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Physicists Do What Einstein Thought Impossible

Soulskill posted more than 3 years ago | from the i'm-not-sure-he-cares-anymore dept.

Science 193

An anonymous reader writes "Einstein worked on Brownian motion (the movement of small particles in a fluid as they collide with the fluid's molecules) in 1905, but said it would be 'impossible' to determine the speed and direction of a single particle during this dance. Now researchers have gone and done it, by suspending a dust-sized glass sphere in air (which slowed down its dance moves, since it had fewer collisions with spaced-out air molecules than it would have had with water molecules). The researchers held the sphere in place with 'laser chopsticks,' and then watched how the glass bead bounced around to determine its direction and speed (abstract)."

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193 comments

Magic words... (5, Funny)

fahrbot-bot (874524) | more than 3 years ago | (#32327162)

You had me at "laser chopsticks".

Re:Magic words... (5, Funny)

vandoravp (709954) | more than 3 years ago | (#32327226)

"Laser chopsticks" sounds way cooler than "optical tweezer" from TFAbstract. They should've gone with that in the paper.

Re:Magic words... (4, Funny)

infinite9 (319274) | more than 3 years ago | (#32327268)

Laser chopsticks suck. They keep cooking your sushi before you can get it to your mouth.

Re:Magic words... (0)

Anonymous Coward | more than 3 years ago | (#32327914)

No they don't. They are needed to attach the lasers to the sharks' heads.

Re:Magic words... (3, Funny)

Anonymous Coward | more than 3 years ago | (#32327946)

Laser chopsticks! It dices, cut, cooks and fries! Call now and receive a free shark!

Made in China!

Re:Magic words... (3, Funny)

Tetsujin (103070) | more than 3 years ago | (#32327286)

You had me at "laser chopsticks".

Interesting... How do you suppose laser chopsticks would compare to, say, a laser spanner, or a sonic screwdriver?

Re:Magic words... (2, Interesting)

dgatwood (11270) | more than 3 years ago | (#32327844)

I drank a sonic screwdriver once. They don't taste nearly as good as you might think.

Re:Magic words... (0)

Anonymous Coward | more than 3 years ago | (#32328142)

Sonic is serving alcoholic beverages now? Shit, and I liked them already for their shakes and burgers. I'm heading there for lunch NOW!!

Re:Magic words... (1)

interkin3tic (1469267) | more than 3 years ago | (#32327370)

You had me at "laser chopsticks".

So you could say it was the optical tweezers that caught your eyes.

Re:Magic words... (3, Funny)

Hurricane78 (562437) | more than 3 years ago | (#32328408)

Then the eyes caught fire.
And the fire caught your hair.
Until the firefighters caught your smoldering remains in a urn.

Now it’s your turn. ;)

Re:Magic words... (1)

SnarfQuest (469614) | more than 3 years ago | (#32327598)

You had me at "laser chopsticks".

It's that stupid shark that makes handling them harder than regular chopsticks.

Re:Magic words... (1)

Hurricane78 (562437) | more than 3 years ago | (#32328346)

I thought the magic word was “impossible”. Because every time someone says that, someone else will prove it possible only seconds later. Or at least die trying. ^^

Also: Someone, ages ago, said that something is impossible, and now we can do it... News at 11. :)

Re:Magic words... (0)

Anonymous Coward | more than 3 years ago | (#32328522)

I'd love to see that.

To avoid confusion (4, Insightful)

CorporateSuit (1319461) | more than 3 years ago | (#32327170)

Laser chopsticks were invented to keep chow mein hot until the end of the meal.

Re:To avoid confusion (1, Funny)

Anonymous Coward | more than 3 years ago | (#32327252)

No, "Laser Chopsticks" were invented so that sharks with frickin' laser beams could eat their sushi without all that chasing and chomping.

Re:To avoid confusion (1, Funny)

Anonymous Coward | more than 3 years ago | (#32327482)

How did this get modded "insightful"? It's a joke, you idiots.

Re:To avoid confusion (4, Insightful)

IQgryn (1081397) | more than 3 years ago | (#32327934)

The Funny mod doesn't grant any karma, so people will sometimes mod something they enjoy Insightful even if it isn't.

Re:To avoid confusion (0)

Anonymous Coward | more than 3 years ago | (#32327548)

And the cauterization prevents you from getting hungry again an hour later.

