The origin and evolution of the universe

Standard Big bang model
Big Bang model (big explosion) said that the universe started with an explosion about 15 billion years ago. At the explosion, the cosmic size is considered to be zero, so the energy density and temperature are extremely large. After the explosion, the universe expanded and cooled, allowing it to become structures as we see it today.

At least three theoretical and practical bases lead to the model. It is interesting to know that a writer is the first person to assume that the universe must have a point of departure. Olbers paradox (1823) said that if the universe is infinite in space - it must have so many stars that when we look at the sky, our eyes always meet a star. And we will see the sky is always as bright as the sun, even at night. The reality of the night sky was dark. In the long prose poem Eureku in 1848, Edgar Poe said that it was because the stars did not have enough time to light the whole universe. And the dark night sky proves that the universe does not exist forever. Not only does it stand up to the challenge of time, but the theory also plays a decisive role in forming the Big Bang theory.

The second theoretical basis is the general theory of relativity, which assumes that space-time is a dynamic and material-dependent quantity while controlling matter (note the conception of Engels, assuming no-time is the form of existence of matter. That leads to no-time work as the form of material existence. That leads the time - the time and therefore the universe can have a beginning and an end, an idea originally Einstein also sought to resist.

The practical basis of the model is the discovery of Hubble's expansion universe in the 1920s. The universe is currently expanding and galaxies increasingly distant from each other prove in the past they are close together, when the universe is small in size. than. Reflecting back in time will go to the time of birth, when the whole universe is concentrated at one point, where there is infinite energy density, temperature and curvature. And an explosion will make the universe born.

However, too much material density or gravity can cause the universe to shrink as soon as it expands. Along with other causes that Alan Guth assumes inflation expansion, allows the universe to increase in size 1030 times in just moments (from 10-35 to 10-32 seconds after the explosion). Overcoming that boundary of failure, the victorious universe expanded and created everything, including ourselves.

It is the hot universe model of standard inflation expansion. In 1991 when the Hubble telescope on the Cobe satellite measured the remnant radiation background from the past explosion as predicted, the Big Bang model was widely acknowledged.

Open issues

Big Bang is the best model today, but of course it still has many problems, including singularity and ultimate beginnings. Physics shakes away from singularities, where a certain quantity reaches infinite value - something that is only in the abstract mathematical world. Big Bang is such a bizarre point and that is something to avoid. Big Bang then created the universe, so what gave birth to Big Bang? It is no good when the church welcomes the model, because watching Big Bang embody the creator.

One way to avoid the singular problem is the string theory of particle physics (basic). The string theory of the most basic element of the universe is not a particle (like electrons, quarks .) but a wire or a super-wire with 10 dimensions. Up to 5 string theory and by 1995 it was found that they were just a version of a fundamental theory rather than 11-dimensional membrane theory. The different types of vibrations of membranes are expressed into basic particles that we see. The old point of view is that the particle is essentially a non-sized point substance, leading to a singularity, and the membrane is not because they have a defined size, though very small.

The bad start problem is more complicated. One way to solve the problem is to examine the end. The universe is expanding forever or gradually shrinking in a big case (Big Crunch)? If the universe is sufficiently material, the gravitational force will gradually overcome the expansion and the universe is sufficiently material, the gravitational force will gradually overcome the expansion and the universe will have a singularity. And the explosion that created us could possibly be the result of a previous contraction. That is the model of Wheeler 's reincarnation universe, with elastic cycles connected to a circle like Buddhist philosophy, a way to avoid the ultimate beginning.

Unfortunately Big Cruch is not the perfect mirror symmetry of Big Bang. When the universe shrinks, the Photon will get more energy due to the gravitational field. And the universe at the end will be hotter than the beginning. As a result, the explosion became even stronger. That proves that the universe still needs an ultimate starting point, just like the model has only one Big Bang. The poet still has not lost his excitement.

Revolution last millennium

The concept of reincarnation implies that the universe has enough material to shrink. But that concept was rejected in 1998. Observing the supernovae led to a revolutionary conclusion: the universe is expanding rapidly. That is unhappy news because the model of reincarnation is preferable, where the universe and life can die nonstop.

Why is the universe expanding faster and faster? The answer is quite simple: because of the lack of material needed. More importantly, it seems that the universe contains a special form of energy that has an antigravity effect.

