Okay boys and girls. Ask a theoretical physicist anything! (about theoretical physics) (and only if you're 18 or older) Or tell him something he doesn't know.

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Anonymous Tue Mar 8 11:24:04 2011 No.2663945 [Reply] [Original]

Okay boys and girls.

Ask a theoretical physicist anything!

(about theoretical physics)
(and only if you're 18 or older)

Or tell him something he doesn't know.

>>	Field Commander, the Army of the Light Tue Mar 8 11:25:04 2011 No.2663948 File: 38 KB, 343x266, 1299582205665.jpg [View same] [iqdb] [saucenao] [google] Physics is a hoax.

>>	Anonymous Tue Mar 8 11:26:04 2011 No.2663949 What field and level? Also, at what point do we get to label ourselves as physicists?

>>	Anonymous Tue Mar 8 11:27:04 2011 No.2663957 Will M-theory replace String Theory as a description of the quantum world?

>>	OP Tue Mar 8 11:28:04 2011 No.2663959 >>2663949 what? Field or level? Point? Ourself? Just do it, see what happens.

OP Tue Mar 8 11:30:04 2011 No.2663963

>>2663957
>implying implying
Me serious answer would be that string theory is not established as a fundamental thory which describes the world, and if you are there, doing string theory, then you might consider this a good part of M-theory.
But I don't really know M-theory. Who does anyway..

>>	Anonymous Tue Mar 8 11:30:04 2011 No.2663964 ever thought about dealing with reality instead of just theories (gausses)?

>>	Anonymous Tue Mar 8 11:30:04 2011 No.2663966 Could Cold Fusion ever occur?

>>	Anonymous Tue Mar 8 11:31:04 2011 No.2663968 OP, suppose we solve the mystery of mass and learn all there is to know about the Higgs... Will there be any practical application? More specifically, what are the chances of actually manipulating gravity?

>>	Anonymous Tue Mar 8 11:31:04 2011 No.2663970 >>2663959 >theoretical physicist >do it, see what happens what?

>>	OP Tue Mar 8 11:32:04 2011 No.2663971 >>2663966 I hardly ever say "no" to a "could question". You will also find hardly any people who are actually working on it. >>2663964 no.

>>	Anonymous Tue Mar 8 11:32:04 2011 No.2663973 where are the missing resonances?

>>	Anonymous Tue Mar 8 11:35:04 2011 No.2663983 at what energy level do you think we'll find the higgs? And who is going to find it first? Fermilab or CERN

>>	Anonymous Tue Mar 8 11:35:04 2011 No.2663985 >>2663966 http://www.lenr-canr.org/ The best overall place for news and info on cold fusion, they are firmly in the proponent camp but they also publish things from those against

OP Tue Mar 8 11:36:04 2011 No.2663990

>>2663968
knowing all about the Higgs will/might give a consistent mathematical description (if you wanna call QFT consistent to begin with) but you know, there will always be another question.
And the higgs, or very high particle physics in general, will not give you any cool tech directly. but maybe people will come up with new stuff once a good theoretical basis is here. In this sense it would be better to discover something else than the higgs - because if it's really the higgs, then we have just conformation. If there is something else (other particles or whatever) then newer maybe more radical ideas will get recognition

>>	Anonymous Tue Mar 8 11:36:04 2011 No.2663995 >>2663983 >Fermilab >Find the higgs Nope

>>	Anonymous Tue Mar 8 11:37:04 2011 No.2663996 >>2663959 you totally dodged the questions: to what extent are you qualified to call yourself a theoretical physicist? have you ever published anything in a journal? and what is you're field or research?

>>	Anonymous Tue Mar 8 11:38:04 2011 No.2663999 >>2663990 QFT is based on analyticity, crossing symmetry, cluster decomposition and unitarity. whats not consistent about that?

