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Physicists Propose New Kind of Quantum Tunneling

ScuttleMonkey posted more than 5 years ago | from the good-ideas-debunked-the-fastest dept.

Math 163

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.

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let's hear it for optimism (3, Funny)

phantomfive (622387) | more than 5 years ago | (#27657029)

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.

Re:let's hear it for optimism (3, Informative)

who knows my name (1247824) | more than 5 years ago | (#27657123)

Does anyone else get an uneasy feeling about the use of the word debunk in the summary?

Re:let's hear it for optimism (2, Interesting)

DreamsAreOkToo (1414963) | more than 5 years ago | (#27657807)

Lets face it, if FTL travel isn't possible, the human race is doomed. Therefore, having the attitude that it is impossible is not useful to anyone. I know that as a scientific mind, you're supposed to follow logic and precedence. But if you plan to make a groundbreaking discovery, you pretty much have to chase what's believed to be impossible.

If there's any limitation to the scientific mind, it's that it dismisses the far out there, which is (sometimes) the next step forward.

Re:let's hear it for optimism (0)

Anonymous Coward | more than 5 years ago | (#27657831)

So, to put it more succinctly, you advocate that we delude ourselves?

*If* FTL travel is possible, we'll find out eventually, but in order to do so, we need scientific rigor - and that's dependent on a skeptical mind. What you're advocating is essentially a return to the dark ages; alchemy rather than chemistry, just on the somewhat lower level of physics instead. Don't confuse trying to debunk something with not wanting for it to be true - that's the whole POINT of the scientific method.

On the other hand, if FTL travel is impossible, all bets are off, anyway.

Re:let's hear it for optimism (5, Insightful)

pleappleappleap (1182301) | more than 5 years ago | (#27659497)

So, to put it more succinctly, you advocate that we delude ourselves?

No, but I advocate that we advance science with the hope that our hypotheses might be correct, rather than with a firm belief that our hypotheses are incorrect.

Re:let's hear it for optimism (1)

TheRaven64 (641858) | more than 5 years ago | (#27658001)

Lets face it, if FTL travel isn't possible, the human race is doomed

Why? If FTL is impossible then it is unlikely that there will be a single human civilisation spanning the galaxy, but that doesn't preclude interstellar travel. Even at 10% of the speed of light it would be possible to colonise the entire galaxy in as little as a million years; a small fraction of the time that life has existed on this planet and much less time than some of the previous dominant species have survived.

Re:let's hear it for optimism (1)

pleappleappleap (1182301) | more than 5 years ago | (#27659523)

I wonder if we'd be able to proliferate quickly enough, however, to prevent ourselves from being wiped out by a catastrophic occurrence in our local neighborhood within our galaxy. Say, a supernova a few hundred light-years away.

Re:let's hear it for optimism (1)

rbanffy (584143) | more than 5 years ago | (#27659043)

"Lets face it, if FTL travel isn't possible, the human race is doomed."

That's not a valid assumption. It is absolutely viable to colonize planets around other stars with slower than light travel. It's just not practical to do round-trips. There probably are many viable rocks within a 20 light-year radius.

We need the kinds of non-reactive propulsion needed to propel spaceships to the speeds needed to reach their destinations before the grand-grandchildren of the crew forgets what they are doing.

Without FTL, all that's doomed is the space-opera.

Re:let's hear it for optimism (1)

pleappleappleap (1182301) | more than 5 years ago | (#27659549)

I'm not completely convinced that 20 light-years is nearly "far enough".

Re:let's hear it for optimism (1)

KeensMustard (655606) | more than 5 years ago | (#27659267)

Lets face it, if FTL travel isn't possible, the human race is doomed.

No it isn't.

Or to put it another way - the absence of FTL travel makes no difference to whether or not the human race is doomed.

Therefore, having the attitude that it is impossible is not useful to anyone. I know that as a scientific mind, you're supposed to follow logic and precedence. But if you plan to make a groundbreaking discovery, you pretty much have to chase what's believed to be impossible.

On the same basis then, we can validly expect to find unicorns. After all, we imagine they exist through stories and myth - the same basis for reality as FTL travel.

If there's any limitation to the scientific mind, it's that it dismisses the far out there, which is (sometimes) the next step forward.

Let us also pursue alchemy. Why limit our minds?

Re:let's hear it for optimism (2, Insightful)

Fleeced (585092) | more than 5 years ago | (#27657277)

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?

