Comment Re:Question: Uncertainty Principle (Score 1) 136
I agree that Hawking might have jumped to his conclusion rather abruptly. However, it is valid.
Heisenberg Uncertainty Principle says that the error in your measurement of the momentum times the error in your measurement of the position must be greater than or equal to Planck's constant divided by two. The important thing to keep in mind (and what Heisenberg didn't realize when he first proposed it) is that it's not just your error in measurement, it's the very nature of the universe to not be a well-defined particle.
So, if you looked at a pure vacuum, you would know it's momentum is EXACTLY zero, so your error in position would have to be infinite. This makes no sense, so a pure vacuum is impossible.