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Asked by samwhitepro to Adam, Joanna, Louise S, Louise W, Marcus on 19 Nov 2012.
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Joanna Giles answered on 19 Nov 2012:
Hi Samwhitepro!
If Isaac Newton did not sit under a tree, and an apple didn’t hit him on the head, and he didn’t come up with the his famous gravitational law – we would still have gravity.
You probably normally think “Gravity is why I’m not floating around off the ground” but it is so much more than that. Gravity is the attraction force between two objects (or masses), so it’s not only why your body is attracted to the ground it is also why the moon doesn’t spin out of orbit – The Earth’s gravity holds the moon in orbit, so it can’t just go off in a straight line. So,if you were holding a ball on a string and spinning it around you in a circle. If you were to cut that string (which would be the same as no more gravity), the ball would fly off.
The moon has gravity upon it too – but because it is so much smaller than the Earth, the force between the moon and the person is much less. That is why you would have seen Astronauts doing ginormous jumps on the moon and floating a lot more than on Earth!
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Louise Walkin answered on 19 Nov 2012:
Hello! Yes, even if we hadn’t discovered it it would still be here making sure that the things we drop hit the ground! Gravity exists everywhere in the universe but it has different strengths which like Joanna said is the reason why you can bounce around so easily on the moon. The strength of gravity reduces with distance but we do have a gravitational pull from the sun and we also have a gravitational pull from the moon – this is what causes the tides in the sea! 🙂
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Adam Paige answered on 19 Nov 2012:
It is true that gravity would exist whether Newton discovered the maths of it or not. But if we didnt have a THEORY of gravity we would not understand how planets move or how much energy would be needed to escape the gravitational pull of the Earth. So we would not have space travel or air travel. We would not have satellites in orbit above the earth so we would not have mobile phone technology, sat navs or google earth.
We also would not have Einstein’s theory of relativity, or a knowledge of black holes or astrophysics, or indeed a Big Bang model. All of these are based on gravitation.
All in all, the world would be a much poorer place without the discovery of the law of gravity.
Comments
Robert commented on :
Did you know Newton’s theory of gravity was scorned by some? Because although he said that there was a force between two objects, he didn’t say what actually drove the objects together.
Interesting, in these days of the Higgs boson…