What time is it?
Turns out that depends on many things.
Military people count time quite sensibly, as minutes and seconds within 24 of our hours.
For them, 2:20 in the afternoon is simply 1420. The rest of us are often unsure whether someone means before or after noon when they suggest a time to rendezvous for romance. And time is always different for all the zones around the globe, of course. It must be confusing for those poor folks near a time zone border who live on one side and work on the other. They could get to work at a time before they left home, for example.
We divide our year arbitrarily into 12 months, but what is a year? For us, it’s one trip around our star, or about 365 days, and a day, of course, is one earth rotation. But on Mars a year is 687 of our days, and a single day on Venus is 243 of our days, but a day on Jupiter is only 10 of our hours. A year on Uranus lasts over 84 of our years, on Pluto it’s 165 of our years. Nobody on Earth can live so much as a single Pluto year even if they drink veggie smoothies and don’t watch politicians debate.
It takes our star about two minutes to rise and clear the horizon; in other words it appears to move its own diameter in 2.13 of our minutes. But on Mars sunrise takes 1.44 of our minutes, on Mercury it’s 16.13 of our hours, while for a maximum type-A Neptunian, it’s but 2.85 Earth-seconds. Yet of course the sun is not really moving at all in relation to any of us.
All this was hard enough to sort out, but then along came that electric-haired Einstein who, one of our centuries ago, told us in his relativity theory—long since now a proven fact—that time is not a constant and is really quite unreliable because it moves slower under increasing gravity or under increasing speed. Near the speed of light (186,000 miles in a single one of our Earth-seconds) time nearly brakes to a relative stop. This means that time moves a little slower for somebody standing at our equator, zipping along at 1,100 miles per hour as the earth rotates, than for somebody standing on the north pole, who is only turning around in place as the earth rotates (you’d think they’d get dizzy), but astronauts on the ISS are in an even slower relative time frame because they’re doing 17,150 mph to keep from falling onto Disney World or New Jersey. But wait just an Earth-minute, they’re in zero gravity so they also experience a faster time factor. Luckily, all their time variations don’t work out to zero or they’d never get anything done. They’re already wasting enough of whatever their time frame is playing with their weightless food and beverages.
On some huge dervishing distant planet, a hundred of our years unfold while only a single minute elapses for us. Wow. Imagine how THOSE poor creatures would feel waiting in line at the DMV.
And consider the geniuses who figured out how to make the GPS system work. The satellites are speeding so their time slows down by our Earth-based reckoning. They’re in elliptical orbits so their distances from earth and their speeds are constantly varying too, so . . . Anyway, those clever GPS math wizards had to accommodate half a dozen different time-shifting gremlins just so you can find your way to the World’s Biggest Gator attraction somewhere in Florida before you run out of ethanoled gas.
The next, ah, time somebody asks you the time, it’s okay if you tell them you honestly don’t know and nobody else in the universe does either.