Older blog entries for amatus (starting at number 7)

The article in Nature.

The article in Nature.

Real-time single-molecule imaging of quantum interference : Nature Nanotechnology : Nature Publishing Group
A nanofabricated diffraction grating and single-molecule imaging are used to record the build up of the quantum interference patterns for molecules with masses as high as 1,298 AMU.

Syndicated 2012-03-26 15:50:04 from Plus Public Activity Feed for David Barksdale

A movie of phthalocyanine modecules demonstrating quantum interference, cf. http://en.wikipedia.o...

A movie of phthalocyanine modecules demonstrating quantum interference, cf. http://en.wikipedia.org/wiki/Double-slit_experiment

Syndicated 2012-03-26 15:17:04 from Plus Public Activity Feed for David Barksdale

How to see around corners

Syndicated 2012-03-21 14:16:19 from Plus Public Activity Feed for David Barksdale

This is all well and good, but can the rope be knotted such that the nails must be removed in a p...

This is all well and good, but can the rope be knotted such that the nails must be removed in a particular order?

[1203.3602v1] Picture-Hanging Puzzles
Abstract: We show how to hang a picture by wrapping rope around n nails, making a polynomial number of twists, such that the picture falls whenever any k out of the n nails get removed, and the pictur...

Syndicated 2012-03-20 19:33:07 from Plus Public Activity Feed for David Barksdale

Turns out the Fermi bubbles are a shockwave of matter from stars that a black hole fails to eat. ...

Turns out the Fermi bubbles are a shockwave of matter from stars that a black hole fails to eat. Or something.

Fermi Bubbles Are Burps from a Star-Eating Black Hole - Technology Review
...and they may also explain the cosmic ray "knee" problem, one of astronomy's biggest mysteries.

Syndicated 2012-03-19 14:10:13 from Plus Public Activity Feed for David Barksdale

NASA posted about some findings of the Fermi Gamma-Ray Telescope. I'm intrigued by their graphic ...

NASA posted about some findings of the Fermi Gamma-Ray Telescope. I'm intrigued by their graphic about "Fermi bubbles" and disappointed they didn't explain what they are.

Mysterious Objects at the Edge of the Electromagnetic Spectrum - NASA Science
NASA's Fermi Gamma-ray Space Telescope is finding hundreds of new objects at the very edge of the electromagnetic spectrum. Many of them have one thing in common: Astronomers have no idea what they a...

Syndicated 2012-03-19 13:50:05 from Plus Public Activity Feed for David Barksdale

Twin Creeks Technologies have unveiled a new way to slice silicon. Instead of all that barbaric c...

Twin Creeks Technologies have unveiled a new way to slice silicon. Instead of all that barbaric cutting with knives—which wastes material and can only get you down to 100s of μm in thickness—they accelerate protons to 1 MeV which penetrate the silicon to an exact and controllable depth in the 10s of μm, the silicon is then heated and the top layer pops right off! The technique is called Proton Induced Exfoliation and can be used to make cheap efficient photovoltaics.

Twin Creeks Technologies - Hyperion
We're reducing the cost of solar generated electricity with a breakthrough technology.

Syndicated 2012-03-13 17:02:31 from Plus Public Activity Feed for David Barksdale

Assuming hexagonal packing, a 0.750 inch in diameter penny [1] is going to "cover" the area of a ...

Assuming hexagonal packing, a 0.750 inch in diameter penny [1] is going to "cover" the area of a hexagon in which the penny is inscribed. That area is sqrt(3)/2 * (0.750 in)^2 [2]. So the cost per area is 1 cent / (sqrt(3)/2 * (0.750 in)^2) = $2.956 / sqft [3].
I'm guessing the author of the caption was using rectilinear packing with a gap of 0.25 inches between the pennies.

[1] http://en.wikipedia.org/wiki/Penny_(United_States_coin)
[2] http://en.wikipedia.org/wiki/Hexagon
[3] http://www.wolframalpha.com/input/?i=1+cent+%2F+%28sqrt%283%29%2F2+*+%280.750+in%29%5E2%29

Syndicated 2012-03-12 14:53:02 from Plus Public Activity Feed for David Barksdale