Physics- Colour

crimson soldier SG

Can anyone help me analyze what determines the "colour of things" that we see?

Not from bio point of view or colour perception but physics.

In terms of absorption, reemission ,transmission and reflection...band gap theory and quantum mechanics..

For example: Why does copper appear red and gold appear, well, golden when an incident white light is shined on them? What are the quantum mechanics principles that are going on within the materials to decide that red/golden light comes out?

skythewood SG

diff wavelength, diff colour

eagle SG

what u mean by quantum mechanics?

You mean sufficient energy for the work function of the electrons for them to jump gaps, and hence emit a photon of energy hf = to the amount of energy between the gaps?

crimson soldier SG

Why does a red object appear red? Because it reflects red light right? But what determines that it reflects red light and absorbs all the rest of the visible spectrum?

SBS2601D SG

Don't know if this is correct but:

We all know that the individual electrons in an atom need certain levels of energy before increasing its energy level state.

The amount of energy required is peculiar to each jump in energy level.

Consequently when photons collide with the electrons (light shines onto the atom), only photons of certain energy levels will be absorbed by the electrons. The others will merely collide and bounce away.

So the colour you'll see is dependant on what photons are not absorbed by the electrons.

Also related: The photoelectric effect.

skythewood SG

Why does a red object appear red? Because it reflects red light right? But what determines that it reflects red light and absorbs all the rest of the visible spectrum?

that's the property of the material, as it can absorb the rest of the colour.

black stuff get hotter faster because they absopt more... and vice versa. you writing thesis or something?