Small Talk #5 - Time
If we sit still and count the seconds for one hour, it will feel like a very long time. But if we watch a riveting movie, that same hour will fly by. It’s not hard to come up with a physiological explanation why, but it shows how time is one of our most elusive concepts. And that makes it a great topic for this week’s Small Talk.
The Illusion of Time
Let’s start with geologic time. It begins with the formation of the Earth, about 4.5 billion years ago. The first eon of our planet is called the Hadean, so named because things were pretty hot around here—lots of volcanic action and a molten landscape. This is when the moon emerged! The Hadean ended about 4 billion years ago, making way for the Archean eon, in which life first appeared. Now, how do you get your head around that amount of time, relative to our lives? A popular reference point is to say that if the history of the earth were 24 hours, humans wouldn’t appear until the last two minutes—and all of recorded history would take place in the last few seconds.
Another interesting comparison is this: The Cretaceous period, when charismatic dinosaurs such as Tyrannosaurus Rex roamed the Earth, lasted about 79 million years. Homo Sapiens have strolled the globe since about 300,000 years ago. That means the types of dinosaurs portrayed in the popular movie Jurassic Park (so misnamed because it ‘sounded better’) existed for 263 times longer than we have! And that’s just one of the three periods in which dinosaurs held court.
But let’s zoom into those last few seconds of Earth’s 24-hour history—and look at our efforts to get a grip on time. In a field at Crathes Castle in what is now Scotland, there are 12 pits arranged according to the phases of the moon. At 10,000 years old, they are the earliest-known calendar. The first known shadow clocks (aka sun dials) appeared in Egypt 3,500 years ago. Since then people have fiddled with getting an annual calendar correct and making better timepieces. In 1582, Pope Gregory XIII signed into effect the calendar we use today, the Gregorian Calendar. But it wasn’t until 1752 that the British Empire adopted it. Lots of confusion in-between.
Speaking of which, the concept of standard time, where we all agree to a worldwide method of saying what time it is, emerged in England in the 1840s, basically so the trains could run ‘on time.’ This expanded to the establishment of worldwide time zones in the 1880s. But even today, the government of China recognizes only one standard time for their country, which is 3,000 miles wide. Or, look at what the eastern time zone does in Michigan’s UP. It seems we’re still a bit confused.
Or perhaps very confused. Although our lives are bound and defined by time, we don’t actually understand what it is. The physicist Carlo Rovelli says, ‘We inhabit time as fish life in water. Our being is being in time.’ He also says that physics doesn’t yet explain how time actually works—or even if it’s real! Let’s just take a duration of time—say, the 2 hours and 7 minutes it takes to watch Jurassic Park. It should be the same amount of time regardless of where you are, right? Wrong. Because time is relative. Mass makes time slow down. So does speed of movement. So if you watch that movie on the top of Mt. Rainier, it will end sooner than if you watch it in Death Valley. If you watch it on a plane, it will take more time than if you watch it in the airport. That’s because the closer you are to Earth, the slower time passes… for you. And the faster you are moving, the slower time passes for you. Now it might be easy to dismiss this as egg-headed and theoretical. But today you can buy time measurement devices precise enough to illustrate the point. You start one on your couch when your friend starts one on Mt Rainier: When you see each other next, his clock will show that more time has passed for him. What this means is that each of us—and every point in the universe—has a unique point of reference in time. There is no universal time.
According to current physics, there’s only one law that distinguishes the past from the future. It’s this: heat can only pass from a warm body to a cold one. It can’t go the other way. Every other sequence of events in physics can be reversed. This law of thermodynamics is the only thing that supports our perception that time flows from past to future. But if you zoom in even closer, and look around the quantum realms where the most fundamental truths are played out, realms that we can only approximate by a mathematics of our own invention, you might conclude that even the direction of time is an illusion and all that exists is simply a continuous reordering of things that doesn’t distinguish a past or future. That’s what Rovelli concludes, anyway.
So where does this leave us? Well, science and history are important and fun, and great for small talk. But I think what really matters is now. The moment we’re living in, doing the best we can. So I hope this American Thanksgiving you are surrounded by the people you love, and together you find a present moment of gratitude, which is infinite if we only allow it to be so.
Have a good one,
Kipling Knox
P.S. In writing Small Talk, I try to use original source material where I can. Along those lines, here are two great books that inspired this chat: Rovelli’s The Order of Time, and Brusatte’s The Rise and Fall of Dinosaurs.
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