Saturday, November 1, 2014

DRAMATIZING TIME

I am, as I’m sure you are, awestruck by those YouTube videos – there have been several good ones – illustrating the inconceivably vast scale of the Universe. Some start at our planet, and soar up through the solar, stellar, interstellar, and galactic, to the intergalactic scale, before returning to Earth, and thence down to the subatomic level.  Visually stunning, and of course (as Tim Minchin would undoubtedly attest) utterly humbling. By taking progressive steps - from large, to vast, to colossal, to stupendous - the Earthbound mind is assisted in that difficult process: humbling itself in the face of the ultimately immeasurable. 

Kilometers and miles were designed for Earthlings. For these off-the-planet measurements you need something much longer; hence the light year, which is supposed to make inter-stellar and inter-galactic distances, if not more comprehensible, at least more manageable. One light year, I remind you is 186,000 x 60 x 60 x 24 x 365 miles. That's "five trillion eight hundred and sixty-five billion six hundred and ninety-six million miles" in English. 5,865,696,000,000 in numerals. A silly number any way you look at it, and yet in galactic terms, at one light year we still haven't got anywhere.

What then of time? How are we to attempt to appreciate the equivalently vast stretches of time involved in the processes which brought about our world, and us? Abstract though the measurement of any distance outside the human scale quickly becomes, we can at least see the stars (outside Manila, on a clear night), but our concept of time is, I think, considerably more abstract, if not totally so. There’s nothing intrinsically visual about time, or, for that matter, anything sensible about it at all.  A clock face is an "analog" of time, but when a clock ticks, what, after all, is being measured? Its periodicity, or the rate at which it ticks, only becomes meaningful when measured against changes occurring in something else. And with vast stretches of time we encounter the same conceptual problems as we do with vase stretches of space. Atomic clocks may help you boil an egg, or get to work promptly on a Monday morning, or measure the speed of light on an idle afternoon, but are useless where an appreciation of evolutionary time is needed. There’s just been so much of it! A number followed by a string of zeroes doesn’t begin to do it justice, and the equivalent words – “a hundred million years”, say – are no less abstract and meaningless than "a hundred million light years". On the other hand, our attempts to dramatize time and thereby make it more tangible are in general frankly ludicrous. “Heaps of time” we venture, limply.  Heaps? What is this? Barrows-full, then? Cartloads? Trainloads of time?

What to do? 

Some two decades back - a couple of spoonfuls of time ago, let's say – ok, on June 15, 1991, to be pedestrian – the world became aware of a Philippine volcano, Mount Pinatubo, with whose name not even Filipinos had for the most part been previously acquainted, because its eruptions occur so far apart – once every 500 years, according to geologists – that the last time it erupted was before the beginning of recorded Philippine history. When it blew, Pinatubo is estimated to have ejected 6 cubic kilometers of material into our atmosphere. In the vicinity of the eruption day became night. Sandy, volcanic dust blanketed Manila, 80kms to the southeast, and finer particles were said to have circled the Earth three times. It was the largest such event recorded in the Twentieth Century. From the earliest rumblings, geologists sort of knew what to expect, because the scars of countless previous eruptions were etched deeply into the surrounding landscape. Pinatubo may well have been puffing away for eons.

This set me thinking: mightn’t one view Pinatubo as a sort of gigantic, geological metronome? The entire recorded history of the Philippines from the dispatching of Ferdinand Magellan in 1521 to the ouster of Ferdinand Marcos in 1986 - is bracketed by just two ticks of this volcanic clock. The entire history of Europe since the Dark Ages can be measured off in three; the entire history of Islam in four, and Christianity in five. The birth of ancient Greece and the lives of Buddha and Confucius occurred a mere six Pinatubo eruptions ago. Ten eruptions back would have seen the beginnings of writing, and twenty the beginnings of agriculture, according to current theory.

Homo sapiens, on the other hand, first walked the Earth some two hundred Pinatubo eruptions ago. Now we’re getting somewhere! Two hundred Pinatubo eruptions, each 500 years apart (assuming both the accuracy of our paleontological deductions, and the metronomic regularity of Pinatubo), separate us from our first truly human ancestors. That’s a lot of time.  Heaps of it.

Two hundred Pinatubo ticks just about wraps it up for humanity. Yet, as with a distance of two hundred light years, we haven’t really scratched the surface of what we're attempting to measure. Geological time, after all, doesn’t really bother with anything under a million years. What larger Earth cycles might there be, to help us get a handle on expanses of time that lie so vastly beyond the human?

Under Yellowstone, I quite recently learned, lies dormant an even more terrifying geological time bomb than Pinatubo: a supervolcano whose 25-mile-wide magma reservoir fills to bursting once every 600,000 years, upsetting the very balance of life on Earth with every cataclysmic belch. That’s one Yellowstone burp for every 1,200 Pinatubo hiccups – enough time to raise the starting gate on the human race six times over.

What might we measure with a Yellowstone clock?  Well, the extinction of the dinosaurs occurred a little over sixty million years ago. That’s “64,000,000” in cold figures; just a few scrawls on this page, which, again, does nothing to help us comprehend the changes represented by that amount of time. Entire continents have shifted during that period. So, to dramatize it a little, that’s one hundred and seven Yellowstone cataclysms (or one hundred and twenty eight thousand Pinatubo hiccups, each the length of all of Philippine history). In this way perhaps one begins to get an inkling of how much time is needed – and indeed was available – for biological evolution to occur. In fact, exactly enough time, to the nearest micro-second, to get us to the glorious pinnacle of planetary evolution that we have attained today.

But looking back beyond the extinction of the dinosaurs even the ticks of the Yellowstone clock become too numerous for human comprehension. Where do we go from here?

The extinction of the dinosaurs, it is now generally believed, was brought about by a massive meteorite collision with our Earth (in the vicinity of what is now the Yucatan Peninsula, though back then even the Himalayas didn’t yet exist, and the outlines of the continents would have borne only the faintest resemblance to their present configuration). If that galactic missile was but a fragment of a much larger cloud of meteors that circles the Milky Way once every 64 million years (an admittedly unlikely supposition), then the age of our universe could be measured at something in excess of a hundred and twenty such galactic circuits. That’s 12,000 or so Yellowstone Units, or some 14 million Pinatubo events each separated by a length of time equivalent to all of Philippine history.  

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