100th Anniversary of Quantum Physics 260
EricR writes "On December 14, 1900, Max Planck presented experimental results in front of the German Physical Society and announced that they could best be explained if energy exists in discrete packets, which he called "quanta." Today is the 100th birthday of Quantum Physics."
100th? (Score:5, Funny)
Re:100th? (Score:5, Funny)
The number 100 is correct.
Slashdot is simply very late with the news this time.
Re:100th? (Score:5, Funny)
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Better than Slashdot grammar / spelling (Score:2, Flamebait)
Re:100th? (Score:2)
hehe.
It took me a while to figure out that this universe would be parallel to itself... (which makes parallel an equivalence relationship).
Re:100th? (Score:5, Funny)
Re:100th? (Score:5, Funny)
delta E * delta t >= h-bar
Therefore, the slashdot editors are being careful about not determining the time too precisely lest Max Planck and the German Physical Society accidently obtain an energy with an order of magnitude anywhere between a butterfly's wings and a supernova.
Re:100th? (Score:2)
No, I'm right. But, so are you, interestingly enough. Anything within about a factor of 10 of h-bar is allowable because of the different ways of calculating those values for a wave-packet.
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Makes sense -- given that we're talking about the uncertainty principle....
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Re:100th? (Score:5, Funny)
Re:100th? (Score:2, Funny)
Re:100th? (Score:5, Funny)
Re:100th? (Score:2)
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Yes, I'm tired of quantum theory being used as a justification for bad science...
Re:100th? (Score:2)
Schroedinger's cat is DEAD (Score:3, Funny)
Richard P. Feynman said... (Score:5, Interesting)
Re:Richard P. Feynman said... (Score:1)
Re:Richard P. Feynman said... (Score:3, Informative)
My favourite quote from a quantum mechanic was Einstein's "Two things are infinite: the Universe, and human stupidity. Oh and I'm not so sure about the first one." If you're worried about the phrase quantum mechanic being applied to Einstein, I suggest you read about the photoelectric effect.
Re:Richard P. Feynman said... (Score:4, Interesting)
What Einstein disagreed with were things like the Uncertainty Principle, the EPR paradox (If he had lived to see it), and most likely even Schrodinger's Cat. He disagreed with the assumptions that led to these conclusions. So Einstein was most definitely NOT a supporter of quantum mechanics as we now know it. Even the greatest can be mistaken.
Re:Richard P. Feynman said... (Score:5, Informative)
I think his main problem was the idea of Universal instantaneous collapse of the wavefunction (which leads to "spooky action at a distance"[2] and God playing "dice with the Universe"). These concepts came from the Copenhagen Interpretation, and was the best way the Quantum theoreticians could think to explain the seemingly counterintuitive results of QM - it's pure philosophy and has nothing to do with the Physics.
Of course not everyone necessarily subscribes Copenhagen now. My personal favourite explanation is the proposition popular in the 80s and in Sliders - that multiple Universes are created at each instant multiple outcomes are possible, each reflecting the different outcomes.
Quantum mechanics as we currently know it includes Bose-Einstein statistics describing the behaviour of systems of integer-spin particles (which leads to the concept of a Bose-Einstein condensate - a highly active area of research today); Light Amplification by Stimulated Emission of Radiation (described at the atomic scale by the Einstein coefficients); quantisation of electromagnetic radiation (proposed by Einstein); Einstein's explanation of the photoelectric effect (for which he received the Nobel prize). Stretching the boundaries a little, there are equations for the equilibrium number of charge carriers in Solid State physics which rely on the quantisation of charge in the material. These are known as the Einstein equations.
Even the greatest can be mistaken.Such as when he removed lambda from his equation on the state of the Universe (his "biggest blunder", indeed :-)).
[1]Point of order: even Schroedinger didn't believe in Schroedinger's Cat. He set it up as a thought experiment to show how absurd QM is (I mean, who could really believe in a dead/alive cat? Not him). The experiment has of course, since been done, sans cat.
[2]He believed that the "instantaneous" collapse of the wavefunction would lead to information being propagated instantaneously throughout the Universe. Of course, the wavefunction is not a measurable quantity so this does not occur.
