One of the most fundamental tenets of modern physics is that in a perfect vacuum — a place entirely devoid of matter — no friction can possibly exist, because empty space cannot exert a force on objects travelling through it.
But despite the conventional wisdom, physicists in the UK discovered that a decaying atom travelling through a complete vacuum would experience a friction-like force, and now they’ve figured out how this reinforces — rather than breaks — Einstein’s theory of general relativity.
“We spent ages searching for the mistake in the calculation and spent even more time exploring other strange effects until we found this (rather simple) solution,” one of the team, Matthias Sonnleitner from the University of Glasgow told Lisa Zyga at Phys.org.