#5minphysics 17 Weighing our Galaxy and Discovering Dark Matter

We return to classical physics today in #5minphysics and show how Newton's discovery of the Universal Law of Gravity on the basis of Kepler's earlier discovery about planetary motion allows us to directly weigh the Earth and Sun, and our Galaxy. Using the Sun's motion around the galaxy we can weigh the galaxy and we discover that it is at least 10 times heavier than can be accounted for by the mass in all the 100 billion stars that make it up. This was the first definitive evidence that the dominant matter in our Universe doesn't shine.

Видео #5minphysics 17 Weighing our Galaxy and Discovering Dark Matter канала Lawrence Krauss