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# Prfessor

• ### What is the name of the pose where someone is facing more than 90 degrees away, but you can still see one of their eyes?

This has to do with field of vision and the fact that the pupil is still visible at 110+ degrees temporal (side away from the nose). I found a couple of research papers with photos of pupils at various angles, one up to 80 degrees, another up to 105 degrees, but on the last one the pupil still looks pretty round. (Something to do with the index of refraction of the cornea increasing towards the edge) I'm look for some pictures right at the limit, which would be easier if I had better search terms.

• ### Can a photon have a frequency four times the age of the universe?

Assuming a quarter-wavelength is the minimum length of an antenna needed to detect electromagnetic radiation, shouldn't that apply to time too? So if a photon had a frequency in the aHz (attoHertz) range, i.e.,

one cycle per 55 billion years, enough time should have gone by since the Big Bang for one-quarter of the wave to have passed us by.

I don't mean if we can detect it, just if it could exist.

7 AnswersAstronomy & Space6 years ago
• ### What is the name of the color halfway between red and orange-red?

Also, halfway between orange-red and orange?

By "orange-red" I mean a color halfway between orange and red.

I need these to be "spectral" colors, which means on a color picker they have 100% saturation and 50% brightness or luma. (In hex code, spectral colors always have two pairs of digits that are either 00 or FF.)

The answer doesn't have to be exact, but it should be a word that doesn't usually mean some other color.

I've looked at vermillion and blood-orange, but am not sure.

• ### Is there any historical connection between Guy Fawkes Day and (American) Thanksgiving?

Just wondering.

• ### What's the longest wavelength of infrared that anyone has ever seen?

Everyone can easily see the light from an 808 nm laser pointer. ("Visible light," 400 - 700 nm, just means whatever wavelengths most people can easily see under ordinary circumstances, not counting lasers and such.)

940nm tactical flashlights look very dim, but you can still see the light. Some people at Laser Pointer Forums (dot com) have seen the light from their 980 nm laser pointers. In one vision experiment people saw 1064 nm (http://www.opticsinfobase.org/josa/abstract.cfm?ur...

Researchers suspect that people can probably see 1100 nm, and that the upper limit may be 1150 - 1200 nm, but they're not sure. Most of my sources are decades old, so I was wondering if anyone ever got any higher than 1064nm.

• ### Where can I get Wood's glass?

I don't know if they make it anymore. If not, would any be available on the antiques market? Does it have too short a shelf life for old Wood's glass to be useful?

I would also be interested in modern replicas, but only if it's made with the original ingredients.

1 AnswerEarth Sciences & Geology8 years ago
• ### Where can I find real Wood's glass for uv pass filter?

I don't mean imitation Wood's glass like Rosco Permacolor dichroic filters. I mean the real thing, made of barium-sodium-silicate glass with nickel oxide.

Apparently they have stopped making the stuff in the Western World, but they often continue to make obsolete technologies in non-Western countries like India and China.