Is there a good reason? Wouldn't it be better to stay on earth?

Hawking: Why do humans go into space? Wouldn't it be better to stay on earth?

1On the afternoon of October 5th, 1 17 Tencent WE Conference was held in Beijing today. Professor Stephen Hawking, a famous cosmologist and professor of physics at Cambridge University, gave a video speech.

Before the video started, Hawking first mentioned two questions. First of all, what do we need to do to ensure that the future of mankind is as perfect as possible within our power? Secondly, why should we consider exploring other livable planets?

"In the past two hundred years, the population growth rate has been exponential, that is, the population has increased at the same rate every year. At present, this value is about 1.9%.

This may not sound like a lot, but it means that the world population will double every forty years. This exponential growth cannot last into the next millennium. By 2600, the world will be crowded.

"Rubbing shoulders and rubbing heels", power consumption will turn the earth into a "hot" fireball. This is at stake. "

Hawking expressed his belief that we can avoid such an end of the world, and the best way is to emigrate to space and explore the possibility of human life on other planets. Just like Europe in 1492, exploring the new world had a far-reaching impact on the old world. The expansion of mankind into space will even have a far-reaching impact, which will completely change the future of mankind and even determine whether we have a future.

Hawking mentioned that the existence of life must be possible on other planets with suitable conditions. Even if this possibility is extremely small, but the universe is infinite, we can still assume that life will appear somewhere. However, if the probability is low, then the distance between the two planets where life appears may be extremely far away.

"Interstellar navigation must be a long-term goal. By long term, I mean the next 200 to 500 years. However, there is another option. Last year, I worked with entrepreneur yuri milner.

Milner), launched a long-term research and development plan-'breakthrough shooting stars', with the goal of making interstellar travel a reality. If successful, some of you here will send probes to Alpha Centauri, the nearest galaxy in the solar system, in your lifetime. Hawking said that "breaking through the stars" is the real opportunity for human beings to move into outer space at first, in order to explore and consider the possibility of moving into space. (Sina Technology)

The following is the original text of Hawking's speech:

Hello, Beijing! I'm Stephen Hawking. Welcome to Tencent WE Conference.

My speech today is about the role of the earth and human beings in the background of the universe. In order to explain it best, I need to start from two dimensions, one is to think about the future of mankind, and the other is to study our choice of exploring space and seeking other potentially livable planets. My purpose today is to ask you two questions. First of all, what do we need to do to ensure that the future of mankind is as perfect as possible within our power? Secondly, why should we consider exploring other livable planets?

One reason is that the earth has become too small for us. In the past two hundred years, the population growth rate has been exponential, that is, the population has increased at the same rate every year. At present, this value is about 1.9%.

This may not sound like a lot, but it means that the world population will double every forty years.

In 2022, I will celebrate my 80th birthday. During this period of my life, the population of the world has increased by four times compared with when I was born.

This exponential growth cannot last into the next millennium. By 2600, the world will be crowded, and electricity consumption will turn the earth into a "hot" fireball. This is at stake. However, I am an optimist. I believe that we can avoid such an end of the world, and the best way is to emigrate to space and explore the possibility of human life on other planets.

But is there a good reason? Wouldn't it be better to stay on earth?

To some extent, today's situation is like Europe before 1492. People at that time probably thought that Columbus's exploration was doomed to be futile.

However, the discovery of the new world had a far-reaching impact on the old world. For those who are deprived of their rights and status and have no way out, the new world has become their utopia. The expansion of mankind into space will even have a far-reaching impact, which will completely change the future of mankind and even determine whether we have a future. It will not solve any pressing problems on the earth, but it will provide a new perspective for solving these problems, so that we can focus on a broader space instead of sticking to the present. I hope this will unite us and face the same challenges.

What will we find when we go into space? Will we find extraterrestrial life, or will we eventually walk alone in the universe? We believe that life was born naturally on the earth, but after a long evolution, it has reached a high degree of harmony with the resources of the earth. Therefore, on other planets with suitable conditions, the existence of life must be possible. Even if this possibility is extremely small, but the universe is infinite, we can still assume that life will appear somewhere. However, if the probability is low, then the distance between the two planets where life appears may be extremely far away.

In the solar system, the moon and Mars are the most obvious choices for space immigrants. Mercury and Venus are too hot, while Jupiter and Saturn are giant gas planets with no solid surfaces. Mars' satellites are very small and are not better than Mars itself. Some moons of Jupiter and Saturn are also possible. For example, Europa, one of Jupiter's moons, has ice, but there may be liquid water below it, which may give birth to life. So how do we determine this possibility? Do I have to land in Europa and drill a hole?

Interstellar navigation must be a long-term goal. By long term, I mean the next 200 to 500 years.

However, there is another option. Last year, entrepreneur yuri milner and I launched a long-term R&D project-"Breakthrough Stargazing", with the goal of making interstellar travel a reality. If successful, some of you here will send probes to Alpha Centauri, the nearest galaxy in the solar system, in your lifetime.

"Breaking through the starry sky" is a real opportunity for mankind to go into outer space, in order to explore and consider the possibility of going into space.

This is a proof-of-concept task, involving three concepts: mini spacecraft,

Photodynamic propulsion and phase-locked laser. "Star Chip" is a fully functional space probe, its size has been reduced to only a few centimeters, and it will be attached to the "light sail". The "light sail" is made of metamaterials and weighs only a few grams. Let's imagine a thousand

A nano-aircraft consisting of a "star chip" and a "light sail" will be put into orbit.

On the ground, the laser array will form a super-strong beam, which will pass through the atmosphere and shoot at the "light sail" in space with tens of GW of power.

The idea behind this innovation is to use light beams to drive nano-planes forward. Although the speed generated in this way is not as fast as the speed of light, it can reach one-fifth of it, which is about 1 100 million miles per hour. Such a system can reach Mars in an hour, Pluto in a few days, Voyager in a week, and Alpha Centauri in 20 years. Importantly, the trajectory of the "star chip" may include "neighboring star B", a planet located in the livable zone of Alpha Centauri, which is similar in size to the Earth. It was in this year that Breakthrough Star cooperated with the European Southern Observatory to further explore the livable planet of Alpha Centauri.

At present, it seems that these may become a reality. But we also see great challenges. The laser of 1 GW can only provide a few newtons of thrust, but because the weight of nano-aircraft is only a few grams, it can just overcome this problem. But the engineering challenge is enormous. Nano-vehicles must experience extreme acceleration, extreme cold, vacuum and protons, as well as collisions with space dust and other garbage. In addition, due to the influence of atmospheric turbulence, it is very difficult to aim the laser group with the total power of 100 GW at the solar sail.

There are still some serious problems. How to make hundreds of lasers converge when they fluctuate in the atmosphere, how to push nano-aircraft without burning them, and how to aim them in the right direction? In addition, we need to let the nano-aircraft work in a cold vacuum environment for 20 years, so that they can send signals back to the earth four light years away. But these are all problems to be solved in engineering design, and engineering challenges can often be solved in the end. With the maturity of technological progress, we can expect more exciting tasks. If the "Breakthrough Shooting Stars" program can send back images of livable planets in neighboring galaxies, it will have a far-reaching impact on the future of mankind.

I hope I have answered the question I asked at the beginning of my speech. As an independent species, human beings have existed for about two million years. Our civilization began about 10,000 years ago, and its development has been steadily accelerating. If mankind wants to continue the next million years, it is necessary to boldly go forward and set foot in places that no one has ever been before!