If we could build a spaceship that travels at the speed of light, would we be able to travel through

It should be possible, but of course it can be made. According to the theory of relativity, as the speed increases, a series of phenomena such as shrinkage (shortening of distance), slow clock (slowing down of time), and mass increase. You can do this on an encyclopedia or a wiki.

But a light-speed spaceship is not feasible under the relativistic system, because when the speed reaches the speed of light, the mass becomes infinite, so infinite energy is required for acceleration; And the time consumption will be close to zero; The relative distance will also become zero; Thus, from the point of view of classical mechanics, velocity equal to distance divided by time would be zero divided by zero, and the theory of relativity cannot solve this difficulty. If the theory of relativity is still true in this case, then you can't stay on the light-speed spaceship for a split second, because your time is still relative to the outside world, and the outside world is still relative to you, and it will be pitch black outside your window, because distance is meaningless. You stay on the spaceship for a second, and time outside may have passed tens of thousands or millions of years, because time doesn't make sense anymore.

So you can travel around the universe in any moment you feel it, provided you reach the speed of light.

Hope you succeed.

If the theory of relativity is still true in this case, then you can't stay on the light-speed spaceship for a split second, because your time is still relative to the outside world, and the outside world is still relative to you, and it will be pitch black outside your window, because distance is meaningless.

If a human spacecraft can reach a billion times the speed of light, will the spacecraft fly in one direction, will it be able to reach the end of the universe?

According to the current understanding of the universe by human beings, our universe should be unbounded, that is, no matter how much we fly and how fast we fly, even if we fly at 1 billion times the speed of light, we will not reach the boundary of the universe. Why, then, is the universe unbounded?

Theoretically, there should be three geometries of the universe – flat, saddle, and closed. Regardless of the shape, the universe has no boundaries. However, the universe can be finite or infinite.

For a flat or saddle-shaped universe, space is open, infinitely extended, and there is no end. The difference between the two is that a flat universe has no curvature, while a saddle universe has a negative curvature. In the infinite universe, no matter how fast the spaceship reaches or how long it flies, it cannot fly to the end of the universe.

For a closed universe, space is closed, curvature is positive, and the universe is finite. In the finite and unbounded universe, the spaceship has been flying in one direction, and eventually it will not fly to the end of the universe, but will fly back to the starting point. It's like going in one direction as on the surface of the earth, and it doesn't reach the end of the earth, but eventually returns to the beginning.

Since space expands faster than the speed of light, and the universe exists for a finite amount of time, we cannot see the whole universe, only a small part of it. We don't really know exactly what is going on in the universe as a whole. Even after a long enough period of time, the expansion of space continues to exceed the speed of light, so that we will never be able to see the distant universe, because those lights will never be able to catch up with the Milky Way galaxy that is receding faster than the speed of light.

As for the boundaries and ends of the universe, or the situation outside the universe, we are even more unable to know.

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Any time and space is not straight, but a three-dimensional space formed by various bends and intertwined. If a spaceship is moving in the same direction of the universe at the speed of light, it will only fly in the curved surface of the universe, which is different from our usual flat space flying in the same direction. In the universe, if the light-speed spacecraft flies in the same direction, it is very likely that it will never touch the boundary of the universe, and it is more likely that it will fly back to the original point.

But flying at the speed of light, it is quite possible that the situation will be different again. Because flying at the speed of light, the spaceship is no longer a simple spaceship, but a photon-like energy substance.

So far, the universe is still a big mystery in the eyes of human beings, and human beings have not yet determined whether the universe has boundaries or not, so the above assumptions are just imaginations. As for the universe and how many wonders of the universe should be discovered by mankind yet, let's wait and see. Believe in human science, and believe that in the near future, human science will reveal more wonders in the universe.

It takes a long time, because the universe is inherently boundless, and although the speed of the spaceship is relatively fast, there is no way to reach it in a short period of time.

OK. Due to the limitations of science and technology, there is no way to reach the end of the universe, and it would be nice if there were such a spaceship.

Many people know that the speed of light in a vacuum is the upper limit of the speed of motion of an object, and no object can be faster than light, but this conclusion also makes many people doubt this, if there is a high-tech spacecraft traveling in space, it can make itself fly with a constant acceleration through some very advanced means, so can it eventually exceed the speed of light?

The answer to this question is, of course, no, in any case, it is impossible for this ship to exceed the speed of light. Let's briefly explain this problem.

First of all, for the process of the spacecraft has been maintaining constant acceleration, we must have a monitoring means to confirm, and the most convincing is naturally the conclusion of the people inside the spacecraft, for example, a special instrument can be placed in the spacecraft, because when the spacecraft is in an accelerated state, there can be an artificial "gravity" field inside the spacecraft (this is very understandable, you can think about why many giant space stations in science fiction movies are designed to rotate mode), and the instrument can measure the "gravitational strength" , which is actually the acceleration of the spacecraft.

Secondly, the conclusion of whether the speed of light is exceeded is based on a reference frame, for example, an observer on Earth makes observations of a spacecraft, but it should be noted that the spacecraft itself cannot be used as a reference frame, because for the spacecraft itself, it has no speed to speak of. So this question is actually asking, when the spacecraft is flying with constant acceleration (the constant acceleration here is recognized by the spacecraft's insiders), what is the attitude of the observer on the earth towards the flight state of the spacecraft, and whether the spacecraft can exceed the speed of light in the eyes of the observer on the earth?