Not necessarily... the more exciting an idea is, the more interest it attracts, and so the quicker its ideas are either proven true or false... or, since we're dealing with quantum physics, we'll discover a whole bunch of other stuff which makes absolutely no sense, but is nonetheless true.

Re:let's hear it for optimism (4, Insightful)

TheRaven64 (641858) | more than 5 years ago | (#27658033)

Not necessarily... the more exciting an idea is, the more interest it attracts, and so the quicker its ideas are either proven true or false.

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. The best most theories can hope for is being shown to be a reasonable approximation within certain constraints. Eventually it may be possible to find a theory which both makes meaningful predictions and isn't contradicted by experimental results for a much longer time, but this hasn't happened yet and is unlikely to for quite a long time.

Physics is not about finding things that are 'true' it is about finding things that make useful predictions. Newtonian motion is not 'true', but it makes predictions that are sufficiently accurate (as long as you are not travelling at more than a tiny fraction of the speed of light or near a very large gravitational force) that we can use them.

Re:let's hear it for optimism (0)

radtea (464814) | more than 5 years ago | (#27658481)

Ideas in physics are never proven true.

I'm not sure what this idea of "true" is that you keep talking about. You seem to want to preserve a false-to-the-point-of-incoherence idea of truth, and then say that physics doesn't produce propositions that fulfil this incoherent idea as if that was somehow a limitation on physics, rather than a demonstration of a mistake about the nature of truth on your part.

Nothing anywhere has ever looked remotely like anything close to your incoherent idea of "true", except in the delusional fantasies of philosophers and theologians.

Truth is what allows us to understand and manipulate the world in controllable and predictable ways, and nothing more. Any other idea of truth is a fantasy, a useless concept made up by low-quality thinkers who can't distinguish between fantasy and reality.

Physics certainly produces truths by this quite ordinary standard. Newtonian physics is true. So is quantum mechanics. So is relativity. As opposed to Cartesian physics, phlogiston theory and the mechanical electrodynamics of Lorentz and Poincare', which are false.

This is the huge downside of the fantasy-land, all-unicorns-all-the-time idea of "truth" that delusional philosophers promote: it leaves us with no coherent way of talking about the perfectly ordinary distinction between false Cartesian physics and true Newtonian physics, which is a USEFUL and IMPORTANT distinction, unlike the distinction between true Newtonian physics and the delusional fantasy that philosophers for some inexplicable reason want to call "truth".

Re:let's hear it for optimism (1)

dollargonzo (519030) | more than 5 years ago | (#27658825)

I'm not sure I get what you mean by "truth". As the GP said, physics is about making useful predictions within constraints. Under whatever definition of truth you choose to use (it's hard to tell from your post), it would inherently require contradictions to abound. I certainly don't like any definition that allows us to derive contradictions, since that means we can derive anything, which is certainly pretty useless.

One of the biggest advances in scientific thinking in the 20th century is Popper's analysis of falsification and that induction doesn't exist (or at least doesn't really work). Philosophers have struggled for centuries to come to some understanding regarding when induction works and when it doesn't. Not letting scientific theories ever be "true" solved a LOT of problems, since once you prove something true, it can never be false-- and this isn't just a cop out; from a logical standpoint, proving something true and falsifying it are asymmetrical. To prove something true requires you to show validity for an infinite set of cases, whereas falsification only requires you to find one counterexample, and this is why designing experiments that can potentially falsify your theory is so useful (and also why string theory is criticized for not predicting anything that can be tested). Scientists have moved away from the old definition of truth (as you seem to understand it) for good reason.

Re:let's hear it for optimism (1)

Dragonslicer (991472) | more than 5 years ago | (#27659013)

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 may be a bit behind the times, but the Law of Conservation of Energy comes to my mind pretty quickly.

Re:let's hear it for optimism (0)

Anonymous Coward | more than 5 years ago | (#27659057)

This idea has actually been around for a while. [docstoc.com] If you read the essay at the link, and manage to get most of the way to the end of it, you will find the idea in there.

Re:let's hear it for optimism (-1, Troll)

Anonymous Coward | more than 5 years ago | (#27657331)

What does tunneling have to do with FTL travel? They are completely unrelated.

Please explain to me the following... (0)

V!NCENT (1105021) | more than 5 years ago | (#27657335)

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?

Re:Please explain to me the following... (3, Informative)

damburger (981828) | more than 5 years ago | (#27657645)

Um, I am not sure where to start.

