This is a universe full of miracles. Among them, the biggest miracle is that it gave birth to life and produced intelligent life that can observe and think about the universe. To get to this point, many prerequisites are needed, such as the large-scale structure of the universe.
The existence of galaxies, stars, planets, chemical reactions, the origin of life, etc. These are all coincidences with incredibly low probabilities.
The essence of the universe is physics (this sentence is questionable), and its operation is governed by physical laws. Many physical laws contain a large number of physical constants, and the values of these constants determine the final shape of our universe. Yes.
It is said that all coincidences and miracles in the universe are due to the values of these constants falling within some very small ranges. If the values of these constants change even slightly, our universe will be completely different. Not only will it not be able to breed life,
Not even galaxies or stars will appear.
Therefore, people often call such a universe a fiuned universe or a knife-edge universe.
Let's take a look at the outrageous requirements for the accuracy range of physical constants to reach the current state of the universe.
1. The universal gravitational constant appears in many physical laws from Newton's law of universal gravitation to general relativity, and is crucial to the macroscopic structure of the universe. The value of this constant should be familiar to everyone: 6.67 X 10^-11.
If the gravitational constant is 10^-36 smaller than the current value, the star will not be able to exist stably. Its own gravity cannot compete with the radiation pressure from core fusion, and it will collapse in an instant.
If the universal gravitational constant is 10^-40 larger than the current value, under the influence of too strong gravity, the universe will be filled with black holes and there will be no more stars.
10^-36 is a number that is too small for the human brain to understand. The following example may help you understand it. If you connect 10^36 sand grains with a diameter of 0.1 mm, its length will be observable
114 times the diameter of the universe (93 billion light years). At such an unimaginable length, if you remove a grain of sand, the entire universe will collapse.
In addition, there are other parameters that play an important role in the current state of the universe. Some of them are physical constants, and some are the result of the interaction of multiple constants.
2. The efficiency of stellar nuclear fusion is 0.007, which means that when hydrogen is fused into helium, 0.7% of the mass is converted into energy. This parameter is determined by several other physical constants, including the size of the strong interaction force.
If the value of this parameter is 0.006, then complex chemical elements will not be able to exist, and the complex chemical reactions on which life activities depend will not occur. If the value of this parameter is 0.008, then all hydrogen elements will quickly disappear after the big bang.
Exhausted. However, not all physicists agree with this view. They believe that as long as the increase in the strong interaction does not exceed 50%, hydrogen can exist stably for a long time.
3. The density parameter of the universe is the ratio of the density of matter in the universe to the critical density (critivity). This value is approximately equal to 1. If the density of matter in the universe is too large and the dark energy is not enough to promote the expansion of the universe, then the universe will explode in the Big Bang.
It used to shrink rapidly. On the contrary, if the matter density of the universe is too small, it cannot provide enough gravity to form stars.
4. The cosmological constant describes the ratio of dark energy density to the key energy density of the universe. The magnitude of this constant is 10^-122. This minuscule value determines that it can only work on a scale of 1 billion light years. If it
If it were not so small, stars and galaxies would not be able to form.
5. The third lowest energy state of the carbon 12 atom is 7.656MeV. If this value is lower than 7.596MeV or higher than 7.716MeV, the carbon element produced by the star will not be enough to support carbon-based life. Similarly, it is necessary to create the necessary materials to meet the needs of life on earth.
For the oxygen element, our requirement for the size range of the strong interaction force is 0.5%, and the requirement for the size range of the electromagnetic force is 4%. Of course, if you believe that other elements, such as silicon, can also support life, you can ignore this
a little.
There are many such examples, such as the fine structure constant, the dimensions of the universe, etc., so I won’t go into details here. However, one thing that cannot be ignored is that the final state of today’s universe is the result of the action of all these factors. They must simultaneously
Falling within the specified range. Therefore, the probability that we get the universe today is the product of all small probabilities. You may be able to imagine what kind of jackpot we have won.
Whether from a scientific or philosophical perspective, a precisely tuned universe is an unavoidable question. So why do we get such a universe that seems to be specially designed for us?
The first thing we must consider is that physics has not developed to the extent of answering all questions in the universe. The physical constants that currently seem independent of each other may be related to each other at a deeper level. In the future, we may find that the current state of the universe is
The probability is much greater than the calculation above.
Here's a look at various attempts to explain a precisely tuned universe.
1. Intelligent design
An answer that is easy to think of is: the universe was designed by more advanced intelligent beings, whether they are gods or aliens that we cannot understand. The purpose of designing such a universe is to breed life in it, or as an experiment, see
Let’s look at how long it takes for the germs of life to spread throughout the universe. If we extend this idea further, we can even assume that our universe is just a virtual world of a computer system.
Opponents of this view point out that it would be too inefficient to create such a huge and incredibly long universe just to feed a few creatures on an inconspicuous little blue star (after all, we have not yet discovered the reliability of extraterrestrial life)
Evidence). In fact, this does not effectively overturn the idea of intelligent design, because the first bacteria in the petri dish may also raise the same question.
However, the extent to which this answer solves your problem depends on how pious you are about your faith. If you believe that an all-powerful God is the ultimate answer to all questions, the existence and origin of this God cannot be questioned.
, then you don’t need to think any further. On the contrary, if you want to continue to use scientific research methods to think about the principles of the existence of intelligent designers, you will find that you have fallen into an infinite loop: being able to design
Intelligent creatures out of the universe are certainly more difficult to understand than the universe itself.
2. Anthropic principle
Supporters of the anthropic principle believe: "If the universe had not been accurately adjusted to its current state, humans would not exist, and we would not be able to observe and think about the universe."
There are many versions of the anthropic principle. Among them, the weak anthropic principle holds that the possible values of parameters in physics and cosmology are not completely equivalent, and the universe prefers those values that allow carbon-based life to evolve.
The strong anthropic principle goes a step further and believes that the universe must have properties that allow certain stages of life to develop. The final anthropic principle believes that information processing processes containing intelligence will definitely appear in the universe, and once they appear, they will not perish.
Opponents of the anthropic principle argue that this view cannot be tested or falsified, and that it reverses the relationship between cause and effect. Human beings evolved to adapt to the universe, rather than the universe adapting to humans. Hawking also believes that our universe is not like humans
It is as special as described by the selection principle.
3. Multiverse theory Among the many explanations, the multiverse theory is probably the view most closely related to physics. This view believes that all values of physical constants are possible and must exist. It is just that they exist
In different universes. The universe we live in happened to get the existing constant value, so it finally got the current state of the universe, and intelligent life that can observe and think about the universe appeared. And other universes got different constant values, so
They may collapse quickly after the Big Bang and return to the singularity, without forming galaxies or stars; in some universes, stars may be destroyed in a flash of ignition, unable to evolve life.
There are many different versions of the multiverse hypothesis in current physics. The hypothesis that can be used to explain the precisely adjusted universe is probably only the version based on string theory or M theory. For details, please refer to What is the relationship between string theory and parallel universes? However, regardless of
Both string theory and multiverse theory are currently unverifiable. Similarly, a precisely regulated universe is also an unanswered question.
(Author: Zhihu Ma)
(This chapter is free and will be deleted if infringed.)