How do we know the time... precisely? The question is more complex than it first appears, says Richard Fisher. I'm looking at a warning sign inside a laboratory in London. "Do not touch the maser," it ...

SHOULD AULD acquaintance be forgot, and never brought to mind? Maybe. There’s no point dwelling in the past. But as time marches on, how does one learn to dwell in the present? What is time and how do ...

A new definition of time suggests that what we once thought was a fundamental element of our physical reality could actually just be an illusion created by quantum entanglement. That's a very bold ...

There is an elegant, simple, and entirely accurate way to define the second. A second is 1/86,400 of the time that it takes the Earth to rotate once on its axis. With 24 hours in a day, 60 minutes per ...