Re:Richard P. Feynman said... (Score:2)
As an aside, have you had a chance to read the 1916 paper he wrote, which in the middle treats the laser phenomenon? Everyone references it, but I wonder how many have actually read it (see the other thread). It is very hard to come across, and I spent about a year looking for an English translation (On the Quantum Theory of Light [electromagnetism?])... very frustrating. Not even the world-class library at Bell Labs had a translation, though they did have the original german manuscript...
Re:Richard P. Feynman said... (Score:2)
I think his main problem was the idea of Universal instantaneous collapse of the wavefunction (which leads to "spooky action at a distance"[2] and God playing "dice with the Universe"). These concepts came from the Copenhagen Interpretation, and was the best way the Quantum theoreticians could think to explain the seemingly counterintuitive results of QM - it's pure philosophy and has nothing to do with the Physics.
Of course not everyone necessarily subscribes Copenhagen now. My personal favourite explanation is the proposition popular in the 80s and in Sliders - that multiple Universes are created at each instant multiple outcomes are possible, each reflecting the different outcomes.
I think you're confusing two different phenomena here. The Copenhagen Interpretation is more about explaining the wave-particle duality observations. In a two-slit experiment it can be proven conclusively that some aspect of a photon travels down both slits simultaneously. This can be explained best by a wave. But in the photoelectric effect there is a cutoff wavelength before the number of electrons emitted is proportional to the intensity of light. Thus (and you should read the details cause it's nonobvious from what I've said), photons must be quantised, as well as localised (this is clear if you send one photon at a time down a double slit experiment.
So how can light (and later we find all matter) be both a particle and a wave? Well, the Copenhagen Interpretation says that it's a quantized wave. Thus, it travels as a wave, then collapses to a single point upon interation with any other measurable property. This interpretation properly explains all current experimental results, but it has philosophical problems in that it violates the principle of locality, the principle that something in one place can't instantaneously affect something in another place.
The multiple worlds theory does not explain this paradox. Still, Einstein's theory, that there are hidden variables contained within the wave itself, has not been disproven completely. Bell's theorem, in answer to the EPR paradox, only disproves certain simple hidden variables theories.
At this point now I'm out of my league of expertise, so I'll defer to someone who's taken more than QM I.
Re:Richard P. Feynman said... (Score:2)
I was indeed talking about two separate things, however it appears that I was not clear in distinguishing them. I shall try and separate the two a little.
The Copenhagen interpretation does not say that matter is a localised wave. It says that matter is described by a wavefunction that extends over the whole Universe. It further says that when a measurement is made on some property of the wavefunction (e.g. the momentum, which is the first derivative of the wavefunction) then it must be found that the wave funtion is an eigenfunction of that property's operator. If the wavefunction previously was not, then it is said to "collapse" into one.
Einstein did not like the Copenhagen interpretation because it allowed for "spooky action at a distance" and various apparent paradoces.
When I pointed this out, someone replied to say that Einstein was not what we would think of as a Quantum Mechanic. I supplied evidence of multiple instances in modern QM where the groundwork was done by Einstein, including Bose-Einstein statistics, BECs, the photoelectric effect and others. The photoelectric effect is important because it was the first theory to give credibility to Planck's quantisation of the EM field.
I did not relate the photoelectric effect to Copenhagen. Oh and BTW your comment "in the photoelectric effect there is a cutoff wavelength before the number of electrons emitted is proportional to the intensity of light" is misleading. Properly there is a cutoff frequency given by, in meta-LaTeX, $h\nu_{min}=\Phi$, where $\Phi$ is the work function of the metal. It is an important distinction because the frequency of a photon with given energy is a constant, whereas the wavelength is variable and depends upon the refractive index of the medium.
Apologies if you thought that I was connecting the photoelectric effect with the Copenhagen interpretation. Of course any good philosophical interpretation of QM will be Physics-independent and yield correct answers for any problem. And the problem that Einstein had about non-locality is moot - here's a thought experiment for you, I hope it's explained succinctly enough - my degree doesn't have a very large written component!.
Imagine a source that emits two photons at a time, in opposite directions. We know that they must be oppositely polarised, so if I can set the polarisation of the photons you can measure them and I can send you a binary message, can't I?
We try it. I stand two light years away from the source in the -x direction with a Polaroid, you stand with a similar polaroid two light years away in the +x direction, and a detector one meter further away along the same axis. Now you keep your polaroid oriented so that it only transmits photons polarised with the z axis, I can choose whether to set mine along the z or y axes. So if I set a photon polarised y, you will see a photon in your detector. If I set a photon polarised along z, you will not. One and zero. We have a data transmitter. Or do we?
