Meditações - we don’t share the same time in different places

If all this sounds terribly abstract, that’s because it is. But there’s some relatively simple proof to support the notion time is a fluid, human concept—an experience, rather than inherent to the universe.

Imagine, for example, that you are on Earth, viewing a far-off planet, called Proxima b, through a telescope. [Carlo] Rovelli explains that “now” doesn’t describe the same present on Earth and that planet. The light you on Earth see when looking at Proxima b is old news, conveying what was on that planet four years ago. “There is no special moment of Proxima b that corresponds to the present here and now,” Rovelli writes.

This might sound strange, until you consider something as mundane as making an international call. You’re in New York, talking to friends in London. When their words reach your ears, milliseconds have passed, and “now” is no longer the same “now” as it was when the person on the line replied, “I can hear you now.”

Consider, too, that we don’t share the same time in different places. Someone in London is always experiencing a different point in their day than someone in New York. Your New York morning is their afternoon. Your evening is their midnight. You only share the same time with people in a limited place, and even that is a relatively new invention.

in Quartz