Eli5: When you shine a bright light under your fingertip, making your finger orange, is the light actually illuminating through the entirety of your finger?

586 views

Eli5: When you shine a bright light under your fingertip, making your finger orange, is the light actually illuminating through the entirety of your finger?

In: Physics

3 Answers

Anonymous 0 Comments

Yes it is. With stronger and stronger lights, you could gradually light up thicker and thicker parts of your body, show the veins and even bones.

However, it is not shining right through like a transparent material. It just lights up the entire fingertip and making the whole thing glow, that’s why you can’t see the bones, because it’s diffused and doesn’t glow.

Anonymous 0 Comments

Yes, it is–well, around the fleshy part, at any rate. The bone would block the light, but the skin and flesh diffuse it around so you can’t see a shadow of the bone.

Anonymous 0 Comments

In cgi, simulating this is called “subsurface scattering”.
https://en.wikipedia.org/wiki/Subsurface_scattering