A type of single-celled organism could be the key to answering the age-old conundrum of what came first.
Devised by Greek philosophers thousands of years ago, these paradoxes will leave you scratching your head.
Physics student Germain Tobar has come up with the mathematics for what he calls 'paradox-free' time travel.
If the universe is teeming with intelligent alien civilizations, then why have we yet to discover any?
A new theory has put forward the possibility that killer robots have wiped out all intelligent alien life.
Physicists have come up with a new theory for time travel that avoids the infamous 'grandfather paradox'.