Anonymous Tue Mar 8 11:39:04 2011 No.2664005

It's my understanding that nothing can travel faster than c.
It is also my understanding that velocity is relative.
Furthermore, my understanding states that the universe is expanding.
Assuming all three assumptions square with reality, my question is this:
Can two galaxies on opposite ends of the expanding universe exceed .5c/-.5c as seen from a "sidewalk" vantagepoint? If they can, hasn't something just been violated? If not; Why not?

Anonymous Tue Mar 8 11:40:04 2011 No.2664010

>>2663996
I didn't understand the question.
Mainly because I said >questions about theoretical physics
and not about eductation, religion, etc., etc.
I haven't published anything in paper sorry (only arXiv)
reasearch would be something beyond standard model particle physics

>>	Anonymous Tue Mar 8 11:41:04 2011 No.2664012 could you elaborate a little on how phonons and electrons interact under low temperatures? And what makes the cooper-pairing possible?

>>	Anonymous Tue Mar 8 11:41:04 2011 No.2664013 >It's my understanding that nothing can travel faster than c. Tachyons can

>>	Anonymous Tue Mar 8 11:42:04 2011 No.2664014 how often do you use matlab? What kind of functions do you use most often? Do you think its possible to make a contribution to physics when you don't have access to a lab?

>>	Anonymous Tue Mar 8 11:42:04 2011 No.2664016 >>2664013 So can unicorns. Your point was... what, exactly?

Anonymous Tue Mar 8 11:43:04 2011 No.2664019

>>2664005
No. You have to look at the distortion of spacetime, relative to the observer, from each galaxy's "point of view." This is probably the most commonly asked question when people first start reading about special relativity. Just read a little more and you'll get your answer.

(Not OP)

>>	Anonymous Tue Mar 8 11:43:04 2011 No.2664021 File: 53 KB, 760x468, The_Waiting_Game.jpg [View same] [iqdb] [saucenao] [google]

>>	Anonymous Tue Mar 8 11:44:04 2011 No.2664025 >>2664010 care to post a link to you're paper on arxiv

OP Tue Mar 8 11:44:04 2011 No.2664029

>>2663999
ya, it's fine.
I just wanted to avoid renormalization talk here, actually.
If you know lots about thysics you're invited to chat along here btw.
I'm doing this for my entertainment mainly

>>2664005
"sidewalk" vantagepoint?
viewed from the earth they can both travel at 0.9c, no problem there

>>	Anonymous Tue Mar 8 11:45:04 2011 No.2664032 >>2664016 That unicorns are not hypothetical subatomic particles

>>	Anonymous Tue Mar 8 11:46:04 2011 No.2664035 >>2664019 distortion of spacetime is misleading... its SR. metric is constant

>>	Anonymous Tue Mar 8 11:46:04 2011 No.2664036 How can the result of a measurement of a component of the spin of a spin-1/2 particle turn out to be 100?

>>	Anonymous Tue Mar 8 11:46:04 2011 No.2664038 >>2664005 since space it's self is expanding there is no reason why galaxy's cant measure each other at superluminal speeds (faster than light) some quasars are observed to do this

Anonymous Tue Mar 8 11:47:04 2011 No.2664043

how many dimensions are there?
also, how can you say that other dimensions exist?
aren't they just a way to acomodate things that can't be explained if there's only just the 3 dimensions we can see?
I say it's bullshit.

it's like tachions.
we have no idea how this happens, so we use tachions
what are tachions? tachions are particles that can't exist.
same with all the bullshit theoritical physicist make up

>>	OP Tue Mar 8 11:47:04 2011 No.2664044 >>2664014 1) if I have to (not too often) 2) hmm... if? vertcat, repmat? I can't come up with comething good right now 3) yes.

>>	Anonymous Tue Mar 8 11:48:04 2011 No.2664048 >>2664032 As long as the distinction you're aiming at is that unicorns aren't particles then we can agree.

Anonymous Tue Mar 8 11:49:04 2011 No.2664052

>>2663945

I'm undergrad studying Mathematics. The uni that I'm at Manchester has little Physics options like QM.