Several decades ago astronomers saw the universe contained only ordinary light matter. Seeing the rotation speed of galaxies so fast, it is assumed that the dark matter is 10 times more luminous than the light (so that the gravitational force is sufficient to compensate for the centrifugal force rotated by the galaxy, if not the galaxy will disintegrate). Dark substances are divided into two categories; Common types (like brown dwarfs, black holes .) and strange types (such as mass neutrinos, axions or Wimp hypothetical particles .). Now it is necessary to add new types of matter or energy, called dark energy, which accounts for two-thirds of the cosmic mass:

Ingredient

Ratio (%)

Illustration

Radiation

0.005

Light, other electromagnetic radiation .

Bright substance

0.5

Sun, stars, planetary systems .

Ordinary dark matter

3.5

Black holes, brown dwarfs, black dwarfs .

Strange dark substance

26

Massive neutrinos, axion hypothetical particles, wimp .

Dark energy

70

Vacuum energy or fifth component .

The nature of dark energy with negative pressure (to create antigravity) is probably a long-term challenge to physics and cosmology.

First is vacuum energy. Physical vacuum is not nothingness, but is filled with particles - virtual antiparticles, cessation and destruction due to Heisenberg's uncertainty principle. Accordingly, it is not possible to accurately determine the values ​​of the associated physical quantities (such as position and speed, the value of conjugated physical quantities (such as position and speed, value and So the variation of a physical field .) So the energy of the foot is not different, because if the zero is equal, the variability is also zero, meaning that the two quantities are determined exactly at the same time, which It is due to particle generation and virtual antiparticle, for example, in 1cm3 before our eyes, there are always 1030 virtual electrons, they have the effect of counting, like the Casimir effect. The energy is 10120 times greater than other forms of matter, a figure that stunned physicists!

The second candidate is the fifth element (pun according to Aristotle, who views the four elements of water, fire, air, and earth that make up the universe). The simplest is that a quantum field changes very slowly over time, the mechanism that explains the period of inflation expansion. Another possibility comes from the physics of virtual extra dimensions, ie the 10-dimensional or 11-dimensional wires mentioned above. In this theory, ordinary matter lies on three-dimensional membranes. The membranes are close to each other on the 11th afternoon. The light that follows the three-dimensional membranes to our eyes takes billions of years, while the gravitational (or anti-gravitational) effect comes immediately in the left direction, creating value. extremely large estimates as just said. However, mathematical difficulties make it possible to produce a complete model in the short term but also in the future.

Membrane patterns and touches

In order to solve two peculiar problems and the ultimate start, at the end of 2001 Steinhardt, Turok, Khoury, Ovrut and Seiberg scientists proposed membrane models and touches, see if Big Bang is not the beginning - time , which is the transition point between the expanding and shrinking phase earlier. This is the reincarnation model, but has advantages over other reincarnation models.

The model assumes our universe is a three-dimensional membrane floating in four-dimensional space. Another membrane - a parallel universe - sits right next to the micro gap in the direction of the order. This universe is closer to the skin, but we can't see or touch it. These membranes act like springs together: pull back when the membranes are far apart and eject when they come close, causing the membranes to vibrate away and get close. They are sequentially colliding as Big Bang. The original Big Bang energy is colliding energy; there are densities (clearly seen on the fossil radiation background measured by the Cobe satellite in 1991 and the seed that develops into later galaxies) are the wrinkles of the membrane. In the process of oscillation and impact, the films can still stretch themselves.

Compared to the standard inflation model, this model has the advantage of not needing dark energy to explain the increasing expansion of the universe. It is simply the 'spring' energy. According to Turok, another advantage is that the oddness only appears in the fourth dimension (when the two films collide, the distance is zero), the lightest of all the singularities. And since the expansion continues before and after the collision, the photons will not gain more energy, so Big Crunch is not hotter than the Big Bang, allowing the elimination of the ultimate beginnings, a favorite theological subject.

Of course the model also left many problems. First, the lightest is still weird. Next, it is unclear how minor fluctuations or wrinkles of the re-membrane appear and touch. According to Linde, a model of inflation, it is like throwing a chair into a black hole and hoping it will be reborn. Then the nature of spring force is also an unsolvable problem. However, many astronomers welcome the model, because as the famous string theorist Veneziano at Cern says, we can accept the idea of ​​Big Bang as a result of something rather than the cause of everything.

