Prof. Padraig Dunne
Humans have only being flying airplanes for a little over 100 years but Santa has been doing this for centuries. I thought maybe physics could help us figure out how he does it. Getting all those presents to millions of girls and boys in one 24-hour period on Christmas Eve takes some doing, after all.
Physics is the science that looks at how things react and interact. Anything that has a mass and takes up space is called "matter". Physics looks at the interaction of matter and energy so it includes mechanics, heat, light and other radiation, sound, electricity, magnetism and the structure of atoms.
Consequently, physics offers some glimpses of understanding into how Santa gets around the whole world in one night. According to the Theory of Special Relativity by Albert Einstein, the faster you travel, the slower your clock ticks -- so, by travelling incredibly fast, Santa may actually have more time to get around the world. This effect means that as Santa travels through space, possibly at nearly the speed of light, seconds are passing for him while the hours tick away on Earth.
So there is mystery here for sure, and as with many mysteries, science -- and physics in particular -- can only shed light without providing a complete answer. Physics gives us a way to look at the world, where theories are built and tested by experiment and observation.
But for now we can just sit back and enjoy Christmas without having to know all the answers. Merry Christmas!
QProfessor Padraig Dunne, Head of the UCD School of Physics