I was wondering, if it's possible to do a PhD in Physics if I get a high first in Maths?

Also, what fields of Maths should I try to get a PhD in if I can't do Physics? Heard Geometry is good like Differential geometry.

>>	Anonymous Tue Mar 8 11:49:04 2011 No.2664053 >>2664029 then, if you're in one of the galaxies, the other galaxy is going away at 1.8c omg i just broke physics

>>	Anonymous Tue Mar 8 11:50:04 2011 No.2664057 >>2664043 Shut it, troll. Either ask a honest question or don't at all.

>>	Anonymous Tue Mar 8 11:50:04 2011 No.2664060 >>2664029 "exceed". So the relative velocity would remain at 0.9c even if they kept exceeding 0.5c relative to eachother indefinitely?

Anonymous Tue Mar 8 11:50:04 2011 No.2664061

>>2664005

Not OP, but:

The expansion of the universe is not motion through space. It's expansion of space itself. Huge difference. (It's not traveling from point A to point B, it's the distance between point A and point B increasing.)

Also, the universe does not have edges.

Also, there is no "sidewalk vantage point." No frame of reference is more privileged than any other.

But yes, objects that are far enough away from us are increasing the distance between us at a rate that is greater than the speed of light. That is one reason the size of the observable universe is limited - because information from those objects can never reach us, even in an infinite amount of time.

>>	OP Tue Mar 8 11:50:04 2011 No.2664064 >>2664036 Don't know what you mean. If by results you mean the eigenvalues of the operator then it can't >>2664043 I don't know how many dimensions there are. Do you believe in Spin or Temperature? It's also not that obvious.

>>	Anonymous Tue Mar 8 11:51:04 2011 No.2664065 If I somehow got back/forward in time, what would I see? An empty space with me being the only matter or exactly the same world? And why?

Anonymous Tue Mar 8 11:51:04 2011 No.2664069

>>2664057
i'm not trolling
all i'm saying is that all this crap is bullshit.

they base the theories on something that doesn't work.
something that jus explains something they don't understand. And then from there they make up 200 more theories. What if the first theory they base it on was already wrong?

>>	Anonymous Tue Mar 8 11:53:04 2011 No.2664076 >>2664061 If this is true, how do we know the universe is 13,7 billion years old. I thought the whole idea was based on winding back the expansion. If we can't see beyond a particular point in the expansion, how can we conclude that it isn't infinite?

>>	Anonymous Tue Mar 8 11:54:04 2011 No.2664079 how does superfluidity relate to superconduction?

>>	Anonymous Tue Mar 8 11:54:04 2011 No.2664080 >>2664069 how would your GPS work without special and general relativity??? it would suck

OP Tue Mar 8 11:55:04 2011 No.2664082

>>2664052
>(about theoretical physics)
you can also ask math questions but I don't want to talk about education, or rather I have no idea how I could help you

>>2664065
this is kinda scifi but I'd say that if you go consciously back in time you just see everything around you going backways, if this is what you're asking

>>	Anonymous Tue Mar 8 11:56:04 2011 No.2664088 What's keeping the rulers of the riot-countries from employing wide-beam 1W> IR lasers to instantly blind their peasant uprising?

>>	Anonymous Tue Mar 8 11:57:04 2011 No.2664094 >>2664052 Differential Geometry is a good step towards physics. There's a field of research called 'mathematical physics' you might be interested in that.

>>	Anonymous Tue Mar 8 11:57:04 2011 No.2664096 >>2664076 I don't know what "beyond a particular point in the expansion" means. Expansion is the same everywhere. As for how we know how old the universe is, there are several ways: http://en.wikipedia.org/wiki/Age_of_the_universe

>>	Anonymous Tue Mar 8 11:57:04 2011 No.2664097 What's your opinion on anthropic solutions to apparent fine tunings in physics?

