The Scale of Time & Space

By -

Recently I felt the urge to read something substantial, so I scanned my bookshelves and selected Paul Kennedy’s 1989 survey of 500 years of political and economic history called The Rise and Fall of the Great Powers. Of course, the book came out just before an absolutely remarkable dozen year period in which the entire world was turned upside down several times. It is precisely the kind of book I love reading: jam packed with tales of the flow of monarchs, political leaders, economic cycles, wars, and discoveries. My highlighter pen has been quite busy the past couple of days.

This book got me thinking about how difficult it is for humans to think in real terms about just how big, small, long, or short things in our lives are. As an example, I believe we consider periods of time as far, far longer than is appropriate while at the same time have absolutely no honest image in our heads about how incredibly tiny we are and how gargantuan space is. It’s a matter of scale, warped, I believe, by our own failures in perception.

Let’s take this history book, for example. 500 years might as well be 500 million to most people. It seems like an incomprehensibly long period of time, mainly because our own lives are limited to about 75 years or so. Our own lifespan seems to be “the known universe” as far as we are concerned, so reading about events from, say, the year 1550 is little different than reading about the Big Bang.

This simply isn’t realistic, however. and I’ve thought of a very simple mental exercise to bring this home. Instead of thinking in terms of years, which is mentally hampered by our own egocentric lifespan, think of it in terms of something else familiar to everyday life: cash.

Think about $10. That’s a nice, manageable amount. Enough for a good hamburger. Or, alternately, enough for a package of Beyond Meat (God knows they could use the sales). It’s a figure, and a scale, that we use all the time.

Now think about $100. Ten times bigger, but still quite comprehensible. There are $100 bills in circulation all over the place. It’s enough for a medium-sized trip to the grocery store. Now bump it up to $500. That’s about half my monthly utility bill (I’m not kidding……….I consider it a victory when it’s only three digits). All these are comprehensible, everyday sums of money.

So now let’s jump to a vastly larger figure……………let’s make it $20 billion. That is approximately Elon Musk’s tax bill from the exercise of his options. Instantly, this is a figure that our minds simply don’t grasp. Perhaps you have seen the infographics which show the palettes of cash that represent figures that big, just to try to get it through your skull how much bigger $20 billion is compared to, let’s say, $500. They’re just numbers, but our brains – – or mine, at least – – does a really lousy job “scaling” those differences in a visceral sense.

Let’s use the money metric in terms of time. Swapping out “dollars” for “years”, consider the figures I’ve cited above. 10 years is easy to think about (that’s a little more than half of Slope’s lifetime). 100 years isn’t much different. And, anchored as we are now to the cash examples above, 500 years honestly isn’t that far away. If we lived 750 years instead of 75, the notion of 500 years would make total sense, and we could truly embrace the stories of the men and women of history as fellow human beings whom we could understand, empathize with, and appreciate. They would cease to be abstract. They would be fellow travelers.

20 billion years, however – – – that’s older than the universe, as science presently understands it. So we can certainly let ourselves off the hook for failing to appreciate just how unfathomably long ago the Earth was formed, or life emerged, or even when dinosaurs roamed around. So if one truly concentrates on the whisper-thin slice that written history represents versus the entire timetable of our planet, a book like Professor Kennedy’s can spring to life in ways that it did not before.

Allow me to take this issue of “scale” one bit further, but in the opposite direction. My point with that is that we think of 500 years as ungodly and incomprehensibly long, when in fact it’s just the blink of an eye, and with a little effort, we can accept that, even viewed with the yardstick of human lifetimes, we can plausibly reach back to the age of Queen Mary from where we are right now. At the opposite end of the mental spectrum, I believe our brains do a wretched job understanding how utterly and terrifyingly empty the universe is, and how far away objects are from other objects.

Here, again, our egocentrism is the culprit. We judge size and distance based on our experiences. Six feet tall makes sense to us. 100 yards away makes sense to us. And even the moon and the stars above “feel” the same distance since our eyeballs perceive them on that hemispherical black dome that constitutes the night sky.

But it isn’t like that at all. So let’s engage in another fun, simple mind experiment. Let’s think about space.

Imagine a football field which, even as an ardent non-sports-fan, I’m able to do. Take a marble and place it at the 50-yard line. That’s the sun. Now take a grain of sand, which you have thoughtfully brought along for this mind experiment. Go out two yards and place the grain of sand down. Whoops, you can’t see it anymore, but no matter; you know it’s there. That’s our home planet. That’s everything we know. Earth.

OK, now that take that entire football field – all 100 yards of it – and shrink it so that its width is only about 5 inches – – the size of a compact disc – – instead of 100 yards. At this point, your eyes can’t see the sun (which, remember, what proportionately the size of a marble just a moment ago, when it was sitting on a football field). And you certainly can’t see the Earth. It’s all just too tiny. And you can hold the entire solar system (and more!) in your human hand, because it is CD-sized now.

OK, so how far away, on this scale, is our nearest galactic neighbor, the Andromeda Galaxy? I think most people would intuitively say it was a few miles away which, given the fact our entire solar system is right there in your hand, seems like a big enough figure. Keep holding that CD in your hand as you consider this: the Andromeda isn’t a few miles away. Or a hundred miles. Or even as far as the moon.

I am suddenly reminded of a commercial parody from a third of a century ago………..

The actual answer is…….a billion miles. To put it another way, go all the way from the palm of your hand to the surface of the sun, and you’re almost 10% of the way there. As jaw-dropping as that is, I don’t even think this little mental exercise conveys just how holy-Lord-that’s-incredible far away the Andromeda Galaxy is.

And it’s all the more amazing, since if it was visible in our own nighttime sky, Andromeda would be this big (again, your head should explode considering all of this, but trust me, my head isn’t exploding either; it’s just incomprehensibly far and huge):

This is a long way to go to make a simple point, which is this: our forebears weren’t cavemen. They didn’t die out with the dinosaurs. They were just like you and me, and they didn’t live that long ago. History is much richer and alive, I think, if we accept that any of these figures were only just here a few moments ago.