1,214 reputation
415
bio website N/A
location The South
age 23
visits member for 2 years, 5 months
seen 5 hours ago

2d
awarded  Altruist
Dec
20
comment Dependence of kinetic friction on relative velocity
Well, for starters do you understand why it shouldn't really depend upon relative position (like gravity)? If so then velocity is the next obvious candidate.
Dec
20
comment Dependence of kinetic friction on relative velocity
In different regimes you might approximate the dependency by some power law, e.eg., proportional to $v$ or $v^2$, but in general there is no simple mathematical function you can write down that will represent the exact dependency.
Dec
20
comment How would gravitons couple to the Stress-Energy tensor?
This question runs a high risk of ordering outside the domain of mainstream physics. Since we don't yet have a quantum theory of gravity, providing a complete account of the behavior and interactions of gravitons is just not something we can do at this time.
Dec
19
awarded  Investor
Sep
10
awarded  Nice Question
Aug
9
comment Why is it more convenient to consider space or time as a continuum?
@bobie Because plancke units are too large. Suppose you have a circle with radius equal to one plancke unit. If you try to calculate the area of the circle of this unit circle via "integration" with $dA$ equal one plancke unit-squared, you get an area of 4 units-squared instead of $\pi$.
Aug
9
comment Why is it more convenient to consider space or time as a continuum?
The primary benefit of regarding space as a continuum is calculus.
Jul
23
awarded  Yearling
Jul
12
comment Is the universe infinite?
@Sayans25 That said, there is a wealth of partial results on the conditions for / implications of a finite/infinite universe. See en.m.wikipedia.org/wiki/Shape_of_the_Universe#Global_geometry
Jul
12
comment Is the universe infinite?
We don't know the answer yet, and on some level we're not even completely certain the questionable answerable. It would sure be neat if someone figured it out though.
Jul
11
comment Why time is considered a dimension?
I think the question the OP is trying to ask but doesn't know how to is why the dimension of time is considered to be a geometric dimension as opposed to just being a parameter off in its own category (like the dimensions of charge, mass, temperature, etc.).
Jul
11
revised How does quantization solve UV catastrophe in black body radiation? What would happen if there was no Planck constant $h$?
Added latex; minor grammatical fixes
Jul
11
suggested approved edit on How does quantization solve UV catastrophe in black body radiation? What would happen if there was no Planck constant $h$?
Jun
1
answered Measuring the nearest order of magnitude
Jun
1
comment Measuring the nearest order of magnitude
@Freddy You obviously can't stop at just the formula that gives $L$ as a function of $d$, because the problem asks you to give a number for $L$, not a function, and you don't have a number yet. So it's time to guess a value for $d$. This step makes some students uncomfortable at first because the worry over how to guess "the right value". Take a deep breath and guess anyway. You can always guess again.
Jun
1
comment Measuring the nearest order of magnitude
What rob said. Moreover, that's the entire purpose of questions like these. The question intentionally forgets to tell you how big $d$ is, forcing you resort to a guess and deal with the uncertainty that unavoidably enters into your result. This is the difference between an actual physics problem as opposed to mere applied math problems.
May
26
comment Icecube experiment at the North pole instead of the South?
The biggest reason is probably because the North Pole is in the middle of the Arctic Ocean. The IceCube laboratory was able to be installed 1 kilometer below the surface of the Antarctic ice sheet because the depth of the ice sheet goes down almost 3 kilometers, and below that is solid land. At the North Pole, the ice is a mere 10 feet thick in most places before you hit liquid water, and even that 10 feet might melt altogether come summertime.
May
26
comment The path integral and Feynman diagrams
"The leap from path integrals to diagrammatic computations isn't obvious (to me, at least)". Don't feel bad. It wasn't obvious to Schwinger either, and he shared the Nobel Prize with Feynman for his work on the darn stuff. It's a highly non-trivial result.
May
21
comment time dependent current/ magnetic field
You could in principle use Jefimenko's equations, but I imagine that's a bit overkill here.