Anonymous Tue Mar 8 11:57:04 2011 No.2664098

>>2664069
You are.
You don't know neither about the reasoning nor about these ominous fundamental theories, yet you somehow know it's bullshit.
Einstein and all the quantum guys got the same shit in their time and look where we'd be now with out those theories.

>>	Anonymous Tue Mar 8 11:58:04 2011 No.2664100 >>2664088 sunglasses

>>	OP Tue Mar 8 11:58:04 2011 No.2664099 >>2664079 I'd say both rely on a phase transition http://en.wikipedia.org/wiki/Phase_transition these occour if some parameters like, like temperature, take some specific values or cross boundaries

Anonymous Tue Mar 8 11:58:04 2011 No.2664101

>>2664052
you would probably not be accepted for a phd in physics
manchester has a great and extensive physics department
if you want to be a physicist tell your advisor now depending on what year you are in you could switch or you could be put back into earlier years

>>	Anonymous Tue Mar 8 12:00:04 2011 No.2664110 OP, you're a student, aren't you.

>>	OP Tue Mar 8 12:00:04 2011 No.2664111 >>2664097 not a fan. When it come to higher theories I'm rather intersted in the math than in prediction things that won't be tested in my lifetime and such

>>	OP Tue Mar 8 12:01:04 2011 No.2664113 >>2664110 I'm not post doc, yes

>>	Anonymous Tue Mar 8 12:02:04 2011 No.2664115 >>2664101 dirac was an electrical engineer remember, and then studied applied maths. of course you can do a PhD in a theoretical physics subject with a maths degree.

>>	Anonymous Tue Mar 8 12:03:04 2011 No.2664120 >>2664110 i don't think he's even a student. he wont talk about education, he wont link to his paper on arxiv and he shows no better understanding than a lot of people here probably a self declared garage scientist

OP Tue Mar 8 12:06:04 2011 No.2664130

>>2664120
- why would I want to talk about education? aren't there enough threads on /sci/ about that already?
- and why would I wan't to post my actual name on 4chan?
- If you have an actual question, then you will get my answer if I know it.
- As I said, I someone wan't to just explain something or have a discussion then I'd love that too

>>	Anonymous Tue Mar 8 12:06:04 2011 No.2664131 >>2664120 OP knows his stuff. You apparently don't

>>	Anonymous Tue Mar 8 12:06:04 2011 No.2664136 File: 6 KB, 396x95, Untitled.jpg [View same] [iqdb] [saucenao] [google] Can you solve this?

>>	OP Tue Mar 8 12:07:04 2011 No.2664139 - As I said, if someone wants to

Anonymous Tue Mar 8 12:08:04 2011 No.2664144

>>2664115
that was a long time ago things have changed

to do a phd in a field of physics which is not you're previous field you may have to do extra classes
one guy i know was rejected entirely because his courses were a bit to theoretical

if you wan't to be a physicist change now it is possible to do it later but you may not be able to, it will be a lot harder and a harder to get a phd with funding

>>	Anonymous Tue Mar 8 12:08:04 2011 No.2664145 Why does laser-light have black dots in it, and is this an unavoidable property of laser?

>>	Anonymous Tue Mar 8 12:08:04 2011 No.2664146 Could ancient aliens with superluminal transit capabilities have warned the Mayan people about the approaching wall of a bubble of lower-energy vacuum, due to arrive in 2012?

>>	OP Tue Mar 8 12:09:04 2011 No.2664153 File: 14 KB, 421x170, exp.png [View same] [iqdb] [saucenao] [google] >>2664136 the calculation by hand will probably require some Residues

>>	Anonymous Tue Mar 8 12:10:04 2011 No.2664159 >>2664131 not really. he's just saying pretty much what i would say if i were pretending to know physics, and i'm a pure maths graduate. this is OP's wish fulfilment thread

>>	Anonymous Tue Mar 8 12:10:04 2011 No.2664161 >>2664153 i just typed the same into mathematica :-)

>>	Anonymous Tue Mar 8 12:10:04 2011 No.2664163 >>2664120 This. OP is a sophomore at best.

