Time is an Illusion, a construct, a theoretical thing. And a song.
Time - Pink Floyd
You are young and life is long and there is time to kill today
And then one day you find ten years have got behind you
No one told you when to run, you missed the starting gun
When you are young, the summer lasts forever. Maybe to the point that you are bored and yearning to return to school. Now, a year goes by in what seems like a month.
Why is time an illusion? Well, it all started a long time ago when you had a different "clocks" that ran your life, your stomach and the sun. It was as local as it can get and you didn't need worry about missing that video meeting or train from two time zones away with millisecond accuracy.
For the sake of simplicity, I will not be diving into the physics of space/time and relativity, it would take too much time. This will just be a look at the geometry of the earth and it's relationship with the sun.
Also for the sake of simplicity, we will call the earth a round thing, it is not in fact completely round, it bulges at the equator but the difference between measuring the circumference at the equator and around the poles is just a tiny 41.727 miles, nothing when you are looking at almost 25,000 miles circumference.
At the equator, the sunrise moves at 1,037.56 miles per hour.
That's 17.3 miles per minute.
And .288 miles per second.
So, when is noon?
The noon where the sun is directly overhead, not lunchtime noon.
Or as NOAA defines it:
ESRL Global Monitoring Laboratory Global Radiation and Aerosols
solar noon - (see also: solar time) Defined for a given day for a specific longitude, it is the time when the sun crosses the meridian of the observer's location. At solar noon, a shadow cast by a vertical pole will point either directly north or directly south, depending on the observer's latitude and the time of year.
In the eastern most place in the US, Lubec, Maine, solar noon happens at 12:33:23 EDT.
The western place I will be using is the Illinois Indiana border for the eastern time zone is Ambia, Indiana, where solar noon is 13:55:40 EDT.
So solar noon for the eastern time zone varies by almost an hour and a half.
So where is the real solar noon where it will match up with EST?
Baldwin, New York.
About 350 miles from Lubec Maine and over 700 miles from Ambia, Indiana.
And yet, if lunch is at 12:00 and everybody eats at the same time is it really the same time or just the illusion of the same time.
Time - Pink Floyd
The time is gone, the song is over, thought I'd something more to say
Earth's circumference Wikipedia
Earth's circumference is the distance around Earth. Measured around the Equator, it is 40,075.017 km (24,901.461 mi). Measured around the poles, the circumference is 40,007.863 km (24,859.734 mi).
ESRL Global Monitoring Laboratory Global Radiation and Aerosols