Posted on 07/26/2018 11:43:06 AM PDT by Heartlander
Let alone balancing it before spinning to said high speeds. Actually, only the purely balanced ones can survive those speeds. Good luck finding one. :-)
That deserves a WOW.
5.56mm
If a dental drill spun at 600,000 RPM, it would be out the bottom of your jaw, or top of your head, before the dentist could say "open wide."
Who edits this stuff?
I was thinking of some things somewhat less ambitious, like a propeller.
Of note, a pure synchronous electric motor must set spinning at a proper rotation speed to sync with the applied electrical input, thereby maintain rotation. It is not self-starting.
The optically driven rotor likely is not synchronous with the light applied. The circularly polarized light does manage to provide an offset momentum kick to the rotor ends, which results in rotation from startup.
Way cool!
“The White–Juday warp-field interferometer is an experiment designed to detect a microscopic instance of a warping of spacetime. If such a warp is detected, it is hoped that more research into creating an Alcubierre warp bubble will be inspired.”
“The Alcubierre drive remains a hypothetical concept with seemingly difficult problems, though the amount of energy required is no longer thought to be unobtainably large.”
https://en.wikipedia.org/wiki/Alcubierre_drive#Alcubierre_metric
Perhaps the rotor/light interaction changes the polarization of a reference light source. The differential then allows determining the rotation rate.
Boy, what’s the torque like on that baby?
I’m thinking it will need lots of gear for the holeshot.
60 billion RPM’s. How do you measure that?
A non-contact tachometer.
But it would have to go to ELEVEN, or maybe higher?
It’s the force of the laser times the distance between the axis and the end of the little crystal thingy.
A small number times another really small number.
The momentum, however is the mass times the velocity.
Even though the weight of the little crystal thingy is small, the angular velocity of this bad boy is pretty massive.
That wouldn’t be such a super small number, but it would still be small.
Just a mini radiometer, pumped up by lasers.
I have an old Crooks radiometer around here somewhere(next to the drinking bird).
Hit it with a laser and it would surely spin extra fast.
When can I get one at Harbor Freight?
Just look for a Crooks radiometer on Amazon.
A small number times another really small number.
I’m thinking, that is a polite way of saying that any real-world advantage, would be eaten by friction loss?
The part spinning at a rate exceeding the speed of light is supposed to increase infinitely in size. No?
I think it’s way cool, even though way above my pay grade. Still, I’ll keep watching for the future theories, applications, and discoveries that result. Along the way, some genius-level physicist who’s able to explain these things to mere mortals invariably turns up. FUN!
By my rule-of-thumb calculation, an object 320nm long being rotated would have a path whose outer circumference is about 1 micrometer.
So 60B rotations / sec would be 60M meters per second (at the outer edge).
Or around 37000 miles per second.
That’s about 20% light speed.
Perhaps others here can double-check my math.
In this case, there would be zero friction loss, or near zero friction loss because this contraption is in a vacuum.
The folks doing this experiment claim vacuums aren’t really empty, and there ARE some particles in vacuums. If that’s true, the number can’t be zero friction.
However, consider that 68 billion revolutions is 6.8 x 10^10, and that happens per second. Multiply that by 2 x pi, and that’s the distance the end of the little spinner goes in one revolution. So the v is 10^11 nm/s, roughly. That’s a big number, but what is the mass of the little crystal thingy you multiply that v number with? 10^-9 grams? Who knows, maybe less? The momentum would be in the hundreds of nm g/s. Not a huge number.
Maybe measuring an electrical field created by lots of electrons moving around and around and around...
60 gigahertz. It’s measurable, in the upper end of the microwave part of the spectrum. I work with radars for tank level measurement that operate around 23 GHz.
Probably more like 1491.
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