Who decides how long a second is? - John Kitching
6:16
Einstein's twin paradox explained - Amber Stuver
5:16
How fast is the speed of thought? - Seena Mathew
7:21
Who Invented the Metric System (and Why It Isn’t As Perfect as You Think)
5:49
Why can't you put metal in a microwave? - Aaron Slepkov
17:35
How a quartz watch works - its heart beats 32,768 times a second
23:51
Por Que esse Número Está em Todo Canto?
7:59
The Obscure System That Syncs All The World’s Clocks
5:22