Bernardo Rivero

Charge sitting on a metal body spreads out over the outside and the field inside cancels, so a lightning strike runs along the shell and into the ground. Faraday saw this effect two centuries ago, and it explains more than storms. It is why a phone call can drop in a lift, why microwave oven doors have a mesh you can see through yet radiation cannot cross, and why cables are wrapped in braided metal. The holes only need to be much smaller than the wave. That also means a convertible or a fibreglass body gives no such protection.

How do you prove the Earth spins without leaving the room? Léon Foucault hung a heavy weight on a long wire in 1851 and let it swing. Nothing pushes it sideways, so it keeps swinging in the same plane, yet the floor slowly turns beneath it and the swing seems to rotate. The crowd in Paris watched a ring of pegs fall one by one as the plane moved across them. Spin rate depends on latitude: at a pole the plane turns once a day, at the equator it never turns. The effect comes from the Coriolis force, the same one that steers hurricanes.

What is colder than outer space itself? A cloud of gas called the Boomerang Nebula. It blows gas away so fast that it cools below the faint afterglow of the Big Bang that fills the rest of the sky, making it the coldest known natural place. At the other end, the Large Hadron Collider smashes lead nuclei together to make a droplet of quark-gluon plasma, the kind of matter that filled the universe in its first microseconds. It lives for a tiny fraction of a second. Lord Kelvin proposed measuring temperature from absolute zero in 1848, which is why this ladder starts at the floor of the scale.