Levitating Graphene Is Fastest-Spinning Object 146
techbeat writes "A flake of exotic carbon a few atoms thick has claimed a record: the speck has been spun faster than any other object, at a clip of 60 million rotations per minute. Previously, micrometre-sized crystals have been spun at up to 30,000 rpm using an optical trap. It is thanks to graphene's amazing strength that the flakes are not pulled apart by the much higher spinning rate, says Bruce Kane at the University of Maryland in College Park. Spinning could be a way to probe the properties of graphene, or manipulate it in new ways."
neat (Score:5, Interesting)
can you give it enough mass to make it into a decent flywheel?
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can you give it enough mass to make it into a decent flywheel?
More precisely, you mean its moment of inertia [wikipedia.org]. It'll make a decent flywheel, if it has low moment of inertia but very high velocity, since the product of these two is what counts.
In this case if you increase the mass (thereby increasing the moment of inertia) the system will just tare itself apart due to centrifugal forces. The thing here is that they could make it spin really, really fast because graphene is very light. For one it is made up of a single sheet of graphite (2D crystal) and graphite itself
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Ok, I was with you until I read the word "centrifugal"... I was under the impression that science left that word behind long ago for "centripetal". At least that's what we were taught in the 80's. Has it come back in fashion to use it?
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Obligatory xkcd [xkcd.com]
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'nuff said [xkcd.com]
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That's a very inertial-frame-centric view of the Universe, but it isn't true except for very deviant definitions of "real" that also rejects relativity and implies that gravity is not "real" (for it, too, is a fictitious force, which isn't the same as saying it isn't real).
The GP is actually correct.
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can you give it enough mass to make it into a decent flywheel?
no problemo [nrao.edu]
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Can we use them as flywheels?
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Even electrical signals, which move at close to the speed of light, have to be sent on smaller and shorter pathways in modern chips to get speedups.
They run at gigahertz speeds, which implies nanosecond timings. A flywheel with decent mass spinning a million RPM is only four orders of magnitude away from the speed of light.
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They run at gigahertz speeds, which implies nanosecond timings. A flywheel with decent mass spinning a million RPM is only four orders of magnitude away from the speed of light.
It all depends.
Speed of light: 300e6 m/s
Speed of micrometer scale graphene flakes spinning at 60 million rpm:
2*pi*1e-6/1e-6 = 6 m/s = 21.6 km/h
I think you can get any material spinning at 60 million rpm at micrometer scale. Tensile strength is not very important at these speeds.
It is a nice trick though.
Nyh
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GGP said flywheel, not flake.
Reminds me ... (Score:2)
Re:Reminds me ... (Score:5, Funny)
Next time you teach someone to drive a manual, don't let them touch the accelerator until they learn how to use the clutch..?
Re:Reminds me ... (Score:5, Funny)
And avoid girlfriends who think it's OK to twist and pull the stick shift violently, whether it's ready or not. Could be indicative of future, uh, problems.
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Yeah. My car doesn't have a safe word.
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This isn't as funny as it is practical. Any manual transmission car with a decent idle control system can be driven without touching the gas pedal given the clutch is used gracefully. Trying to teach someone how to drive a manual car via "gas in, clutch out" is a sure way to simultaneously fail to teach them the right way to drive, and ruin your clutch.
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Yup, an old uncle taught me and my cousins how to use the clutch by getting us to hold his truck on a slope using just the clutch and then being able to go forward and backward with the clutch. Fun stuff.
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while I've certainly driven cars with the right level of torque (especially diesel turbo utes with huge torque figures... had one that could do 30kph in first without touching the accelerator)
this is not a rule. this is not 100% informative, i would pay money to anyone who could have done anything but stall my last car without giving it a little throttle, and it had a very powerful motor.
but also an exceedingly heavy triple clutch. (to be fair _everyone_ who got in that car stalled it the first time they tr
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A buddy had a '67 Corvair that had been a NASA camera platform for filming planes landing. The roof was chopped off, a 327 small block was installed in the back seat and a plywood platform on top of the engine.
You could have the car in 4th gear and let off the clutch too fast and it spin the tires. So much torque in such a light car!
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The size of the engine doesn't matter, you can do the same on cars with tiny engines if you're careful. The wussiest car I ever drove was the 16v 1.2 that my instructor had, and even that was fine starting off even up up a slight slope with no throttle.
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Depends on how much torque the engine produces and at what speed. A Yamaha R6 I4 and a Harley V-twin will react very differently.
Awesome (Score:1)
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No, but it could be made to create indestructible ballet dancers.
Think of it. No more sprained ankles...no more broken toes...it would revolutionize the culture!
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No, but it could be made to create indestructible ballet dancers.
Think of it. No more sprained ankles...no more broken toes...it would revolutionize the culture!
Yeah, but people will still be unable to agree which way her silhouette [about.com] is spinning!
This is a great leap forward... (Score:3, Funny)
... in Dradle technology.
uhm, 30 000RPM? (Score:4, Informative)
Summary fscked up. 30 000RPM isn't exactly much at all.
Ie. almost all RC (radio controlled) model brushless motors can do 30k RPM, and some brushed motors can do that as well...