Re:To avoid confusion (1)

MBGMorden (803437) | more than 3 years ago | (#32327910)

Nonsense. No one, except me apparently, actually eats chow mein.

I've never actually ordered chow mein without the clerk checking to make sure I didn't really mean lo mein.

Once they checked twice. Ordered chow mein.

Them: "You want chow mein not lo mein?"
Me: "Yep, chow mein."

Them: "You SURE you want chow mein right? Chow mein have no noodle.".

I get the feeling that they have to redo most chow-mein orders . . .

Re:To avoid confusion (1)

Shadow of Eternity (795165) | more than 3 years ago | (#32328366)

That's strage because Chow Mein IS a noodle dish, the name means literally "stir fried noodles" whereas lo mein means "mixed/stirred noodles".

Re:To avoid confusion (2, Informative)

MBGMorden (803437) | more than 3 years ago | (#32328498)

Must be regional variation. Around here chow mein is mostly cabbage with onions, celery and your choice of meat cooked in. No noodles at all. Looking at the wiki article on chow mein, that particular dish looks like what is usually called chow mei-fun in the local restaurants.

Infinite Improbability Drive (4, Funny)

natehoy (1608657) | more than 3 years ago | (#32327178)

How will the Infinite Improbability Drive work now? It depended on Brownian motion. Now probability can never come off 1:1 and it'll never work!

We must discover time travel immediately so we can go back and stop these researchers immediately! I mean, sooner!

Tomorrow is Towel Day! We cannot allow a travesty like this to stand.

Re:Infinite Improbability Drive (4, Insightful)

sorak (246725) | more than 3 years ago | (#32328146)

So are you suggesting that the infinite probability drive is improbable? Maybe it can run off of it's own improbability.

Re:Infinite Improbability Drive (1)

Hurricane78 (562437) | more than 3 years ago | (#32328452)

Well, since it is pretty much impossible, it might be too powerful for this universe. ;)

Then again, we might have a brand-new trans-universe vehicle. Tadaaaa!

Re:Infinite Improbability Drive (2, Insightful)

rickb928 (945187) | more than 3 years ago | (#32328252)

By design, all claims that the Improbability Drive doesn't actually work are false.

Claims that it doesn't work well are also false.

Nice try, though. Tea is the secret. They only MEASURED Brownian motion, no word on how they might either predict it, control it, or even duplicate it. But if they could in fact duplicate a Brownian circumstance, the Improbablity Drive stil works, because, well, despite the elegant engineering, it is improbably successful. Or something like that. Keep your towel handy.

Keep in mind (5, Insightful)

Anonymous Coward | more than 3 years ago | (#32327184)

When people say "impossible" they generally mean "not possible given what I currently understand about XYZ"

Unless Einstein explicitly said "this will not be possible, ever"

I mean, heck the article demonstrates this itself:

"In 1907, Einstein likely did not foresee a time when dust-sized particles of glass could be trapped and suspended in air by dual laser beam “optical tweezers.”"

I'm sorry but: No freaking shit. In 1907 I doubt many people would have foreseen that

Re:Keep in mind (5, Funny)

noidentity (188756) | more than 3 years ago | (#32327464)

"In 1907, Einstein likely did not foresee a time when dust-sized particles of glass could be trapped and suspended in air by dual laser beam "optical tweezers.""

I'm sorry but: No freaking shit. In 1907 I doubt many people would have foreseen that

Warning: Do not attempt to foresee any more laser-related developments with remaining eye.

Re:Keep in mind (2, Insightful)

Nevo (690791) | more than 3 years ago | (#32328154)

My understanding is that Heisenberg pretty much said "this will not be possible, ever." But I'm not a Heisenberg nor an Einstein so I'll have to read TFA to find out what's going on.

No Fair (1, Informative)

Anonymous Coward | more than 3 years ago | (#32327220)

You changed the outcome by observing it.

Re:No Fair (1)

Theolojin (102108) | more than 3 years ago | (#32328328)

You changed the outcome by observing it.

True dat. If they hadn't seen it, it wouldn't have happened.

Is a glass bead a single particle? (0)

Anonymous Coward | more than 3 years ago | (#32327232)

It sounds like they got close, but no refutation.

Bad Experiment or Bad Reporting (2, Insightful)

olddotter (638430) | more than 3 years ago | (#32327240)

If you "hold it" doesn't that effect the out come of the experiment? Is this a bad test or just bad reporting?

