3 ms·

> I was hoping I could find something natural that spun faster ... A bit unrelated to your comment, but the original experimenters could have spun a buckyball

by lutusp 13y ago

> I was hoping I could find something natural that spun faster ... A bit unrelated to your comment, but the original experimenters could have spun a buckyball instead of a sphere of calcium carbonate and gotten much, much higher rotational velocities. I hope they think of this.

jlgreco 13y ago
Are buckyballs big enough to hit with their laser?
dalke 13y ago
Can you kindly explain how even a UV laser, with a wavelength of about 200 nm, can apply enough torque on a buckyball about 1.1 nm across? My first thought was that the EM field would be essentially uniform, so what you propose wouldn't be possible. What am I missing?
- lutusp 13y ago
  > Can you kindly explain how even a UV laser, with a wavelength of about 200 nm, can apply enough torque on a buckyball about 1.1 nm across? No chance. But it turns out there are larger fullerenes: http://en.wikipedia.org/wiki/Fullerene#Other_buckyballs http://en.wikipedia.org/wiki/Fullerene#Other_buckyballs But as it turns out, the larger fullerenes aren't as strong as C60, so my original idea probably wouldn't represent any easily achieved advantage.
  - dalke 13y ago
    As jlarocco and others point out, based on astronomical evidence, we know that C60 buckyballs are plenty strong enough to rotate at a much higher speed than this macroscopic experiment: For example, "Hydrogenated fullerenes and the anomalous microwave emission of the dark cloud LDN 1622" (www.iac.es/folleto/research/preprints/files/PP06009.ps ) says: > The recent detection of anomalous microwave emission (5–60 GHz) in LDN 1622 by Casassus et al. can be explained as the result of electric dipole radiation from hydrogenated fullerenes. The bulk of the emission (10–30 GHz) appears to be associated with 60–80 carbon atoms fulleranes with a degree of hydrogenation of C:H ≈ 3:1. ... > The emissivity of fulleranes with more than 240 atoms are already two orders of magnitude smaller than that of the C60 hydride and peaks at a frequency of ∼3 GHz, far below the frequencies relevant to the anomalous emission detected in the cloud. It looks like C240 should be able to handle 1GHz rotational speeds without a problem.
  - mtdewcmu 13y ago
    The torque comes from the object's ability to polarize light, AFAIK, so buckyballs would probably not work with this design.
ctdonath 13y ago
Spinning a buckyball so the surface moves at speed of light requires six million million million RPM. Just sayin'.

by lutusp 13y ago

jlgreco 13y ago

Are buckyballs big enough to hit with their laser?

dalke 13y ago

Can you kindly explain how even a UV laser, with a wavelength of about 200 nm, can apply enough torque on a buckyball about 1.1 nm across? My first thought was that the EM field would be essentially uniform, so what you propose wouldn't be possible. What am I missing?

lutusp 13y ago
> Can you kindly explain how even a UV laser, with a wavelength of about 200 nm, can apply enough torque on a buckyball about 1.1 nm across? No chance. But it turns out there are larger fullerenes: http://en.wikipedia.org/wiki/Fullerene#Other_buckyballs http://en.wikipedia.org/wiki/Fullerene#Other_buckyballs But as it turns out, the larger fullerenes aren't as strong as C60, so my original idea probably wouldn't represent any easily achieved advantage.
- dalke 13y ago
  As jlarocco and others point out, based on astronomical evidence, we know that C60 buckyballs are plenty strong enough to rotate at a much higher speed than this macroscopic experiment: For example, "Hydrogenated fullerenes and the anomalous microwave emission of the dark cloud LDN 1622" (www.iac.es/folleto/research/preprints/files/PP06009.ps ) says: > The recent detection of anomalous microwave emission (5–60 GHz) in LDN 1622 by Casassus et al. can be explained as the result of electric dipole radiation from hydrogenated fullerenes. The bulk of the emission (10–30 GHz) appears to be associated with 60–80 carbon atoms fulleranes with a degree of hydrogenation of C:H ≈ 3:1. ... > The emissivity of fulleranes with more than 240 atoms are already two orders of magnitude smaller than that of the C60 hydride and peaks at a frequency of ∼3 GHz, far below the frequencies relevant to the anomalous emission detected in the cloud. It looks like C240 should be able to handle 1GHz rotational speeds without a problem.
- mtdewcmu 13y ago
  The torque comes from the object's ability to polarize light, AFAIK, so buckyballs would probably not work with this design.

ctdonath 13y ago

Spinning a buckyball so the surface moves at speed of light requires six million million million RPM. Just sayin'.