The human eye can see ‘invisible’ infrared light - The Source - Washington University in St. Louis (source.wustl.edu)
from fossilesque@mander.xyz to science@mander.xyz on 02 Mar 2024 18:49
https://mander.xyz/post/10308311

#science

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SheeEttin@programming.dev on 02 Mar 2024 19:52 next collapse

tl;dr:

The research was initiated after scientists on the research team reported seeing occasional flashes of green light while working with an infrared laser. Unlike the laser pointers used in lecture halls or as toys, the powerful infrared laser the scientists worked with emits light waves thought to be invisible to the human eye.

But packing a lot of photons in a short pulse of the rapidly pulsing laser light makes it possible for two photons to be absorbed at one time by a single photopigment, and the combined energy of the two light particles is enough to activate the pigment and allow the eye to see what normally is invisible.

“The visible spectrum includes waves of light that are 400-720 nanometers long,” explained Kefalov, an associate professor of ophthalmology and visual sciences. “But if a pigment molecule in the retina is hit in rapid succession by a pair of photons that are 1,000 nanometers long, those light particles will deliver the same amount of energy as a single hit from a 500-nanometer photon, which is well within the visible spectrum. That’s how we are able to see it.”

Neat! But please don’t shine lasers into your eyes even if it’s supposed to be invisible.

Valmond@lemmy.mindoki.com on 02 Mar 2024 21:12 collapse

Also, isn’t it wildly known that some people see some shades of infra rouge?

vampire@lemmy.world on 02 Mar 2024 21:59 next collapse

I’ve always been able to see the IR light from those depth sensing cameras used for facial recognition on laptops, as well as those sensors old android phones used to use to detect if they’re face down on a table or up to your ear.

It just looks like dark red to me. My science teacher in highschool told me it’s not common but some people have a wider spectrum of light thats visible to them than others. This special gift from nature has not meaningfully impacted my life in any way, shape, or form.

Zikeji@programming.dev on 02 Mar 2024 22:09 next collapse

I had just assumed those were supposed to be visible. Like the lights the Xbox Kinect had.

But if they aren’t, that’s annoying lol. Same deal with hearing the high pitch frequency old CRTs would emit.

CookieOfFortune@lemmy.world on 02 Mar 2024 22:45 next collapse

The CRT thing is pretty common I think, you just lose your high frequency hearing as you age.

Zikeji@programming.dev on 02 Mar 2024 23:13 next collapse

Yeah, I was using it as an example of annoying things fitting around the same niche lol.

474D@lemmy.world on 03 Mar 2024 00:21 next collapse

I lost it at a Cypress Hill concert

bitchkat@lemmy.world on 03 Mar 2024 04:01 collapse

The high pitch squeals just move to inside your head.

CookieOfFortune@lemmy.world on 03 Mar 2024 07:10 collapse

Ugh this has become very true as I’ve aged :’(

UPGRAYEDD@lemmy.world on 03 Mar 2024 08:39 collapse

Its not intentional as much as it is a cost savings

UPGRAYEDD@lemmy.world on 03 Mar 2024 08:39 collapse

Thats mostly because the vast majority of IR lights and led’s also emit visable light. To get an ir light to not also emit within the visable light spectrum is much more expensive.

Audrey0nne@leminal.space on 02 Mar 2024 22:12 next collapse

Do you suppose the green flash phenomenon should be revisited? A combo of light, atmosphere and the human eye seems reasonable to me.

catloaf@lemm.ee on 03 Mar 2024 03:15 collapse

Considering it’s been photographed I don’t think the human eye is a factor.

Audrey0nne@leminal.space on 03 Mar 2024 03:31 collapse

What does being able to capture it on film have to do with it?

elmicha@feddit.de on 03 Mar 2024 09:16 collapse

When you take a photo, your eyes are not involved (apart from setting up the camera). The light comes from the source and goes through the camera lens onto the film or camera sensor, your eyes are not a factor at that point.

Audrey0nne@leminal.space on 03 Mar 2024 13:54 collapse

Yes in a vacuum where you are only trying to capture a pinpoint light source. The sun is many orders of magnitude greater and refracted through an atmosphere of gas, water molecules and dust. Are you saying none of these are factors in the ability for a camera to capture what the human eye can only observe in very specific circumstances? If I’m still wrong, please explain yourself better than just basic information on how a camera works.

Eeyore_Syndrome@sh.itjust.works on 03 Mar 2024 01:32 next collapse

I can barely see normal visible red.

Stupid Deuteranomaly

plinky@hexbear.net on 06 Mar 2024 00:22 collapse

weird stuff, i could have been in pnas if i was dumb enough to work with laser without safety goggles <img alt="meow-floppy" src="https://www.hexbear.net/pictrs/image/9875e349-be09-463a-b8fd-4d9315e3ac30.png">