You are spouting physics buzzwords with no apparent grasp of what they are or what they mean. Don't try and learn about science from the media - this is the kind of confusion that results.

Dark matter is just matter we can't see. It almost certainly has nothing in particular to do with the Higgs Boson, which is a proposed mechanism by which all matter (dark or otherwise) has mass.

The barrier in question is a potential barrier, and seeing as we live in a three dimensional universe it is a three dimensional barrier; sometimes a potential barrier will be represented in 1 or 2 dimensions for clarity.

Re:Please explain to me the following... (1)

who knows my name (1247824) | more than 5 years ago | (#27658009)

technically dark matter is matter we can't detect. i.e. if there is dark matter it is weakly interacting - which obviously is a real pain if you are trying to work out if it exists.

Re:Please explain to me the following... (1)

damburger (981828) | more than 5 years ago | (#27658119)

I used 'see' as a common term for 'detect'. The majority of non-dark matter in the universe is things we can't see with human eyesight.

Re:Please explain to me the following... (1)

holmstar (1388267) | more than 5 years ago | (#27659687)

"Can't currently detect in a direct way" would be a better description.

Re:Please explain to me the following... (0)

Anonymous Coward | more than 5 years ago | (#27658745)

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?

This is hilarious.

Re:let's hear it for optimism (1)

newcastlejon (1483695) | more than 5 years ago | (#27657349)

The glass is merely twice its required capacity.

Re:let's hear it for optimism (1)

JustOK (667959) | more than 5 years ago | (#27657539)

Glass is fine. Received less than ordered.

Just a silly joke... (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#27657031)

Q: Why did Lamb Armstrong leave Sheryl Cow?

A: He was no longer sexually attracted to her after she had a moooooooooo-stectomy!

What? (-1, Troll)

Anonymous Coward | more than 5 years ago | (#27657043)

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?

Re:What? (2, Insightful)

NewbieProgrammerMan (558327) | more than 5 years ago | (#27657057)

...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.

[citation needed]

Re:What? (-1, Offtopic)

Jane Q. Public (1010737) | more than 5 years ago | (#27657321)

This is not Wikipedia. http://tinyurl.com/2c9np [tinyurl.com]

Re:What? (1)

NewbieProgrammerMan (558327) | more than 5 years ago | (#27657363)

(1) It's supposed to be funny.

(2) I'm not the one making the extraordinary claim that quantum theory is utterly flawed.

(3) There's not enough days left in my life to slog through all the woo-woo sites that I'd get if I googled for claims that QM is wrong.

(4) I'm just fucking lazy, and like to poke fun at people making outrageous claims. This *is* Slashdot, after all.

Re:What? (1)

Jane Q. Public (1010737) | more than 5 years ago | (#27657375)

Mine was intended as humorous, too, so let's all relax.

Re:What? (0, Offtopic)

ZeroExistenZ (721849) | more than 5 years ago | (#27657415)

Mine was intended as humorous, too, so let's all relax.

Ok, Jane. I'm all relaxed, so very relaxed... what now?

Re:What? (0, Troll)

Swizec (978239) | more than 5 years ago | (#27657811)

Mine was intended as humorous, too, so let's all relax.

Ok, Jane. I'm all relaxed, so very relaxed... what now?

Blowjob time.

Re:What? (0)

Anonymous Coward | more than 5 years ago | (#27657639)

+1 Insightful for (4)

Re:What? (1)

NewbieProgrammerMan (558327) | more than 5 years ago | (#27657067)

Where's the revolution when you need one?

In the spirit of flammable open-source retorts: so, where is it? Post a patch or STFU.

Re:What? (4, Insightful)

phantomfive (622387) | more than 5 years ago | (#27657087)

Where's the revolution when you need one?

Yeah, why haven't you been doing your math and physics to create this revolution that you see so clearly?

The standard model isn't wrong, any more than newtonian physics is wrong. It works great until you get to the edges, then of course you need relativity, but no one knew that until a few hundred years after Newton when we started getting experiments with strange results. Einstein was the one who explained those results.

Physics models are explanations of what we observe, which is why experiments are crucial. Unless we make more observations, we will have nothing to do but extrapolate current theories, which as you mentioned, break down at extremes, since we don't have as much experimental data at those points.

You want a revolution? Make one!

