Colin Fredericks

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529 reputation
25
bio website
location Cambridge, MA
age
visits member for 2 years, 2 months
seen Jul 8 at 15:35

May
6
comment Terminal velocity?
You mention "all collisions are inelastic"; are you given the amount of elasticity in the problem, or are you just speaking from your own thoughts on that one?
Mar
27
comment How do permanent magnets manage to focus field on one side?
Since I don't have this in front of me: Are you certain that the whole thing is actually a magnet? Is it possible that they are just backed with a thick layer of some similar-looking substance that prevents them from getting close together and exerting a strong repulsive force?
Aug
11
comment Triple slit experiment
But it does state that blocking one of the slits in the double-slit destroys the pattern. To my understanding, detecting the passing photon with minimal disruption to it does not destroy the double-slit pattern.
Aug
11
comment Triple slit experiment
True, but so does the original question.
Aug
9
comment Why do people rule out local hidden variables?
I will note that the free will vs. determinism debate often assumes that probability plays no role. You may be better served by thinking of not a sliding scale between "free will" and "determinism," but as a triangle with "randomness" at the third point. If there's a philosophy stackexchange site, that's probably the place to ask about free will.
Aug
9
comment Is quantum perturbation theory taught in college?
Additional supporting data points: It was taught in the undergrad classes I took at RPI. We did not get into field theory or second quantization.
Jul
12
comment Why do we think of light as a wave?
You are correct - that's what I get for simplifying my language too far.
Jul
2
comment Could someone remind me of what we mean by zero electric field “inside” a conductor?
"Inside a conductor" usually is taken to mean literally within the medium of the conductor - in the metal. The example @jak is using would normally be phrased as "in a pocket..." or "in a bubble..." or "in a cavity within the conductor".
Jun
21
comment Why do we think of light as a wave?
I didn't vote it down, but there are three things that struck me about your answer. First, it's a little incoherent and could be better organized. Second, you attribute interference patterns to particle behavior, when they're actually wave behavior. Third, you answered with material that seems to be way above the level of the original post, and would probably just be confusing. Those are probably why people voted your answer down.
Jun
20
comment Why do we think of light as a wave?
How familiar are you with electric charges and electric fields? If you know some about them, I can give an answer that is a bit more in-depth and accurate without having to explain electromagnetism along the way.
Jun
1
comment boundary conditions
Ok! Just wanted to make sure. Thanks!
Jun
1
comment boundary conditions
No offense, but this sort of sounds like a homework problem. Is it?
May
17
comment Why do we need the quantity momentum?
While it's true that energy can't be created or destroyed, it can end up in forms that aren't useful to us. In a car engine, for example, you use chemical energy in the fuel to give kinetic energy to parts in the engine, but some of the energy turns into heat, which isn't useful. (In fact, most of it ends up as heat; engines are not very efficient.) In introductory physics we often talk about energy "lost" to friction or deformation.
May
15
comment how to calculate minimum torque a DC motor needs to move the wheels
Minor nit-pick: if friction with the floor is too low, or your torque is too high, you could skid out and have trouble moving because of that. Other than that, good explanation.
May
15
comment Why is a black hole black?
If you're familiar with tensor calculus, John Rennie's answer should be fairly easy to follow.