Mercury Practically Zero”

Humans have known about electricity for thousands of years, but it wasn’t until the turn of the 20th century when scientists finally discovered one of its most puzzling attributes. This millennia-long delay, in part, was because humans had no way of simulating temperatures approaching absolute zero, or -459.67 degrees Fahrenheit.

That changed on April 8, 1911, when Dutch physicist Heike Kamerlingh Onnes, while experimenting with liquid helium, plunged the metal Mercury all the way down to just 3 Kelvin. With his assistant soon shouting “zero, zero, still zero!” from a nearby room, Kamerlingh Onnes jotted in his notebook, “mercury practically zero,” a reference to the metal’s complete lack of electrical resistance.