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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.


May
26
revised Which planet in the solar system is it?
edited tags
May
26
answered Time travel outside of light cone without causality violation
May
26
comment Why do turbine engines work?
(Note that a pressure gradient will still cause a torque on the compressor, even if it opposes the flow.)
May
26
comment Why do turbine engines work?
"cause a greater amount of torque (in terms of absolute value)."
May
25
comment Why do turbine engines work?
I will make the same comment I made on John Rennie's answer. The question isn't "why doesn't the exhaust gas flow out through the compressor?" but "why does the pressure gradient from combusting the fuel push on the turbine more than it pushes (in the opposite direction) on the compressor?".
May
25
comment Why do turbine engines work?
I don't think this really answers the question. The question isn't "why doesn't the exhaust gas flow out through the compressor?" but "why does the pressure gradient from combusting the fuel push on the turbine more than it pushes (in the opposite direction) on the compressor?" If the flow is not supersonic, it's not unreasonable to think these two torques should be equal, even when there's air flowing through the engine. (And to be honest, I've never understood why they aren't either.)
May
25
revised What does an analog voice transmission look like in the visible spectrum?
added 372 characters in body
May
24
comment What does an analog voice transmission look like in the visible spectrum?
@brentonstribe I think you understand right, but you wouldn't lose any detail in the signal because as Davidmh says, the frequency of light is much higher than that of the audio signal modulating it. With a photodiode you can get the audio signal back, and in fact high-end amplifiers sometimes have circuits that do this, in order to isolate sensitive circuitry from possible power surges.
May
24
comment What does an analog voice transmission look like in the visible spectrum?
@davidmh yeah, Wikipedia says bass singers can only go down to about 80Hz. I'll update my answer when I get a chance.
May
23
comment Regarding the theory of the origin of water on earth through meteorites, why wouldn't the water evaporate on impact?
Of course it would evaporate, but then later the vast majority of it would condense again and fall as rain. As far as I'm aware it's not completely accepted that comets brought a substantial proportion of Earth's water, but it's a pretty mainstream theory.
May
23
revised What does an analog voice transmission look like in the visible spectrum?
added 286 characters in body
May
23
answered What does an analog voice transmission look like in the visible spectrum?
May
21
comment Natural units of information
Done. (I'd have done it before but I was in a hurry.)
May
21
revised Natural units of information
added 567 characters in body
May
20
comment Natural units of information
Yes, you're right, and in retrospect your post must be where I got it from. (I made notes on it at the time and it seems I forgot to make a note of where I found it - sorry about that.)
May
20
comment Intuitively, why does removing solutes cost $k_B T$ of free energy per molecule?
I have no idea if it's relevant or not (I think this is a great question!) but I recently came across a purely mathematical example of an entropy that comes to $\frac{1}{2}\log_2 e$ bits, or half a nat -- see my second answer here: physics.stackexchange.com/questions/91780/…
May
20
answered Natural units of information
May
20
comment Is there a conveniently small unit of volume for talking about molecules?
@KyleKanos I considered that, along with the average volume of a water molecule, but in the end I decided it's better to use the "standard" unit for this situation (if it exists), because if I train myself to think in terms of non-standard units it will become harder to communicate with other scientists.
May
20
comment Is there a conveniently small unit of volume for talking about molecules?
It's for considering volume changes rather than absolute volumes. Typically, volume changes are rather smaller than the volume of an individual molecule, unless the reaction involves a phase change to or from the gas state, in which case it goes up to $k_BT/p$ per molecule ($\approx 4\times 10^{-26}\;\mathrm{m^3}$ at standard $T$ and $p$). From working through a few examples, though, it seemed like it would be more convenient to use a smaller unit.
May
20
comment Is there a conveniently small unit of volume for talking about molecules?
$nm^3$ are a bit big, but actually I guess cubic Angstroms are probably the obvious choice, I just hadn't thought of it. (But the most important thing is whether people actually use those units for this purpose already.)