PARTICULARLY since the introduction of the theory of relativity, the problem of the ether has been a bone of contention among physicists. They have been divided into two camps; one unwilling to let go ...

After Albert Einstein published his special theory of relativity in 1905, he spent the next decade trying to come up with a theory of gravity. But for years, he kept running up against a problem. He ...

Surprising as it may sound, 107 years after the introduction of general relativity, the meanings of basic concepts are still being worked out. More than a century after Albert Einstein unveiled ...