You sneeze, and your head jerks. A friend slaps you on the back, and you lurch forward.
These experiences create g-forces, or gravity forces, five times greater than the gravity you usually feel. Each one lasts only a second, so you don’t really notice them. But if they lasted longer, you would definitely feel their effects.
It’s the same in a microgravity, or near-weightless, environment. If you could spend just a few seconds in microgravity, it wouldn’t have an effect on your body. But let’s say you’re on the International Space Station (ISS). If you were up there for any length of time, you would notice the effects.
