How far away is the Sun?

Глава 1Light takes timeYou know your street and your city. But how far is it to the next big house in the neighborhood — the Sun? Nobody has ever been there, and nobody has sent a tape measure. And yet we know its average distance to within a few meters.0 из 1 уровней

Глава 2Measuring the skyNobody has walked to the Sun or a star. So how do we know how far they are? With a thumb, a planet crossing the Sun and a lot of patience.0 из 3 уровней

1. Уровень 1Light takes its time
2. ГОТОВУровень 2Measuring with your thumb
3. ГОТОВУровень 3A light-year is a distance
4. ГОТОВУровень 4Closer means faster