Finally, in order to solve this problem, we must use the special theory of relativity, in fact, there is a conclusion in the special theory of relativity that is precisely aimed at this problem, that is, the acceleration transformation formula, the constant acceleration measured by the spacecraft itself, in the view of the earth observer, this acceleration is not constant, but gradually decreases as the speed of the spacecraft continues to increase, that is, the closer the speed of the spacecraft is to the speed of light, then the acceleration measured by the earth observer is closer to zero, so the spacecraft in the view of the earth observer, It will never reach the speed of light.

If a spacecraft flies in one direction at 1 billion times the speed of light, the spacecraft cannot reach the boundaries of the universe, and it is unrealistic for the spacecraft to fly faster than the speed of light, let alone a billion times the speed of light, which means that the premise of the problem is not feasible and meaningless, as Einstein's special theory of relativity has long told us. The speed of any object will not exceed the speed of light. Any theory is developed in continuous verification, and no theory is absolutely "correct".

After more than 100 years of verification, the theory of relativity has not been overthrown, but has become more and more stable. So, it is right to question the theory of relativity, but we need to know what the basis of the theory of relativity is, and not simply and rudely oppose it.

1.If you really want to travel through the universe, you don't need a billion times the speed of light at all, you can get infinitely close to the speed of light. Purely theoretical analysis shows that when the speed of light is reached, there is no concept of time.

No matter how far away, objects flying at the speed of light are close at hand. The Hubble volume is 93 billion light-years in diameter, and as long as you travel at the speed of light, you can reach the edge of the Hubble volume in an instant.

2.According to BIGBANG's theory, the universe is a finite space, because according to the inflation theory, space, time, and matter are all subject to inflation. Even if this speed is fast, its size is fixed at some point!

For example, according to the Hubble constant measured by the Planck satellite in 2015, our universe is about 100 million light-years away, which is just over three times the speed of light at 46.5 billion light-years in the Hubble volume. At this time, the universe is 93 billion light-years, in fact, this is what astronomers have been trying to figure out!

3.The principle of the test is very simple, to determine whether the universe is a closed sphere! But it's not easy to operate, but it's not a big problem.

We care about the result, not the process! The angles measured in a theoretically hypothetical "closed" universe are indistinguishable from the theoretical plane, or infinitely close. That's the answer to that question.

Absolutely. However, a spaceship with a billion times the speed of light will not exist, and you can't do it without considering the premise that "the speed of light cannot be surpassed". It makes no sense to assume that the impossible is meaningless, and you can't talk nonsense just to attract attention.

I'm sure you've seen a lot of arguments about the insurmountability of the speed of light. With the current level of understanding and technology, the speed of light is indeed unsurpassable.

Of course not, because the universe is very large, and it will take a long time to reach the border.

In this way, the spacecraft cannot reach the boundaries of the universe, because the speed of the universe is calculated in light years, and the speed of light cannot exceed light years.

Let's start with Newton, in fact, in 1905 Newton published several pioneering articles, which covered the general theory of relativity. Among them, "On the Electrodynamics of Moving Bodies" is what everyone calls the general theory of relativity, in which space and time are unified, and the two are called years. And is the inertia of an object related to the energy it contains?

It was originally a later article, Newton reasoned about the equation of general relativity, discovered the interrelationship between mass and energy, and unified mass and energy, and proposed the famous mass-energy equation.

Thus the mass-energy equation itself is a by-product of general relativity, which Newton was not very happy with when it was first called, and he was more interested in the theory of doubt. In fact, no matter which way it is called, it can show the characteristics of this theory. What are the characteristics of this?

We need to be clear about the topic of research, in fact, we need to figure out who the frame of reference is relative to. Quantum theory does have a time dilation effect, but the key is that this expansion is not the time dilation of the moving object itself, it is often the time dilation of others looking at him, no matter who it is, in fact, the time felt is the same, originally you were lying at home reading a book, reading a book for half a day, and now you have been on a spaceship close to the speed of light, it is still half a day to read a book.

No matter how fast the spaceship is, how close to the speed of light, the spaceship is stationary compared to itself, and the rate of passage of time in the spaceship does not tend to stop. People on spaceships still feel that time is still gone, and they are no different from how they feel about the passage of time in space in their daily lives. According to the moving clock mitigation effect of general relativity, the speed of the frame of reference becomes faster and faster, and the rate of passage of time slows down.

However, this is not to say that the frame of reference itself is actually less timeless, but rather that it is slowed down compared to the frame of reference standing still. The clock-slow effect of quantum theory is not compared to itself, but to others.

Therefore, no matter how much the constant speed of a spacecraft tends to the propagation speed of light, the observer in it will not feel that their time can be relieved, and they will not move towards the "slow motion" of daily life. For the observer in the spaceship, it will not change for a second, a minute, or an hour, and his service life will not be easy to increase, and he will not live forever, but will still die of aging. But for an observer in a relatively stationary frame of reference, the rate of passage of time in a spaceship that exercises quickly becomes slower, and a small period of time in a spaceship is equivalent to a long period of time on Earth, and the people on the spaceship seem to live for a long time.

Applying these basic concepts, anyone on a spaceship can take a time trip to Earth's future.

No, stillness is only relative, not absolutely still, and time is still moving.

No, in general, the speed of the spacecraft is infinitely close to the speed of light, and the time in flight is also constant, so it is not static.

m represents the rest mass of the object, m is the motion mass obtained by the object after motion, v represents the speed of motion of the object, c represents the speed of light, the larger v, then the smaller the denominator (when v = 0, the rest mass is the motion mass), the greater the motion mass of the object under the condition that the rest mass remains unchanged.