How we are able to see something even in pitch darkness?

Question

How we are able to see something even in pitch darkness?

Answer 1

You know those night vision goggles?  They let you see even in the dark?  It turns out that they have an infrared camera.  They send that signal to a little video screen which lets you see.  You can't normally see infrared light.  But where does the infrared light come from if it's dark?  Simple.  All hot bodies, like the Sun and the really hot chick who lives across the street, emit light.  The Sun is SOOO hot, that it emits high energy and high frequency light in the visible part of the spectrum.  But the hot girl across the street emits light in the infrared part of the spectrum.  The goggles pick this up and show it to you.

This isn't the same as beer goggles.  That's when you think the fat chick across the street is good looking.  You don't look through the beer, you drink it.  And hot she is.  She's much smarter that that stupid blond.  And smart is the new healthy.  You're gonna have some really bright kids with her.  Here's a drink to your health.

Answer 2

  You could see nothing in pitch darkness if you use light.

  Bats use ultra sound so they need no light.

  Some snakes use infra red so again they need no light.

  So without some artificial illumination we can see nothing.

Answer 3

We can't

Answer 4

We can't.  But there is almost always a little light around, from stars, the moon, etc.  

If you were ever in a photographer's darkroom, where all sources of light are truly sealed off, you'd know that you can see absolutely nothing.  

Answer 5

You are not able to see anything in complete darkness.  "Seeing" implies that there is some visible light.  The reason why it seems like you can see in the dark is because it is extremely rare for humans to experience true darkness.  A moonless night has light from the stars and skyglow from ionized air in the upper atmosphere.  A room with closed doors usually has some light coming in through under the door or through the window blinds.  It is really hard to create perfect darkness in the modern world.  Photographers try to create this in darkrooms usually by having a windowless room with two doors and a black hallway in between them, but sometimes a sliver of light still steals through.

One of the great natural phenomena of all times is to go deep into a cave and turn the lights out.  Most cavers do a blackout during a caving trip to experience this.  You have to put away glowing watches and everything because they are extremely distracting in pure darkness. It's almost incomprehensible.  But if you get to experience true cave darkness, you will not see anything.  Your eyes will eventually have trouble with having no visual input and they will start to "see" things that are not there.  It is your brain's way of making up for the absence of information.  Try it sometime; it is incredible!  But if you have one person with one glowing watch hand, your eye will latch onto that tiny shred of light and all of the weird visions will go away.