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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.


Jun
17
comment Why isn't the best case classical solution to the CHSH game 100%?
This is getting silly. How can a question about the CHSH game be off topic on a physics site? The idea that questions have to be "about physics" has always been a bit flaky (i.e. blatantly subjective), but if you're going to draw the line here it's just ridiculous.
Jun
16
revised How do I create a direct current with a magnet? The magnet is not to be moved in the direction of the wire
edited tags
Jun
16
comment Reconciling “The Big Crunch” with the 2nd Law of Thermodynamics
Huw Price discussed this subject in depth in his 1996 book Time's Arrow and Archimedes' Point (prce.hu/w/TAAP.html). Price argues that entropy must indeed decrease in a big crunch, because it is the time reverse of a big bang, in which entropy increases. Note, however, that due to more recent observations the expansion of the universe is now thought to be accelerating (the cause of which is unknown but is referred to as "dark energy"), so it is no longer thought that a big crunch will occur. (This does not resolve the question, however!)
Jun
13
comment At an instant, does a system of gravitational charges exhibit equivalent behavior to a time-reversed system of like electric charges?
@SpacetimeEngineer entropy doesn't have anything to do with it. I illustrated my answer with a two-body system in order to male that clear. There are no entropic effects in a two-body system, and hence the time reverse looks much like the forward version. Of course I can't construct an orbital system out of like charges, but that only supports my argument.
Jun
12
comment At an instant, does a system of gravitational charges exhibit equivalent behavior to a time-reversed system of like electric charges?
That isn't correct though. Two like charges initially at rest will accelerate away from one another. Play it backwards and they decelerate as they move toward one another, implying a repulsive force and not an attractive one.
Jun
12
answered At an instant, does a system of gravitational charges exhibit equivalent behavior to a time-reversed system of like electric charges?
Jun
12
comment What is the motivation for introducing “ontological state” in 't Hooft's deterministic quantum mechanics
From reading a few of 't Hooft's papers a while ago, I got the impression his motivation was very similar to what I wrote. I guess the part I didn't answer was "would the Schrodinger equation itself to be sufficient, since it is already deterministic anyway?". If I get time I will try to formulate a good answer to that and post it.
Jun
12
comment What is the motivation for introducing “ontological state” in 't Hooft's deterministic quantum mechanics
I gave an answer to a similar question a while ago (since migrated to Philosophy.SE) which you might find helpful. philosophy.stackexchange.com/q/6670
Jun
11
comment What is a real world application of Madam Curie's life work?
Are you looking for real-world applications of radioactivity (in which case it's a fairly easy question to answer), or do you mean something else?
Jun
10
comment Entropy was created after inflation?
I don't know much about cosmology (so this is a comment not an answer), but entropy is not a form of energy. Entropy gets created by lots of processes (for example: mixing fluids, cooking eggs, applying the brakes, letting a hot object cool down), and it doesn't break the first law. In this case I would guess that energy is converted into heat from some other form.
Jun
10
comment What makes running so much less energy-efficient than bicycling?
@WetSavannaAnimal that's kind of an amusing image - I like it - but it's hard to imagine how the two organisms could conspire to exert a continual torque on the axle without running into the same problems a single organism would have...
Jun
9
comment Not Quasi-static, yet reversible process? Is this a valid example?
2. In principle there could be viscosity/friction operating during free expansion. This would result in a small increase in temperature. But in the ideal case there need not be - if the atoms are small enough you can assume there are no collisions at all. This results in the temperature remaining constant. But the process is still irreversible, even in the ideal case where there's no friction. There is no paradox here - friction is one possible cause of a process being irreversible, but there are many others.
Jun
9
comment Not Quasi-static, yet reversible process? Is this a valid example?
... The subtle thing is that for a photon gas, such a machine can be constructed, in the form of a curved mirror. So free expansion of a photon gas is considered reversible, but free expansion of a normal gas isn't, even though in many ways the processes are equivalent. But bear in mind that this is technically true for any irreversible process: if we could precisely reverse the molecules' motion, we could reverse it. (I say all this only for completeness. Your best bet is probably to ignore it most of the time; virtually all thermodynamics texts will just say the expansion is irreversible.)
Jun
9
comment Not Quasi-static, yet reversible process? Is this a valid example?
@user50166 it's no problem, don't worry! 1. that's quite a difficult and subtle question, but the usual way of looking it is that it's really the expansion itself that's irreversible. In free expansion the temperature remains constant, so there is actually no dissipation into heat as the gas hits the walls of its container and equilibrates. The subtle thing is that if you had a special machine that would reverse the motion of every particle then the gas would return to its initial state. But in practice no such machine is likely ever to exist, so we say expansion is irreversible...
Jun
9
comment Not Quasi-static, yet reversible process? Is this a valid example?
No, free expansion is a classic example of an irreversible process. The volume increases but the temperature remains constant, whereas in reversible (quasi-static) expansion the temperature decreases. The irreversibility is not due to friction, it's just due to an increase in the volume accessible to each particle.
Jun
9
answered Not Quasi-static, yet reversible process? Is this a valid example?
Jun
9
answered Will the black hole size increase?
Jun
7
revised (Special Relativity) Points that can be seen by an observer
edited tags
Jun
6
comment Of all the electrical energy used in a home, is there any portion that won't eventually become thermal energy in the home?
Air conditioning! I think that's the only one that's likely to be really significant.
Jun
6
comment Of all the electrical energy used in a home, is there any portion that won't eventually become thermal energy in the home?
Ah - of course the really significant one is air conditioning, which is specifically designed to cool the house and put heat outside. But I think if you're not using air conditioning, it's safe to say that the vast majority of power will become heat inside the home, at least for a time until it leaks out again.