Gravity The Film – But How Weightless is Outer Space?
Outer space is vast and inhospitable. Good reason for Oscar winning actors Sandra Bullock (49) and George Clooney (52) to venture out of Earth’s atmosphere into a seemingly simple, but in fact complex environment: weightlessness.
The Plot of Gravity-the-Film
Medical engineer Dr. Ryan Stone (Sandra Bullock) is on her first space mission, accompanied by veteran astronaut Matt Kowalski (George Clooney), who is commanding his final expedition. During a spacewalk, debris from a satellite crashes into their space craft destroying most of it and leaving them stranded in space with limited air. Tethered together, they start to make their way back to the International Space Station, which is in a nearby orbit. But this appears to be almost impossible on weightless conditions.
Outer Space Isn’t Weightless
What is weightlessness in fact? The attraction force of the Earth is one of the craziest forces in nature. It keeps us on the ground and forces everything falling back to the soil. And it is still there, even in space – weaker though, but never stopping. Strictly speaking, there is no weightless condition, because the Earth, Moon, planets, and the sun, they all pull and tug with their individual forces of gravity.
Bullock and Clooney float in space though, because another force is tearing at them: The force of acceleration makes everything moving away from Earth. Now, as long as gravity gets our heroes down and speed pushes them upwards with the same force, they won’t neither fall to the ground nor escape into the Universe – this is what we call weightlessness. But not only astronauts and the ISS benefit from zero-gravity. Every satellite orbiting our planet operates on that principle.
Satellites measure the invisible forces in space
There are hundreds of satellites flying above our heads. TV-satellites for example or weather satellites. In November, three new spacecraft will join: The ESA-satellites of the Swarm constellation circle our planet in three different orbits in order to precisely measure the magnetic field of the Earth. Magnetism is such a mysterious, invisible force, and we still don’t know much about it. Just as about gravity, the force discovered by the British mathematician Isaac Newton about 300 years ago.
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