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Scientists Create 'Fastest Man-Made Spinning Object'
dryriver sends this news from the BBC:
"A team of researchers claims to have created the world's fastest spinning man-made object. They were able to levitate and spin a microscopic sphere at speeds of up to 600 million revolutions per minute. This spin speed is half a million times faster than a domestic washing machine and more than a thousand times faster than a dental drill. The work by the University of St Andrews scientists is published in Nature Communications. Although there is much international research exploring what happens at the boundary between classical physics and quantum physics, most of this experimental work uses atoms or molecules. To do this they manufactured a microscopic sphere of calcium carbonate only four millionths of a meter in diameter. The team then used the minuscule forces of laser light to hold the sphere with the radiation pressure of light — rather like levitating a beach ball with a jet of water. They exploited the property of polarization of the laser light that changed as the light passed through the levitating sphere, exerting a small twist or torque. Placing the sphere in vacuum largely removed the drag due to any gas environment, allowing the team to achieve the very high rotation rates. In addition to the rotation, the team observed a 'compression' of the excursions or 'wobble' of the particle in all three dimensions, which can be understood as a 'cooling' of the motion. Essentially the particle behaved like the world's smallest gyroscope, stabilizing its motion around the axis of rotation."
"You guys ain't even seen angular velocity until you've seen my press conference work."
Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
"A team of researchers claims to have created the world's fastest spinning man-made object."
A politician?
--
BMO
n/t
I swear to God...I swear to God! That is NOT how you treat your human!
Are you telling me a dental drill spins at 600,000 RPM? I seriously doubt that. That's ridiculous, it would burn your teeth and anything else it touched. You wouldn't even be able to hear the high pitch whine of the drill at that speed.
I guess that depends who you ask Wikipedia the speed of a modern dental drill is up to 800,000rpm - but the source cited only supports up to 400,000 rpm. these guys say somewhere around 350,000rpm and 400,000rpm - which seems to agree with the other product results turned up by a google of "dental drill rpm."
So -- if you're looking for a quick fake fact and you accept wikipedia as gospel truth - yeah, dental drills operate at over 600,000rpm - apparently the folks that sell dental drills say 300,000rpm to 400,000rpm is more realistic - still in the range of 1/1000th - off by a factor of 33% - but its PR speak.
I know the team member who first suggested this research. As a kid, he was obsessed with spinning tops, bicycle wheels and everything else he could find that spins really fast. Looks like that passion of his spun out of control as he grew older!
Well, once you get into the quantum mechanical realm, you can get things "spinning" pretty darn fast, though you require increasingly "nuanced" definitions of what "spin" means as you transition from the familiar world of classical mechanics to quantum-mechanical systems.
The magnetic moment of a proton in a 1T magnetic field precesses at ~2.7*10^8 Hz (which produces the signals that NMR looks at).
Put an electron in a 1T magnetic field, and it is precessing at ~2.7*10^11 Hz.
A proton's "intrinsic spin" of hbar/2, for an object with the mass and radius of a proton (~1GeV/c^2, ~10^-15m), would "classically" be equivalent to something spinning at hbar/(2*r^2*m) ~ 6.3*10^22 Hz. An electron has an intrinsic spin oh hbar/2, and a size of 0, "equivalent" to an object "spinning" infinitely fast... of course, at this point, it doesn't make much sense to describe the quantum mechanical spin as though it were a "classical" spinning object.
Optical trapping can sometimes make use of radiation pressure, but that's generally not how you optically trap a particle, nor is that how they did it. Radiation pressure is characterized by absorption and reflection (like tennis balls hitting a wall). To trap a particle, you use refraction (when modeling the system with ray optics).
http://en.wikipedia.org/wiki/Radiation_pressure
http://en.wikipedia.org/wiki/Optical_tweezers
The change in index of refraction between water (or air) and your particle causes the light rays to "change direction" as they enter and leave the particle. There is a net momentum transferred to the particle in the direction of the focus of the laser beam, thus trapping the particle at the focus.
I used to have a brushless R/C motor that would turn 65,000 RPM, and I decided it would be cool to try and make a VCR head turn 250,000 RPM.
It would spin like a top for over an hour, and made for one awesome display of 'look the fuck out' if you let it fall on edge like a wheel.
The gyroscopic force was crazy, it was hard to move it all. I would let it slide out of the bearings and land upside down on my table and then lift the table up slightly and make it crawl uphill and try and drive it around as it spun on the stub of the shaft.
My quest for 500,000 RPM ended rather abruptly as the bearing stuck and pulled the head and very unbalanced lower part (where the head used to be mounted that contained the bearing) out of my hand and it began tearing chunks out of whatever got in the way as it bounced around my room and I ran like hell!
I wish I had another VCR;)
(I'm not responsible for any injuries if you try this yourself)
Cheers!
Per minute? You Americans use some odd units. The correct unit for dental drill rotational speed is Hurts.