2,986 reputation
817
bio website about.me/danieldf
location Providence, RI
age 38
visits member for 3 years, 9 months
seen Feb 22 '13 at 21:12

Feb
2
answered Your favorite Physics/Astrophysics blogs?
Feb
2
answered How could spacetime become discretised at the Planck scale?
Feb
2
comment Give a description of Loop Quantum Gravity your grandmother could understand
@Marek: that's exactly right: the term "loops" come precisely from this decomposition in terms of Ashtekar variables and how they relate to Wilson loops, etc. In this sense, i think it's very fitting that both, String Theory and LQG, hinge on the same object: flux algebras. ;-) (Glad to be back! :-)
Feb
2
answered How do we resolve operator ordering ambiguities when quantizing generic nonlinear second-class constraints?
Feb
2
answered Give a description of Loop Quantum Gravity your grandmother could understand
Dec
9
awarded  Precognitive
Nov
25
comment Can special relativity be deduced from $E=mc^2$?
@David: I had the low speed expansion in mind when i made the comment above — of course, the case where $p = 0$ is contained in this expansion. ;-)
Nov
25
answered Correspondence principle
Nov
24
answered Can special relativity be deduced from $E=mc^2$?
Nov
23
comment Introductions to discrete space-time
@mtrencseni: Yup. But, i think you can understand CDTs as a Discrete Differential Geometry endowed with a Causal Structure. So, in the sense of "reducing to the basics", i think it'd be best to understand what it means to discretize geometrical objects (eg, Diff Forms), and then add causality to the mix.
Nov
23
comment Why is it hopeless to view differential geometry as the limit of a discrete geometry?
@dmckee @Hans: Discrete Differential Geometry is the name of the game — there's much that can be done.
Nov
23
comment Why is it hopeless to view differential geometry as the limit of a discrete geometry?
@Hans: when you say that $\hbar\rightarrow 0$ recovers classical mechanics, i objected, correct? So, i provided a link to explain the tip of the iceberg behind my objection.
Nov
23
revised Introductions to discrete space-time
added 170 characters in body
Nov
23
comment Why is it hopeless to view differential geometry as the limit of a discrete geometry?
@Hans: you can look for decoherence in quantum mechanics and also Bose-Einstein condensates, etc.
Nov
23
comment Why is it hopeless to view differential geometry as the limit of a discrete geometry?
@dmckee: i just saw the other question... it would have been nice to know this beforehand though, ie, it would have been nice to have had this information in the question, so we're not lost. Thanks for the 'heads up'. :-)
Nov
23
answered Introductions to discrete space-time
Nov
23
answered Why is it hopeless to view differential geometry as the limit of a discrete geometry?
Nov
23
answered Are gauge choices in electrodynamics really always possible?
Nov
17
comment How does gravity escape a black hole?
@Nogwater: Even though DavidZ already answered, i just want to offer my 2¢: things that happen inside a black hole (eg, mass increase) affect the curvature of spacetime, and this can be measured from the outside. You can choose to understand this via the Holographic Principle, but you don't necessarily need to: it's vanilla Differential Geometry (and Topology).
Nov
17
awarded  Nice Answer