No. Because the photons that are emitted by the source are initially randomly polarised (or unpolarised, if you like). So whichever orientation I place my polaroid in, statistically we should expect 50% of the photons to be transmitted. No matter what I do, you will always see a random 50% of the photons in your detector. There is no useful information transmitted, and relativity is preserved.
Re:Richard P. Feynman said... (Score:2)
OK, I agree with all that you said, including that I properly should have said frequency rather than wavelength. But your comment about Einstein's non-locality being moot I don't think is quite right.
Imagine a source that emits two photons at a time, in opposite directions. We know that they must be oppositely polarised, so if I can set the polarisation of the photons you can measure them and I can send you a binary message, can't I?
Sure, but this is easily explained by a hidden variables theory. One photon was always polarized one way, the other was always polarized the opposite way.
The current QM theory says that both photons were initially polarized both ways. Then when the measurement was taken the photons instantaneously collapsed into opposite polarizations. This is a much different interpretation, at least philosophically.
There is no useful information transmitted, and relativity is preserved.
Einstein's problem with non-locality was not just that relativity could be destroyed, it went to a fundamental belief about the universe. Perhaps it would be incorrect, but it should only be thrown out if there were absolutely no other way to justify experimental results.
Does Bell's theorem put us in that position? I have a couple more years of studying before I can even have an opinion on that one.
Re:Richard P. Feynman said... (Score:1)
Re:first official freek-out recorded? (Score:2)
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Re:first official freek-out recorded? (Score:2)
Cramer came up with an explanation, the Transactional Interpretation [washington.edu]. Gribbin gives a reasonably good explanation of it in "Schroedinger's Kittens".
Re:first official freek-out recorded? (Score:2)
Perhaps you already knew all of this. I am not a physicist, but hopefully this helps.
Re:Richard P. Feynman said... (Score:2)
Then, about three chapters in, the book makes something explicit: From here on out, don't try to understand it, just trust the mathematics
Re:Richard P. Feynman said... (Score:3, Informative)
Basically, formalism in quantum mechanics is expressing quantum mechanical ideas in the language of QM, namely linear algebra. Operators and observables (physical quantities like position, velocity, etc.) are represented either by matrices or " notation". This allows one to delve further into quantum mechanics, and allows one to use mathematics to predict phenomenon. In a sense, this complication of the mathematics for simple problems (like the hydrogen atom) allows one to do more complex problems (like the hydrogen atom in a magnetic field, where the energy levels of the orbitals will split).
So today, quantum is taught by trying to relate basic concepts in QM to those in classical mechanics (such as postition, energy, momentum, etc.) in the first few chapters in a book. Then to faciliate communicating QM ideas, formalism is introduced. It's like no one wants to write three plus two equals five, when 3+2=5 will suffice. This allows more difficult problems to be tackled more easily.
Re:Richard P. Feynman said... (Score:2, Informative)
All are better than Goswami, though.
BTW, with reference to this article [slashdot.org], if you know math up through differential equations and want to learn about QM, I highly recommend Griffiths' book. It's not a reference text like Liboff, but it contains more than enough math so that it's not handwavy.
Re:Richard P. Feynman said... (Score:2)
Re:Richard P. Feynman said... (Score:2, Insightful)
I the same sense, I do not "understand" why the world would obey something as counterintuitive as quantum mechanics. On the other hand, I can see the close mathematical analogy to classical mechanics (which we have all accepted), so it is not hard to imagine that this might actually work. Using the postulates of quantum mechanics, I can then calculate a huge amount of new stuff that I did not understand before I learned quantum mechanics.
I think my conclusion is that there is no such thing as understanding exactly why nature follows a certain set of rules. It's just that experiments lead us to believe that the mathematical formalism gives us something that looks like the reality around us. And besides devine intervention, that's the only thing we can ask from our theories. Clinging to the believe that understanding should be more than that is what religion is all about, but it has little to do with science.
Enrico Fermi Institute - Dec 2nd (Score:5, Informative)
Check out the University of Chicago's Physics Department [uchicago.edu] for all the information you could want to know about modern research in quantum physics.
