There is nothing more certain than the inexorable march of time, each second dutifully ticking ahead at fixed, predictable increments. It’s the one certainty in a world of uncertainties, right? How many times have our movie heroes “synchronized their watches” in order to meet at a precisely coordinated time in order to save the world from some nefarious villain or another? How many New Year’s Eve parties have culminated with delirious attendees screaming the countdown to midnight in a gleeful chorus, watching the final seconds of the dying year slipping away? How often have we been engaged in conversations like this …?

Grandfather: Here comes the mailman. I see him roundin’ the bend, stirrin’ up a bunch of dust.
Grandmother: Yep, that’s him all right, and he’s right on time.
Grandfather: Always is.
Grandmother: Just like clockwork.

… or this …

Tickety: Time sure flies when you’re having fun, huh Tock?
Tock: I prefer Kermit the Frog’s take on that subject.
Tickety: What do you mean? What does he have to say about it?
Tock: Time’s fun when you’re having flies.
Tickety: I knew I shouldn’t have asked.

We pin a lot on the concept of time. We do notice when people are consistently on time or consistently late. We do look back on a day filled with fun and sense that it passed quickly. We do feel like a boring or drudgery-filled day seems to pass glacially. So, which is it? Is time something that can always be counted on as an absolute or does it change based on our mood or situation?

The truth is that the passage of time is most definitely NOT consistent; however, it has nothing to do with the tastiness of our flies or the dreariness of our days. Two things, in particular, influence how fast time actually passes.

1) Gravity
2) Velocity

It seems strange, but clocks run more slowly the closer they are to the source of a strong gravitational field. It has nothing to do with the mechanical nature of the clocks. The same thing happens to digital clocks and even clocks that measure radioactive decay to mark time. This is a scientific fact that has been proven over and over again. As a matter of fact, the GPS system in your car or on your phone has been calibrated to take into account the difference in time between you on the ground and the satellites you are communicating with. Time passes more quickly in orbit. The difference is small, but cumulative. Uncorrected, it would result in your GPS unit sending you to all sorts of unintended destinations. The truly weird thing to ponder related to this concept is that your head is a tiny bit older than your feet, unless you stand on your head a lot.

Velocity is the other factor that can (and does) impact the passage of time. As you move faster, time slows down. This change is negligible until you start to move really fast. You can’t synchronize your watch with that of a friend and then have one of you run around the block a few times in the hopes that the watches would drift apart. But, if you could attain the speed of light, all time would completely stop – relative to you. To use a more easily understood example, suppose you are travelling in a spaceship going 99% of the speed of light. Let’s imagine that you are sent on a journey that will see you maintaining that velocity for one year. When you return to earth, you find that a little over seven years have passed for those people you left behind. Everyone and everything you left would be seven years older when you returned. This would seem incredibly weird to all involved because each person would think that time passed in a perfectly normal fashion from their perspective. You would have experienced exactly one year. Your earthbound friends would have perceived you to have been gone for seven years.

Both effects on the passage of time have been directly and repeatedly observed within well-documented scientific experiments. Go ahead and Google that if you don’t believe me. It’s true. Time is not constant. The ticking of the clock on your wall at home is ticking at a pace relative to you, your velocity and your position in space. You can’t tell, from your perspective, that it’s not in synch with time experienced by bodies in motion or in proximity to different sources of gravity. The only point of reference you have is the one you inhabit. This handy-dandy little nugget of science could be useful for those awkward moments when you are late for something. For example …

Isaac: Where have you been? You should have been here six hours ago?
Albert: What are you talking about? I’ve only been gone an hour.
Isaac: Poppycock, you fuzzy-haired nincompoop! You left here at eleven this morning and said you would be back for lunch. Here it is six in the evening and you are just now waddling in.
Albert: Isaac, my friend. You must have been struck upon the crown by a falling object of some sort. You are confused. I’ve only been out an hour.
Isaac: Look! Look at the clock on the wall there. What does it say?
Albert: Straight up six o’clock.
Isaac: See? I told you. You’ve been gone seven hours.
Albert: But, look at my watch. It shows that it is indeed noon.
Isaac: I don’t understand. So, your watch is wrong.
Albert: No. It isn’t. I am a busy man, Isaac. I had a lot to do and a lot of ground to cover in that hour. I was travelling at nearly the speed of light to get it done. Seven hours have passed for you while I was gone for an hour. It’s not my fault that you are so sedentary.

(A spirited fistfight ensues wherein Isaac pins Albert to the ground and gets him to admit he reset his watch and tried to use physics to cover up his tardiness.)

This article was written by Tilmer Wright, Jr. Tilmer is an IT professional with over thirty years of experience wrestling with technology and a proud member of the Authors Guild of Tennessee. In his spare time, he writes books. His second novel, The Bit Dance is a cautionary tale about what can happen when technology runs away from its creators. You can find links to Tilmer’s books at the following location: https://www.amazon.com/Tilmer-Wright/e/B00DVKGG4K%3Fref=dbs_a_mng_rwt_s…
His author information web site is here: http://www.tilmerwrightjr.com/
Photo of hourglass by Michael Himbeault. Used under Creative Commons license. File unchanged from original found here: https://upload.wikimedia.org/wikipedia/commons/8/85/Hourglass_.jpg Creative Commons license: Michael Himbeault [CC BY 2.0 (https://creativecommons.org/licenses/by/2.0)]