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I'm a post-doctoral researcher with a wide range of interests. My career is in complex systems science (or maybe cybernetics) and the origins of life, but I also have research interests in

  • the foundations of statistical mechanics and its relationship to information theory
  • Earth systems science
  • non-equilibrium thermodynamics in general

I'm also generally interested in the foundations of quantum mechanics and in black holes, though I wouldn't say I'm an expert on those things.

It's probably worth noting that despite the fact that my research is in physics-related areas, all my degrees are in other subjects. If I occasionally seem to start talking in an alien language, this is probably why.


Jul
25
awarded  Nice Question
Jul
25
comment Drop a star in a river
See also physics.stackexchange.com/questions/37912/…
Jul
25
revised What is the easiest way to stop a star?
added the update
Jul
25
awarded  Enlightened
Jul
25
awarded  Guru
Jul
24
revised Is it better to build a space elevator from GEO down to the surface of the Earth?
added link, fixed some mistakes
Jul
24
comment Is it better to build a space elevator from GEO down to the surface of the Earth?
@FixedPoint this page has a diagram that should help explain what I meant in my previous comment, and also has lots of information on space elevators away from the equator.
Jul
24
comment Is it better to build a space elevator from GEO down to the surface of the Earth?
@FixedPoint I would guess that things get quite tricky as the base gets near the Earth's poles, because (in a frame of reference that rotates with the Earth) there are two forces acting on the cable: the centrifugal force pulling it at right-angles to the Earth's axis, and gravity pulling it towards the centre of the Earth. By the time you actually get to the pole, I imagine gravity will win out, making the cable lie flat against the ground for part of its length. (This depends on the weight of the cable and its geometry.) I imagine this puts a limit on how far from the equator you can get.
Jul
23
revised Is it better to build a space elevator from GEO down to the surface of the Earth?
added 408 characters in body
Jul
23
answered Is it better to build a space elevator from GEO down to the surface of the Earth?
Jul
23
revised Velocity of 2 balls with different masses on a moving train after the train brakes
added 50 characters in body
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
I've made some of my comments into an answer in case you want to accept that, or you're welcome to make your own if you prefer.
Jul
22
answered Velocity of 2 balls with different masses on a moving train after the train brakes
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
Although, some people will tell you you shouldn't use $F$ because there isn't "really" a force acting on the balls. But when you get to much more advanced physics (general relativity) you'll find that the use of $F$ in this sort of situation is unavoidable.
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
Yes, the argument in your comment on Akash's answer is correct.
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
I think it's intended as a trick question. If you haven't covered air resistance yet then the answer is "neither of them - they both move at the same speed", and unless your teacher was making some other assumptions that I don't know about, her argument is incorrect. In the train's reference frame they both get the same acceleration, so they move in the same way. It's exactly the same reason why (ignoring air resistance) the two balls would fall at the same speed if dropped from a tall building.
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
@YatharthROCK in the real world, a smooth surface doesn't imply no air resistance, of course - but in the idealised world of physics test questions, air resistance is often ignored unless it's specifically mentioned in the question. "Smooth surface" implies that you should ignore friction between the balls and the surface, and it would be a slightly odd question if they wanted you to ignore friction but take account of air resistance, especially without specifically mentioning it. (Though of course, if the book has covered air resistance recently then it's different.)
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
By the way I tagged it as homework according to the homework policy - but this is a good question according to that policy, so it won't be closed.
Jul
22
revised Velocity of 2 balls with different masses on a moving train after the train brakes
deleted 32 characters in body; edited tags
Jul
22
comment Velocity of 2 balls with different masses on a moving train after the train brakes
Since the question says "kept on the smooth surface", you're probably supposed to assume there are no forces acting on the balls at all.