Oh, and December 2, 2002 was the 60th Anniversy of the first self-sustaining controlled release of nuclear energy [uchicago.edu]
Sorry about the spelling... (Score:5, Informative)
CERN [www.cern.ch]
The Enrico Fermi Institute [uchicago.edu]
Fermi National Accelerator Laboratories [fnal.gov]
Agronne National Laboratories [anl.gov]
Los Alamos National Laboratories [lanl.gov]
Yep, all the information you could want on modern Quantum Physics.
Re:Sorry about the spelling... (Score:2)
I absolutely agreed that it is not the case that all modern quantum physics is done in high energy physics. Alot of collaboration tends to happen at these locations, however, which drives the entire field forward differently than at other places.
boo hoo (Score:5, Funny)
My thoughts on the matter. (Score:5, Insightful)
It is all so amazing and we must realize that any theories we come up with will never be able to describe things as a whole. It is basically the universe trying to understand itself...when it already knows. Dang....now I am getting into Zen philosophy so I will jsut shut up becasue I don't know where this is leading towards.
Re:My thoughts on the matter. (Score:2, Interesting)
Newton was, conceptually, completely wrong on some important points when he came up with his ideas of gravity. Did we throw his theory out the window when Einstein came up with Relativity? Heck no! Any useful scientific theory predicts something. Things like Newtonian physics are extremely useful, and to a large degree, correct at describing every day phenomenon. It was a requirement on the theory of relativity that it in some way incorporate, or reduce to, Newtonian physics.
Any GUT theory will have to do this. We won't really be throwing anything out the window, just adding to our knowledge. In same cases (eg Newton), even though the older theory is wrong, it is still very widely used because at the velocities, masses, and energies of every day life on earth, it is quite accurate.
If we find some way to replace QM, or incorporate gravity and QM, then relativity and the Shroedinger equation will both have to somehow be a part of the new theory, because the both accurately describe the universe.
Tim
Re:My thoughts on the matter. (Score:2)
For those of you who don't afraid of where this is leading towards, here are some interesting links between buddhism and fundamental phisics.
Quantum sunyata [btclick.com]: Basically, what quantum theory says is that fundamental particles are empty of inherent existence and exist in an undefined state of potentialities. They have no inherent existence from their own side and do not become 'real' until a mind interacts with them and gives them meaning. Whenever and wherever there is no mind there is no meaning and no reality. This is a similar conclusion to the Mahayana Buddhist teachings on sunyata.
Sunyata - the emptiness of all things [btclick.com]: It is important to emphasise that the mathematical equations of quantum physics do not describe actual existence - they describe potential for existence. Working out the equations of quantum mechanics for a system composed of fundamental particles produces a range of potential locations, values and attributes of the particles which evolve and change with time. But for any system only one of these potential states can become real, and - this is the revolutionary finding of quantum physics - what forces the range of the potentials to assume one value is the act of observation. Matter and energy are not in themselves phenomena, and do not become phenomena until they interact with the mind.
Buddhism copes with Science [buddhanet.net]: "If there is any religion that would cope with modern scientific needs it would be Buddhism." -- Albert Einstein
A cosmic religion [buddhanet.net]: "The religion of the future will be a cosmic religion. It should transcend a personal God and avoid dogmas and theology. Covering both the natural and the spiritual, it should be based on a religious sense arising from the experience of all things, natural and spiritual, as a meaningful unity. Buddhism answers this description." --- Albert Einstein
About buddhism [dharma-haven.org]: "Buddhism has the characteristics of what would be expected in the cosmic religion for the future: It trancends a personal God, avoids dogma and theology; it covers both the natural and the spiritual, and it is based on a religious sense aspiring from the experience of all things, natural and spiritual, as a meaningful unity." --- Albert Einstein.
My favorite quote of Albert Einstein: "Imagination is more important than knowledge".
Zen and physics (Score:2)
Have you read Heisenberg's "Physics and Philosophy?"
The major problem people are having with QM, the reason this "Zen" thing keeps coming up, is that QM says something incredibly strange about the world: the results of any experiment or measurement are inextricably tied up with the very act of measurement. QM seems to shatter the idea that an objective universe exists independently of the observer.
What QM is trying to tell us is that there is no way to actually draw a line between observer and observed. That's why people always bring up Zen (or Buddhism in general), since one of its major philosophical principles is that the separation between self and universe is an illusion.
