Reputation
3,277
Next privilege 5,000 Rep.
Approve tag wiki edits
Badges
12 19
Newest
 Good Answer
Impact
~72k people reached

  • 0 posts edited
  • 0 helpful flags
  • 46 votes cast
Nov
13
comment Are the physical laws scale-dependent?
@j.c.: you're correct, on both counts: i did have something else in mind; and the $\epsilon$-expansion is very good thing to keep in mind. ;-)
Nov
13
comment Are the physical laws scale-dependent?
It's very hard to find non-trivial solutions to the Renormalization Group eqs; in the end of the day, they are the ones that end up determining how a certain phenomenon in a given scale will behave in another. But, i'm not sure i'd go as far as saying "never"… but it is pretty hard.
Nov
13
comment Are the physical laws scale-dependent?
@Sklivvz: this is far from being a matter of opinion: there are macroscopic quantum effects: Bose-Einsein condensates being a good example.
Nov
13
comment Are the physical laws scale-dependent?
@Sklivvz: it's not true that wavefunction collapse is related to scale; see quantum decoherence. For more on this, see my answer below.
Nov
13
comment Are the physical laws scale-dependent?
@mbq: show me a single "Newtonian dynamics" effect that predicts the phenomena of Radiation decay, e.g., X-Ray radiation. Yet, its effects are very "macroscopic": you can get your X-Ray slide with you and show it to your doctor. Radiation decay is a purely quantum effect.
Nov
13
answered Are the physical laws scale-dependent?
Nov
13
comment Are the physical laws scale-dependent?
Sklivvz: the statement of "scale independence" in Physics is usually associated to Conformal symmetry, ie, whether or not the theory in have in hand has conformal symmetry. In this sense, GR is scale dependent, for not all solutions of Einstein's Field Equations are conformally symmetric.
Nov
13
answered Is a “third quantization” possible?
Nov
13
answered Monte Carlo use
Nov
13
awarded  Commentator
Nov
13
comment What is an “Idea” in terms of time space and matter?
@LarsH: That's why i made a point, above, about "Representation Theory". Physics consists of the modeling of physical reality through a certain 'representation' of the phenomena at hand. In this sense, your criticism would not hold.
Nov
13
comment What is an “Idea” in terms of time space and matter?
@Gerard: i don't think you understood the question: it's not asking how ideas play along in Physics, but rather what they are "made" of.
Nov
12
comment What is an “Idea” in terms of time space and matter?
@DavidZ: I tend to agree with you, with only one exception: "Representation Theory". All objects in Physics have a certain representation that ultimately grants us calculational power. If this discussion here will be about different ways to represent information, i think it should be allowed. Otherwise...
Nov
12
answered Evolution in the interpretation of the Dirac equation
Nov
12
comment Is energy really conserved?
@coneslayer: that's a good example. The principle behind the calculation that Sean performs is what i mentioned above, "global hyperbolicity". In some general grounds, you can think of it this way: if changing reference frames can change your matter content, why would the number of particles remain constant?
Nov
12
answered What is an “Idea” in terms of time space and matter?
Nov
12
answered Is energy really conserved?
Nov
11
answered Books for linear operator and spectral theory
Nov
11
answered What is necessary for a causal set to be manifold-like?
Nov
11
comment Is it possible/correct to describe electromagnetism using curved space(-time)?
Just to add a reference to Eric's answer: Maxwell's Eqs in Curved Spacetimes.