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Physicists Propose New Kind of Quantum Tunneling
KentuckyFC writes to tell us that scientists from the UK and Germany are proposing a third kind of quantum tunneling. They propose that a quantum particle is capable of changing into a pair of "virtual particles" capable of passing through a potential barrier before changing back. The supposition also provides some interesting methods of possibly testing string theory. So many interesting and useful possibilities, I guess that just means it will be debunked faster than other scientific theories.
So many interesting and useful possibilities, I guess that just means it will be debunked faster than other scientific theories.
Your glass the wrong size often there, mate?
A good percentage of us believe FTL travel is possible. You came to the wrong place with that attitude.
Qxe4
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A: He was no longer sexually attracted to her after she had a moooooooooo-stectomy!
The fact that the current theory is so complex that theorists are still able to trawl through it and make all sorts of new predictions indicates to me that they're making it all up as they go along. Where's the theorists when super-coliders are producing particles that don't fit the current model? Oh I bet they'll be dancing in the streets if the LHC finds the Higgs-Boson, but the evidence is clearly stacking up that quantum theory, and with it string theory & m-theory, are pretty much all wrong and utterly flawed.
Where's the revolution when you need one?
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Great!... Now we need to not only guess if Schrodinger's cat is alive or dead but also if it is still inside the box as well.
I just tunnel over SSH. It works fine...
From the paper, it looks like this is enough stronger than a hypothesis, to justify the appellation "theory". There's enough information to build detectors that can discriminate the rate of tunneling (if any, of course) between this virtual particle mode, the conversion mode, and "classical" (uncertainty) tunneling.
Time for the experimentalists to take their shot at confirming/denying this one.
One question, though, about the conversion mode: where's a reference for a description of the impetus for the conversion? Is it a sort of uncertainty where the "current" mode of the particle is one of the allowed states of its energy, an oscillation like neutrinos, or does the string (if you go there) pick up energy from an extra-dimensional impact (changing its "tune") then release it in another impact or emission to return to the previous state?
I am new to everything quantum. Is that barrier FTFA less than three dimensions? Or am I mistaking that barrier with something else?
And if that's the case, then isn't this dark matter just energy not 'captured by' the Higgs Boson particle or whatever it is that the Higgs is?
Here be signatures
I thought that this was the exact idea behind Hawking radiation, but the barrier in that example was the event horizon of a black hole? I can't see that this is anything different except for the barrier? How is this a new idea?
They already don't quite understand the two types of quantum tunneling they already have, and they want to have a third? Everyone knows that you get your existing shit in order before you go expanding, especially in the current economic climate. Like two types isn't enough already anyway!
Who do they think they are, string theorists??
I object to using the term debunk when referring to disproving a scientific hypothesis that was put forth in good faith by those willing to have it tested. The word debunk means to expose bunkum - which originally meant empty speech and which came to mean claims made by people who knew they were spewing crap.
The proposed model may turn out to exist only in the brain of a couple of overcaffeinated physicists, but it is not bunkum and cannot be debunked.
If Slashdot were chemistry it would look like this:Cadaverine
The proposed mechanism sounds vaguely like the the mechanism for Hawking radiation, in which a pair of virtual particles becomes separated at the Schwartzwald horizon of a black hole, with one particle being trapped forever inside the horizon, and the other particle becoming 'real' and escaping.
Theoretical physicists do come up with their best hypotheses on 4/20.
Prisencolinensinainciusol. Ol Rait!
While I accept quantum mechanics and its power to describe the sub atomic universe, I still have no idea where this claim about QM being used in the development of the transistor comes from. I learned about transistors using a theory of electrons and "holes" and in fact this viewpoint comes from no lesser source than Shockley himself.
I've never seen a theoretical description of any transistor device that required any form of quantum mechanics for its explanation. Given the fact that transistors are to this day, macroscopic devices, I still fail to see how QM comes into their theoretical explanation. It's a subatomic theory.
May the Maths Be with you!
Only if they use gravity bongs.
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I totally agree with you that quantum mechanics is very well tested and extremely accurate in every domain we can test.
However, it is known to be wrong. Quantum mechanics (and even quantum field theory) is incompatible with general relativity. As far as I know, no one knows how to reconcile the two. It's the same situation as blackbody radiation prior to quantum theory - we have one model that works on one scale, and another model that works on another scale, but they are known to be incompatible.
The difference is that we don't have the technology to build experiments in the contested domain - experiments in which we measure quantum effects in an acceleration/gravity field strong enough to have measurable GR effects at a quantum scale.