Re:Zen and physics (Score:2)
Whoa, hold on. I never said (nor does Zen ever state) that the universe is "imaginary." That is meaningless bullshit, and people unfortunately often misinterpret Zen that way. What Zen (and all forms of Buddhism, really) states is that there is no objective universe. The universe does not exist independently of any observer or "object" within it. It is the dualism between observer and universe which is illusion. You've taken my original statement ("A and B are equivalent") and interpretted it as "A cannot exist without B." That doesn't follow logically.
The objective universe exists. But once we get to a fine enough scale, it's simply impossible to measure something without changing it. What's so counterintuitive about that?
Nothing, in a lot of cases. The classic example is trying to measure the temperature of a thimbleful of water with a thermometer -- by putting the thermometer in the thimble, you change the water's temperature. But Schrodinger's cat is both alive and dead, until I (the observer) look in the box. Are you saying that isn't counterintuitive? Or are you saying Schrodinger was wrong?
Re:Zen and physics (Score:2)
It's a grammatical problem. "B influences A" and "B is a subset of A", when uttered as profound statements, are easily inferred as "A does not exist without B."
I understand what you're saying. I just don't think most peole who blurr Zen and QM do.
Nothing, in a lot of cases. The classic example is trying to measure the temperature of a thimbleful of water with a thermometer -- by putting the thermometer in the thimble, you change the water's temperature. But Schrodinger's cat is both alive and dead, until I (the observer) look in the box. Are you saying that isn't counterintuitive? Or are you saying Schrodinger was wrong?
I think Schrodinger was wrong. Or rather, incomplete.
"Until we open the box and Learn if the cat is alive or dead, we must act & plan as if it were both alive and dead."
The cat is either alive or dead. However, until we determine which is which, we need to have a box to bury the cat in & enough food to feed the cat.
Re:My thoughts on the matter. (Score:1)
You Sir, Are An IDIOT (Score:2)
. I'm just an
advocate for not blatantly charging forward and
basing new things on old things that aren't much
better than voodoo. It's ok to say "We don't
really know".
Ummm... Mr.-Most-Important-Person-in-the-World, just because YOU don't understand it doesn't make it invalid, or useless. Without quantum physics (which IS incidentally the topic of discussion), you wouldn't have transistors and their elk, culminating in the computer with which you posted this backwoods tin-foil-hat-wearing drivel.
The tornado-in-a-can doesn't look too impressive compared to a 1/4 inch square chip that can simulate the folding of protein, or powers a Korg Triton.
An academic in his free time using a computer figured out why the shower curtain in a shower gets sucked in with a few days of his spare time. The guy who invented the tornado in a can took 15 years of on/off effort.
That is why we have academics working in institutions on that wacky shit, because we want to put the stuff it into practice ASAP.
You can't tell me you don't want warp drive, because that would be frickin' cool. We gotta slog through the simple stuff (GUT) before we can start bending the rules...
Since i'm not smart enough to make a joke here (Score:4, Funny)
Re:Since i'm not smart enough to make a joke here (Score:2)
Quantum Mechanically Speaking, (Score:5, Funny)
Re:Quantum Mechanically Speaking, (Score:2, Funny)
Basis of all science (Score:4, Interesting)
Through the wave of all the 2002-1900=100 jokes here, I would like to salute Mankinds greatest discovery, Qauntum Physics. This shows teh flexibility of the human brain, able to work with 4 dimensions (Relativity) to now (26 dimensions), and even something as strange as Quantum Mechanics, that defies our imagination and relies purely on reasoning, yet so powerful, it gave us the best of the last century's inventions, including the device you're staring at.
Quantum Mechanics is more than the kind of Physics that allows engineers to make locomotives. Its even more than what allowed us to land on the moon. As a warmer, we get nukes and the mighty computer. This physics promises us glimpses of the time the Universe was born, the quantum computer, time travel, teleportation, and many other things we have'nt imagined yet.
Physics has always been the foundation of knowledge, and it was replaced 100 years ago (+- 2 years). I think we're in for much bigger surprises this century.
Re:Basis of all science (Score:5, Funny)
Sounds like your brain is a little too flexible right now. Go home and sleep it off, dude.
