If we don’t hold a glass tight enough in our hands, it will fall. It does not stay in the air and does not fly up, but – unfortunately – always lands on the ground. This is due to the laws of gravitational force: mass bodies attract each other. And because the earth has a very large mass, glasses fall.
Gravity, affects how we deal with everyday things. For a long time this approach seemed to us quite natural, because we knew nothing else than life on earth. Gravity has been there since the beginning of time.
How life changes when gravity is different?
We could only really see through space travel. The further we move away from the earth, the weaker its attraction. Gravity cannot be completely switched off, even in space.
Weightlessness, as we know it from videos from the International Space Station (ISS), only arises when gravity and centrifugal force cancel each other out there.
The centrifugal force comes about because the ISS moves around the earth in an orbit. It is also who pushes us against the outer wall in a carousel.
Life on the International Space Station differs fundamentally from our everyday life. The astronauts can let go of their glasses without falling. On the other hand, the morning shower is already a challenge: the water drops no longer fall down, but just float around.
How gravity affects our body?
Weightlessness sounds tempting if you have trouble getting up in the morning. But it has serious effects on our bodies, which make life in space extremely tiring.
Many astronauts suffer from disorientation in the first days in space because the sense of balance in the inner ear works with the help of gravity. Gravity on the moon is just enough for that. But in space we literally no longer know where is up and down.
In addition, astronauts experience circulatory problems and headaches. The reason behind this is a different distribution of body fluids.
The immune system also weakens under weightlessness. And the bones and muscles break down because they are hardly in use anymore. The astronauts have to exercise every day to counteract this effect. Still, when they are back on Earth, they need time to relax.
A jellyfish, on the other hand, which has no bones and muscles, collapses on land. So our body is perfectly adjusted to gravity on Earth. While the climate on our planet has changed over and over again, its gravity is the great constant for the evolution of living things.
Could we get used to a different kind of gravity or weightlessness? How long would it take? This cannot be answered today because there are no experiments in space spanning several generations. In fact, the question of what influence gravity has on our lives is one of the central research questions in space projects.
Incidentally, research on this topic is also carried out on Earth. As part of a bed rest study , the German Aerospace Center (DLR) is investigating how the body changes in weightlessness. Lay people can also participate.