Nevermind so many other things which do spin reaaally fast ...
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No peak power is much lower. 30krpm is where the torque kicks in.
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A brushless motor is not a crystal being spun in an optical trap.
The world record for the 100m dash is 9.58 seconds. That an F16 could do it faster is irrelevant to that claim.
Of course why they chose to mention that, given it isn't using the same technique, is a mystery. But they never claimed that was some kind of general spinning speed record.
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The previous article [nih.gov] that is referenced records rates of 500 rotations per second - which is 30,000rpm.
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If only they'd thought to attach their single microcrystal to a brushless motor...
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I guess I shouldn't complain, but I have to wonder why my dumbest jokes are getting mods like "Interesting" lately... This is worrying.
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Poor clubwrx never saw it coming...
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30k rpm = typo (Score:1)
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or maybe 30k RPS?
Re:30k rpm = typo (Score:4, Informative)
No typo. Read the original abstract: http://www.ncbi.nlm.nih.gov/pubmed/19424395
500 turns per second. But your HD isn't put to rotation by a light beam - that's the news of this article, not the speed.
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Video? (Score:3, Interesting)
No wait, even if we have a video that ran at one million frames per second all we would see is an immobile object. At two million frames per second we would see it move instantly by 180 degrees...
How did they calculate that 60 million rotations per minute again?
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So after RTFA(bstract):
At micro-torr pressures, torques from circularly polarized light cause the levitated particles to rotate at frequencies >1MHz, which can be inferred from modulation of light scattering off the rotating flake when an electric field resonant with the rotation rate is applied.
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My guess would be that they calculate based on measuring the amount of energy input into the system and subtracting what is observed escaping.
I bet if I read TFA that would eliminate the need to make guesses, but this is slashdot.
Re:Video? (Score:5, Interesting)
No wait, even if we have a video that ran at one million frames per second all we would see is an immobile object. At two million frames per second we would see it move instantly by 180 degrees... How did they calculate that 60 million rotations per minute again?
They shoot a laser beam through the sample, which they measure with a detector at the other side. Then they apply an electric field to the flakes at high frequency (> 1 MHz). They scan the frequency of the electric field from 4 kHz up to 3MHz. When the frequency of the electric field is the same as the frequency of the rotating flake you get a resonance [wikipedia.org] which appears as a sudden spike in the laser detector. That's how they know what the rotation rate is, and the dielectric response of graphite to an electric field is well known so they can cross check this with theory.
...and technically we do have video systems that can acquire data up to 1 peta Hz [wikipedia.org] (or if you're american you'd say 1 quadrillion Hz). Femtosecond lasers are used in chemistry for more than a decade now to image fast chemical reactions.
Hope this rambling post helps!
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From the abstract linked above:
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Rain Man.
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The same way they calculate rotations in a Dynaflex powerball, albeit on a larger and more precise scale.
Niven's dream (Score:1)
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I'm the general... (Score:2)
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more funding is on the way (Score:2)
politicians can't wait for this technology to become usable.
That is impressive but not as interesting as... (Score:4, Funny)
...when I watched an idiot EN3 (Petty officer 3rd class) walking on a prop shaft cover (which he knew he wasn't supposed to do) while we were under way and slipping and engaging the tiny tiny tiny tiny little gear that was intended to turn the shaft in port to avoid warping. I don't remember the ratio of the gear but it was something on the order of a few hundred thousand to one (it turned the shaft once every 90 minutes or something) and when this dipstick engaged it (someone was doing maintenance on it so it was unlocked) the shaft was doing 150 rpm or so. I remember doing the math at the time and figuring out the max RPM on the gear was somewhere along the lines of 35 million plus rpm. Now, the gear didn't make it that high since it disintegrating with what sounded like a bomb going off. Thank God it was small as it blew holes through bulkheads, steel covers, blew the cover off the rocker arms on the diesel engine 20 feet away. Nobody was hurt except for some ringing ears. Ahh, those 3 years in the Navy before I go to university, what things we learned... Hehe. BTW, the 'instant petty officer' was upside down in the reduction gear lube sump the minute we got back into port as punishment (the cheng [chief engineer] had him practicing his needle-gunning skills in the bilge two hours every morning in the meantime.)
Re:That is impressive but not as interesting as... (Score:4, Funny)
When I worked as a mechanic I once saw a crankshaft pully come off at speed. My co-worker was replacing a timing belt on an older for Escort and had a bit of trouble getting it lined up properly. When he figured it out he got all excited and hopped in the car without actually bothering to bolt the pully to the crank... so when he fired it up, and it worked, he got all excited and revved the engine a few times. This sped up the inevitable march of the pully down the end of the crank, where it ran out of room and fell off while doing about 4000rpm. It bounced twice in a shower of sparks, and the third time it "hooked up" and shot across the floor of the garage like a rocket. Needless to say, the engine died and the pully was now in more than one piece, as was the bit of wall it smashed into. My co-worker was devastated, but the rest of us were in stitches. :)
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Fortunately, not literally! :)
Other elements (Score:4, Interesting)
I wonder how fast you could spin a nitrogen molecule before it falls apart? It should be calculable. Would hydrogen go even faster?
