Why can people (at least some of them) see the glow of an IR LED?
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Why can people (at least some of them) see the glow of an IR LED?
Well... Because of genetic variation and such, perhaps it's possible for some people to detect light a small way into infrared?
I'm not an expert, but there doesn't seem like there should be a completely clear cut off for visible light. I mean, some people can hear things other people are unable to.
...speaking extremely simplistically, the greater the health of the human eye the greater the range of light it can detect. At times this can be a concern when the health of one eye is greater than another.
AFAIK the light output of any LED is not confined to a single wavelength--you get a quite wide spread of wavelengths, although the output is obviously brightest at the diode's specified output. Response of the human eye is also spread out rather wider than the frequencies usually termed visible, so if you have an IR LED whose wavelength spread drops down close to visible, and someone whose eyes are sensitive slightly outside that range, the two overlap and make the IR LED visible.
(Shouldn't this have gone in the physics questions thread, though? :smallwink:).
I didn't know that was possible. Does that mean that those people can see heat signatures too, or is that too faint?
I'd guess that heat signatures are far too faint and much too far into the infrared spectrum.
I have a question: Why do classmates frequently try to kill me in my dreams? None of us dislike each other. My sister tried to gut me with a cloth rotary razor in a dream once too.
You expect logic from the dream world?
Dreams rarely mean anything. so you don't have anything to worry about.
I think they're attracted more towards the light(or whichever component is used to make starch) rather than the heat.
Fun fact: Even vegans are technically eating dead bacteria(descendants). The first "plants" were cyano-bacteria type things, basically bacteria that stumbled on a way to fuse the abundant light with the chemical soup around them, creating energy. Over time, as with animals, groups of these aggregated, then specialised into plant cells(each cell holding the blueprints for every other cell, in addition to its own, but not able to convert itself into them).
Presumably, this means that each cell of a plant should have all of the awareness of a bacterium, but with specialisation, individual cells have varying levels of sensitivity to different stimuli. Does that make sense?
Edit: Another fun fact. Owl in Chinese translates as Cat-headed Eagle/Raptor.:smallbiggrin:
If you were stand right next to the exact north pole, and ran around it in circles, would you be days ahead of the world?
Right sorry to drag this back up but I can't find anything about this Doctor Caroline Leaf other then when she is trying to sell her books. Can't find out where she got her doctorate or in what, can't find ANY published papers by her and from the blurb of her books they look like new age bull**** that has as about as much scientific value as other new age bull**** (also known as none).
So if you have some links to peer reviewed papers by her on this I would like to read them.
Does this really need to be brought up again?
Really? Cat translates as Cat-Headed Eagle/Raptor?
Actually makes sense when you think about it. An owl is a bird of prey, like all raptors (birds not dinosaurs). Eagles being the most famous of the raptors, it's believable that the same word is used for both in China.
And the head of an owl is remarkably cat like.
It's amazing what sort of weird facts are out there.
Typing "Owl" into Wikipedia, after clicking the link to the Chinese version of the website: 貓頭鷹
That's the more common name. I guess scientifically, it's 鴞. For those who can read Chinese but can't see it due to size, it's the word for "number" on the left(sound modifier, so the sound is something like "hao4") and the word on the right is the word for bird(because it is).
Apologies for the diversion, back to your regularly scheduled English. :smallbiggrin:
It's good to know that English isn't the only weird language out there.
Naming things from things already known is hardly unknown in English.
Lots of things we call cats, from polecats to civet cats, aren't actually felines but got named for such because they kind of, sort of, remind us of cats.
Even then, it's actually a measure of time in Earth's reference frame related to how long it takes Earth to go around the sun. If you got a fast enough shuttle you could take off from Earth and come back looking a lot younger than most of your friends, but that's basically it. And it would need to be really fast (an appreciable fraction of c).
Conversely, if you wanted the day to last forever(or at least a long time), go to Venus. It takes longer to make a single spin about the axis(a day) than it does to complete one orbit about the sun(a year). And it rotates in reverse to the Earth. If Venus had plants and animals, their cycles would be utterly alien to any other life on any other planet in this solar system.
PS. Venusian days and years are both in excess of 200 Earth days. The Venusian day is about half an Earth month longer than the year though.
Okay, this one is much more practical then theoretical and also fairly basic.
But I got my hands on a pair of white, chinese counterfeit chucks for 17€ and I also intend to get some organge cloth dye.
Now how would I get these markings on them? :smallbiggrin:
I dyed a pair before, and the thread does not take the dye, so I even got that covered. Stiching it on would be the most simple solution, but also require a lot of work and wouldn't look that great.
Wax and stencils?
That would be my guess.
Why, when talking about the theoretical terraforming of a planet for colonization, is Mars suggested so much more than Venus? Venus has enough mass to hold an Earthlike atmosphere, for one thing.
Do bees taste their own honey?
(Troy and Abed: Community)
Mars has just a thin and cold atmopshere, something you can quite easily compensate for with heating and pressurized housing and suits.
The atmopshere of Venus is in one word "Hell". You have 490° C and 93 times the pressure of earth on ground level. Even with extensive terraforming, you won't be able to get anyone down to the surface of Venus. The pressure is close to what you have at the bottom of the Challenger Deep and at close to 500 degrees, getting a vehicle down to 30 degrees interior temperaure would be a huge obstacle. With terraforming, you might get the temperature down considerably, but that still leaves you with the insane air pressure that will simply crush anything not specifically made for such conditions.
I assumed that it would be easier to siphon off the huge amount of excess air, which would also fix the temperature. Atmospheres don't accumulate exceptionally quickly, so that would suffice for a while.
But Venus is about the same size as Earth, and if I am correct pressure is proportinal to volume, so it would be similar to moving the entire oceans off earth. Or maybe even twice as much. That's a LOT of gass we're talking about.
If you're going to remove the atmosphere, there's the question of what you do with it. You suck the atmosphere off, and vent it into space? It will just settle back to the planet eventually. Removing the atmosphere would be a massive project in terms of effort and cost.