How do we actually know what the time is? Is there some “master clock” that all time zones are based on? And if so, what does THAT clock refer to?

Question

EDIT: I believe I have kicked a hornet’s nest. Did not expect this to blow up! But I am still looking for the “ur time”. the basis for it all. Like, maybe the big bang, or something.

In: 5399

Answer 1

Time is relative, and not just in an E=MC2 kinda way. It used to be that time was based on noon. Whenever the sun was at its highest point was noon. Sun dials made it more predictable by having a clock but usually there was a big clock on the town square that everyone had to use(like Big Ben. If you could afford a watch you simply sync it with the town clock.

As transportation became faster with trains this made it clear that every town having a different time would complicate train schedules. Eventually time zones were created to make a uniform system.

Now we have computers that synchronize to a clock like the atomic clock in Colorado. There is also one in Greenwich England. They use a lot of very accurate astronomy but basically use the same principle of “noon is when the sun is highest” but on a very precise scale.