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Relativity Finally Meets Quantum Theory?
Posted by
chrisd
on Thu Nov 28, 2002 04:18 AM
from the yahoo-seriously-cool dept.
from the yahoo-seriously-cool dept.
prion86 writes "Physisist Fotini Markopoulou Kalamara (try saying that 3 times fast) believes she has found a way to blend relativity with quantum theory. The article can be found on the Scientific American site."
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Relativity Finally Meets Quantum Theory?
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stereotypes? (Score:3, Funny)
Stereotype are appropriate (Score:4, Insightful)
She may well have some contribution to make, but that's not how you get your picture in a magazine. You get your picture in a magazine by looking good. I used to work as a TV cameraman, and we always interviewed the hottest chicks we could find. Why not? They have opinions too. And they draw audiences, thus spreading the word.
"A spoonful of sugar helps the medicine go down / In the most delightful way" as Mary Poppins put it.
So sexist remarks are very appropriate. Pile'm on.
Re: Noether , Mitner (Score:4, Interesting)
If it turns out she's right, a whole new generation of scientist will grow up thinking that women are only good with kitchen-related things
only ignorant people think so even today.
STW for Emma Noether's and Lisa Mitner's stories.
(Lisa Mitner was like an underdog^2 : both a jewish and a woman
in the pre-Nazi regime. So off the Nobel went to who was very
probably the less-deserving coleague)
The real challenge... (Score:4, Interesting)
Re:The real challenge... (Score:4, Interesting)
All this is really about is loop quantum gravity (LQG) vs. string theory (M-Theory). String theory has been getting closer to making the world make more sense but in this article its just another competing theory.
Re:right, testing is the real challenge (Score:4, Insightful)
When you have a two dimension world you plot on the x and y axis'. When you add a third dimensions you can have infinite points using in space using the same x and y coordinates.
When you add time to the third dimension it does nto change the thrid dimension at all. Two things can exist in the same place (a big no-no in physics) only if they do so in a different time.
If you want to use soem type of "hue" explaination for the fifth dimension it would work like this. You have your regular 4 dimensional world we live in, then you add one more. Now each point in time is defined by x, y, z, time, and "hue". You can have infinite space inside the same old 4 dimensions. If you never changed the "hue" rating of your existance it would be like living on a two dimension sheet in a three dimensional world.
Who knows if we really live in 4 dimensions? Im not saying we dont but there are some ways to explain why we would not have seen extra dimensions if we didn't live with em... but alas the turkey is almost done so i gotta go
happy thanksgiving
Loop Quantum Gravity (Score:5, Informative)
Re:The real challenge... (Score:5, Funny)
Re:The real challenge... (Score:4, Funny)
Stephen Hawkings doesn't make it understable for laymen originally, they just rigged his voice box to a thesaurus and voila...
Stephen Hawking (Score:5, Funny)
I suspect people haven't yet forgiven him for creating the Daleks.
Clarification... (Score:5, Informative)
Merely mixing relativity and quantum theory has been done for years and years - the form of the strong nuclear force was found by Yukawa to be a solution of the Klein-Gordon equation - which was proposed in 1924. The relativity papers were published in 1905, 1908.
OK, so I haven't actually clarified anything at all, have I?
Re:Clarification... (Score:4, Informative)
The juicy bit - and the bit that's worth a Nobel prize or few - is linking General Relativity (GR) with quantum physics. Once this is done, gravitation is unified with the other fundamental forces, physics is complete and I can go and find a proper job
Re:Clarification... (Score:4, Informative)
Merely mixing relativity and quantum theory has been done for years and years - the form of the strong nuclear force was found by Yukawa to be a solution of the Klein-Gordon equation - which was proposed in 1924.
True that, but even SR and QFT have serious fundemental problems.
TTBOMK the EPR paradox and the basic definitions of what
exactly constitutes a measurement and when/why/how does the
WF collapse simultaneously (remember "simultaneous" is a
non-existing term in SR) are still unresolved.
these are not "show-stopper" bugs in that people do exact,
experimentally tested calculations with known theories.
But they mean that although mixing QM and SR has been done for years,
A consistent unifying model is not available.
