The billion-frames-per-second camera does not work like a normal camera... It is not a camera capturing an image every billionth of a second. They fire the flash and take a picture. They fire the flash and take another picture delayed by a billionth of a second. They keep doing that until they build up enough frames to string together a movie. You cannot record something moving because there may be a second-or-two between "consecutive" images. The molecules of everything move way more than you would think in the time between shots.
The billion-frames-per-second camera does not work like a normal camera... It is not a camera capturing an image every billionth of a second. They fire the flash and take a picture. They fire the flash and take another picture delayed by a billionth of a second. They keep doing that until they build up enough frames to string together a movie. You cannot record something moving because there may be a second-or-two between "consecutive" images. The molecules of everything move way more than you would think in the time between shots.