Add Yahoo as a preferred source to see more of our stories on Google. Novel quantum gate. A new heralded photonic gate entangles two four-level qudits, using orbital angular momentum instead of ...

In 1919, physicist Theodor Kaluza hypothesized that extra dimensions might solve some outstanding problems in physics. And while we haven't found any evidence yet for anything outside our normal ...

We all know we live in three-dimensional space. But what does it mean when people talk about four dimensions? Is it just a bigger kind of space? Is it "space-time," the popular idea which emerged from ...

Whether space-time exists should neither be controversial nor even conceptually challenging, given the definitions of “space-time,” “events” and “instants.” The idea that space-time exists is no more ...

A pair of photons enters an optical maze, and sometimes they leave as something new. Not new in the everyday sense, since both were still photons when they came out. But new in the way they share ...