Re:What? (0)

TheRaven64 (641858) | more than 5 years ago | (#27658073)

It works great until you get to the edges, then of course you need relativity, but no one knew that until a few hundred years after Newton when we started getting experiments with strange results. Einstein was the one who explained those results.

I think you are giving Einstein a bit less credit than he deserves there. He spotted (some of) the flaws in the Newtonian model before there was any experimental evidence to contradict them. When he first published, his results were taken to be theoretically interesting but not particularly practically applicable - just interesting permutations of the mathematics. It wasn't until Eddington observed that stars appeared to move during an eclipse that there was an experimental result that contradicted Newton but not Einstein.

Quantum mechanics was the other way around. The double-slit experiment showed that the classical model was wrong, but there was no theory pre-existing to explain the result. A few years later, there were a lot of them, none of which was particularly satisfying (or easy to unify with relativity).

Re:What? (1)

Lloyd_Bryant (73136) | more than 5 years ago | (#27658299)

It wasn't until Eddington observed that stars appeared to move during an eclipse that there was an experimental result that contradicted Newton but not Einstein.

Sorry, not an astronomer, but I was under the impression that the inability of Newtonian mechanics to properly account for the precession of Mercury was well known before Einstein's time...

Re:What? (0)

Anonymous Coward | more than 5 years ago | (#27658653)

Your history is a bit off. During Einstein's time there was a lot of thought experiments along similar lines to that of Einstein. There were also many places were Newtonian physics could not explain the observations including, but not limited to, Mercury's orbit around the sun and the Michelson and Morley experiment.
The eclipse was experimental evidence that matched Einstein's prediction of what would happen according to his theory.
As for the double-slit experiment, I don't remember(memory is a bit fuzzy so could be wrong) it showing problems in classical physics until much later. The first experiments that really showed the quantum effects of light were the photoelectric effect (See Einstein, 1905) and Compton Scattering(Compton, 1923). I admit the really funny behavior associated with QM came later and the double-slit experiment played a role.

Re:What? (1)

BakaHoushi (786009) | more than 5 years ago | (#27658845)

This is a problem I see quite often when people try to "counter" a popular scientific theory. They give an example of where the results get blurry and assume some new theory, right around the corner, will topple centuries of research and we will begin anew. Such things are an extreme rarity. For example, if we discovered an entirely new theory of gravitation, hypothetically, that better explains how large bodies move in space, it won't likely change the fact that here on Earth, gravity is fairly constant everywhere. And it turns out that mass ISN'T as constant as we once believed... but, quite frankly, when you're an engineer designing a bridge, it's constant enough.

New data rarely warrants throwing out the old data. It usually just adds new conditions. I.E., Mass is constant when at rest. As you pointed out, Newtonian physics works great under pretty much any circumstance you'll run into on Earth.

Re:What? (5, Insightful)

Grokmoo (1180039) | more than 5 years ago | (#27657127)

You make a mistake in lumping quantum theory in with String Theory.

There is at present no evidence whatsoever that quantum mechanics, quantum electrodynamics, and so on are wrong. These theories are the best tested theories in human history (certain predictions about energy levels such as those in the hydrogen atom have been verified to 12 or so digits of accuracy.) Quantum mechanics is at this point the best tested and thus most probably correct theory in physics by far. This does not mean that there isn't another underlying theory that will make somewhat different predictions, but the differences would have to be fantastically small.

String theory, on the other hand, has basically no evidence against it, but also virtually no supporting evidence. This is mostly because it hasn't really come up with much in the way of testable claims.

Re:What? (2, Interesting)

Jane Q. Public (1010737) | more than 5 years ago | (#27657341)

There is always MoND, which explains some of the same things as "Dark Matter" and "String Hypothesis", and then there are also some recent findings that suggest that the Universe is not expanding after all... which would throw the String Hypothesis right out the window.

Re:What? (4, Insightful)

damburger (981828) | more than 5 years ago | (#27657675)

But it is worth mentioning that any new physics at this point, be it MoND, String theory or anything else, is more like a refinement of existing theories than a complete overhaul. If we were very wrong about the laws of physics, then our technology which relies on being tightly fine tuned to them (space probes for Newtonian dynamics, GPS systems for relativity, anything with a semiconductor for quantum mechanics) simply wouldn't work. They do work, and the work with astonishing accuracy.

Re:What? (1)

boot_img (610085) | more than 5 years ago | (#27657979)

MoND does a good job of explaining rotation curves of spiral galaxies, but that's about it. It fails on the scales of clusters of galaxies, as even its proponents acknowledge. Nor does it make useful predictions for the growth of large-scale structure.