Re:Bad Experiment or Bad Reporting (1)

noidentity (188756) | more than 3 years ago | (#32327350)

I guess it's sort of like how you can determine the position and velocity of (almost) anything by locking it still in some known place. I wonder whether Einstein meant in general, rather than in this specific case.

Re:Bad Experiment or Bad Reporting (1)

Kilrah_il (1692978) | more than 3 years ago | (#32327840)

If you "hold it" doesn't that effect the out come of the experiment? Is this a bad test or just bad reporting?

After years of observing experimentations and reporting, I would venture to guess that the later is more probable than the former... but I may be wrong.

Re:Bad Experiment or Bad Reporting (2, Insightful)

Chris Burke (6130) | more than 3 years ago | (#32328014)

Because you can come up with a question that is not explicitly answered by the article does not necessarily imply either a bad experiment or bad reporting.

It means you probably want to read the paper.

Re:Bad Experiment or Bad Reporting (1)

Machtyn (759119) | more than 3 years ago | (#32328314)

Not having read the paper, I would assume they took this into account by first learning how the lasers affected the particles (perhaps by suspending the dust thin glass in a vacuum). Once the knowns are known, they can subtract that out of the final results and observe the actual result.

the article will be updated soon (1)

tscheez (71929) | more than 3 years ago | (#32327250)

heisenberg compensator sounds so much better than laser chopsticks.

Re:the article will be updated soon (2, Interesting)

Kronon (1263422) | more than 3 years ago | (#32327618)

This shows the onset from the ballistic regime into the diffusive one. They can resolve the motions of the glass bead from single collisions all the way up to a statistical ensemble of them (on which scale Brownian motion is observed). I.e. this has more to do with classical statistical mechanics than quantum mechanics.

Upstart Einstein (1)

Shugart (598491) | more than 3 years ago | (#32327258)

It's about time they put that upstart Einstein in his place!

Re:Upstart Einstein (1)

e2d2 (115622) | more than 3 years ago | (#32327778)

Einstein - what a fucking noob! He thought he could hide his ignorance behind $10 words. We got you now you SOB!

As one might say (1)

PlasmaEye (1128377) | more than 3 years ago | (#32327288)

As Schrodinger might say, "the cat is out of the box and moving toward the door at a velocity of 2m/s."

Well that's prety neat... (0)

Anonymous Coward | more than 3 years ago | (#32327302)

But what I think would be a lot cooler is if they could take all that random kinetic energy and point it in some particular direction.

It's probably not possible in reality, but the imagination reels when envisioning the velocities that could probably be achieved if it could be done.

Re:Well that's prety neat... (1)

Jeng (926980) | more than 3 years ago | (#32327406)

The ability to make something so aerodynamic that it actually creates motion at rest would be so awesome.

Too bad it would be something small like an atom or a neutrino.

What an idiot (5, Funny)

ayahner (696000) | more than 3 years ago | (#32327380)

Ha. Einstein. What an idiot.

Re:What an idiot (0)

Anonymous Coward | more than 3 years ago | (#32327486)

Really, the fucker had it coming, you know.

Re:What an idiot (1)

gyrogeerloose (849181) | more than 3 years ago | (#32328128)

Ha. Einstein. What an idiot.

Yeah. Not only did he predict that it would be impossible to measure Brownian Motion, he predicted that no Slashdotter would ever get laid.

Oh, wait...

gasp (0)

Anonymous Coward | more than 3 years ago | (#32327468)

Won't someone please think of the optical tweezers!

This Einstein Fella is a Hack (5, Funny)

PatTheGreat (956344) | more than 3 years ago | (#32327480)

This Einstein fella - I keep on hearing about how he's been proven wrong or might be proven wrong or how people are picking his ideas apart. It's like he hasn't even SEEN a modern physics paper in like, the last 50 years.

Re:This Einstein Fella is a Hack (5, Funny)

ImprovOmega (744717) | more than 3 years ago | (#32328244)

Yeah, and when was the last time he published anything? I doubt he'll make tenure at this rate.

Slightly Squiffy Reporting... (5, Insightful)

Anonymous Coward | more than 3 years ago | (#32327498)

Einstein only said it was impossible from a tecnical point of view. Given he used brownian motion as direct evidence for the atomic/molecular nature of matter I am pretty sure he appreciated that with future technology it may be possible to do this kind of experiment...

