How Can We See Black Color

You see black all over the place on even the most sunshine filled days with your eyes wide open... You see neither infrared nor ultraviolet, but it's all around you. Ask a bee how he finds the nectar in a flower.

Yes, well, being a fully qualified neurologist, I can say with absolute certainty that you are completely and irrevocably insane. The worms you see are a symptom of a particularly nasty form of insanity, and you should be spade or neutered as soon as possible.

That will be $300.00. Thank you.

Thanks Vermin for advice. But I have very fine eye sight. As an amateur astronmer, I can see stars up to magnitude 6 (though I need very thin specs 0.5 for reading, at this age of 55).

Also, I have tried couple of times looking towards mid day Sun directly for almost 1 minute. (I will not advise anybody to try it). I get blinded for almost half an hour after looking towards Sun, but then my sight is again fine.

Yes, well your eyes are not in question here. It's your brain - and I'm sorry to inform you that staring at the Sun is a symptom of an advanced case!

That will be another $300.00 please.

Hi gsuhas!

You're kidding about looking directly at the noon sun for almost one minute, right? I mean, I thought Vermin was just kidding around when he made remarks about insanity.

You scare me, man.

OK. Assuming you have actually been looking at the sun as you say you have...

you are to cease and desist, stop and quit, and never never never do that again. If you do, I'll call your momma to come and slap you upside of the head... get some sense into you. Man, if you thought you couldn't see anything for about 1/2 hour from deliberately trying to destroy your eyesight, wait until you see the stars your momma's gonna give you with that whack.

Back in the old days, really certifiably insane fools who illegitimately called themselves 'yogis' used to actually stare at the sun until they went blind, and then ---just to show you how crazy the world can get--- they were revered and copied by others seeking 'enlightenment'...who also went blind. Truly a case of the blind leading the blind.

There is absolutely no use for doing such a thing unless you are trying to deliberately blind yourself as well. And after you're blind, which may not be long, you'll be one very sorry dude for being such a dork! (with apologies to all the committed dorks in here)

What the hell kind of stupid thing are you trying to achieve?

^{I know, I know..."What's my point?" Don't ask. ((*Deeeep sigh of exasperation.*))}

Mark

See? I told you he was insane!

That will be another $300.00 please.

^{And by the way, that's Dr. Dork to you.}

Cheque's in the mail.

Isaac Newton used to stick sharp things (bodkins ?) behind his eyeballs. Oh hang on, he was mad, and also sniffed too much mercury vapour.

Hi Kris!

Yeah. You don't want to sniff too much of that stuff.

Mark

Then the question arises - What do you want to smell? Please keep it clean!!!

Thanks for concern. Vermin may say it Insane.

Still I did it with all dire implications, as I am amateur astronomer. Not only once but twice. I never advocated it in my lectures on Astronomy, solar eclipse etc. (I am well known for astronomy in my city).

Take my word, it is not easy even to open the eyes towards Sun. After looking to Sun, next half an hour I was not really blind, but I could see bright images of Sun dancing in my eyes.

After trial, I checked my eyes in National Institute of Optalmology, head of which is again amateur astronomer. He could see two black spots in both of my eyes.

In spite of all these facts, still I can see stars of magnitude 5 to 6 by naked eye (beyond which normally human can not see by naked eye).

I would have gone to Vermin with $600 cheque, but unfortunately he is not optalmologist.

Another incidence of total blindness I experienced will also be of interest to you. While sitting in train window, with elbow in window, the window fell down on elbow. The shock was so severe that I was totally blind for more than an hour.

It was total dark (black), but I do not remember if still some noise was there. The pains were so severe in my elbow that I didn't remember to note the noise (or no noise)

Now let me see if I got this right. You hit your crazy bone so hard you went blind? For a half hour? Do you keep your Johnny Walker next to your Aqua-Velvet and do people ever tell you your aftershave smells faintly of a peat bog?

But the shock must have paralyzed the retina in his elbow don't ya think?

No Johney Walker. I told the true story. Now again it is the subject in the court of Vermin, the neurologist.

I pronounce you legally dead... Now go out there and have some FUN!!!

That'll be $300.00.

Hi, gsuhas!

OK. Just take care of those eyes.

