What is the speed of dark?

Question: What is the speed of dark?
- Keywords:
  dark
Asked by WaterMeloneee to Alison, Hannah, Jonny, MarthaNari, Paul on 23 Jun 2015.
- Jonny Brooks-Bartlett answered on 23 Jun 2015:
  
  Dark is basically the absence of light as opposed to it being something. We only see dark because there is no light there.
  
  This means that dark doesn’t move at all. So it’s speed is zero metres per second. My supervisor would kill me if I forgot to put my units on.
- Paul Brack answered on 25 Jun 2015:
  
  Here’s pretty much the same answer that Jonny gave, but with a groovy video thrown in: http://www.iflscience.com/physics/what-speed-dark

Question: What is the speed of dark?