimensions of time and space, the properties of elementary particles, and many so-called physical constants are not part of the basic laws of physics, but are simply the result of a process called "symmetry breaking." For example, theoretical physicists believe that our universe once consisted of nine equal dimensions. In the early history of the universe, only three dimensions participated in the pull of space, forming the three-dimensional universe we observe now. The other six dimensions are now unobservable because they are curled up on a very small scale, with all matter spread across the three fully stretched "surfaces" (which, to the ninth dimension, is just one surface, or a "membrane").
It is not particularly surprising to us that we live in a 3+1-dimensional space-time. When the partial differential equations describing nature are elliptic or hyperbolic equations, that is, when one of space or time is 0 or multi-dimensional at the same time, it is impossible for the observer to predict the universe (purple and green parts). In other cases (hyperbolic equation), if n > 3. Atoms cannot exist stably, n
Thus, we say that the symmetry of space is destroyed. The uncertainty in quantum waves causes different bubbles to disrupt their equilibrium in different ways as they expand. And the results can be weird. Some of these may extend into four dimensions; others may form only two generations of quarks instead of the three we know of; and some of the universe's fundamental physical constants may be larger than ours.
Another way to create a second multiverse is to go through the full cycle of universes from creation to destruction. In the history of science, this theory was proposed in the 1930s by a physicist named Richard C. Recently, two scientists, Paul J. Steinhardt of Princeton University and Neil Turok of the University of Cambridge, elaborated on this. Steinhardt and Turok proposed a model of a "secondary three-dimensional brane" that is fairly close to our space, but with some translation in higher dimensions. See “Been There, Done That,” by George Musser; News Scan Scientific American March 2002 Parallel universes are not really independent universes, but the universe as a whole—past, present, future— — formed a multiverse that could prove to contain as much diversity as the disorderly expansion of the universe. Additionally, Waterloo physicist Lee Smolin has proposed another theory with similar diversity to the second multiverse, in which the universe is created and mutated through black holes rather than through membrane physics.
Although we cannot interact with other things in the second multiverse, cosmologists can indirectly point to their existence. Because their existence can be used to explain the randomness of our universe. An analogy: Suppose you walk into a hotel and find a room with the house number 1967, which is the year you were born. What a coincidence! At that moment you were stunned. But your immediate reaction is no coincidence. There are hundreds of rooms in the entire hotel, and it’s normal for one of them to be the same as your birthday. But if you see another number that has nothing to do with you, it won't trigger the above thoughts. What does this mean? Even if you know nothing about hotels, you can use the above method to explain many accidental phenomena.
To give another more pertinent example: examine the mass of the sun. The mass of the sun determines its luminosity (i.e., the total amount of radiation). Through basic physical calculations, we know that only when the mass of the sun is within a narrow range of 1.6x 10 30 ~ 2.4x 10 30 kilograms, can the earth be suitable for life. Otherwise the Earth would be hotter than Venus, or colder than Mars. The mass of the sun is exactly 2.0x10^30 30 kilograms. At first glance, the Sun's mass appears to be an astonishing case of luck and coincidence. The masses of most stars are randomly distributed in the huge range of 10 29 ~ 10 32kg, so if the mass of the Sun is randomly determined at birth, the chance of falling within the appropriate range will be very small. However, with the experience of the hotel, we understand that this superficial accident is actually the inevitable result of a large system (here refers to many solar systems) (because we are here, the mass of the sun has to be like this). This observer-dependent selection is known as the "anthropic principle." Although it's understandable how controversial it has been, physicists have widely accepted that this selection effect cannot be ignored when testing fundamental theories. & gt& gt& gt& gtThe world that we humans can see is only one space in the universe, called a one-dimensional space. There are four spaces in this universe. The second dimension is the underworld, and the third dimension is called the underworld, which is what we humans call the underworld. After people in the human world and the underworld die, their souls are extradited to the underworld, which is what we usually call death. The last four-dimensional space, which is the heaven, is the place where the balance of the four realms and the gods is maintained.