who used math to show that the planets move in ellipes, not perfect circles, around the sun

Question

anonymous · Answer

Isaac newton, in a letter to his friend.

anonymous · Answer

http://www.youtube.com/watch?v=danYFxGnFxQ answer is at 1 minute

anonymous · Answer

The first to assert the planets moved in ellipses, based on observational data, was Johannes Kepler.  Isaac Newton was able to predict that the planets would move in ellipses if they (1) followed his rules of inertial motion, and (2) that motion were the result of his universal law of gravitation.

anonymous · Answer

So who used maths to show it?

anonymous · Answer

They both did, of course.  You can't reduce observational data to Kepler's First Law without using math.  But you also can't prove Kepler's First Law follows from F=ma and universal gravitation without math.  The "with math" part is kind of silly, honestly.  Without math, about all you can do in science is write down observations.  You can't draw any conclusions at all.

anonymous · Answer

I agree completely, but it seems the question is asking for one person.

anonymous · Answer

Quite a bad question really.

anonymous · Answer

I can't help that.  The question is badly worded.  It isn't clear if the questioner wants to know who showed the planets move in ellipses from direct observational data -- that would be Kepler -- or who showed they ought to theoretically, based on the best physics of the day -- which would be Newton.

You just have to know the context and the teacher to answer this question right.  It's unfortunate there isn't always an answer choice saying "This question is badly worded, and the person writing it should receive 10 lashes."  I'd pick that a lot.

anonymous · Answer

:)