When I was talking about balancing a stick, I mentioned the moment of inertia. Moment of inertia is different than mass, but I like to call it the “rotational mass”. What does mass do? Things with ...

When you think of space missions, you might think of humans walking on the moon or rovers rolling around on Mars. But there's a whole bunch of other awesome space missions too. One of these events was ...

The rotation of stars in galaxies such as our Milky Way is puzzling. The orbital speeds of stars should decrease with their distance from the center of the galaxy, but in fact they all have the same ...