Mark

Apology accepted.

woho ! ! ! careful there gsuhas.... looking at the sun directly burns your retina ...

so you may feel you sight is ok after 30 min... but remember that its minus a couple of retina cells ...

=======================================

Thanks Vermin for advice. But I have very fine eye sight. As an amateur astronmer, I can see stars up to magnitude 6 (though I need very thin specs 0.5 for reading, at this age of 55).

Also, I have tried couple of times looking towards mid day Sun directly for almost 1 minute. (I will not advise anybody to try it). I get blinded for almost half an hour after looking towards Sun, but then my sight is again fine.

__________________
ONE WHO KNOWS THAT HE KNOWS NO, IS WISE PERSON

In 1970, there was a total eclipse of the sun on the East coast of the US. Now I was smart enough to know not to look at it directly, so I wheeled a studio TV camera out to the door, pointed that at the sun, and watched the whole thing on a video monitor. Only later did I discover the cost of a new plumbicon tube for the camera.

There were 3 Total solar eclipses in India between 1980 to 2000.

I saw two of them 14th Feb 1980 and 24th Oct 1995. Both of these i saw with naked eye.

Third one 11th Aug 1999, I could not go in totality belt.

Did you see my post about caves? It's really black in there. You do get some flashes from time to time (are they Purkinje flashes? don't remember), but they're like the stars you see when your momma smacks you up side the head for looking at that hot fox down the street. You don't see any gray or "worms' or anything like that. You need to wait about 15 minutes.

Exactly. My wording may be wrong. We see no real dark. May be some flashes, some noise! Even after wait of 30 minutes.

What you see really depends on what the light level is outside. Close your eyes and cover them with your hand. Then be in a booth with someone arc welding...I've seen shapes through them both.

Eyelids nor hands are completely opaque

The eye senses the absence of light. That's why if you go in a room with no windows and shut off the lights all you see is black.

>>>>The eye senses the absence of light. That's why if you go in a room with no windows and shut off the lights all you see is black.<<<<

Pardon me, Roger, but I think it is, actually, the visual cortex of the brain that senses (and makes sense out of) when no light is stimulating retinal cells of the eye. Retinal cells (rods & cones) react to light photons and convert them, chemically, to neural stimuli, which are then fed to the vision centers in the brain. If the eyes receive no light stimulation, there is no chemical reaction, and consequently, no neuro-electrical stimulation sent via the optic pathways to the cortex. If no stimuli reach the visual centers, then the brain interprets this as no light or black.

Brains do not need eyes to interpret a total lack of light or total blackness; just ask any person, who is totally blind.

Skeeter,

Your last two posts to me were:

"When someone attacks me I, usually, attack right back. Methinks you started the attack game, and apparently, the moderators welcome this type of diatribe. Come to Montana and I'll bust your nose. :-)"

and

"That's what I suspected... you are a yellow liberal."

Now I have no problem with you but have no interest in any sort of conversation or discussion with you. I'm asking you to please leave me alone.

>>>>Now I have no problem with you but have no interest in any sort of conversation or discussion with you. I'm asking you to please leave me alone.<<<<

Done. My last post with your name attached was, merely, to correct your post in which you had provided erroneous information. My intent is to not argue with anyone that tends to be irrational. In the future when I read misinformation that you post, and I choose to post a correction, I will just post without any reference to you, which I regret not doing in my last post. Sorry if I caused you any embarrassment.

No problem at all, semantics don't embarrass me.

Also, I'm sorry you have the misconception that I'm irrational. Here are some of my recent work presented at the American Physical Society March Meeting.

http://meetings.aps.org/Meeting/MAR08/Event/76188
http://meetings.aps.org/Meeting/MAR08/Event/76653
http://meeting.aps.org/Meeting/MAR08/Event/76653

Here's some additional work of mine
http://www.fisica.unlp.edu.ar/hfi2007/invitedtalksandoralcontrib/02-tuesday/05-OA3-Das.pdf

But seriously, thanks for telling me how the eye works, even though I'm in charge of the Optical areas here at GlobalSpec. I'm sure you thought you were telling me something I didn't know.

What! No pictures?! Dang!!!

