In Infared you see heat etc. But what would you see in UV?

Answer 1

There's confusion about heat and infra-red.

Any electromagnetic radiation emits photons, and *any* photons can heat a target - it's just that, by the time you get to the short wavelengths around infra-red, photons are energetic enough to cause significant heating.

The photons in your microwave oven are doing a pretty good job of heating, too!

So, the question can be answered one way - any wavelengths of normal intensities (leaving aside the microwave!) around infra-red and shorter have heating effects - think of how the sun's UV can cause sunburn.

So the best answer comes from this question: what materials respond to any particular wavelength?

For visible light, a white/shiny object responds well, and we can see it. For U-V, a fluorescent object (such as some gemstones and minerals) responds by re-emitting visible light, which we then see.

Without the fluorescent effect, you'd need an instrument a bit like night-vision goggles, but one that picks up U-V and displays it as visible light, and such "image converters" do exist.

The alternative is to use a U-V sensitive TV/digital camera, or U-V sensitive photographic film.

Many insects can see into the near U-V range, and some flowers reflect U-V in patterns that are attractive to those insects.

Answer 2

In UV light, you would see fluorescence, phosphorescence, and bioluminescence. Different materials and substances may emit visible light when exposed to UV radiation, allowing them to be detected. UV light can also reveal hidden patterns or markings that are not visible to the naked eye.