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 ...

The relationship between quantum mechanics and classical physics has baffled scientists for decades. In the quantum world, particles can exist in multiple states at once—a phenomenon known as ...

New impressions A visualization of a curved space–time “sea” from the general-relativity simulations carried out by the authors.(Courtesy: James Mertens) From the Genesis story in the Old Testament to ...

Einstein's theory of gravity — general relativity — has been very successful for more than a century. However, it has theoretical shortcomings. When you purchase through links on our site, we may earn ...