wrote:
On Jun 5, 3:03 am, Winston wrote:

I respectfully disagree.
Our researchers cleverly implied that
changing the thickness of a metal oxide layer (and the resulting
emissivity changes) had something to do with the changes
in the light bulb but the two effects are quite different and
have nothing to do with each other, IMHO.

The filament is in a vacuum. Heating it does not cause it's
surface to mix more readily with oxygen because there is no
oxygen to speak of, in the vicinity of the filament.


I did not note any reference to " metal oxide layer "

The article cleverly melded two *different* physical changes
together, making it appear as if they were the same.

The article mentions the use of the laser to change the color
of metal ala:

http://machinedesign.com/article/mas...ic-colors-1211

That is a heat process. The source doesn't need to be a femtosecond
laser. You can use any sufficient source of high quality heat
(and oxygen) to do that. We've all seen it as HAZ discoloration:
http://commons.wikimedia.org/wiki/Fi...d_with_HAZ.jpg

So if one modified the surface of the filament so
that it would radiate less IR and more visible light, the light bulb
be more efficient.
Theoretically, I agree. This isn't what our researchers were doing,
however.


Hmmm. I thought the whole article was about how the researchers were
modifying the surface of the filament.

Yup. That was the clever part. You and the U.S. Air Force Office of
Scientific Research were prompted to assume that the two different
physical changes were directly related.

"In 2008, his team used a similar process to
change the color of nearly any metal to blue, golden, and gray, in
addition to the black he'd already accomplished."

[Please refer again to the HAZ photo link. What colors do you see?
I see gray, blue, and golden starting from the most heated area
to the least heated area of the HAZ.]

Here is a smoking gun:
"Guo and Vorobeyv used that knowledge of how to control the size and
shape of the nanostructures—and thus what colors of light those
structures absorb and radiate—to change the amount of each wavelength
of light the tungsten filament radiates."

What was this 'similar process'? I'll bet you a dollar that it was
localized heating of a metal sample to grow a color-reflective
oxide layer. How is that related to the process of vaporizing a tiny
chunk out of a tungsten filament?

My point is that there is no relationship between these two
concepts other than one can use heat in specific forms
to accomplish them.

--Winston



--

We now return you to the economic collapse, already in progress.