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Comments:
<0> hello
<1> hey all
<1> my perpetual motion machine is really working now, it's not just an idea
<1> it's powering this computer
<1> okay j/k
<1> anyway anyone here?
<2> me and Manyfold at least
<2> Manyfold: it appears the second course in quantum mech we have deals with relativistic quantum mechanics
<1> is cl***ical physics allowed in here?
<2> yes
<0> pgm: without doing many particle systems?
<0> barely
<2> Manyfold: hmm, i think it is a separate course called many-body phenomena
<0> argh this must be done before attemping qft
<2> Manyfold: but how does relativistic quantum mech compare to quantum field theories
<0> relavistic qm lays the foundation for qft
<2> Manyfold: ok i see, so i cant skip relativistic quantum mech
<1> acceleration due to gravity is given as 9.8 m/s**2
<1> but there should be a centrifugal force acting on a body on earth, because the earth is rotating
<1> which by my calculation is about .03 newton, but i could be wronge
<1> http://www.google.com/search?q=1+kg+*+(2+*+pi+/+1+day)+**+2+*+radius+of+earth
<1> so is that slight force included in the number given as acceleration due to gravity, or not?
<0> pgm: yyou start off with E^2=c^2p^2 + m^4c^4
<0> setting H=E
<2> Manyfold: yes, seems familiar
<3> araizen: the centripetal force should not be included in the acceleration due to gravity
<2> Manyfold: Dirac & Klein-Gordan equations?
<0> we see that the relativistic hamilton is H=(c^2p^2 + m^2c^ 4)
<1> so a 1 kg object on earth should really have a force of about 9.77 N acting on it, not 9.8 N?
<1> on the equator
<0> ups i added an m^2to much sorry
<0> it's late here
<0> yes
<3> araizen: yes i would imagine the normal force on an object sitting on the surface of earth would be slightly less than mg
<1> ap1: thanks, it's great that I can start wondering about something and come here and get an answer
<2> depends on where you are on Earth
<3> indeed, g varies
<0> but the klein gordon equation is of second order in time while the nonrelativistic shroedinger equation is off first order
<0> pgm: so you will linearize it
<0> ( E - c sum_i a-ip_i -b mc^2)( E + c sum_j a_j p_j + b mc^2) =0
<0> so [a_i,a_j]_+ = 2delta_ij 1
<2> araizen: i got something like this Fcoriolis = mrw^2*sint(-cost i + sint k) for coriolis force, t = latitude, i, k unit vectors
<0> ans [a_i,b]=0
<0> pgm see that?
<2> ok no, but go on, i understand the point ;)
<0> well then compute this first
<2> i used to do more advanced stuff that i didnt understand, like computing some meson stuff with QCD
<1> pgm: interesting, i was only looking at the centrifugal force
<2> araizen: if the object is moving relative to earth you need coriolis force too, and note that i wrote there wrong it should read Fcentrifugal
<0> this will bring us to the dirac equation (id/dt + ica laplace -b mc^2)psi = 0
<0> here i set hbar =1
<1> pgm: yeah i see that, i'm reading up on it
<0> and a is a vector including a_i with 1,1,3
<0> pgm do you know the dirac-picture?
<2> Manyfold: no
<0> http://en.wikipedia.org/wiki/Dirac_picture
<2> Manyfold: mmh
<0> mmh??
<0> sorry have to go we could continue later
<0> if you like
<2> ok
<2> when?
<0> BACK
<0> pgm: are you still there?
<0> thischannel is so empty lately
<2> yes
<2> but i intended to go to sleep now ;)
<2> Manyfold: hello
<0> :(
<0> okay then have you checked the anticommutator relations
<2> well how long time would you want to spend anyway?
<0> course you'll see something special about them
<2> hmm, no
<0> pgm: what s
<0> pgm: what do you mean with how many time i want to spend anyway?
<2> well how much time you got?
<0> i'll go to bed too
<2> heh, ok
<2> Im probably too dumb for you
<0> i just wanted you to see that the a's appearing in the linearization are of the form {(r,0),(0,r)}
<0> where r are the pauli spin matrices
<2> oh, well thanks, but better quit anyway, too tired to be interested in that now ;)
<2> laters
<2> saving the log though
<2> bye
<4> hi, i have a quuestion, anyone free?
<1> hi, chopchop
<1> doubt i can help you
<1> but i can ponder with you
<4> :D
<4> what is the effect on a material exposed gamma rays?
<4> i read bout gamma ray on wiki but still have no answer
<1> hmm, it might depend on what the material is
<1> a human, a hunk of metal, etc.
<4> as what i know gamma ray knocks electrons out of the atoms but
<4> what if the material itseft emits gamma ray? what happends in this case?
<4> helo?
<4> hello
<5> anyone can explain how the spin of the electron were decided as ? what behavior indicated that as reasonable
<0> DanF_DrC: i don't undrstand your question
<5> electron has s= right? why?
<5> what experiment pinpoints that. what deductive reasoning
<6> DanF_DrC: The Stern-Gerlach experiment
<5> spanks
<6> chopchop_: It's just energy transferring around, so the effect on material depends on the material when you look beyond that
<4> hondje: does it loses electron or something?
<6> gamma radiation can ionize things
<4> yeah, but how about thing that exposes gamma ray? i still dont get it
<6> you mean why does a source emit gamma rays?
<4> "you mean why does a source emit gamma rays?" => can u answer this
<4> may be that will help :D
<6> well, the simplist way to understand it is looking at a nuclear reaction
<6> lots of good examples of that which explain radioactive decay in a fairly direct way, and the principles go over to other areas
<6> I'm not very good at explaining though
<4> hondje: ok, thanks
<6> mostly the nucleus emits energy when it comes down from being excited
<6> like how electrons drop shells, same general idea at work
<4> so, as what u said, gamma ray is just a way to emits energy when a atom is being excited?
<5> maybe look at the design of some gamma ray light bulbs
<5> hmm this spin business seems interesting. seems fundamental
<6> yeah, fairly critical stuff
<0> DanF_DrC: spin is fundamental but what is your question'?
<5> a spin that is not actually a spin but a boolean property. digital
<5> not so much a question. I'm looking for ways to attack the wave/particle situation, looking for an underlying mechanism
<5> this seems to be at the heart of it
<5> very curious property that it's like oriented magnetism but not actually having an orientation. doesn't that almost smell like it dispells magnetism as a relativistic electric force
<0> DanF_DrC: spin is something that conforms to the same algebra as angular momentum
<5> or at least hints at a deeper less cl***ical story
<5> except no vector right?
<5> has no alignment
<0> spin is a completly quantum mechanical characteristic
<5> hence not like normal ang mom
<0> cl***ical mechanics adds m*** electrodynamics adds charge qm adds spin
<5> qm adds more than that but sure
<0> DanF_DrC: what you have to get accostumed too to discuss qm is operators and comutators
<0> if you look into particle wave duality learn about fouriertransform
<5> what about fourier? I'm sort of trying to avoid the qm math terms like operators and stick to experiments so as to not get stuck with any tempting and perhaps erroneous/limiting conclusions inherent to that
<5> I don't want events to be black box
<0> well you have to interpret experiments somehow
<5> I know about fourier transform
<5> sure
<0> thats what math is for
<5> I disagree. math for finalizing the idea once you get it
<5> is
<0> then tell me what happens if you tranform a delta-dirac distribution
<5> not familiar with that distribution
<0> http://en.wikipedia.org/wiki/Dirac_delta_function
<5> you mean a step function?
<5> gives a particular infinite series. is that relevant?
<0> the delta-dirac-distribution is the derivative of the heavyside-stepfunction
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