We often hear people say: “seeing is believing, hearing is believing”. Maybe many people think this sentence is right. Only what they see with their own eyes is true. But many examples tell us that seeing is not necessarily believing, and eyes can deceive people. Take some simple examples, such as some magic tricks, some gamblers in casinos, you stare at each other, what do you think What you see is true, but in fact your eyes have been cheated, and the result is often false.
This is an example in real life. It would be more correct to use what you see in astronomy rather than in space exploration. Jillian Scudder, Professor of the University of Sussex in the UK, explained that human’s understanding of external things is affected by both light and space.
Although the speed of light is very fast, it also needs a medium and a certain time for it to travel in the air. What we see in front of us is not its real-time state, but its past state. At the same time, due to the effect of external forces, space will be distorted to varying degrees, which makes the form of things we see more unlikely to be its real form.
The distance between the stars in the universe is very far. Let’s take Mars, which is relatively close to the earth, as an example. Human beings observe Mars on the earth through the reaction of light. Astronomers calculate that it takes about 40 minutes for light to go from the earth to Mars, and then return to the earth from Mars, based on the longest distance from Mars to the earth.
Although a planet generally will not change greatly, even if it has passed thousands of years, some planets may only change slightly, but from the microscopic point of view, the microscopic particles that make up the planet are changing all the time. Therefore, Mars 40 minutes ago is completely different from Mars 40 minutes later, and the Mars we see is not its real-time state.
Mars is relatively close to us. It takes 40 minutes for light to travel back and forth. If it’s a distant planet, it will take longer time for light to travel back and forth, at least a few years, many decades, hundreds of years or even thousands of years. Therefore, when we observe the celestial bodies in the deep universe, we often see their past forms. If the stars are very far away, we may see what they looked like tens of thousands of years ago. We don’t know what they are now.
There are some star bursts in the universe. We can’t see the real-time situation. When we can observe them, it may have been hundreds of millions of years or even billions of years. Therefore, the universe we see is not the present universe, nor the most real universe. It is only a miniature of the past universe. Because things are constantly changing and developing, the past universe can not completely represent the present universe.
The exploration of the universe ultimately needs field investigation to determine the real situation, but this is affected by the speed. With our current human science and technology, it is impossible to go to the field to explore these celestial bodies in the depth of the universe. Only in the future, when the speed of human spaceship reaches the speed of light or even breaks through the speed of light, we can fly faster than the speed of light. Maybe we can watch it in real time To the real universe, some celestial bodies and scenes in the depths of the universe are no longer illusions for human beings, and it is not only to see the past, but to cross the space and reach the target position for real-time observation, so that we can see what the real celestial bodies are like.
I believe that in the future, human beings can do it. We are looking forward to this day.