Re:Basis of all science (Score:3, Funny)
Naah, once we get SDI working and perfect Genetics, it's just Future Tech 1, Future Tech 2... for as long as we keep bothering with science spending.
--
Benjamin Coates
Definitions (Score:2, Informative)
When Planck was studying spectra, he was mostly dealing with photons, and then layed down the fundamental parts of quantum theory, outlining the physics behind these "digital" packages, which Einstein later defined as photons.
Ok, Slow news day. Other cool Dec 14th events: (Score:3, Informative)
this page [todayinsci.com] talks about some other interesting scientific events that have their anniversary today:
1986 - First non-stop, non-refuelled flight around the world
1967 - Announcement of first synthesis of biologically active DNA
1962 - Mariner transmits information from first-ever rendezvous with Venus
Argh this is all B.S.! (Score:1)
Re:Argh this is all B.S.! (Score:2)
Incisive comment... my money is on it being the 102nd :)
(which in fact it is, as this page [todayinsci.com] reveals).
But in Russia there is no word for... (Score:2)
Quantum Physics -- entanglement (Score:2, Insightful)
Re:Quantum Physics -- entanglement (Score:2, Informative)
What do you think you mean by manipulate the particles?
The only thing entagled particles share is spin. If you move one particle the other does not also move.
The Heisenberg Uncertainty Principle still applies, so that it is possible for a particle to travel faster than light, but it is not possible to send a signal faster than light. The proof by contridiction for that under quantum theory is still quite simple.
How does one use a single subatomic particle to "cause" a nuclear blast? The statement is meaningless.
Most of the people here have read the Ender series and know what an ansible is. A science fiction story does not equal a quantum mechanics theory.
Jason
Re:Quantum Physics -- entanglement (Score:4, Informative)
"it doesn't even matter how far apart they are in the universe; they'll always do the same things at the same times no matter where they are in the universe"
Wrong wrong wrong wrong wrong. Quantum entanglement says that the two particles *started off the same (or opposite or some such relationship of the initial states). It follows, then that if you do not *observe* either particle for quite some time, and take the two of them far distant from one another, then the instant that you *observe* the state of one particle, you immediately *know* the state of the other particle (wherever it is).
This gives at first pass the illusion that you have gotten information at faster than the speed of light... I mean, you did just *instantaneously* learn the state of a particle far, far away, right? That's gotta mean that you communcated with that thing way over there, right? No. Not at all.
Now, what makes this interesting is the fact that quantum mechanics tells us that if you don't *observe* either particle's state, then neither particle has actually "picked" a state yet. So, it's as though the one particle *told* the other one that "hey I was observed at state A, so you must now occupy state B". So, now it appears that information has traveled faster than the speed of light... and I won't argue that point, because last I knew better scientists than me were still duking that one out.
However, one thing that anyone with a basic understanding of this can agree upon is the fact that there is no way to *use* the possible information transfer involved in the collapse of a wave function to TRANSMIT INFORMATION. Why? Well, there is no way to observe a wave function directly. You can only measure some operator on a wave function (like energy, position, spin), and by doing so, you collapse the wave function into an eigenfunction of that operator. However there is no way to tell whether the eigenfunction you observe is the result of *your* observation or someone elses. In other words, you can't tell if you collapsed the wave function or if someone else did, and quantum entanglement doesn't *do* anything other than pre-collapse the wave-fcuntion for you.
Face it: The Universe is just plain Fscked (Score:3, Funny)
God is teasing us. We cannot have our cake and eat it too. QP is just like this all over. If I was religious, I just might interpret this as a big Neener Neener Neener from the beyond. It is the biggest sign of a Teasing God since the discovery that zits appear mostly on the body parts most visible to the public. Does the act of observing a face cause zits? Nobel in there for somebody.
If only... (Score:2, Informative)
God bless this man (Score:3, Informative)
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Max-Planck-Institut für Plasmaphysik [ipp.mpg.de] - [ Translate this page [google.com] ] ...
Das Max-Planck-Institut für Plasmaphysik untersucht die physikalischen Grundlagen
für ein Fusionskraftwerk, das - ähnlich wie die Sonne - Energie aus der
Description: Garching (Deutschland)
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www.ipp.mpg.de/ - 14k - Dec. 13, 2002 - Cached [216.239.39.100] - Similar pages [slashdot.org]
Max Planck Institut fuer Radioastronomie Bonn [mpifr-bonn.mpg.de] - [ Translate this page [google.com] ]g en [google.com]
[english]. Aktuell, Das Institut. Forschung, Mitarbeiter.
