If the reflected light coming off an object was in the spectrum of light invisible to me would it be?

Question

visible or invisible?

Is it possible this is happening around us now?

Is it possible to create something that reflects light in this spectrum?

Answer 1

Whether an object is visible or invisible depends on what it is doing only in the visible part of the spectrum. If it absorbs visible light, it will be black. If it passes visible light, it will be transparent.

Glass, for instance, which is highly absorbing in infrared, is transparent in the visible.

Answer 2

It would depend on if the part of the light spectrum that was reflecting off of the object. If it's only reflecting say...UV, then it would be invisible to us, but if it reflected UV and a part of the visible spectrum we would see the visible part of the light that was reflected off of it.

It's perfectly possible that it's happening as we speak, I'm sure that there's many materials that reflect parts of the spectrum that are invisible to us. An example would be any metal object that shows up on radar. They reflect microwaves generated by the radar dish which allows the radar to see them. We can't see microwaves, but we can reflect them.

As for creating something that reflects only that part of the spectrum, that's something they still haven't figured out yet, as anything we make reflects part of the visible spectrum. If we made it reflect only part of the spectrum we can't see with our eyes then it would be the perfect camoflage, though unless the wearer of the material were to allow a little visible radiation in, it would be a double blind situation. The observer couldn't see the object, while the person wearing the material wouldn't be able to see the outside world.

I hope this answers your questions.

Answer 3

If the only light reflected by the object was in a range not visible to the human eye, the object would be invisible.

I doubt that it's happening, though, or we'd be bumping into invisible objects.

We do have objects that reflect invisible electromagnetic energy (and light is one small part of that spectrum). They are called "dish antennas". The dish reflects incoming radio waves back to the central antenna mounted above the dish, which converts the signal to electricity and sends it on to the TV. However, the dish also reflects visible light, so that the neighbors know that you can watch the big game when the cable is out.

Answer 4

Moon reflects light, but visible light is only a very narrow range in the total electromagnetic spectrum. Sun emits the whole electromagnetic spectrum, and as light is reflected by the Moon, other electromagnetic waves could be reflected in different amounts. There are Moon images, as seen in X rays or gamma rays, this means that the Moon reflects these rays, too. More over in gamma rays Moon looks brighter than the Sun! I think the Moon reflects UV radiation but in a lower degree. So i don't think we should wear shades at night, because the amount of UV radiation is insignificant. Try to search astronomy pages to find out if there are Moon images taken in UV radiation!

Answer 5

Interesting! An object has substance whether or not you can see it. The Black Bird used by the US Air Force was invisible to humans below because of the use of light absorption. The spectrum of light is the color and there are many colors that we see only as shades of gray because they are outside the spectrum, but you can still see the object. A color blind person sees the object in shades of gray when he cannot see the color. Answer: Visible.

Answer 6

The object would be visible but would appear to be black in color. If the background is also black, only then would it be invisible.

The dyes in photographic films are deliberately designed to absorb in certain ranges of the visible spectrum but to transmit in the infrared. When dyes of all three colors are present in large quantity, the film is opaque (black) to visible light but still clear to infrared. You can also buy filters for photographic use that block visible light but transmit infrared. Either of these could be backed with a reflector of infrared light to produce an object that reflects infrared but absorbs visible light.

"Hot" and "cold" mirrors do not absorb any light to speak of but are deliberately manufactured to let visible light through and reflect infrared light (a "hot" mirror) or vice versa (a "cold" one). It would be no great trick to create an object that strongly reflected infrared but absorbed visible light by backing a "hot" mirror with a piece of black velvet to absorb the transmitted visible light.

Something like that happens with flowers whose colors are not limited to those humans can see. Bees, for example, can see into the ultraviolet part of the spectrum but are blind to red light. Some flowers, when photographed by ultraviolet light, reveal "color" patterns quite invisible to humans. Some birds see into both the infrared and ultraviolet as well as throughout the visible part of the spectrum. You can find flowers that these birds pollenate with patterns in the infrared that are also quite invisible to us.

This happens with ordinary lawn grass as well. We see grass as green, not black, but it also reflects very strongly in the near infrared. In an infrared photo, the foliage looks almost snow-covered but still retains its original texture.