Professor Brian Cox appeared on ITV’s ‘This Morning’ to explain to hosts Ruth Langsford and Eamonn Holmes the (kind of) complicated theory.
“Einstein gave us the answer in 1905 with his special theory of relativity,” he said on 21 December.
“What Einstein told us, which is true, is that if you get closer to the speed of light you go faster and faster and then distances shrink.”
Bear with him.
“Let’s say Santa’s going around the globe now, so he starts off in Canada and he goes whizzing across to Europe,” Cox continued.
“Now that’s 3,000 miles or something.
“But if you’re going very close to the speed of light - let’s say 99.99999% of the speed of light - distances shrink in that case by a factor of 7,000.
“7,000 miles is one mile when you’re travelling close to the speed of light.”
We never said the explanation was a simple one.
So if your child argues that it’s impossible for Father Christmas to travel to every child’s house on Christmas eve, just tell them that (or point them in the direction of Einstein’s theory of relativity and confuse them even more).
‘This Morning’ is on weekdays from 10.30am.