# Can a spaceship fly at the speed of light? If it is realized, will it enter another time and space?

With the popularity of time travel novels, time travel movies and TV series in recent years, have you ever imagined that you could travel back to ancient times at some time to experience the life of the ancients? Now, let’s talk about whether we can travel through time and space through science and technology?

Once a scientist put forward a conjecture: if the speed of light can be exceeded, then time will go back. However, Einstein’s theory of relativity tells us that no object in the world can move faster than the speed of light. So how can we go faster than light?

There is an idea to build a spaceship, and its flight speed can be infinitely close to the speed of light. Because the speed of human and spaceship is relatively zero, so the speed of human motion can also be infinitely close to the speed of light. At this time, if humans run on the spaceship, then the absolute speed of humans will not exceed the speed of light?

Although this idea looks perfect, it is not feasible at present. The highest human record in the 100 meter race is 9.48 seconds, which is very small compared with the speed of light. To achieve this idea, the speed of the spacecraft can only be increased to infinitely close to the speed of light. According to Einstein’s mass energy equation E = MC ^ 2, all the energy of any object is contained in the mass at rest. If the object starts to move, the kinetic energy and other forms of energy generated in the motion will increase the mass of the object.

At this time, many people will question that in our daily life, the mass of objects is constant and will not change with the change of speed. But in fact, when the speed of an object is much lower than the speed of light, although the mass of the object will also increase, the increase in mass is so small that we can’t feel it at all. Relevant studies show that when the moving speed of an object reaches 10% of the speed of light, its mass growth is only 0.5% of the original mass.

The curve of mass proportional to velocity is not nonlinear, but increases geometrically. As the speed of an object gets closer to the speed of light, its added mass becomes larger and larger. In other words, when the speed of an object is infinitely close to the speed of light, its mass is infinite. According to f = ma, the closer the object is to the speed of light, the greater the energy required to accelerate, but the energy itself has mass. Therefore, according to our existing technology and theory, our spacecraft can not reach or even exceed the speed of light. Because photons have no mass, they can move at the speed of light.

However, no matter how fast the spaceship is, the speed of the people on the spaceship is still static compared with the spaceship. When the spaceship advances at a constant speed, people can move freely on the ship. But if the speed of the spacecraft reaches or even exceeds the speed of light, then the situation is different.

When the spaceship that the astronauts take reaches the speed of light, the space around them will disappear, and time will be still. That is to say, they will disappear into our world. No one can find them, maybe they have entered another universe, or they have entered another space-time, but they may never return to our world.

However, before they disappear, we will see them moving very slowly, because their time is getting slower. From the perspective of the observer, they may have disappeared in the world, but their images may still last for hundreds of thousands of years.

Xiaobian thinks that this superluminal spaceship may not be built in the next 10000 years. Because the speed of light is the ultimate speed of the universe, and it is a constant. If we want to exceed the speed of light, we must open up new ways. If the wormhole can be proved to exist, we may be able to achieve the speed of light in another way.

*What do you think of this? Welcome to comment area.*