TED英文演说-人类如何才能到达恒星中英文演讲稿.docx

第 第 PAGE 1 页 How humanity can reach the stars 00:04 Were here at the University of California, Santa Barbara to discuss a dream of humanity: the ability to exit our solar system and enter another solar system. And the solution is literally before your eyes. 00:19 So I have two things on me that you have -- I have a watch, and I have a flashlight, which, if its not on you, its on your phone. So the watch keeps time, and my flashlight just illuminates my environment. So like art, to me, science is illuminating. I want to see reality in a different way. When I turn on the flashlight, suddenly the dark becomes bright, and I suddenly see. 00:40 The flashlight and its light, which you can see coming out -- the light on my hand is not only illuminating my hand, its actually pushing on my hand. Light carries energy and momentum. So the answer is not to make a spacecraft out of a flashlight, by having the exhaust come out this way and the spacecraft goes that way -- thats what we do today with chemistry. The answer is this: Take the flashlight and put it somewhere on the Earth, in orbit or on the Moon, and then shine it on a reflector, which propels the reflector to speeds which can approach the speed of light. 01:10 Well, how do you make a flashlight thats big enough? This isnt going to do it, my hand doesnt seem to be going anywhere. And thats because the force is very, very low. So the way that you can solve this problem is taking many, many flashlights, which are actually lasers, and synchronizing them in time, and when you gang them all together into a gigantic array, which we call a phased array, you then have a sufficiently powerful system, which, if you make it roughly the size of a city, it can push a spacecraft, which is roughly the size of your hand, to speeds which are roughly 25 percent the speed of light. That would enable us to get to the nearest star, Proxima Centauri, which is a little over four light years away, in less than 20 years. 01:53 Initial