That said, there's another issue with quantum mechanics. To my knowledge, there is no clear definition of what a "good observation" is, or what happens in a non-good observation. For example, in the classic two slit experiment, you are either observing (entangled with) the electron as it passes through the slit, or you are not. But in fact, it seems to me you are almost always varying degrees of "sort of" entangled with the electron. By which I mean there are particles that interact with you that give you statistical information about which slit the electron goes through, but not clear information.
By the way, regarding the "new method" of tunneling in the post... that doesn't sound new at all, to me. The standard Feynmann diagram model of quantum mechanics involves identifying all the ways a particle could get from here to there (including splitting into other particles and rejoining) and summing over them to find the likelihood a particle will be at the target location. Not having read the article, I'm guessing they just analyzed those "split into two particle" paths and discovered that they contribute more in some scenarios than people had believed before.
I guess that just means after extensive testing of this hypothesis, it may or may not lead to a theory..
Okay buddy, I fixed your post. It's a shame people still utilize the word 'theory' for almost every context. This is almost universally true with regard to science critics commenting on the very subject they hate.
Where's my sock? There it is...
Ideas in physics are never proven true.
The insight above is basically the philosophy of science of Karl Popper. Theory implies experimental predictions. If experimental predictions are false, then theory is false.
Then Thomas Kuhn pointed out that it's even worse than that. Really, it goes: Theory+Auxiliary Assumptions => prediction. If prediction=false, then (theory=false OR auxiliary assuptions=false).
The OR in that statement can never be completely eliminated. For example, if you assume there is a small invisible planet somewhere inside the orbit of Mercury, you can exactly reproduce the results of General Relativity using only Newtonian Mechanics. With enough auxiliary assumptions, you can make any theory work.
Because of this, you can never completely falsify any theory either, which makes the process of switching theories very fuzzy, social, aesthetic, and generally much messier than scientists want it to be. Kuhn coined the term "paradigm shift" to describe this process.
"All proofs inevitably lead to propositions which have no proof! All things are known because we want to believe in them." -- Frank Herbert
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Ideas in physics are never proven true. They are shown not to contradict any existing evidence, that is all. I can't think of any more than a few decades old which have survived even this.
I can: Relativity (both Special and General) and Quantum Mechanics. These have been around for over 100 years (since 1905). SR and quantum theory are the two most precisely tested scientific theories ever.
Technically speaking, is it possible to know if something is *almost* universally true?
This won't be debunked, its true. Once you look at the feynman diagrams its obviously a possible effect.
If you read the paper and not the very bad summary in the article - along with a wrong diagram - then this is not what they are suggesting. They calculate the neutrino digram shown in the article and which you estimated and come up with a probability of O(10^-130) times a function of the neutrino mass, barrier thickness and photon energy. This would be an interesting way to measure neutrino mass if the probability were not so low.
What they are actually wanting to test is whether there are new, fractionally charged particles out there. So this is not something that is guaranteed to work. In fact I do not see how we would not have already seen such particles before now in virtual effects in K and B experiments if nothing else...but I have not looked at it in detail.
I find it interesting that I browse a site that casually has a story like this: "They propose that a quantum particle is capable of changing into a pair of 'virtual particles' capable of passing through a potential barrier before changing back" sandwiched between two stories about video games, as though they both belong in the same broad category (of "nerdy" or something).
Property is theft.
The standard model isn't wrong, any more than newtonian physics is wrong.
Sorry but we know that both Newtonian physics and the Standard Model are wrong - in the case of the SM we just don't know exactly how it goes wrong yet - other than neutrino masses which are easy to fix. Just because Newtonian physics works for everyday events does not make it correct - it is fundamentally wrong but it is a good and useful approximation to what is really happening.
In the same way the SM is also wrong. It has no explanation of gravity, a huge fine tuning problem and no explanation of Dark Matter and Baryon number violation. So we know that fundamentally it is wrong since it does not explain all the phenomena of the Universe we live in. However it is a very good approximation and correctly models all the phenomena we can produce in the lab. It is really what we call an "effective field theory" which means that it is a low energy approximation of a fundamental theory. Unfortunately we just don't know what that fundamental theory actually is.
I believe it's actually the fourth. Quantum macroparticle tunneling was first documented in 1987.
While the speed of light may or may not be a cosmic speed limit, we DO know that we CAN not only slow down, but speed up light. So regardless if we can make things move faster than light, we can make light move faster than "light in a vacuum."
There was a /. article several months back about how some scientists in a lab were able to make light #1 move backwards, and #2 move backwards faster than it moves forward in a vacuum. Considering this, 186,000 miles/second is no longer the cap of speed.