If you are in a pitch black room and you put on night vision goggles, what do you see in the mirror?

Question

Remember, there is nothing on the walls in the room except for a frameless mirror, and all you have is night vision goggles. Think of what is needed to create a reflection in the mirror; light.

Answer 1

You don't see anything, unless you have some sort of light source. Night vision goggles amplify available light... they don't substitute for the lack of it.

Answer 2

There are several aspects that has to be considered.

The night vision goggles can only amplify the existing light and the sensitivity depend on the wavelength of light, Similarly the ability of the mirror to reflect also depends on the wavelenght of light.

First is the sensitivity of the night vision goggles. Is it sensitive to infrared emitted by the body of the person ( remember the person is in a room of which the temperature may not be too far from that of the person and even if the night vision goggles are sensitive to infrared the sensitivity may not be enough to differentiate the viewer from the walls.

The second point is the reflectivity of the mirror. As the room is dark the visible light is absent. In absence of visible light , image may be seen only if the mirror can reflect infrared and the goggles are adequately sensitive to infrared. As glass is impermeable to infra red if the mirror is an ordinary one it will not reflect infrared.

As available night goggles are not sensitive to Ultra violet and human body does not emit UV . UV is not relevant to this case.

In short unless one is using specialized night vision goggles which are highly sensitive to IR and special mirror which can reflect IR the person may not see any thing but darkness.

However if the above requirements are fulfilled he may see a thermal image of himself.

Answer 3

The answer is nothing I suppose... I understand where you are going with this. If there is no light then the mirror has nothing to reflect (in essence it can't "see" you back). However if the room was completely pitch black, you would not be able to see anything anyway. Night vision goggles need at least a tiny amount of light in order to function. It takes that light and enhances it so that you can see.

Answer 4

I think, night vision works on light too, only it takes very, very little light to operate. So if you look in the mirror and there is very little light you will see an image of yourself wearing the goggles looking back at you. Because the mirror will reflect any light, even very little so the goggles will function; even if it is not enough light for you to see an image in the mirror with the naked eye. The eye don't always see in very low light level situations, that is why the goggles were designed to operate in this manner.

Answer 5

IR goggles working on Infra red light and not Thermal Imaging goggles which sense temperature differences like body heat in the woods

You would need a light source, which could be IR as well (invisible to the naked eye).


Next I believe that glass blocks IR so an image in a glass mirror would not be possible as the glass would block the IR from the silver. Maybe a steel mirror would work.

If the IR ligh source is mounted on the gogg les facing a reflective surface would dazzle the IR sensors because you would be pointing the light source at the mirror as well. So you would have to illuminate yourself with IR light from the side and view any reflected IR with the goggles.

Answer 6

I'm not certain on this, but I *think* night vision goggles utilize a little bit of IR (Infreared), which you would indeed see in the mirror (due to body heat), in very low light situations, or perhaps this can be switched on/off.

I *do* know that they only enhance the lijght that is present in the visible however. I know they are quite complicated in how they work, and I think the color image you see thru them is not necessarily the same from pair to pair.

So, I tend to think you'd see a human-shaped figure in the mirror, but it would lack detail, and I can only guess and say the color is either a white'ish or greenish color.

Anyone have any corrections....I would be interested too. I'm just going by what I know. I've not taken it upon myself to investigate them.

Answer 7

Night vision sees Infrared or IR light and most Night vision systems will produce there own IR if there is absolutely no other light source. A mirror will reflect any light not just visible light. If you point a TV remote at a mirror so it comes back to your TV it will change the channel. Remotes work with IR too.

Answer 8

"Pitch black" means absence of any visible light. If the night vision goggles are infrared-sensitive, then what you would "see" is an image of the heat produced by your body. Whether or not the infrared radiation would reflect in the mirror would depend upon the physical characteristics of the mirror. For example, a gold mirror is used in space telescopes specifically to reflect infrared light. http://www.jwst.nasa.gov/mirror.html

Answer 9

well usually night vison goggles use IR lights to help at night when is pitch black the IR light will reflect on the mirror therefore iluminating your face if looking directly at it. If there are not IR iluminators then you would not be able to even find where the mirror is.

Answer 10

If there is absolutely no light source, not even ultraviolet or infrared then you won't even see your own hand with the goggles, but if you can see with the goggles then you'll see the same thing on the mirror because ultraviolet and infrared also bounce off the mirror.