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visits member for 2 years
seen Feb 11 at 12:25

Nov
7
comment Thermodynamics and cross entropy
Sorry, but I don't understand. You are telling me that if I put a system of T1 in contact with a bath of T2 the work I can extract is different from putting a system of T2 in contact with a bath of T1?
Nov
7
comment Thermodynamics and cross entropy
I have a doubt. If Dkl represents the maximum work we can extract from two thermodynamic bath, why it is not symmetric? Namely Dkl(Q|P)/=Dkl(P|Q).
Nov
12
comment Vacuum energy and perpetual motion
Thanx, anna but i know the problem of conserved quantity in curved spaces. In my opinion the question is actually more subtle, because in our universe we can define a universal time, indeed we can speak of the age of the universe.
Nov
9
comment How relative humidity and temperature affect rainfalls
Good answer, but lacking of one point. Why is relative humidity more imortant then absolute humidity in precipitacion levels?
Jul
28
comment Identifying a critical phenomena?
@RonMaimon first order transition are included because i say very clear "...mean or variance, of some physical quantity, are not finite" namely first and second order transition.
Jul
13
comment Funny recurrence in escape velocity calculation of some planets
i am sorry, i guessed that 1h is one hour in all the world. This question is not on the calculation of escape velocity, but in the strange feature of it so i quit the basic formula $\sqrt{2G M/r}$.
Jul
5
comment Dimension of vector resulting from tensorial product
@Pepx depends on the subset of matrix you are talking about (symmetric, antisymmetric, unitary...). In the most general case the dimension is indeed n*c.
Jul
5
comment Dimension of vector resulting from tensorial product
@Pepx look here en.wikipedia.org/wiki/Cross_product . Anyway the right definition is that of Cristoph.
Jul
5
comment Dimension of vector resulting from tensorial product
@Karsus matrix is only a square table of numbers. Then depending on the way they tranforms we can call in a different ways.
Jul
5
comment What is the relationship between Energy, Entropy, and Information?
Entropy measure the total variation of energy. If the system is going on a more foundamental state loose a part of energy and entropy increase, on contrary entropy is diminished.
Jun
9
comment Hipothetical universe history with power law distributed matter
Ok, sorry. What i mean is that matter and light form "clusters" with no characteristic length.
Jun
9
comment Wick rotation and the arrow of time
Bar Mosche What does it means from the physical point of view?
Jun
8
comment Lacking of scale and distribution moments
@LubosMotl I did not understand your last statement, by definition a distribution has to satisfy $\int_{\Omega}f(x)dx=1$. So what you mean when you saying "normalizable distribution"?
Jun
7
comment Lacking of scale and distribution moments
yes i know this property, but i am talking of distributions. As you almost surely knows every distribution with not finite variance behaves asymptotically as a power law (stable distributions). Anyway you almost convinced me.
Jun
5
comment Lacking of scale and distribution moments
@LubosMotl well, can you post a reference?
Jun
5
comment Lacking of scale and distribution moments
@LuboŇ°Motl i'm sorry but i strongly disagree with your argumentation, if they are scale free you cannot take any dimensional argument as possible solution.
Jun
5
comment Lacking of scale and distribution moments
@Lubos Moti ...i don't agree. Imagine a random variable y that is power law distributed (You say that there is not a characteristic scale due scaling property). If i take a sum of N random power law distributed variables, the resulting distribution lacks the power law shape. From your point of view this means that the sum of N scale free random variable can generate a non scale free random variable. mmm I don't think so.
May
29
comment Identifying a critical phenomena?
i think so. the problem is that to show that the mean or variance in the data are not finite is not trivial.
May
9
comment The meaning of scale invariance in power law distribution
you can build distribution without mean and variance that are not scale invariant. See stable distributions on wikipedia.
May
9
comment The meaning of scale invariance in power law distribution
I think that there is an error on your changing the limits of integration.