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bio website dotancohen.com
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age 37
visits member for 3 years, 8 months
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Jun
29
comment Does water in the drain follow the distance-squared rule of force?
Thank you John. Linear variation sounds to me as though the soap is spinning as a solid mass, which in retrospect does seem to be the case as I don't notice the shape changing as it spins. How then do the spiral arms form?
Jun
29
revised Does water in the drain follow the distance-squared rule of force?
deleted 17 characters in body
Jun
29
revised Does water in the drain follow the distance-squared rule of force?
added 14 characters in body
Jun
29
accepted Is the environment around an asteroid harsher than in interplanetary space?
Jun
29
asked Does water in the drain follow the distance-squared rule of force?
Jun
27
comment Do observers at different speeds perceive other speeds differently?
And things get even more interesting as the train and/or ball approach the speed of light!
Jun
19
comment Can a planet have a larger diameter than Jupiter?
@M.Na'el: Smaller: less diameter. More massive: more mass. In the same sense that Mercury is smaller but more massive than Ganymede.
Jun
18
awarded  Nice Question
Jun
18
comment Can a planet have a larger diameter than Jupiter?
svn copy -r 42 system://solar Jupiter is just complaining Unrecognized URL scheme for 'system://solar'. What is the URL scheme to get the old version?
Jun
18
comment Can a planet have a larger diameter than Jupiter?
I see, thanks. That sounds like a sound method.
Jun
18
comment Can a planet have a larger diameter than Jupiter?
That paper is a terrific read! I was able to finish it in under 5 minutes and I feel that I comprehended it all, even as a layman. I should read more papers from 1969!
Jun
18
comment Can a planet have a larger diameter than Jupiter?
Thank you Frédéric!
Jun
18
accepted Can a planet have a larger diameter than Jupiter?
Jun
18
comment Can a planet have a larger diameter than Jupiter?
Thank you Terry.
Jun
18
asked Can a planet have a larger diameter than Jupiter?
Jun
9
revised Can human push earth away from the sun?
added 81 characters in body
Jun
9
comment Can human push earth away from the sun?
Thank you for adding that, Anna. I have heard both arguments: that the Earth is approaching and that the Earth is receding from the Sun.
Jun
9
comment Can human push earth away from the sun?
Actually, there is nothing confusing about it. At the point in the orbit where you apply the acceleration the Earth will be moving faster. On the other side of the orbit the Earth will be moving slower, though. Of course, the distance from the Sun at that point will be larger, and that is where you see the extra energy. You can then perform a second manoeuvre at that slower, further point to push the opposite (closer, faster point) out further from the Sun.
Jun
9
awarded  Editor
Jun
9
comment Can human push earth away from the sun?
@Xiè: It is not a matter of efficiency but rather changing the shape (eccentricity) of the orbit and therefore the distance from the Sun (two manoeuvres). You should read the linked article on orbital mechanics.