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Asked by to Dre, Charli, Heather, Oliver, Becky on 25 Jun 2014. This question was also asked by .
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Rebecca Williams answered on 25 Jun 2014:
Gravity is a force that attracts things to each other. We are attracted to the centre of the Earth, so if we trip, we fall down. The moon is attracted to the Earth, so it goes around us in a big circle.
Your favourite scientist Einstein, realised that this force was actually space getting warped around a big object. Imagine sitting in the middle of a trampoline – you will make the trampoline dip down. The Earth makes the space around it dip down. This animation here shows that
So, gravity isn’t something that is created. It is the effect that objects have on the space around them. Gravity is stronger near really big objects, like the Earth. But we all have some gravity. So, you too have gravity! But you’re very small, so your gravity is very weak.
But, we don’t really know what gravity really is. There is a whole field of physics who study this very question!
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Charlotte Flavell answered on 25 Jun 2014:
This is a really interesting question – one that I had to look up, as anything about space is waaay out of my comfort zone 🙂
Becky has already given a really good description of what gravity is so I won’t go over that again, but the second part of your question “why can’t we reproduce it” is interesting.
It would be really useful if we could make artificial gravity as astronauts on space stations wouldn’t have to contend with all that bothersome floating about. Instead, they’d be able to walk around normally and pour themselves a proper cup of tea (which I am sure is the foremost problem on their minds).
While building a space station that is big enough to have it’s own gravity (i.e. planet-sized) probably isn’t realistic, scientists think that a good way to simulate gravity might be to use the force from acceleration or centrifugal force.
The force from acceleration (going faster) you experience when you get on a roller coaster or drive fast in a car. That feeling of being pushed back into your seat. If you were on a space ship that was constantly accelerating there would be enough force to keep your feet on the ground. The problem with this is that you tend to run out fuel pretty quickly!
The other option, centrifugal force, happens when you spin around. Think about the tea cups or the waltzers. When you spin around, you are pushed towards the walls of your tea cup ride. It is possible that a rotating space ship could be built that spins just enough so that we can use that force to walk about.
Neither of these things actually exist in space missions yet, but this is how scientists think we could solve the problems of zero gravity environments…
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