>>	Anonymous Tue Mar 8 12:11:04 2011 No.2664164 File: 77 KB, 790x1023, Atomspin.jpg [View same] [iqdb] [saucenao] [google] >>2664099 that's not really what I meant, but I see that I framed my question badly. How do superconductors and superfluids interact? Like e.g. in a neutron star?

>>	Anonymous Tue Mar 8 12:11:04 2011 No.2664167 >>2664144 Now you're just talking out your ass.

>>	OP Tue Mar 8 12:11:04 2011 No.2664168 >>2664145 I don't know what dot's you are refering to. laser is just "Light Amplification by Stimulated Emission of Radiation", as they say. Photons flyin round >>2664146 yes

>>	Anonymous Tue Mar 8 12:12:04 2011 No.2664171 >>2664144 What about Mathematical Physics. Don't care about the practical side of Physics. Just the theoretical part.

>>	Anonymous Tue Mar 8 12:12:04 2011 No.2664172 Alright OP, what are you working on at the moment? Be technical, I'm a grad student in theoretical physics myself.

>>	Anonymous Tue Mar 8 12:13:04 2011 No.2664182 >>2664168 Shine a laser at the wall or something, you'll see what I mean. It looks gritty, grainy... kind of like TV-noise.

Anonymous Tue Mar 8 12:14:04 2011 No.2664184

>>2664130
fine, tell us some more information about what you research, go into detail you don't have to give up you're identity just summarise you're work in some detail
it would be a lot more interesting if people could read that and ask questions about something you know than teenagers asking high school physics questions

just tell us what you do

Anonymous Tue Mar 8 12:14:04 2011 No.2664186

>>2664159

ok, here is a question, that will show if op knows theoretical physics or not. no one else should know that, because it is a question concerning the formalism of theoreticel high energy physics.

@ OP: how many components has a charged fermion field

>>	Anonymous Tue Mar 8 12:15:04 2011 No.2664191 Why can't we have teleporters?

>>	Anonymous Tue Mar 8 12:15:04 2011 No.2664194 >>2664182 That's called a speckle pattern. I don't know the details, but it has to do with light interference.

>>	Anonymous Tue Mar 8 12:16:04 2011 No.2664197 >>2664171 We have some guys doing mathematical physics in the math department as well as in the physics department. Look around who does what. The boundary of physics and math can get pretty blurry at times.

>>	Anonymous Tue Mar 8 12:16:04 2011 No.2664198 >>2664186 7.

OP is a faggot Tue Mar 8 12:16:04 2011 No.2664200

>>2664171
Study functions of a complex variable, PDEs in general (hell, quantum is an example problem...), and 'statistical physics' (it's kind of a hodgepodge of stuff iirc). You now have your undergraduate foundation. Tack on Differential Geometry and Algebra, depending on what you want to do. Plasma Physics is a lot more vector calculus, so it's probably worth reviewing the interesting things there again.

>>	Anonymous Tue Mar 8 12:17:04 2011 No.2664204 >>2664198 wrong

>>	Anonymous Tue Mar 8 12:17:04 2011 No.2664205 >>2664186 That can be answered by a undergrad...

Anonymous Tue Mar 8 12:18:04 2011 No.2664211

>>2664164
not op
but superconductors and superfluids have very little in common other than the name and as op stated the fact they both have transition temperatures

the physics involved is completely different

i haven't seen any work which showed either effect could take place naturally, i don't know why you mention neutron stars

Anonymous Tue Mar 8 12:19:04 2011 No.2664216

>>2664172
>>2664184
solving differential quations ;_;
But seriously, I wan't to talk about physics, not about me.
I'm capable of answering some questions, I do what I can and not more.
Anyway, why do people here get a kick out of insulting me (or an OP in general)? Are these people naturally agressive or just trolling?

