How come we can see all matter even despite being limited in seeing a range of frequency?

intrptr

Absolute proof either way doesn't exist. But neither does any possible proof exist for the skeptic.

As for me, it would depend on what you were trying to prove. I regard LOTS of things as proof. If you told me that a shunt wound motor will try to reach infinite RPMs if you pull the field connection, well, the equations say it will and if I set it up in the lab, it'll give it a damned good try. I call that proof.

If you say dead Uncle Ned is moving the pottery around, I'm not sure what proof it would require but it would have to be awfully convincing.

Nexusnews
Saw this question posed on another forum and thought it would also bring some healthy debate here as well.

We can see an apple because it reflects red light. A frequency of light we can see. Why is there no object on earth that only reflects a light frequency that we cannot see. Like UV. Let us say that there is an object that only reflects UV or IR frequencies. These objects are real physical objects but cannot be seen by the human eye. Since the earth is supposed to be random, these object should actually exist. Why don't they?

-Nexusnews

Not sure, but I think different frequencies along the EM wavelength have different densities, and the photons in visible light are dense enough, or even packed densely enough, to interact more with tangible matter; thus making it visible, by way of attenuation, to the human eye. In addition, although some animals can see a bit further along the spectrum, I think the human eye evolved specifically to see only these wave lengths as we don't really need to see things that we can't eat, bump into or fcuk. (Darwinism?).

Glass, water.

Samtzurr
Glass, water.

Not everyone has figured that out yet, like the OP and this kid:

NoRulesAllowed

Danbones
glass is kinda hard to see
so is any one atom of anything...
at least I can't see them without my glasses on

edit on 22-2-2014 by Danbones because: (no reason given)

That's a good one.

Yes, in some way (and under some circumstances) glass cannot be seen. But a glass surface can certainly reflect heat (IR).

Simple...would kind of fit the criterion.

glass reflects some heat not much though, a thermopane window is like R 1.5

but if you take a horizontally polarized lens
you get light out the other side
add a vertically polarized lens
you get NO light out the other side
add a horizontally polarized lens
you get light out the other side again

so one wouldn't see anything behind two or more pairs of sun glasses unless the polarization is lined up right

spooky noe...?

dangle a not moving piece of thread in front of a bull frog
no signal from eyeball
move the dangling piece of thread in front of bull frog
signal from eyeball

there are other factors involved beside simple physics