We want to reach the stars. 

But, how fast do spaceships go? The ISS moves at almost 28 000 km per hour. And to leave earth a rocket needs to get up to about 40 000 km, per hour. So if we are talking about going to Alpha

Centauri, our closest naighbour, 4.5 lightyears away, even with the fastest spaceship on the market it would take tens of thousands of years to get there. Light, on the other hand, just a few years - the speed of light is 300 000 km / second. But to go that fast you would have to lose all your mass, which you can't. But what if we tried to make a spaceship as small as possible?

Avi Loeb is a professor at Harvard, and one of the minds behind a project called Breakthrough Starshot Initiative! 

Hosted by Ausha. See ausha.co/privacy-policy for more information.