Transcript

NARRATOR:

60 Second Adventures in Microgravity. Number 1, What Is Microgravity? Gravity is pretty useful. It keeps our feet on the ground, ensures the Earth orbits the Sun, and shapes the whole universe. But sometimes it would be really handy if it wasn't there, because when gravity acts on something, there is always an effect, usually from the other forces counteracting it-- like the ground pushing back on us, which we perceive as weight.

So to understand many physical and biological processes, it would be better to take gravity out of the equation. But that's impossible. So instead, we create an environment on Earth in which, as far as possible, all these other forces are balanced out so the thing we're studying appears to be weightless. We call this environment microgravity.

There are many ways to achieve microgravity, but one of the simplest is by using something called a drop tower, which is, well, a tower you drop things off. So relative to each other, objects become weightless and are in an environment of microgravity, but only for a few seconds, until they're back down to Earth with a bang.