615 reputation
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location London, United Kingdom
age 29
visits member for 3 years, 8 months
seen Sep 4 at 18:03

Phd student


Jun
6
comment What does cross-track wind mean?
@Georg: "You can English good enough.." Lol.
Jun
6
comment Formulas for ball rolling in a bowl?
Knowing a bit more about your background will help people to pitch answers at the right level. Are you familiar / comfortable with vector calculus? In what language are you attempting to program it in? How experienced with that language are you?
Jun
4
comment Can heat be transfered via magnetic field in a vacuum?
In light of the discussion ensuing from your answer I'll give you a (IMO) deserved +1. I'd like to see that calculation though.
May
27
comment Is it outside science to figure out the precise string compactification of our universe?
@Mitchell: The two comments you made in conversation with Peter Woit more than constitute an answer to the OP's question, and a good one at that. Transfer them over and I'll certainly give it +1 ;)
May
26
comment How does non-commutativity lead to uncertainty?
If I could nominate this answer for an award I would. Since there are none, +1 will have to suffice. Great job though.
May
24
comment Graduate Physics Problems Books
Take it you've thrown away all your old lecture notes, problem sheets and past papers then? They surely would be the best place to start.. I've given the question +1 all-the-same as I would also be interested in others' suggestions.
May
19
comment Solar System Capture of Orphan Planets
For the orbital period you mention, I'd imagine the effect on the Sun be very, very small indeed. Also, for a highly elliptical orbit, the magnitude of the effect must also depend on where on the ellipse this 'lonely' planet happened to be at the time; due to its varying angular velocity about the barycenter.
May
19
comment Do the laws of physics evolve?
@Dmckee: Regarding your first realated link - considering the fine structure constant in its capacity as the QED coupling, it scales logarithmically with energy; as a consequence of renomalization. Whilst its value at zero energy has been shown to be near-enough constant, for practical calculations at typical energies during the cosmic evolution it value has surely been diminishing as the Universe cools, no?
May
19
comment Do the laws of physics evolve?
Thanks @John. I did take a look but I'm always a bit sceptical of anything Smolin says. He has been known to come up with quite a few crack-pot theories over the years.
May
19
comment Do the laws of physics evolve?
B: Thanks for your answer. My intuition was that any change in the physical laws, whether we call that an evolution or not, would be a quasi-distrete change - perhaps corresponding to a change of state of the Universe as a whole (such as quark-gluon plasma => hadronized particle epoch.) I find it strange that the constants mentioned seem to change smoothly whereas the actual form of the equations seem to go from being applicable to non-applicable (or visa-versa) rather abruptly. Presumably a TOE should be able to reduce to the appropriate formalisms both before and after the change(?).
May
19
comment Do the laws of physics evolve?
To the anonomous down-voter: would you care to explain your reasoning?
May
19
comment Do the laws of physics evolve?
@HDE: Yes I was a little unsure about the phrasing there. Whould it be more correct to ask if the laws 'remain form-invariant thoughout the lifetime of the Universe?' If I can further improve the wording please suggest how and I will edit accordingly.
May
18
comment Online QFT video lectures
Stanford also have a number of freely available lecture courses. Susskind has posted courses on CLASSICAL MECHANICS QUANTUM MECHANICS, SPECIAL RELATIVITY, GENERAL RELATIVITY, COSMOLOGY, STATISTICAL MECHANICS, QUANTUM ENTANGLEMENT 1, QUANTUM ENTANGLEMENT 2, QUANTUM ENTANGLEMENT 3, BASIC PARTICLE PHYSICS, and THE STANDARD MODEL. Whilst none of these are specically QFT, you'll probably find th eStandard Model ones useful. newpackettech.com/Resources/Susskind/PHY30_2B/…
May
18
comment Famous physicists' quotations
@dmckee: "...complaints are part of why they are unsustainable." - I don't follow your reasoning. Furthermore, I really feel it would be to the detriment of the site if questions such as this are not permitted.
May
18
comment Famous physicists' quotations
@Ted Bunn: Oh well, I guess that's what happens when one quotes a quote that was already a quote etc. Chinese wispers effect.
May
18
comment Famous physicists' quotations
@ Nick: Well. Yes. I see your point, but that doesn't detract from it potentially becomming a very interesting thread. In it's defence, those other questions couldn't possibly have a universally prefered answer either; and they're not closed. I suppose it could have been phrased 'what's the best famous physicist quote, and why' but that would only differ in semantics.. ;)
May
18
comment physics- momentum ( a space question)
A little nitpicky perhaps but using the same $m$ for mass and meters could be a little confusing.
May
18
comment Is anti-matter matter going backwards in time?
Great answer. +1
May
18
comment physics- momentum ( a space question)
Hint: 1st: velocity $ v=d/t $, substitute in distance and time to find the required velocity. 2nd: momentum is conserved. $ p=mv $ for both the astronaut and the spanner, equate them. Rearrange to solve. All the best ;)
May
17
comment How is a magnetic field translated into physical force?
@Justicle - to quote Feynman from 3min58 in the aforementioned video: "when you ask, for example, why two magnets repel - there are many different levels, it depends on whether you're a student of physics or an ordinary person who doesn't know anything." I therefore have two points to make to qualify my previous comment: 1/ To quote the FAQ for this site "Physics - Stack Exchange is for active researchers, academics and students." and 2/ you asked a 'how' question and not a 'why'. That said, if you're happy with this hand-wavey style of answer then I'll happily let sleeping dogs lie..