(unless this QLC stuff, which is new to me, does satisfyingly
address those issues.)
Agreed, with some extensions and clarifications... (Score:5, Insightful)
Wavefunction 'collapse' has some interesting details to be worked out, and some deep matters of interpretation that could use clarification, but it also to date presents no conflicts between experimental results and theoretical predictions. Wavefunctions follow the time-dependent Schrodinger equation, always. It's just when the quantum mechanics extends substantially into macroscopic systems with very large numbers of degrees of freedom, the dynamics of the many-body correlated wavefunction becomes quite complex and our regular intuitions can't keep up very well.
One thing to keep in mind is that wavefunctions do not exist, according to a reasonable definition of exist. The only thing that exists is that which can be measured, that which is physically observable, that which is accessible to an experimental observation. A wavefunction is not physically observable. It is a mathematical tool used to make predictions about experimental results. The simultaneity of collapse of a wavefunction isn't like the simultaneous collapse of say an egg carton. All physical properties related to the process of collapse of an egg carton can be measured by experiment as a function of distance across the carton: density, shear forces, stresses, shape, etc. Not so for a wavefunction.
Not Martha Stewart (Score:3, Insightful)
As a student of physics, this is still a bit beyond me, but I'll be there soon. Things like this pop up occasionally -- most disappear. The theory has to make predictions that can be tested and verified. Just getting QM and gravity together mathematically is not enough.
Tim
Don't know about her theory but... (Score:3, Insightful)
"Having fun is essential, because otherwise you get stressed out. You think, I have to show the universe is made out of atoms, and aaaaahhh, you flip out! So you want to keep loose."
One experiment could be to track gamma-ray photons from billions of light-years away. If spacetime is in fact discrete, then individual photons should travel at slightly different speeds, depending on their wavelength
Cooking? (Score:3, Insightful)
She talks about physics like it's cooking. (at the beginning), and In the meantime, she's hard at work, and waiting for the oven bell. (at the end).
Why are women always associated with cooking? Maybe she does cook well but that's not the point of the article... so why open and close it with that?
Re:Cooking? (Score:4, Insightful)
' she says, "to take this ingredient and another one there and stick something together."'
The author simply extended her own analogy. What's wrong with that?
Re:Cooking? (Score:5, Insightful)
It looks like the cooking analogies CAME FROM THE SCIENTIST HERSELF. Perhaps you should try to convince her to act less stereotypically feminine -- because you say so.
--
Correct spelling of "Glass Ceiling": C-H-I-L-D-R-E-N.
Re:What's cooking (Score:5, Insightful)
This post points to a serious lack of understanding:
The hall of shame is not for scientists who were wrong,
it is for con artists cheating the scientific world
most of the scientists are usually wrong. One cannot do
real research w/o being wrong occasionally.
Schon was a cheat and a liar and I hope he rots on some
deserted island somewhere.
F&P announced results they knew they could not be sure of to the general public, which just doesn't have the right tools to test them.
They were not just wrong, they were deceitful.
AFAIK this woman does NOT claim she united GR and QFT. She sais
she has made a theoretical improvement which still needs to be tested.
Even if she turns out wrong, she is very far from the
halls of shame. Quite the opposite.
Physisist? (Score:5, Funny)
Try saying "physicist" once, and slowly.
Not to troll... (Score:4, Insightful)
Honestly, how many of you would not be totally stuned if a girl looking like that introduced herself to you (first big surprise
Metaphysical physics.... (Score:4, Interesting)
Personally I like this version of unified relativity but I'm very certain that there will be many nay-sayers concerning her metaphysical POV of light cones and spin networks as personal and individual interpretations of the universe... though it is really nice to hear a published physicist speak about overlapping collective conciousness and the impact on perceived physics of the universe.
Totally different from the humaniora terms (Score:4, Insightful)
There is a sad tendency of some less honrable people at humaniora to try to tie their pet models of the weak (consensus reality, social consructionism, cultural relativism, whatever it is called this month) to physical theories like quantum physics and even Einsteins relativity theory, apparently to give them some extra credibility.
Apart from it being bad science to apply models outside their domain, these attempt are never really based on more than some shared terms, even if this usually is hidden by a flood of words.
