6:19
How to Measure the size of Earth!
The Gentleman Physicist
4:58
We Got The Radius Of The Earth!
1:46
A Challenge Involving Hobgoblins.
5:02
Foucault's Pendulum: Watch the world turn.
1:50
A challenge of glass melting proportions!
7:37
Is Molten Glass Transparent?
4:19
A Magnetic Challenge & Some Great Channels.
4:55
The Magnetic Challenge Answered!