I have no idea what you mean when you say it explains the same things as the "String Hypothesis."

Re:What? (1)

Colonel Korn (1258968) | more than 5 years ago | (#27659149)

There is always MoND, which explains some of the same things as "Dark Matter" and "String Hypothesis", and then there are also some recent findings that suggest that the Universe is not expanding after all... which would throw the String Hypothesis right out the window.

MoND is more like a curve fit through all the existing data than an explanation of its cause. Every time some new piece of data shows up, the curve fit is redone and the mechanics of MoND change to match the new big picture. At any given time, it's self-consistent, but it's never made a prediction that was then proven correct by later evidence.

Re:What? (0)

V!NCENT (1105021) | more than 5 years ago | (#27657359)

Maybe they are all in a way true. Einstein had it wrong with E=MC^2, but some parts of the two theories are probably true, like the light that bends, etc.

How about we stop flaming each other? Saying "That's BS" as a scientist, isn't exactly the way a scientist should be thinking and researching. The entire idea is that scientists prove and disprove parts of science by thinking beyond "Pffff BS" and "It's just the way it is because".

Re:What? (4, Insightful)

damburger (981828) | more than 5 years ago | (#27657711)

I suggest you take up the notion that E=MC^2 is 'wrong' with a survivor of Hiroshima or Nagasaki. If matter/energy equivlance were wrong nothing nuclear would work. Including the Sun, which is essentially a giant, gravitationally bound, thermonuclear explosion.

The notion that light bends is not 'probably' true, it IS true because it was famously measured by Eddington during a solar eclipse. There seems to be some notion amongst the general public that Einstein pulled relativity out of his butt and physicists just accepted it because it was cool. This is not the case at all.

Special relativity was accepted because it explained phenomena that could not be explained by previous theories, and because it has been constantly verified by experiment ever since (time dilation has been measured on aeroplanes using very accurate atomic clocks, and mass dilation is a daily fact of life in any particle accelerator facility you care to name).

General relativity was accepted only because someone went out there, took some measurements, and saw they confirmed Einstein's predictions. Furthermore, we now have everyday technology that depends on GR being, admittedly within certain bounds, correct.

Re:What? (0)

TheRaven64 (641858) | more than 5 years ago | (#27658117)

There is no point arguing with anyone who quotes E=MC^2 as part of relativity. The correct formula, which anyone who studied physics at school, let alone university, would know has a momentum component as well. Special relativity is probably the most recent bit of physics that can be considered easy (i.e. school children can work out all of the underlying mathematics without too much help) and so trying to argue with anyone who failed to understand it is unlikely to be worthwhile.

Re:What? (1)

damburger (981828) | more than 5 years ago | (#27658187)

Technically yes, the 'correct' formula is more complex; but you use plain old E=MC^2 when you are working with nuclear reactions (because momentum is negligible in a solid lump of uranium) - and that is the context most people use it in.

Re:What? (1)

squoozer (730327) | more than 5 years ago | (#27657855)

I think you sum up quite nicely what a lot of people are failing to understand|: what ever new models / theories we come up with they have to account for everything we currently observe and the new things that current models / theories don't explain correctly.

I think a lot of people think that when we discover a theory of everything or at least the next quantum mechanics we will suddenly unlock the ability to teleport our selves, have faster than light travel and a multitude of other things that are strictly in the realm of science fiction. Taking faster than light travel as an example: everything we know tells us that it is fundamentally forbidden by the laws of the universe, that isn't about to change because we better explain the event horizon of a black hole. It's like saying that because we discover this amazing new theory the apple that hit Newton on the head would fall up rather than down! It might tell us how to generate anti-gravity but that is totally different to re-writing the rule book.

Re:What? (1)

Kashgarinn (1036758) | more than 5 years ago | (#27658439)

That's something I've been wondering about.

- When people claim that string theory has no supporting evidence.. I'm wondering whether some classic tests which perhaps quantum scientists used to prove quantum theory lend themselves to test string theory as well?

Or is that the wrong way to think about string theory?

Re:What? (1)

Grokmoo (1180039) | more than 5 years ago | (#27658899)

Yes; in principle the same sorts of tests that have been done for quantum mechanics could be done to test string theory. The example I gave above is a good one; string theory would predict slightly different energy levels for the hydrogen atom.

