any idea?

what's the speed of darkness..?

darkness is not a thing, it has no speed

you could say that about light!

Darkness is only the lack of light. I suppose you could consider darkness to be the thing and light to only be the lack of it. In that case, the speed of darkness is the same as the speed of light.

light is a thing, it is made up of photons. If you want to know how fast darkness propergates, it is simply the speed of light as darkness is the lack of light.

Obviously it's faster than light otherwise how would it get out of the way in time for the light to arrive?

The question seems funny but it is not.

The very concept is used by electronicians when they describe semi conducting materials.

Electrons are flowing one directions and holes are flowing into the opposite direction.
Then what is a hole? Answer: A place where there just been a electron that have left.

Originally posted by FabianFnas

Then what is a hole? Answer: A place where there just been a electron that have left.

Originally posted by XanthosNZ
No actually a hole is a place that could hold an electron but doesn't currently. There are holes present in P doped semiconductors even though they never contained an electron.

Basically it's a useful method of describing behaviour nothing more.

It dosen't get out of the way in time for light to arrive - IT IS NOT A THING - it is the lack of light so when the light arrives it no longer exists, by definition

P.S. It is very much simpler that the concept of holes

Originally posted by FabianFnas
As I just said...

Originally posted by XanthosNZ
I was confused by this bit:
"A place where there just been a electron that have left."
which I took to mean you were saying that a hole is what you have just after an electron moved. Except that's not always the case.

Darkness has no speed.
Darkness is not a thing and cannot travel and therefore does not have a speed.
Darkness is simply a state. You can see it as, for a lack of words, the default state of light. Where there is no light the state of an area will be dark.

are you then saying that nothing exist within darkness..?

NO!! How would you get that from that explanation?
It actually meens that darkness does not exist in light.
or more correctly, in the presence of light.