no boundary condition

A no boundary condition is the idea that the universe is finite but has no boundary (in imaginary time). The no boundary proposal, proposed by Stephen Hawking, predicts that the universe would start at a single point, like the North Pole of the Earth. But this point would not be a singularity, like the Big Bang. Instead, it would be an ordinary point of spacetime, like the North Pole is an ordinary point on the Earth. According to the no boundary proposal, the universe would have expanded in a smooth way from a single point. As it expanded, it would have borrowed energy from the gravitational field, to create matter.