Öffentlichkeit, Intranet. webmaster@mpifr-bonn.mpg.de.
Description: Bonn (Deutschland)
Category: World>Deutsch>...>Astronomie>Forschungseinrichtun
www.mpifr-bonn.mpg.de/ - 2k - Cached [216.239.39.100] - Similar pages [slashdot.org]
Re:God bless this man (Score:2)
Re:God bless this man (Score:2)
Yet, he invented something in his lab that parallels the importance of Einstein, Feynman, and Wright's findings -- quantum physics!
even back then, it was not one-genius alone.
Science is a social phenomena. Heroe-worship is not a bad thing in itself,
just remember that those heroes were a part of someting greater than a single human.
Be it Saint Albert (E), Isaac (N), Karl (G) or Max (P), they were part of the "church", and the credit falls to many others as well.
Public Advisory (Score:5, Funny)
As such, there is a risk of discussions developing that involve people talking out of their
completely uninformed ass. Some of the most common symptoms of Quantum Ass-Talking Syndrome (QATS) involve the following topics:
If you feel the urge to discuss these topics, we advise that you immediately consult somebody who knows what the hell they're talking about. If further trouble develops, a dose of reality is recommended.
Re:Public Advisory (Score:3, Funny)
That was cool! My thanks for attempting to ease the frequent pain experienced by those of us who have taken even a single undergraduate QM course, as a result of the spread of QATS among our friends and associates.
QATS is a strange disease; it inverts the normal parasite-host relationship by causing pain only in those exposed who are not susceptible.
Hopefully we will someday find a cure for QATS among the vector population. Failing that, I guess we can pinpoint their energy level so precisely that they disappear, or someth-Oh no! I've been infected! Someone please help me!!...
Re:Public Advisory (Score:3, Funny)
QATS is a strange disease; it inverts the normal parasite-host relationship by causing pain only in those exposed who are not susceptible
The term "Physics Karaoke" springs to mind.
Re:Public Advisory (Score:2)
Absolutely. It is generally accepted at my university that the physicists are the worst singers in the Faculty of Science. In my experience, biochemists generally are the most talented by far.
In Soviet Russia.... quantum tunnels you! (Score:2, Interesting)
As Hawking said (to paraphrase)... not only does God play dice but some times he throws them where no one can see.
One of the things i find so funny about it is how much physicist seem to hate it, even the ones that helped found it!
However it is the most accurate theory in modern physics, which is why it has become known as the standard model.Perhaps string theory or M-theory can help make it a bit more astetic... which seems to be what most physicist go for these days.
/. submission queue (Score:4, Funny)
What Planck actually discovered (Score:5, Informative)
Somehow, Planck worked out an equation which yielded that wavelength distribution quite precisely. I believe that it is correct that his model was a "what if" conjecture about energy exisiting in discrete packets.
As discussed, the rest is history.
53 years of passing time has dimmed my memory, but I'm pretty sure that is the story.
Re:What Planck actually discovered (Score:4, Informative)
Plank showed, by solving statistically-mechanically, a series of independent discrete quanta(estimating the photon oscillation as simple-harmonic), the allowed spectrum was consistent with the observed data.
Lucky for him, simple harmonic oscillators have that exact energy spectra (E=hbar*omega(N+1/2)) where N is the energy-level (or quantum number) of the oscillator. Lucky guess, or insight of pure genious. No other (that i know of) systems have such an energy spectra (evenly-spaced, singly occupied). simple examples are particle-in-box and hydrogen atom.
This method of the blackbody radiation as quantum simple-harmonic oscillators is also very nearly similar to calculating the specific heat of crystals (Einstein method for independent oscillators, but corrected by Debye for coupled oscillators up to a sharp cutoff frequency).
This, though, ushered in new tidings, not just for pure quantum physics, but for statistical physics of quantum objects (bosons, fermions) which have different statistical distributions than classical particles (maxwell-boltzmann statistics). paved the way for solid-state physics to burgeon forth (hello transistors!!!)
