Zero Gravity

Zero gravity means that you are totally weightless. Astronauts spend great lengths of time in zero gravity. Some of them has spent more than 170 days in orbit around the Earth.

It sure is fun to be weightless and floating on air, but what sort of problems are there in a zero gravity world? First of all you can forget the concept that "what goes up must come down!" So, that means anything you throw in any direction will continue it's way until it collides with something.

It doesn't matter how much does the object weight, because even the heaviest objects can be moved with a flick of the finger. In point of fact it's better to have large objects than small ones. Since everything you have can float away itself. The smaller the object, the bigger the risk of losing it. That's why in space stations every moveable objects has a marked place and they have their own magnets or Velcro tape to keep them in place.

Eating and drinking is also a problem in space. A glass of water quickly becomes a floating bubble. You can also forget about doing the washings and the necessary toilet-things by the conventional way. When it's time to go to bed, astronauts, in fact, sleep in zip-up bags attached to the walls, somewhat like bats.

Weightless conditions also cause some strange things inside the human body. Perhaps the worst thing is that the astronaut's bones start losing calcium quite fast. This makes the bones weaker and more fragile. That's why astronauts must take exercise while up in space. Nevertheless many astronauts find it difficult to walk for a few days after returning to Earth.

In future, if humans are going to stay in space for indefinite periods, science has to discover new solutions to these problems.

References: English Update Highlights 5, WSOY, 2000, s. 26-27