'Evil Theory' Monday

The above models all have dark energy problems. So from 1983, Mordehai Milgrom (israel) proposed Mond, ie Newton's dynamic change (Modified Newtonian Dynamics). He assumed that the law of Newton's F = ma would turn into F = ma2 at low accelerations, size 10-10 m / s2. That means only a smaller force or less matter is needed to accelerate the galaxies. And the dark matter or dark energy will be automatically excluded.

The astronomers initially rejected Mond. But the successes in explaining galactic formation and evolution (recent measurements consistent with Milgrom's prediction many years ago) convinced some scientists. However, they did not think the Newtonian motivation was wrong, but considered a practical supplement, when calling it the MIFF, the formula that made the Milgrom Fitting Formula (Milgrom Fitting Formula).

Finite or infinite universe?

Consider Mach's principle, assuming that the inertia of the object is due to its interaction with the entire universe. Can be better understood by considering centrifugal force on a bucket of water. When you turn the water in the tank, the water surface will sink: we say it is affected by centrifugal force. Is that because the water is spinning against the standing tank? Absolutely not, because when turning both the barrel and the water at the same speed, the water surface is still concave. Mach said that the water surface is concave because 'knowing' it is rotating towards the whole universe. In other words, inertia is due to the interaction of the entire universe on objects. So the universe must be finite. If the infinite universe is inertia will be infinitely large: Everything cannot change the state of movement, something contrary to reality.

But that is only our universe. Many assume the dual-wave universe or the munltiverse, each with its own rules. Recall the impact film, not just two but more. Or imagine blowing bubbles of bubbles, each bubble is a single universe. Bubbles can be held together by wormhole holes. According to general relativity, they are shortcuts to spacetime regions in a bubble, even connecting cosmic bubbles to each other. They allow the energy to erupt between bubbles. It can be imagined that such an eruption is the Big Bang that gave birth to the universe in which we live.

Thus we may be living in a finite single universe. This single universe is one of the numerous membranes or bubbles of an infinite multiverse. Anyone can be satisfied, like the infinite or finite universe.

This hypothesis helps eliminate the supreme creator. In the famous work "Mysterious Tone" (translated into Vietnamese), Trinh Xuan Thuan put his faith in the light and believed that he wanted to put his faith in hope, not despair. According to him, finding a suitable bubble for life among endless bubbles is impossible, as well as seeing life as just a random variable that does not satisfy human self-esteem. I think the problem is the opposite. If man is created by a supreme being, we are just puppets. Then there will be no free will of Bergson; there is also no choice of one of the different possibilities, as a way of self-determination of fate - the basic characteristic of humanity. If we appear as the wonderful combination of randomness and of course we need to live worthy of all the difficulties of birth. And that can have humanistic meaning.

How is multiverse born?

As mentioned above, each single universe is finite but the universe can be infinite. That they show it contains an infinite amount of energy, meaningless physically? Thankfully not so.

Quantum quantification allows particle pairs - virtual antiparticles, or 'bubbles' to appear from a vacuum, as long as we disappear after a short lifetime. The less energy foam is, the longer it lasts. Because the gravitational field energy is negative, the energy contained in the material is positive, so if the multiverse is flat (although the single universe can be curved), the two forms of energy cancel each other out and the multiverse energy exactly zero. Then quantum rules allow it to exist forever. In other words, it is the uncertainty that causes the universe to emerge from nothingness, an idea so unique that when listening to Gamow at Princeton in the 1940s, Einstein stood in the middle of the road, nearly two people almost was stabbed by the car.

We can ask questions, so where does nothing come from? Perhaps that is an unreasonable question. Rather than asking the question, why is there an uncertainty about the universe to be born? And are there more fundamental questions?

Finally, please emphasize the consistency between micro and macro. It is through the micro nature that science can understand the universe. Opinions suggest that re-ductionism, an analytical-based approach to increasingly deepening the microstructure of the world, has lost its ability to perceive as unfounded. In the book The Final Theory of Dreams, 1992, Steven Weinberg, a physicist who won the Nobel Prize for merit for uniting weak and electronic interactions, devoted two chapters to critique philosophers and advocates. for the argument with the analysis.