However, there is a slight practical problem. While we can measure these things to phenomenal accuracy (10 or 12 digits) the predictions of string theory would only become different from the predictions of quantum theory at somewhere in the range of 25 to 35 digits, depending on the theory. These differences are so far beyond our current ability to measure that there is very little hope for any sort of confirmation of string theory in the foreseeable future.

Because of this fact and the fact that there is no clear mathematical reason to favor one string theory in particular (there are infinite possible variations), string theory has in the end contributed essentially nothing to modern physics.

Re:What? (0)

Anonymous Coward | more than 5 years ago | (#27657649)

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.

Oh really? And I thought god tells them how he build the world and they just write it down.

See, we don't have a handbook about how the universe works in some language we don't understand, and we just have to translate the pages. Making it all up as we go along is the only way there is. In the real world you can never proof that some rule applies. You can only gather evidence with observations. And it really is not that important whether the theory is true as long as it just describes our observations very good.

Re:What? (5, Insightful)

damburger (981828) | more than 5 years ago | (#27657655)

I never ceased to be tickled by people loudly and ignorantly arguing against the reality of quantum mechanics USING A MACHINE DRIVEN BY FUCKING SEMICONDUCTORS. Its like the flat Earth society getting its message out through satellite television.

Quantum mechanics, like any science, is not a religious doctrine. It doesn't have to be complete and all encompassing to be right; it just has to fit the observations for everything we have tried so far. When it stops fitting the observations, we will give it up (or more likely, refine it in some subtle way) and move on.

Re:What? (1)

notmyusualnickname (1221732) | more than 5 years ago | (#27657973)

[Curses lack of mod points]

Re:What? (1)

TheRaven64 (641858) | more than 5 years ago | (#27658143)

I think a lot of the blame can be given to the media, who use phrases like 'prove true' in physics articles. Physics is never proven true, it is only proven false or proven useful (in some cases both - Newtonian mechanics is the obvious example - we know it's wrong, but in most cases it's within a tiny fraction of a percentage point of being right, which is close enough).

Re:What? (1)

pleappleappleap (1182301) | more than 5 years ago | (#27659695)

This leads to a fundamental axiom, that truth is more of a philosophical concept than a scientific one. Sometimes that distinction can seem hazy, but I believe it's there.

QM explains Transistors? (0)

ObsessiveMathsFreak (773371) | more than 5 years ago | (#27659015)

I never ceased to be tickled by people loudly and ignorantly arguing against the reality of quantum mechanics USING A MACHINE DRIVEN BY FUCKING SEMICONDUCTORS.

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.

Re:What? (1, Insightful)

Anonymous Coward | more than 5 years ago | (#27659123)

First of all, I'm not debating with you the usefulness of quantum mechanics and Quantum Electro Dynamics, instead I would like to stress the multiple interpretations of physics in a more meta-physical method. Lets put your argument into phlogiston theory, and see how it functions:

- modified quote
I never ceased to be tickled by people loudly and ignorantly arguing against the reality of phlogiston theory USING A MACHINE DRIVEN BY FUCKING HEAT. Its like the ... satellite television.
- end quote

Now for the second part of your argument: actually modifying a theory when it no longer fits the observations is something many bigot believers who are in the habbit of too theoreticaly interpretting their own religion, constantly do.

Most scientific changes have been brought up by fundamentally challenging the premises on which everything else is based, for example: is there an atom, or are there fields? do we view space as carthesian, as exponentional, in 3 dimensions or more? can we prove anything at all in certainty, by making observations? (a certain problem in Quantum Mechanics in relationship with induction) what logical language do we need to base our observations on, and does the logical language we use modify our view of the world?

Now, our current epoch in physics has been long standing, still based on the principles of relativity theory and quantum mechanics, fine-tuned, admittedly, but not fundamentally challenged. Come to realize there are differences in perception between those who view a theory as 'real' (there are indeed electrons, photons, etc.), and those who find a theory sufficient (giving no judgement on the existence of the former mentioned entities). Neither can be right, but both can twist the perceptual position of the interlocutor.

Is real but rare (5, Informative)

physburn (1095481) | more than 5 years ago | (#27657125)

This won't be debunked, its true. Once you look at the feynman diagrams its obviously a possible effect. Trouble is, it will have a very low probability, at each end of the conversion possible you've got two weak force vertices, and one of the heavy 80/90 GeV/c^2 W or Z weak force carriers. So the total amplitude goes as E^2/M_w^2 g_w^4 and square that for a probablity. So for photons that might need to tunnel (optical frequencies about 1eV) you have a tunnelling probability of 10^-18, that so very rare physicists will probably never see it.