Did they *really* prove they exactly measured it? (4, Insightful)

jeffmeden (135043) | more than 3 years ago | (#32327526)

If the glass bead were moving in such a way that was too subtle for them to measure, would they even know they couldn't measure it? What if Einstein was right and was simply implying that the movements eventually broke down so far that they were unobservable (similar to Planck's work)?

Re:Did they *really* prove they exactly measured i (4, Insightful)

Zantetsuken (935350) | more than 3 years ago | (#32327738)

Exactly - they went and spouted "Oh, look at us, we disproved (Great Person X)'s work!" when all they really did was use selective reading and ignore the other half the book about the Uncertainty Principle [wikipedia.org]

New unit of size.... (1)

Arimus (198136) | more than 3 years ago | (#32327532)

Since when is 'dust' a unit of size?

Re:New unit of size.... (5, Funny)

misosoup7 (1673306) | more than 3 years ago | (#32327602)

Since when is 'dust' a unit of size?

Since they made chopsticks out of monochromatic light.

It's derived from the Library of Congress (0)

Anonymous Coward | more than 3 years ago | (#32327624)

The stuff collects along the back shelves, dont'cha know.

Re:New unit of size.... (1)

Zerth (26112) | more than 3 years ago | (#32327664)

You're right, never has been. It is a range of sizes:0.001-10,000 micron

Re:New unit of size.... (0)

Anonymous Coward | more than 3 years ago | (#32328034)

Well they did mention "micrometers". So if we take a cube 1 micrometer per side of glass at 5000kg/m3 density that would be around 5e-12g. If we assume a 6-tonne elephant, that would be around 8e-19 elephants, which we can round off to about 1e-18 or one attoelephant.

Re:New unit of size.... (1)

SnarfQuest (469614) | more than 3 years ago | (#32328138)

Since when is 'dust' a unit of size?

How many Libraries of Congress would that be? Or would Volkswagons be a better measure?

Impossible for his time (5, Informative)

repepo (1098227) | more than 3 years ago | (#32327558)

TFA doesn't refute any of Einsteins conclusions about Brownian motion. It only shows that it was something impossible to do at Einsteins time. What a cheap way to grab attention!

Re:Impossible for his time (0)

Anonymous Coward | more than 3 years ago | (#32328132)

Exactly correct.

This doesn't break the uncertainty principle. (4, Informative)

raving griff (1157645) | more than 3 years ago | (#32327580)

I've seen a couple of comments (more than one thread or else I would have posted a reply there) that seem to suggest that this breaks quantum physics by accurately predicting the speed and direction of particles, but it should be noted that the Heisenberg Uncertainty Principle states that it is impossible to accurately calculate both the velocity and its position. Speed and angle are components of velocity, therefor the only conclusion of this experiment is that velocity can be calculated under these conditions.

Re:This doesn't break the uncertainty principle. (4, Informative)

jfengel (409917) | more than 3 years ago | (#32327716)

That's correct. What's at issue here is a matter of engineering, not physics.

Physicists reserve "impossible" for the truly mathematically unavoidable, while engineers expand it to the wildly impractical. When you say something "is" true, you're speaking in the former sense. When you say you "believe" something to be true, as Einstein did, you're speaking in the latter sense.

So it's not overthrowing any physical principles. It's merely confirming something else Einstein said: the universe is not only stranger than we imagine, it's stranger than we can imagine.

Re:This doesn't break the uncertainty principle. (3, Funny)

mortonda (5175) | more than 3 years ago | (#32328284)

It's merely confirming something else Einstein said: the universe is not only stranger than we imagine, it's stranger than we can imagine.

I don't know.... Einstein might want to revise that statement... he never had a chance to try to follow Lost [imdb.com]

Re:This doesn't break the uncertainty principle. (2, Informative)

MattMattMatt (1273714) | more than 3 years ago | (#32328506)

Rest assured, Einstein never imagined the mess that is Lost, since it wasn't his saying in the first place.. Quote is attributed to J.B.S. Haldane [google.com].

Re:This doesn't break the uncertainty principle. (0)

$RANDOMLUSER (804576) | more than 3 years ago | (#32328320)

The Uncertainty Principle only kicks in where the particle (wave packet) size and the wavelength of the observing "light" are approximately of the same order of magnitude. A "dust particle sized" (whatever that means) glass bead is much larger than the wavelength of visible light, else, you couldn't see it.