The models humaniora are actually pretty good in their own domain, as long as one remember they are models useful for dealing with a limited range of problems, and does not attempt to interpret them as metaphysical truths.
Quantum observers (Score:4, Informative)
Uhm, maybe I'm being silly, but... (Score:3, Informative)
But a spin network represents the entire universe, and that creates a big problem. According to the standard interpretation of quantum mechanics, things remain in a limbo of probability until an observer perceives them. But no lonely observer can find himself beyond the bounds of the universe staring back. How, then, can the universe exist? "That's a whole sticky thing," Markopoulou Kalamara says. "Who looks at the universe?" For her, the answer is: we do. The universe contains its own observers on the inside, represented as nodes in the network. Her idea is that to paint the big picture, you don't need one painter; many will do. Specifically, she realized that the same light cones she had used to bring causal structure into quantum spacetime could concretely define each observer's perspective.
Because the speed of light is finite, you can see only a limited slice of the universe. Your position in spacetime is unique, so your slice is slightly different from everyone else's. Although there is no external observer who has access to all the information out there, we can still construct a meaningful portrait of the universe based on the partial information we each receive. It's a beautiful thought: we each have our own universe. But there's a lot of overlap. "We mostly see the same thing," Markopoulou Kalamara explains, and that is why we see a smooth universe despite a quantized spacetime.
So my boggle is this: Until the first "observer" evolved, nothing observed the universe, so it existed in all quantum states simultaneously. If so, how did that first observer ever evolve? Or is she posutlating that the universe's existence is its own observation?
Re:Uhm, maybe I'm being silly, but... (Score:5, Interesting)
The REAL articles... (Score:5, Informative)
Perhaps related... (Score:4, Interesting)
What is interesting is that this can explain the "light cone" phenomenon as well. If we are given that a cell can only be affected by those cells adjacent to it in the network, there is a theoretical fastest response of a system, depending how often the "steps" of the automota occur, and how far reaching are these network edges. For example, if we had two nodes 3 edges away from each other in this great graph, it would take at least 3 "ticks" for either cell to affect the other. Perhaps this is the concept she's using, but with actual physical concepts instead of some abstract idea of cells?
Background for LQG and spin networks (Score:5, Informative)
John Baez [ucr.edu] is a well-known mathematician/math. physicist who works in, among other things, quantum gravity. He is also very well known for the Usenet column This week's finds in mathematical physics [ucr.edu], which is certainly worth a look a t if you're at all interested in these things and have a bit of a mathematics background.
One of the great things about TWFiMP is the writing style: when reading it, one really does get the idea that one understands what's going on. Of course this tends to wear off soon after leaving the computer, but. At any rate, many of the TWFiMP talk about spin networks and quantum gravity, including for example week 43 [ucr.edu] and week 55 [ucr.edu]. Week 110 [ucr.edu] talks specificially about Penrose's spin networks. He mentions some of Markopoulou's work in week 99 [ucr.edu], week 114 [ucr.edu] and week 133 [ucr.edu]. These might provide a bit of a middle-ground between the very fluffy SciAm article and the hard stuff [arxiv.org] on arXiv [arxiv.org].
Of course there is also Markopoulou's recent expository article [arxiv.org], which is a great introduction!
Re:Background for LQG and spin networks (Score:4, Insightful)
Great! We are talking about heavy duty physics, and this line says that all the stuff can be translated to a mathematical algebra, the one about rooted trees to be exact. I could teach nearly anyone what this algebra is in 5 minutes, how for example differentiation in n dimensions is reduced to a simple excercise with graphs (i.e. dots and lines) and concrete physical results can be proven by proving their counterpart in this simple algebra.
Amazing how such a relatively new, seemingly unrelated part of mathematics (Hopf algebra's were put into new perspective in 1963 because virtually the same algebra can be used for approximation methodes like the Runge Kutta method) rapidly ganis such a central place in physics.
Good story. (Score:5, Interesting)
I for one spend to much time being bitter at microsoft and not enough doing interesting things.
Speaking of Loop Quantum Gravity... (Score:3, Funny)
Re:okay.. (Score:3, Funny)
It'll help with that special physisist of your dreams you've had your eye on, of course! Great conversation peice.