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They have a saying... (Score:1, Interesting)
In Romania they have a saying: Go spinning around.
It roughly means go f*** yourself.
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Is it relativistic? (Score:1)
The speed makes me think of what would happen to a rotating sphere that spins so fast the outer portions become relativistic and undergo both spatial and temporal changes relative to the inner core.
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The speed makes me think of what would happen to a rotating sphere that spins so fast the outer portions become relativistic and undergo both spatial and temporal changes relative to the inner core.
The abstract says that the graphene is micron sized, so
v = PI*D*w
D = 1E-6
w = rotational frequency = 1E6 Hz
v = 3 m/s
Sadly, not relativistic.
some neutron stars rotate near light speed (Score:2)
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circumference = pi times diameter (Score:2)
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Your finding validates the GP's comment:
10 km diameter * PI ~= 30 km at the equator
(30 km / rotation) * (1122 rotations / second) ~= 30,000 km / second ~= 10% * c
Perhaps you were thinking of rotations per microsecond?
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1122 times a second sounds like one rotation in something less than a millisecond, no?
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Can you cite something for this? The highest spin rate I could find for a neutron star (XTE J1739-285) [wikipedia.org] is 1122 times a second and it seems that it may not even be the correct rate.
http://en.wikipedia.org/wiki/Pulsar [wikipedia.org]
Ultimate Tilt-a-Whirl (Score:2, Funny)
Spinning microcrystals (Score:2)
Space elevator (Score:2)
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Isn't a carbon nanotube just a rolled-up strip of graphene?
This doesn't sound right. (Score:2)
My understanding is that it is graphite if there's more than one layer and it is only graphene when it is a single layer, which by definition is also a monatomic layer. If this is correct, then you cannot have graphene a few atoms thick. That has no meaning.
Science writing at its finest (Score:2)
was really helpful - I'd always wondered what "circular polarization" meant.
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That's completely wrong, actually. Light always applies some momentum to what it hits, the difference with circular polarised light is that it imparts a spin.
Linear polarised light is the sine-wave shape you've probably seen before, circular polarised light is essentially a spiral around the direction of travel. See: http://en.wikipedia.org/wiki/Circular_polarization [wikipedia.org]
It's used in 3D cinema glasses because there are two kinds of circular polarized light (referred to as left and right handed), which spiral opp
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Oh, this internet sarcasm thing. Sorry, I just thought you were stupid.
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Macroscopic RPM Record (Score:3, Informative)
"As a result, the flakes started spinning at 60 million rotations per minute, faster than any other macroscopic object."
"Previously, micrometre-sized crystals have been spun at up to 30,000 rpm"
Following through to the source of that quote:
"Their short axis follows the direction of the linear polarization of the beam. In circular or elliptic polarization, the crystals are spontaneously put in rotation with a high speed of up to 500 turns per second. It is the first time, to the best of our knowledge, that such a result is reported for particles of the size of our crystals."
So, if the 30,000 RPM crystal is interesting because it was a crystal, or because it was small, fine. But if they're saying that 30,000 RPM was interesting for large objects, ummm, turbocharger turbines spin at up to 150,000 RPM.
That said; 60 million RPM is very impressive.
1 million Avis? (Score:2)
Sorry I can't find the source... but someone commented humorously that "Hertz has a unit named after them, why doesn't Avis?" Avis was semi-sarcastically named as a unit of angular velocity; 1 Avis is 2*pi radians of rotation per second, or 1 full rotation per second.
So this is 1 million Avis.
30K ain't nothing (Score:2)
UMCP (Score:2)
It is the University of Maryland
UMBC, UMES, and UMUC may share the 'University of Maryland' name, but are in no way related beyond the fact their state owned.
Changing Its Mass? (Score:2)
Is it true that relativity predicts that rotating an object increases its mass? Does this graphene apparatus offer a way to test that theory, as the starting mass is small enough to detect small increases as large relative to the starting mass, and the rotation can be high enough frequency to really see the effects of the phenomenon?
WolframAlpha (Score:2)
WolframAlpha needs to be updated now. Did a search on 60 million rotations per minute to find out the period (1×10^-6 seconds), and I noticed this bit of info: ~~ 3 × fastest induced angular velocity (steel ball 0.8 mm diameter suspended in vacuum) (~~ 2×10^7 rpm )
60 million rotations per minute - Wolfram|Alpha [wolframalpha.com]
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60,000,000 RPM is (approximately) 1,000 per millisecond.
No thanks necessary, you're welcome.
Seriously, we could do this all day :)
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Oh SHI- [wikipedia.org]
Re:You know what else spins that fast? (Score:4, Funny)
at a cool million rotations per second, and given the friction coefficient of human skin is about 0.8, I'd say that you have no crotch left.
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wouldn't work unless .... it was an oscillating electric field TRAP!
Re:You know what else spins that fast? (Score:4, Funny)
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no, I don't believe that's the logical conclusion of this thread, but it may be that you are the original AC...
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also, it would have to be microscopic..... oh wait....
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It sounds slow, but what you don't realise is that they're scaling down that hard drive in realtime.