Am I missng something? (1)

Hognoxious (631665) | more than 3 years ago | (#32327620)

Maybe pollen grains aren't "small" but I remember observing them doing Brownian motion in high school. Assuming the microscope is calibrated (i.e. you know the gain) and you can mount a camera on it to capture the movements (or even use a gridded background and call out to an assistant with pen and paper), how can it not be possible to measure the velocity?

Dumb summary (4, Insightful)

Fnkmaster (89084) | more than 3 years ago | (#32327762)

If you read the PhysicsWorld [physicsworld.com] article, you'll see it actually says:

But he believed that it would be impossible in practice to track this motion, given the incredibly short timescales over which the Brownian fluctuations take place

Ahhh... still don't have the original source quotation from Einstein here, but it sounds like Einstein believed it was "impossible in practice" - in other words, that the technology didn't exist at that time to measure rapid fluctuations over microsecond or even nanosecond time scales, and maybe he couldn't even imagine such technology existing.

So he never actually said he thought it was beyond the physical limits of the universe. There was no proof or physical law involved.

Now call me up when somebody figures out how to move matter or information faster than the speed of light (i.e. group velocity greater than c). Einstein really did believe that was *impossible*.

Re:Dumb summary (0)

Anonymous Coward | more than 3 years ago | (#32328532)

You are correct, and further.... they made some assumptions like ... a micro-glass bead has -about- the same -average- kinetic energy as a single air molecule. And then they went on to measure at 5 microsecond intervals. Einstein was specifically stating that he didn't think it would be possible to accurately measure things this small, at the velocities required 10ns, without sufficiently interfering with them as to make the "measurements" inaccurate.

Even with the "laser chopsticks", glass micro-bead garbage, and sheninigans, they do not come close to what Einstein was describing.

Physicists commenting on the work state: But he cautions that it will be difficult to reach the quantum regime. "The necessary refinement in precision may take some time," he explains.
http://physicsworld.com/cws/article/news/42679

Einstein was not even remotely close to being PROVEN wrong on this one yet. Weaksauce.

But I thought... (0)

Anonymous Coward | more than 3 years ago | (#32328120)

Has anyone told Heisenberg about this?

Based on Research by Steven Chu, et. al. (3, Informative)

borroff (267566) | more than 3 years ago | (#32328488)

One thing interesting that isn't mentioned specifically: This work, using "optical tweezers", is based on research done by Nobel Laureate Steven Chu's group at Berkeley. Dr. Chu also happens to currently be the US Secretary of Energy.

No job too big, no job too small, Steve Chu does 'em all.

holy mother of god (2, Insightful)

nimbius (983462) | more than 3 years ago | (#32328540)

this has got to be the coolest science ive seen on slashdot in a while. find a suitable nano-shark and we can start talking laser sushi.

Well I guess Einstein was no Einstein (0)

Anonymous Coward | more than 3 years ago | (#32328552)

Well I guess Einstein was no Einstein...

Velocity/position, isn't that a particle/wave prb? (0)

Anonymous Coward | more than 3 years ago | (#32328562)

As far as I understand:

You can only determine velocity as a function of distance over time. But in the interpretation of particles as wavefunctions, particles can be found anywhere on the wavefunction. You are still able to ring a bell when it has position 1, and then ring a bell when it has position 2, and you could then calculate the "velocity" it must have had as it moved from 1 to 2 over a certain amount of time. It should however be impossible to separate out the portion of movement that is down to simple movement on wavefunction, and movement of the wavefunction itself. The concept of speed only starts to make sense if you start to treat wavefunctions as particles, which ignores that they more around randomly and is therefore only usable for positions and not speed - whilst if you treat wavefunctions as wavefunctions, you can calculate velocity, but position stops making sense.

Any physicist to correct me here?

Nature of Brownian Motion (5, Informative)

vdorie (1106873) | more than 3 years ago | (#32328568)

Brownian Motion is a mathematical construct, which, among other things, is nowhere differentiable (almost surely). You can pin a BM down into sets with high probability, but no, you can't really predict it. It is merely used to *model* the movement of a particle in a fluid, it is not actually the process by which the molecules move. Indeed, "such a path represents the motion of a particle that in its wanderings back and forth travels an infinite distance in finite time. [BM] does not in its fine structure represent physical reality." (Billingsley, "Probability and Measure"). At least the science is interesting.
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