As for the neutron star question I don't really know how they interact. I mean that would require some very technical answer no? Manyparticle systems at high energy, all 4 interactions involved... what can I say?
Let me put it this way: how did you come about the question?

>>	Anonymous Tue Mar 8 12:19:04 2011 No.2664217 >>2664205 well it is just a test, not a proof

>>	Anonymous Tue Mar 8 12:22:04 2011 No.2664235 Is there an intuitive way to understand anomalies and the relations among the charges of particles that follow from them?

Anonymous Tue Mar 8 12:23:04 2011 No.2664237

>>2664171
seriously ignore everyone here including what i said before
but if you know what you want to studies go tell your advisor of studies soon they'll no what's best
if you don't have one find someone in the science support unit or failing that a teaching professor of physics or maths, if it comes to this talk to both
its better to act now and find out its fine, than work had and get a degree you can't use

Anonymous Tue Mar 8 12:23:04 2011 No.2664238

This is how theoretical physics work.
Some dude writes some guesses about how reality works that nobody will read.
So will all the other dudes.
100 years later, someone will figure out which of the theories were correct by conducting experiments.
The dude who guessed right will have a law named after him.
The others won't.
They won't care because they'll all be dead by then.

Anonymous Tue Mar 8 12:23:04 2011 No.2664242

did you know that our thoughts that we think to our selves consciously and unconsciously travel through our nerves as electrical pulses. Electricity makes a voice and you must know that, its a very very inaudible voice which can only be heard by the most expensive equipment, but the thoughts are even more quite but in the end we will hear it as an electrical pulse, they vary depending on what thought, after hearing it we record its data and every thought has its own encryption which was naturally selected but a program now an show what the encryption means and hence we can know what people are thinking. and emitting such inaudible sounds to a human will also mind control

u jelly?

>>	Anonymous Tue Mar 8 12:23:04 2011 No.2664246 >>2664235 i like that question.

>>	OP is a faggot Tue Mar 8 12:23:04 2011 No.2664248 >>2664216 >Anyway, why do people here get a kick out of insulting me (or an OP in general) because this post: >>2663959 was the most retarded answer you could have given. It set the tone for the whole thread.

Anonymous Tue Mar 8 12:24:04 2011 No.2664254

I'm a biochem major heading to med school (graduating next spring), and I want to come back to school after I make a ton of money being a doctor and get a PhD.

It's sort of a toss up between physics and chemistry, what would you recommend? I want to do something beneficial, to leave some small mark on humanity and advance it forward, and I think I could do that with either field.

OP Tue Mar 8 12:26:04 2011 No.2664260

>>2664186
depends on the fermion and the interaction.
if you're talking about spin 1/2 representations of SO(1,3) up to a phase, let's say electrons, then, when coupling it, say to the electromagnetic force, you'd have to stack spinors (two complex entries each) above each other. This is because of the non-compactness of the representation (the non-compactness Lie group representation of the boosts, to be specific).
If you're refering to a Lagrangian in 4 dimensions then you'd use a dirac spinor, i.e. two 1/2-spinors.

Actually, to be more rigurous you'd have to say infinitely many, since these 4 entries take 4 different values in every point of the manifold you're looking at.

Philebus Tue Mar 8 12:28:04 2011 No.2664272

Do you think that relativity and quantum theories as we think of them now will turn out to be essentially mutually consistent in the end, or is one (or both) going to have to be changed so much that we end up basically saying that it turned out to be wrong (just "wrong" like Newtonian mechanics, not wrong like Aristotle)?

Anonymous Tue Mar 8 12:29:04 2011 No.2664275

>>2664216
Due to the anonymous nature of 4chan it's difficult to distinguish between people that know what they are talking about and those that only think they to.

While you so far have been pretty much correct, although a bit on the shallow side, in your answers, I have seen other horrible threads here on /sci/ where people claimed to be some sort of expert and started throwing around half-right to wrong stuff. People believe it and we get the shit we see in other physics threads.

