In the last few decades, researchers have pursued the problem in two separate programs — string theory and loop quantum gravity — that are widely considered incompatible by their practitioners. But ...

In the last few decades, researchers have pursued the problem in two separate programs—string theory and loop quantum gravity—that are widely considered incompatible by their practitioners.

The heavyweight incumbent is string theory, a complex construct that has long had pretensions to be “theory of everything”. The upstart contender, loop quantum gravity, has more modest ...

And it’s a lot: cosmic strings would produce at least a billion loops throughout the visible universe today, researchers report. “Cosmic strings are these filaments which wind and sneak throug ...