I'm hooped!!! My little 56 kbps modem can't load the file! So what were they? Animals? landscapes? Girls?

Let me know if you need more pictures, 'cause I have the Crayon 64 color set, complete with sharpener!

Maaaaann!

Some guys have it all!

Well, I say it's 64 crayons, but that includes a black one, which I can never find. I tried taking out all the others, but heck! It's too dark in there!!!

>>>>"I see you're from Montana. Do you realize you live next to a super volcano? Don't you see how foolish that is? Why do you live there?"<<<<

Oh, geeesh! I thought we were done, then you come back, once again, to try to impress me with some of your past work. You were first to call me "foolish" for choosing to live where I do. Everyone has to live somewhere, so again, it boils down to my choosing a RELATIVELY safe place to reside.

And, once again, you have posted statements that leads someone well versed in ophthalmics to deduct that you don't know the difference between optics and anatomy/physiology of the human vision system.

One measure of a true intellectual can be seen in one who readily admits that he/she doesn't know everything. I enjoy active discussions on a variety of topics, but you just seem enjoy arguing without being able to offer info on a rational level. Perhaps, it is due to insecurity on your part? Doesn't need an answer; just hoping that you might be a bit more introspective.

Regards.

Ya know, I really am impressed with your accomplishments, Mr. Pink. However, I must say my favorite was your performance in Reservoir Dogs.

Go to a paint store and ask for a pint of black paint. I can assure you that such paint actually exists.

How about...

It's reported that they have canned antimatter as well.

Kris, you inspired me.

I searched for canned light, et voila:

If light is in the can, it must be dark somewhere!

you inspired me

A blushingly nice complement. I've been investigating reports of black hiding in my fridge, but the damned door keeps slamming against my head.

Go further in, towards the Darkness...

I know where your going......you ain't gonna get me charging at no windmills ! That picture is either the little known 5th horseman of the apocalypse, or some Spanish dude. Mr Truman Brain frightens me enough all ready, with his tales of oranges and sand-kissed beaches.

The Darkness is your realm, embrace it!

Everything is explained by tales of poltergeist activity. Pubiscent girls are at the root of darkness. Pierro Brovetto and Vera Maxia have stated here that "Poltergeist disturbances often occur in the neighbourhood of a pubescent child or a young woman," the authors note in their paper."

Science has at last discovered the heart of darkness.

Black paint is easy, its that striped stuff that you have to hunt for.... hold on.... Hey apprentice, I'm outta striped paint, can you nick off to get some :P

Technically you can't see any object, just the light reflected by it. Yeah, I know, pickey pickey.

I was thrown out of college for trying to give the dean's wife an enema but before that I was taught that there is not only no known perfect absorber (black box) but there is also no known perfect reflector.

What I wonder about is whether some blind people perceive any visual image, or if they have no visual perception at all, even blackness. My guess is that there are both types of blindness.

Black objects DO reflect light -- at least the black things we're familiar with do. Recently, there was an article in the paper about a technological breakthrough in which a couple guys invented something way blacker than anything man has ever made before. I think they said it absorbed, like, 99.99% of the incident light. Of course, I can't remember any interesting details to pass on -- I think the surface was composed of micro-tubular structures or something. In any case, there's been a recent breakthrough in blackness. Not sure what you'd have to google to learn more...

"Not sure what you'd have to google to learn more..."

Check this link posted by Kris in post #21.

-John

Truly black objects do not reflect light in the human visible spectrum, Truly white objects reflect all light in the human visible spectrum. Since when have we ever been able to achieve optimum conditions?

Once, about 12 years ago. It was great. You should have been there!

Damn it, I told them to put me on the mailing list!

Last time I trust the Postal Service!

ok... so now that we have talked about how we sense the light that is reflected back from various color objects.... Lets ask :

How is light reflected ? Why and by which mechanism some objects absorb certain frequencies of light but not others..... and some objects let some wavelengths go through completely ..... from the whole electromagnetic spectrum radio waves go through most objects.... Then some wavelengths are absorbed and others reflected....

by which mechanism? Lets hear some quantum physics hats .... =)

I will post this as a separate question....

its easy.

if you open your eyes, you can see colourful world.

When you close you eyes, you can see black color.