So, either be careful with calling yourself a "theoretical physicist" or live up to the name. We all solve differential equations, but which, and what for are you solving them? You mentioned something about stuff beyond the standard model, why not elaborate on that?

>>	Anonymous Tue Mar 8 12:31:04 2011 No.2664292 >>2664260 now that convinced me, that OP is very good physicist! i hope people stop misunderstanding the whole concept of his thread

Anonymous Tue Mar 8 12:32:04 2011 No.2664297

I talked to my Biophysics professor about quarks the other day, as I was curious as to what the difference between the different flavors of quarks were. He lost me really fast, but said it has to do with the degree of freedom with which they were measured. Can you explain?

Also, why do electrons have to spin around twice to get back where they started from?

>>	Anonymous Tue Mar 8 12:32:04 2011 No.2664302 >>2664260 See, why not right from start like this?

OP Tue Mar 8 12:33:04 2011 No.2664305

>>2664235
well depending on the word "intuitive", there is alot about anomalies you can learn from understanding "Cern classes" in Yang-Mills theory, but when it comes to QFT I don't "see" anomalies, sorry

>>2664248
ah, ic.
Well to be honest it's just now that I understand the second question. I though he was referring to the 4chan users when saying "ourselfs".
English isn't my language though, maybe that's why

>>	Anonymous Tue Mar 8 12:36:04 2011 No.2664325 >>2664211 dx.doi.org/10.1103/PhysRevB.78.024510 dx.doi.org/10.1103/PhysRevLett.106.081101

OP Tue Mar 8 12:38:04 2011 No.2664331

>>2664272
I'd say it's fairly obvious that they are "wrong" (in the sense you stated), i.e. they will only be limits of higher theories.
General relativity because I don't expect the idea of a smooth manifold to be sufficient and QFT because of... well a thousand things, stating from the difficulties that come up when you try to define a hamiltonian (pretty necessary for everything stating with a Q) in general relativity (because there you don't have any obvious conserved currents in general and thus no "Energy Charge", i.e. hamiltonian.)

But I think there are some strong statements that every theory dealing with particles will turn out to be a QFT in a low energy limit

OP Tue Mar 8 12:46:04 2011 No.2664369

>>2664297
staying vague you can for example disdinguish them by they masses, i.e. muons are 200 times as heavy as electrons or so.

And electrons don't have to spin around twice in a literal sense. if you imagine them to be located point particles then you can spin them any angle and they will look the same and if you imageine them flying in one direction (impuls eigenstates) then you will see the difference for very little angles.
The thing which takes two turns to come back is a phase, which is unobservable.

Like if you consider the solution of the stationairy Schrödinger Equation, say for a harmonic oscilator and then look at the particle density function, you will see that it's time independent, i.e. doesn't move, even if the total solution exp(-iEt)\Psi\ is moving around like a wild monkey. The "phases", like exp(-iEt), can behave as they wish, (maybe this doesn't help)
exp(-it)

>>	OP Tue Mar 8 12:53:04 2011 No.2664392 >>2664275 searching for almost complex structures on evendimensional Riemannian manifolds. >pretty much correct did I say something wrong? It's a bit difficult to give an answer to "how do neutron stars work"

>>	Anonymous Tue Mar 8 12:55:04 2011 No.2664398 >>2664369 Haha naw man that was way beyond anything I've learned, thanks for trying though.

>>	The Doctor Tue Mar 8 12:58:04 2011 No.2664404 File: 45 KB, 499x363, img21.png [View same] [iqdb] [saucenao] [google] Is the speed of photons really magically relation-invariant or is it just down to propagating like a wave relative to the medium of spacetime?

OP Tue Mar 8 13:01:04 2011 No.2664417

>>2664398
the point is that there just is nothing which you could observe (as in "see it") that is behaving in this seemingly strange way.

>>2664404
could you reformulate or elaborate what you mean be "relation invariant"?
What seems to be the magical part about it?