Birthday Party (Score:4, Funny)
Republican Majority Leader, Trent Lott, made a birthday speech congratulating Quantum Physics with its 100 year anniversary, and fondly recalled when during the planning stages of the Manhattan project, scientists were considering building a weapon of mass destruction based on Quantum Physical principles.
"I can tell you now, I wish they'd picked Quantum Physics," Lott said, "If they did, I'm sure the world as we know it would be a better place for white people to live."
And he hated it (Score:4, Interesting)
Not long after, Planck came forward using Boltzmann's ideas. There is some evidence to show that Planck's true hope was that he would be proved wrong -- he didn't like the quanta or probability interpretation at all.
Tim
Chunk physics (Score:4, Interesting)
.. Just had to share that.
Re:Chunk physics (Score:2)
100 years from now... (Score:2)
If I read the article... (Score:3, Funny)
Two year old news from Agnostica.com (Score:2, Informative)
Guess I need to update the site more often.
Nice to know the folks at Slashdot celebrate Agnostica, though!
can never find a good Quantum Mechanic (Score:2)
Re:1900 + 100 = ? (Score:1)
Yes it was, they were a bit slow with it, but its finally here - the slashdot repost.
Tomble answers your questions! (Score:5, Funny)
As you can doubtless see from a second look, it all fits into place that Planck's announcement, which lead to other scientists further investigating the full ramifications of the theory, was the conception of Quantum Physics as we know and love it today. Whilst the title is obviously innacurate, the observation that today is Quantum Physics' 100th birthday is clearly correct, as it is broadly accepted that models of reality have a 2 year gestation period- a similar duration to elephants, I believe.
Sadly, though, Quantum Physics has not been too lucky in love, having had occasional brief flings with 50's icon Relativity, whom everyone would have liked to see it matched up with, but it never quite seemed to work out for them- it seems they just had too many differences.
Although we all wish Quantum Physics well, and it seems surely impossible that such a great catch would never get married (who knows, maybe good old Q.P will be able to patch things up with Relativity after all), it shall obviously not be having any anniversaries for some time yet.
Hope this clears everything up,
Tomble
Re:Belief in a God is stupid (Score:1, Offtopic)
Sorry, all this talk of RPN means I NEED this... (Score:2, Funny)
Notation reverses YOU!
Whereas of course,
In SOVIET RUSSIA,
RPN POLISHES you!
Although strictly speaking, that probably should have been:
In SOVIET POLAND,
Notation YOU! reverses
Whilst SOVIET RUSSIA has it's own method of doing these things, which didn't quite catch on in the west.
Sorry about that, everyone.
Funny! (Score:2)
ttyl
Farrell
Re:Bell's Inequality (Score:3, Informative)
One of the odd phenomena observed in quantum mechanics is the creation of tandem photons from certain kinds of light sources that have the odd characteristic that their dynamic properties are very strongly correlated. That is, if two observers measure the polarization of one photon each, they will observe the same value for the polarization. Quantum mechanically speaking however, if, say, the two photons are polarized at some angle perpendicular to its line of travel, and you set up your measurement apparatus to measure the polarization at a different angle, then QM does not tell you what polarization value you will observe, but gives you a probability. The observed polarization for one photon is essentially random, but the distribution of values for many photons will follow the probability predicted.
Now several physicists, notably Einstein, took this bizarre feat of the correlated photons to mean that the polarization values for the two photons had to be dependent on some hidden variables that QM just didn't know about, but that became apparent in the experiment, which became known as the Einstein-Podalsky-Rosen (EPR) paradox.
Now, in the '60s, along came Bell, who was working on the EPR paradox hoping to prove Einstein et al correct. Bell's inequality reasons what the maximum possible correlation between the two photons should be, assuming that once the two are created, the one cannot affect the other. The problem is, the EPR paradox, when carried out in real experiments, has been shown to violate this inequality: the two photons are much more strongly correlated than they have any right to be according to a hidden-variables-locality-preserved interpretation of QM.
In the mathematical description of QM, this behavior has to do with the fact that in QM the two photons are not treated separately, but must be modelled by one function in hilbert space. The two photons are "phase entagled". Einstein particularly disliked this property of QM because it seems to throw out the principle of locality (no action-at-a-distance), although currently I believe the accepted idea is that no "information" can be sent non-locally using entaglement. I'll leave those questions to a real physicist.
See EPR Paradox [wikipedia.org]