Why does wet cloth or mud appear darker?

[vin300]

This looks like one silly question. Why does cloth or mud appear darker when wet?

 

[arildno]

This looks like one silly question. Why does cloth or mud appear darker when wet?

Why silly?

It is a very good question!

What would YOU think might be plausible answers here?

 

[Gerenuk]

It's indeed a good question.

And a bonus question would be
http://en.wikipedia.org/wiki/Streak_(mineralogy)
:)

 

[Andy Resnick]

This looks like one silly question. Why does cloth or mud appear darker when wet?

It is definitely not a silly question, but it has been asked before:

https://www.physicsforums.com/showthread.php?p=2341210