.

Quantum Mechanics [feeddistiller.com] feed at Feed Distiller, come there and make your own feeds

Re:Is real but rare (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#27657193)

Thanks for doing the hard maths for us. Just out of curiosity what are the chances of the other forms of tunneling that the feature article mentions occurring?

Re:Is real but rare (3, Informative)

physburn (1095481) | more than 5 years ago | (#27657997)

Standard tunnelling goes roughly as

exp(-delta E L/hbar c)

where L is the length it needs to tunnel and E is energy barrier the particles tunnelling though.

The second type of light through walls, depends on there being a axion or some other very light weakly interacting particle for the photons to change into, and so the probability could be anything, depending on the properties of the new particle.

Neither the second or third kinds, depend (much) on the length the particle has to tunnel through.

Re:Is real but rare (0)

Jane Q. Public (1010737) | more than 5 years ago | (#27657217)

What I am curious about is: assume you get the virtual particles which then tunnel: what is the probability that they will tunnel with the same probability, then recombine properly? It seems to me (without having done the math), that there is some possibility here of ending up with a quantum Goretex, or, in other words, a Maxwell's Demon of sorts, no matter how small its effect might be.

Re:Is real but rare (0)

Anonymous Coward | more than 5 years ago | (#27657519)

Read up on black hole evaporation. I wouldn't call it Maxwell's daemon, though, because it's purely stochastic - one time you'll get a positron, another an electron.

Re:Is real but rare (1)

ioshhdflwuegfh (1067182) | more than 5 years ago | (#27658321)

Maybe you were unintentionally alluding to something similar to the black hole radiation? What these guys calculated was for strict tunneling, where you get the probability of a process by which particle turns into a virtual pair and then pair goes through the wall and recombines into the particle again. The process as a whole is taken into account, not "by parts".

Re:Is real but rare (3, Insightful)

Anonymous Coward | more than 5 years ago | (#27657503)

"This won't be debunked, its true. Once you look at the feynman diagrams its......"

And even though everything else may be uncertain, and a thoery which predicts everything down to the smallest bit of truth is lacking, you state with confidence that anything found in feynman diagrams must be true?

Models are just models.

Re:Is real but rare (1)

corsec67 (627446) | more than 5 years ago | (#27657551)

Models are just models.

Maybe, but some [ipernity.com] are better looking than others.

/note to self: it might be a bad idea to post while drinking...

Re:Is real but rare (1)

Valtor (34080) | more than 5 years ago | (#27658877)

/note to self: do not read slashdot with girlfriend beside me. ;-)

Valtor

Re:Is real but rare (1)

BigBlueOx (1201587) | more than 5 years ago | (#27659617)

What is this "girlfriend" thing that you speak of?

Re:Is real but rare (1)

rbanffy (584143) | more than 5 years ago | (#27659187)

There is no such thing as "true" in Physics. There is "fits the measurements" and "doesn't fit the measurements".

Re:Is real but rare (2)

damburger (981828) | more than 5 years ago | (#27657713)

You can't say 'it is true' if it hasn't been observed. Just because it falls nicely out of the maths, doesn't mean it corresponds to a physical reality. Hell, string theory has some nice maths to it.

Because it would be incredibly rare even if it did happen, it being forbidden by some currently unknown physics would not have been noticed before now.

Re:Is real but rare (1, Insightful)

Anonymous Coward | more than 5 years ago | (#27658449)

You speak the language but don't seem to understand the ideas behind physics. Nothing is ever true, it is just supported by experimental observation under certain conditions.
Now go back to your probability theory, yes 10^-18 is rare but that means that if you try 10^18 times, probability favors seeing it once. The real question is can we distinguish it from normal tunneling with in experimental error. If we can't, then it is a useless theory even if it is true.
I suggest going back and reading Feynman's general lectures.

cat (5, Funny)

RuBLed (995686) | more than 5 years ago | (#27657141)

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.

Re:cat (2, Funny)

MadKeithV (102058) | more than 5 years ago | (#27657169)

Instead only try to realize the truth...that there is no cat...or box...or Schrodinger.

