On April 21st, Japan's new, state-of-the-art L0 Series maglev bullet train obliterated its own week-old record for world's fastest manned train, hitting a mind-blowing 375 mph. It's no secret bullet trains* are incredibly badass, but did you know they go so fast they make a sound loosely similar to a sonic boom? Or that some of the most advanced trains use cryogenic cooling to make things more efficient? These are 15 things you never knew about bullet trains.
* "Bullet train" refers to the high-speed trains on the Shinkansen lines in Japan. However, most people also consider several other high-speed rail lines to be bullet trains, so the focus here will be more than strictly Japanese.