/sci/ - Science & Math

>>5733598
Do you know any linear algebra? If so, an intro textbook like Griffiths might be what you're looking for. Or you could read the Road to Reality, like I mentioned above.

>>5733588
> "Any scientist who can't explain his work to a fifth grader is a charlatan." Bernard Vonnigut.

Stuff like that is common to say among laymen, but there comes a point where simplifying things any further will completely dilute their meaning. There are intricacies that can't really be explained with words. In physics, "knowledge" of a theory comes when you develop an intuition about the math itself.

If you want a theory that you can explain without math, QM is pretty much the worst possible choice you could have made. There isn't even a consensus about what interpretation of the theory should be used. The theory *IS* the math.

Are you fairly comfortable with basic calculus? Penrose's Road to Reality is good for a layman who wants a real explanation, and isn't a few hundred pages of shitty analogies that will leave you confused.

Dude, what is this nonsense?

>Time is stopped for one side... does it stop for the other?
Also, I'm not sure what you mean by this. Time certainly doesn't "stop" for the particle when it crosses the horizon, and once it reaches the singularity current physics has no idea what happens to it. So again, I have no idea what you're asking.

What do you mean? Once one of the entangled particles crosses the horizon there's no way to measure its state. So whatever we measure its correlating particle's state to be in (spin up for example) we can only assume by angular momentum conservation that the other particle is in the opposite state (in this case spin down). But there's no way to experimentally verify this, so the point is moot.

Back when I was in high school I used this: http://apphysicslectures.com/

I think vomiting would be a much quicker and more effective method for getting rid of water than consuming diuretics.

>>5729380
>Do the writters expect to not have to place place-holders for circumstantial eventualities that would alter the norm?
What the hell are you trying to say? Stop with the bullshit and speak english.

I suspect a lot of people on /sci/ used to love the guy, mesmerized by the ideas he puts out. Only later, when they actually started studying the stuff, did they get a feel for what physics is actually like. And humans always like to feel special, so they shit on the guy because he's preaching to an audience with a knowledge-base smaller than their own.

>>5729230
I don't know. I've only recently begun QFT myself, and that's SFT. So I imagine you'd need to be pretty familiar with basic ST and QFT.

>>5729194
>>5729189
http://arxiv.org/abs/hep-th/9311172
http://arxiv.org/abs/hep-th/9606057
http://arxiv.org/abs/hep-th/9311173
http://arxiv.org/abs/hep-th/9907016
http://arxiv.org/abs/hep-th/9607111

I'd rather see pretentious idiots with a trivial interest in science than pretentious idiots who are proud of their scientific ignorance. I.e. I'd rather overhear a conversation about speculative stuff like multiverses than overhear 9/11 truthers or creationists.

The speculative, fantastic stuff is what gets a lot of people interested in science in the first place. I grew up watching science channel documentaries, which made me want to study physics.

>>5728487
Zee is good if you're already familiar with QFT, but it's definitely not good as a standalone resource.

Carroll's GR book.
Klauber's QFT book.

This comes from basic nonrelativistic quantum mechanics. In QM you solve for the Schrodinger equation, which is a differential equation, for the wavefunction. When you express the Schrodinger equation in spherical coordinates and use the potential generated by the electric charge of the nucleus, i.e. V=kq/r, then you get a wavefunction which involves Legendre polynomial. When you graph the various energy levels, they give you the funky looking shapes you see in your original pic. The magnitude-squared of the wavefunction is a probability distribution. I.e. if you integrate the probability distribution over some volume, it tells you what the probability is that you'll find the electron inside that volume. So you can think of the pic as roughly the areas where electrons of various energy levels are likely to be found.

>>5726017
Shit, I just realized I wrote that wrong. The exponent should be <span class="math">i(-E_k t+\vec{p}_k \cdot \vec{x})/\hbar[/spoiler].

>How is a projection operator a wave anything?
It's called the "wavefunction" because the equation of motion it satisfies is a wave equation, namely the Schrodinger equation. The general solution to the Schrodinger equation is:

<div class="math">\psi(\vec{x},t)=\sum_k A_k e^{-i(E_k t+\vec{p}_k \cdot \vec{x})/\hbar}</div>

Yes, they're L^2 functions. The wavefunction is just the projection of the state onto the position basis: <span class="math">\psi(\vec{x},t)=\langle x|\psi \rangle[/spoiler]. The interpretation of the wavefunction is that the integral over a particular volume is the probability of finding the particle in that volume.

"Violet, you're turning violet, Violet!"

>>5722728
It means measurement.

>I know that it can refer to the act of measuring a particle, however I've also read of experiments where humans subjects directly "altered" the outcome of an experiment just by looking at it.
What do you mean by "looking at it?" Take the double-slit experiment for example. If you mean "setting up a detector at one of the slits to determine if the electron went through," then that would be an act of observation. It doesn't matter whether or not some conscious being looked at the data, because the detector interacted with the electrons.

If you were to set up a detector that's connected to a computer, have the computer record the data, then toss out the data without looking at it, the electrons would NOT show an interference pattern. In fact, even if the detector wasn't even hooked up to a computer you still wouldn't find an interference pattern. Nature doesn't care what you decide to do with your data, only that the detector interacted with the electrons.

OP, by your post I can't really tell what your beliefs or possible misconceptions may be. Your professors may be (and probably are) right for criticizing them. If you think that deep down the universe follows some non-probabilistic scheme with hidden variable, then your professors are absolutely right. You would indeed be wasting time with that approach. However it's certainly not a waste of time to investigate how nature works, which is, after all, what physics is all about. Seeking a unified field theory may or may not prove fruitful. But wasting time trying to reconcile your naive ideas of how nature "should" work with how it actually does is definitely a bad idea.

>>5721334
Except there's a factor of 1/2 that's missing in front of the v^2 term. The quantity y(t)y'(t) isn't even conserved over time.

>>5721273
I'm having a hard time following this. Where did y(t)y'(t) come from, and why are you taking its time derivative?