Alternatively, perhaps Schrodinger is right now tunneling out of his grave with all these lame jokes ;-)

Re:cat (1, Funny)

bronney (638318) | more than 5 years ago | (#27657377)

Hard to believe it's been 10 years eh. Greatest movie ever.

Re:cat (4, Funny)

JustOK (667959) | more than 5 years ago | (#27657563)

He's just spinning in his grave. We're just not sure what direction he's spinning.

Re:cat (3, Funny)

MadKeithV (102058) | more than 5 years ago | (#27658037)

Strange.

Re:cat (2, Funny)

emlyncorrin (818871) | more than 5 years ago | (#27658145)

That's charming.

Re:cat (1)

TheRaven64 (641858) | more than 5 years ago | (#27658151)

But we know exactly where his grave is...

Re:cat (1)

Joebert (946227) | more than 5 years ago | (#27657225)

There's bound to be at least one person who will argue that the cat rose from the dead and left the box.

Re:cat (1)

KDR_11k (778916) | more than 5 years ago | (#27657265)

I'm not sure I'd want Catbert as the messiah...

Re:cat (2, Funny)

Thanshin (1188877) | more than 5 years ago | (#27657583)

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.

- Year 2137. Classroom -

"...And thus was proved that, until we open the box we can only know one of the animal's five fundamental variables: it's life/death state, location, speed, species and political orientation.

Re:cat (0)

Anonymous Coward | more than 5 years ago | (#27659671)

"But despite all of the progress made in this field, we're still researching on how to deduce its sexual orientation."

Re:cat (1)

damburger (981828) | more than 5 years ago | (#27657721)

Tunnelling is just Schroedingers catflap

Re:cat (0)

Anonymous Coward | more than 5 years ago | (#27657817)

You didn't paid attention to you quantum physics class in primary school, did you?

The cat is dead *and* alive, pretty much the same way it's inside the box, but simultaneously it's out.

I don't know you, but this turn makes me a lot less worried. Go cat, go!

Re:cat (0)

Anonymous Coward | more than 5 years ago | (#27657859)

Darkness there... and nothing more...

(C) Edgar Allen Poe

bah, quantums (3, Funny)

Anonymous Coward | more than 5 years ago | (#27657155)

I just tunnel over SSH. It works fine...

Re:bah, quantums (0, Flamebait)

Jane Q. Public (1010737) | more than 5 years ago | (#27657367)

Well then, how does your pair of virtual particles feel when you are done?

Re:bah, quantums (1)

troll8901 (1397145) | more than 5 years ago | (#27657515)

They're fine. They're connected to me via the Virtual Network Chromodynamics protocol. They're hosted offsite, too big and heavy to carry around, and require their own cooling.

I was wondering if we can mesh these virtual particles together, in a sort of Cloud Collision architecture. For security, we can connect using Virtual Particle Network.

theory, then experiment (2, Interesting)

dltaylor (7510) | more than 5 years ago | (#27657177)

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?

Re:theory, then experiment (1)

Jane Q. Public (1010737) | more than 5 years ago | (#27657311)

There is no "impetus" for the conversion; it is simply a matter of probability.

Re:theory, then experiment (1)

Jane Q. Public (1010737) | more than 5 years ago | (#27657435)

Apologies; I don't know that... I was thinking of uncertainty tunneling.

Re:theory, then experiment (1)

ioshhdflwuegfh (1067182) | more than 5 years ago | (#27657315)

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.

They are both "uncertainty" tunnelings, the standard one being classical and the proposed one would be relativistic.

Is this new? (0)

Crookdotter (1297179) | more than 5 years ago | (#27657433)

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?

Re:Is this new? (1)

Burnhard (1031106) | more than 5 years ago | (#27658301)

Not quite, with Hawking radiation, one of the virtual particles falls back into the hole and one escapes, or something like that.

No, no, no! They cannot do this. (3, Funny)

mrRay720 (874710) | more than 5 years ago | (#27657457)

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??

Serious hypothesis does not equal bunkum (2, Insightful)

paiute (550198) | more than 5 years ago | (#27658003)

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.

Tunneling and Hawking Radiation (0)

Anonymous Coward | more than 5 years ago | (#27658189)

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.

So its true then - (2, Funny)

RevWaldo (1186281) | more than 5 years ago | (#27658203)

Theoretical physicists do come up with their best hypotheses on 4/20.

Heh (1)

SteveFoerster (136027) | more than 5 years ago | (#27659331)

Only if they use gravity bongs.

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