The limits of the universe? The origin of time?

The universe has bounded infinity, in the two-dimensional world it is like a circle, you are walking in the circle, you can't see the end, but it is indeed finite, Ai's cosmic space is a four-dimensional space, and it is also bounded infinite. The universe is closed by itself.

And what was the beginning of the universe? Personally, I think it's pointless, it may have come out of nowhere, and I want to be an idealist on this issue. The God of reason created it.

It seems that this thing is not understandable to people who do not study mathematics and physics: (When our speed relative to the environment is not very large, it is easy to understand the addition of a time dimension in a uniform three-dimensional space, just like an apple, at 9 o'clock and 10 o'clock just to add a time concept to the definition of an object.)

But when the velocity becomes very large, it cannot be understood by conventional models, and an abstract mathematical thing is needed to define it.

It's like we can't find the feeling of limits in the real world.

The above is a personal opinion)

It seems that the physics of the landlord is not very good, and when you understand some physical facts that seem implausible now, I believe you will understand.

Let's put it this way, time is a property of matter, and like length, width and height, it cannot exist outside of matter.

That is, without materiality, there is no way to talk about time.

There is also the ability to convert energy and matter into each other, which is the famous e=mc 2.

Before the big **, there was only energy, no matter, no time, nothing, that is, everything was meaningless to what you know now.

Vacuum is also space, and it also has attributes, so vacuum does not mean that there is nothing.

Okay, that's all I can understand, maybe I don't understand it very well, is there someone who can talk about it?

By the way, downstairs says that our space is three-dimensional, and for now, it can be said that there is a four-dimensional, because the fourth dimension is time.

Modern physicists are working on this issue, but progress is slow. Albert Einstein's universe is four-dimensional, and modern research has speculated that the universe may be ten-dimensional, or more. Two dimensions bend into three dimensions, which is easy to understand because our space is three-dimensional.

However, it is difficult to imagine more than four dimensions. Therefore, it is difficult for us to understand that the universe is finite and unbounded. If you want to figure it out, then think about the four dimensions first.

What was the universe before, I can't figure it out, Hawking seems to have given some explanations, but he didn't make it clear.

You can refer to some scientific information and think about it carefully.

I don't think anyone in the world will know, and there is no need to know, as long as I know how to live a good life now.

It is recommended to take a look at Chen Kaige's Wuji, as long as you run fast enough, time is not a problem.

I've thought about these questions too, but I don't dare to think about them anymore! Fear of a nervous breakdown!

The philosophical answer to solace is that existence and non-existence are relative!

The human mind is also relative!

The mind is revealed, and the consciousness is changed!

Don't believe the eyes, the eyes will deceive you, don't look for the truth, because the truth is not to be found, but to wait, and as for time, it never existed, it was created by man!

I would like to know too. But I don't know???

Don't look at it, don't look at it.

The universe is the unity of time and space, the birth of the universe is the birth of time and space, we regard the universe as a thing, everything has time and space, not only our universe has time and space, all things exist in time and space. For example, the universe has begun, constantly expanding and changing, the shape and appearance are constantly changing, there is no fixed appearance, how to analyze it, there is a way, as of a certain paragraph, the shape and appearance will come out, countless paragraphs show the change process of the universe, this invisible and intangible change connection is called time. Our universe has been 13.9 billion years since then, different times have allowed us to see the development process of the universe, without time, can the universe develop until now?

Time can't be seen or touched, but it does exist objectively, and you can't admit it, do you say that it disappears? Disappearing time is conditional, different spaces are different times, in our universe, the speed reaches the speed of light, the time is 0, our earth is 30 kilometers seconds, how is it possible without time? Because time cannot be seen or touched, and time has always been dreamed of disappearing, human beings do not have this ability, and what ability does the cosmic microbetic human beings have to change cosmic time.

Whether you admit it or not, the time of the universe always exists objectively, and the universe will continue to develop over time, without any transfer of human consciousness. Time is the recorder of the occurrence of events. Time will only pass, it will not return, and time will never return.

Solar System Universe.