Scientists Create 'Fastest Man-Made Spinning Object' 159
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."
Re:Dental drill, 600k RPM? (Score:5, Informative)
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 [wikipedia.org] 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 [dentalaegis.com] 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.
Re:Dental drill, 600k RPM? (Score:3, Informative)
Well, 300000rpm would be 5000Hz, which seems to be about the right frequency of the noise made by my dentist's drill. I'm pretty sure dental drills are compressed air driven, so yeah, another factor of 2 or so is probably reasonably achievable.
Re:So Then What (Score:5, Informative)
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.
Not trapped by radiation pressure (Score:4, Informative)
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 [wikipedia.org]
http://en.wikipedia.org/wiki/Optical_tweezers [wikipedia.org]
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.
Re:Summary wtf (Score:2, Informative)
My washing machine runs at 1500rpm for it's extraction cycle. But most typically run at 1200rpm which multiplied by 500,000 gives you 600,000,000
It's amazing what math does when you actually run the numbers and then take the time to look up the target measurement.
Re:Hey I know! (Score:4, Informative)
>The founding fathers were Christians.
No, they were deists at best, which if you describe this to today's "christians" you'd get a horrified reaction as if they were (horrors!) Unitarian Universalists or ... atheists! Today's "christians" believe that God has a direct hand in the lives of everyone. This is in direct opposition to the "clockwork universe" view espoused by the Deists - "God set everything in motion and then abandoned the work to run on its own."
Which is the only thing that makes sense if you're going to write papers on logic and reason, like the founders did. If you have a god that is fiddling around with everything, where is the room for reason?
The Letter to the Danbury Baptists by Jefferson where he says "I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should "make no law respecting an establishment of religion, or prohibiting the free exercise thereof," thus building a wall of separation between Church & State. and the letter to the Touro Synagogue by none other than George Washington himself prove that the US is not a "christian nation" - that every one shall sit in safety under his own vine and fig tree and there shall be none to make him afraid..
I suggest you read them. They're even short enough for a 4channer to read.
http://www.tourosynagogue.org/index.php/history-learning/gw-letter [tourosynagogue.org]
http://www.loc.gov/loc/lcib/9806/danpre.html [loc.gov]
Jefferson's version of the New Testament Bible only came to 40 pages, after ripping out what he described as nonsense. "I have performed this operation for my own use, by cutting verse by verse out of the printed book, and arranging the matter which is evidently his, and which is as easily distinguishable as diamonds in a dunghill. The result is an octavo of forty-six pages, of pure and unsophisticated doctrines."
People who think that the "founding fathers" were "christian" in the modern sense of the word are wrong. Paine was an atheist and proud of it.
"Hell, the Anti-Federalists argued against the US Constitution because it didn't mention God specifically."
This is also just plain wrong. Rhode Island's history was that of a refuge from the theocracy and other bullshit in the Massachusetts colony, where they did things like hang Quakers. The Charter of 1663 granted to Rhode Island by King Charles II a "lively experiment" in religious freedom - you could be anything you liked and not have to toe the line of Christianity or /version/ of Christianity, for example (since the natives were clearly not Christian). This was basically because of the efforts of people like Roger Williams, who didn't see the natives with the disdain that much of the English did. Go read "A Key into the Language of the Americas" for that and "The Bloudy Tenent" for his assertion that a state church "stinks in the nostrils of God," which was also cited by Jefferson when crafting the First Amendment to the Constitution.
There was an unfortunate time when troops from MA would come into RI chasing "heretics" like Anne Hutchinson.
Because of this history, RI was a hotbed of anti-federalism by the 1780s One of the prominent anti-federalists was from my hometown of North Kingstown, RI - William West. It's because of him (he marched an army of 1000 into Providence to protest ratification in 1788) and others like him that Rhode Island was the 13'th state, the last of the colonies to ratify the Constitution. The point of the anti-federalists was to be anti-central-government, because people like William West saw central government as antithetical to religious freedom, among other things.
And I haven't even mentioned William Penn yet. When you're thrown into prison because of your religious views, you tend to come out of prison severely pissed off and wary of state religion.
Don't try to tell me history. This is my back yard.
--
BMO