>>	Anonymous Tue Mar 8 13:15:04 2011 No.2664462 What is entropy, conceptually? When you imagine it, what do you see?

>>	OP Tue Mar 8 13:17:04 2011 No.2664470 >>2664462 Do you want to talk about the entropy of information theory (shannon entropy) or the entropy of statistical mechanics and thermodynamics?

>>	OP Tue Mar 8 13:17:04 2011 No.2664472 >>2664470 (bolzman entropy is the second one usually called)

>>	Anonymous Tue Mar 8 13:18:04 2011 No.2664476 >>2664470 I really need to study information theory sometime. How dry and boring is it?

>>	Anonymous Tue Mar 8 13:20:04 2011 No.2664493 >>2664476 I find it interesting to be honest. I'm more familiar with bolzman entropy, naturally. But if I have to I can explain the other one as well. ()though I have to go in 15 mins, I will come back later)

>>	OP Tue Mar 8 13:30:04 2011 No.2664542 >>2664462 are you still there? I have only 12 minutes left, so I'll go on with why entropy is important in information theory and I'll come back in 3 hours..

The Doctor Tue Mar 8 13:32:04 2011 No.2664558

>>2664470
Is there a difference between Shannon Entropy(information) and Thermodynamic Entropy other than the application? Concepts seem identical to me at the point, having not yet gotten into the latter,

>>2664404
>>2664417
Hmm magical. It's just an inappropriate strawman. I meant whether light invariably being measured to the same speed in a vacuum is simply photons exhibiting wave properties, propagating at a speed only relative to the medium (spacetime).

>>	Anonymous Tue Mar 8 13:33:04 2011 No.2664566 Hey physicist, what about that discovery that the microwave background radiation is evidence of the universe being some weird dodecahedron. Can you explain it to me?

Anonymous Tue Mar 8 13:36:04 2011 No.2664576

>>2664558
Photons being massless is what gives them an absolute speed. Them showing wave particle duality is mainly due to the Uncertainty principle. Knowing some of their momentum means we can't know their definite position. That's how I took it anyways, correct me if I'm wrong OP.

OP Tue Mar 8 13:42:04 2011 No.2664608

there is this example:

say you got a channel where you can send eigther *beep* or no beep, i.e. 0 or 1. One signal per second. You wan't to transmit a message with an alaphabet of four letters. Lets say these are colored pixels of a black and white picture, say a 4chan .jpg.

Now how do you encode these 4 colors (light gray, dark gray, white, black)? How do you encode the colors lg, dg, bb, ww

a good answer would be
lg=00
dg=01
bb=10
ww=11
thus [00101101011010]
would be
[lg bb ww dg dg bb bb]

to send 7 pixels you need 14 "beep"s or "not beep"s, i.e. 14 seconds. It always takes 2 seconds to send a pixel.

next comes the clou:
say you know that to make up the picture you will mostly need the black pixels
say the chances you'll send bb is 1/2, the chances you'll send white is 1/4 and the chances you'll send one of the grays is 1/8
then you could still code it like above, but there is a better way!
namely:

lg=0
dg=10
bb=110
ww=111

you know every pixel end with 0 or is 3 beeps/not beeps long

not the typical length of a pixel (expectation value) is

1 (1/2) + 2 (1/4) + 3 (1/8) + 3 (1/8) = 1+ 6/8 <8
You can now send faster!
the computation above "1 (1/2) + 2 (1/4) + 3 (1/8) + 3 (1/8)" is the entropy
S=-sum p ln p
it's a minimal bound for information rates

see you in 3 hours!!

>>	Anonymous Tue Mar 8 13:55:04 2011 No.2664650 What are the 11 dimensions of the universe?

>>	Anonymous Tue Mar 8 14:51:04 2011 No.2664937 >>2664650 The 11 dimensions of the universe are length, width, height, your faggotry, your faggotry, your faggotry, your faggotry, your faggotry, your faggotry, your faggotry, and your faggotry.

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/sci/ - Science & Math