Fact of the Day (92)

[HarlequinGoddess]

When glass breaks, the cracks move faster than 3,000 miles per hour. To photograph the event, a camera must shoot at a millionth of a second.  

[Mirela_Narsica]

That seems improbable. I wonder if it is true...

Obviously, Goggle answered me. Here is what I found from Physics.org.