Astronomers have learned from careful study that even if humans develop for another hundred years, they will not be able to fly out of the Milky Way.
In fact, there is a scientific basis for saying this, the moon 380,000 kilometers away is still the farthest place that human beings have ever visited, but with the continuous development of the aerospace industry, one day we will break through the distance of the moon and achieve a farther flight.
This has always been the best wish in the hearts of human beings, but the universe is too big, not to mention the earth, that is, the solar system where our earth is located, is just like sand and gravel in the universe, even if human development rises to a higher level, I am afraid it will be difficult to break through the threshold of the solar system, so let alone leave the galaxy.
And now there are many conditions that limit us, such as the spacecraft developed by our human beings, etc., which can only rely on chemical fuels as a power source, but the efficiency of chemical fuels is very low, and they cannot meet the requirements for long-term work.
You must know that 90% of the mass of a rocket is chemical fuel, and although the spacecraft has a speed of more than 10 kilometers per second, it still takes a long time to fly out of the solar system.
Take Voyager 1, for example, it flew in space at a speed of 17 kilometers per second, but by the time it flew out of the solar system, it was probably 18,000 years later.
Moreover, this is still the solar system, the diameter of the bank system is 100,000 light years, with this speed of more than ten kilometers per second, it is like a snail crawling in the vast universe, when will it be able to leave the galaxy.
And this is still to ensure that there is a chance to fly out of the galaxy under the premise of continuous power, but with the current level of scientific and technological development of human beings, it is simply impossible to complete the power of continuous navigation, of course, this is also one thing.
In addition to the inability of humans to provide the enormous energy and materials required to allow a spacecraft to fly for a long time and at high speeds, there is also no way to solve the food, water, and air needed by astronauts during long voyages.
Even if the above problems are solved, but looking at it, the global aerospace research is only a small part of the universe, and the boundless universe is unknown to us human beings.
We don't know whether the outer space environment is good or bad, dangerous or safe, and in outer space, there are many radiation, microgravity, cosmic rays, etc., all of which can cause serious damage to astronauts' bodies and spacecraft.
Putting these aside, there are also the effects of the external environment, such as meteorites, black holes, etc., which we often hear about, the speed of the spacecraft in front of the meteorite is simply insignificant, and if it is hit by meteorite fragments, it is likely to be fatal.
Black holes are even more terrifying, if you are unfortunate enough to encounter a black hole, in fact, there is no possibility of survival, after all, black holes are things that can even be absorbed into galaxies, these factors undoubtedly increase the difficulty for human beings to leave the galaxy, and increase many risks.
Of course, if our human science and technology can develop to a certain extent, it is only a matter of time to realize intergalactic travel, according to the theory of relativity, time passes more slowly in a moving frame of reference, as long as the time dilation effect, intergalactic travel is also possible.
Let's put it this way, as long as the speed of the spacecraft can reach 99.99999999999992% of the speed of light, it only takes a year to fly to the Andromeda galaxy 2.5 million light-years away, but for our human concept, it takes about 2.5 million years for a spaceship to fly to the Andromeda Galaxy.
So this has always been just an idea, if you want the spacecraft to accelerate to a sub-light speed state in a very short time, you must have a very large acceleration, not to mention whether the spacecraft can withstand it, but the human body can't bear it at all.
After all, that level of pressure is enough to tear the human body apart, but it is not unachievable, the gravity we receive on the earth is about 1g, and the human body is used to the environment of 1g acceleration, if the spacecraft can fly with 1g acceleration all the time.
So long-term space voyage is actually capable of doing it, through big data calculations, if the spacecraft continues to accelerate 1.25 million light-years according to 1g acceleration, and then decelerates continuously by 1.25 million light-years with the same acceleration, then the spacecraft can fly to the Andromeda galaxy in about 29 years.
Of course, according to the current technology, we may not be able to solve it, but there is another way to complete the interstellar crossing, and the method is particularly efficient, that is, through the wormhole, according to the prediction of general relativity, as long as you can pass through the wormhole, you can achieve interstellar crossing.
We have only seen this method in movies, and whether it is feasible or not has to be further studied and proven by us human beings.
However, for experts, using these wormhole theories and warp engines to realize the passage through space is just a kind of reasoning made according to scientific principles, and more directly it is a kind of utopia.