UV light and Astronomy

[Cath]

[mikeDnight]

An interesting video. It was particularly interesting when the presenter said that some people who have no lens in their eyes can see UV light.

Interestingly, throughout the modern history of astronomy, many visual observers have been able to see subtle detail in the cloud tops of Venus. Many astronomical sketches have shown that astronomers from all around the world have drawn detail so similar that they must be seeing something. Some have put it down to imagination or mere contrast effects brought about by the planets brilliance. Many others with the best will in the world see nothing but a brilliant silver disc or crescent.

In recent years images of Venus cloud tops taken in the ultraviolet show exactly the same cloud pattern as has been drawn countless times by visual observers for over a century.

It has been presumed that some people with normal eyesight are sensitive to the UV and that those who are able to detect subtle variations in albedo in Venus clouds must be especially so.

Mike

[Cath]

Quite possible Mike.

I know that I myself can see 850nM which is considered to be near infrared (the opposite side of the human visual spectrum), it looks like an extremely deep red colour. I can't see 900nM though so 850nM is around the lowest frequency I can see.

What that means I do not know. I'm not colour blind in anyway.

[Astrobits]

Horace Dall ( he of the Dall null test, Dall-Kirkham optical design and much else ) could see further into the UV after he had cataracts removed.

Nigel

[pipnina]

Quite possible Mike.

I know that I myself can see 850nM which is considered to be near infrared (the opposite side of the human visual spectrum), it looks like an extremely deep red colour. I can't see 900nM though so 850nM is around the lowest frequency I can see.

What that means I do not know. I'm not colour blind in anyway.

Can you see the remote control bulbs flashing when you press a button? Or maybe see through IR-only surfaces (Like the ones used to disguise the Nvidia 3D vision synchronysing box, I can see very small ammounts of red through them)

[Cath]

Can you see the remote control bulbs flashing when you press a button? Or maybe see through IR-only surfaces (Like the ones used to disguise the Nvidia 3D vision synchronysing box, I can see very small ammounts of red through them)

I can see it if they use 850nM LED's, but not if they use 950nM LED's

[pipnina]

I can see it if they use 850nM LED's, but not if they use 950nM LED's

People who see IR/UV are like super heros to me. Honestly if I had any power it would to be the ability to see the whole spectrum. But maybe not Microwave/Radio because they're a bit ugly lookin'.

[Dave Lloyd]

You're very young pipnina. I wonder if as people age the visual frequencies they can detect contract, either from one or both ends of the spectrum. A little like losing the ability to hear high frequency sound as you age.

[Cath]

People who see IR/UV are like super heros to me.

awww don't say that

We are ALL different (no matter what anyone/anything else might have to say on the matter), we each have our little differences, which is why we are still here. Without those little differences, life, in this universe at least, would never evolve to anything more than an atom.

Pipnina is as special to life as ANY other life form that exists anywhere, be it planet Earth, or otherwise.

Life may well give you a hard time, just as it does to sooooo many others, and in some very unpleasant ways at that, but it can never take away just how important you are.

You are as much a 'hero' as anyone else Pipnina. Anyone that tells you otherwise, is most definitely doing so for reasons only known to themselves.

[pipnina]

You're very young pipnina. I wonder if as people age the visual frequencies they can detect contract, either from one or both ends of the spectrum. A little like losing the ability to hear high frequency sound as you age.

Well, I know that, with age, cells in the retina start to die off. This means my mother can't read in light levels that I can (and could possibly read in darker still at that point).

But as far as light range goes... I'd think that stays about where it is for your whole life considering it's the same three types of cell that detect the different wavelengths.

But I debut our band of visible light decreases with age. If it did, we might start seeing very weird anomalies as gaps in the spectrum between RGB cones would be present.

[Dave Lloyd]

That's a good point but are you saying that rod cells die out but cone cells don't? Perhaps there's less saturation in the colours you see as you get older. Seems the same to me aswhen iI was younger but maybe some people are affected.

[pipnina]

That's a good point but are you saying that rod cells die out but cone cells don't? Perhaps there's less saturation in the colours you see as you get older. Seems the same to me aswhen iI was younger but maybe some people are affected.

I'm not saying cone cells don't die out. Just that they probably don't decrease in the range of colours they detect.

If solour saturation decreases as you get older as well, that's probably because cone cells do die out while seeing the same band of colours meaning your brain has to interpolate some gaps in vision (Like a camera correcting for a dead pixel).

Well, humans are very complicated things. Especially when it comes to perception. Perhaps it's best we don't think about it too hard

[Cath]

Perhaps it's best we don't think about it too hard

That could explain why our race has the awfulness about it around the world we see today ?

[Dave Lloyd]

That could explain why our race has the awfulness about it around the world we see today ?

Sadly, most people just want to get on and live their lives without wishing harm to anyone else. The trouble is a minority won't let us do that. Sorry, going off thread a bit.

[pipnina]

That could explain why our race has the awfulness about it around the world we see today ?

I won't deny apathy is one big problem in our modern world. It's probably incurred by bad education systems, boring office jobs and facebook. (Ok maybe not that last one, although everyone on there seems to not care about anything but weird videos).

In defence of myself, though. Biology is far from my favourite subject and I have much less apathy for physics, optics, maths, software design etc and there's a reasonable chance it's a similar story for you, too, given the forum we're on.

While humans are at least decent at nearly everything, nobody can specialise in more than a handfull of subjects; hence my apathy for biology.

[DaveS]

I know I can ( Or more accurately *could*) see from the H&K line of Ca to the red line of K at 768 nm, and can easily see through a 750 nm photographic IR filter.

But that's just me, YMMV.