As a sci-fi writer, I tend to write about large things — the cosmos, in particular. Cosmologists and astronomers tell us we can detect about 46 billion lightyears’ worth of universe (beyond which apparently lie dragons), and they measure space in parsecs (3.26 lightyears), megaparsecs (1 million parsecs/3.26 million lightyears) and gigaparsecs (1 billion parsecs/3.26 billion lightyears). But even to scientists these numbers are purely abstract. To our Earth-bound intellects, there’s just no way to connect with anything on that scale. And when we can’t connect with something, it floats around in our psyches with no useful context. This is most unhelpful for someone who writes space opera.
When we can’t connect with something, it floats around in our psyches with no useful context.
The picture above is of my main character, Trish, with her runabout. In the story, her little single-seater can travel about 3 parsecs per jump, with a total of 3 jumps on a charge, meaning she can go a little beyond 10 lightyears before having to recharge. And although this is a fairly modest range for science fiction, I was struck by the insignificance of her tiny little ship compared to the distances she travels. So, donning my mental HAZMAT suit, I stepped into the perilous realm of mathematics.
First off, I should state that a lightyear is about 6 trillion miles (6,000,000,000,000), so with that as the base figure, let’s scale down Trish’s ship and adjust accordingly. Take a look at a yardstick — preferably one with metric markings. 1 yard is pretty close to a meter, and a millimeter is one thousandth of a meter, so there will be a thousand millimeter marks on that yardstick. Now, mentally shrink everything down until the yardstick represents one millimeter and all the millimeter markings are now micron markings. That’s the easiest way I’ve found to visualize this. And away we go:
Shrinking Trish’s ship down to the single-micron scale (the smallest human cell) subtracts 6 decimal points from the lightyear figure, reducing it to 6 million miles, which equals 241 trips around the Earth at the equator, or 12 times to the moon and back.
At this scale (a moderately-sized human cell) we subtract 5 decimals, and to equal a lightyear the ship would have to travel 6o million miles, which is in range of Mars when it’s relatively nearby.
At 100 microns (a large human cell) we subtract 4 decimals, and to equal a lightyear on that scale the ship would have to travel to Jupiter at its farthest orbital point from Earth (rounded up to 600 million miles).
Scaling Trish’s ship to 1 millimeter, a lightyear becomes 6 billion miles, or roughly 1.3 billion miles beyond Pluto at its most distant orbital point from us.
At 1 centimeter (2/5 of an inch), we reach the transition zone into figures the human mind can no longer relate to. Even reduced down to this scale, a lightyear is still 60 billion miles. We have no reference point for that kind of distance.
Clearly, a lightyear is an unbelievably vast distance. So vast, that when scaled down for microscopic travelers, it’s still well beyond anything mankind has bodily achieved. But the cosmos is so immense that even at true scale, a lightyear doesn’t get us very far. It’s more than 4 lightyears to Proxima Centauri, our nearest neighbor; and our galaxy is somewhere between 100,000-180,000 lightyears across.
Imagine a ship the size of a human cell traveling to Jupiter at its farthest point from Earth. That’s the relative scale of a lightyear.
For me, this is a big part of why science fiction, and space opera in particular, is such a fascination. The idea of being able to cross those distances for real is too enticing for the mind not to dream about. What would be out there? Is it all just empty and inert, or is it teeming with life and civilizations?
When we stand here on our planet and look out into the vastness beyond, we can’t help but imagine things completely foreign to our Earth-bound conceptualizations. The kind of sci-fi I like goes beyond human-ish beings doing human-ish things. I’m fascinated by ‘more’, and when I look around at our world wondering if this is all there is, my mind and soul cry out a resounding “NO!”
The endless wilderness of open space must hold things we haven’t yet imagined.
With so much still not sorted out about our own situation, the endless wilderness of open space must hold things we haven’t yet imagined. At least, I hope so. If the Earth turns out to be a comprehensive microcosm of all existence, then it’s time for another Big Bang (if there ever was such a thing). Fortunately, science fiction can make that happen — no apocalypse necessary.
Michael is author of the Soulstice Saga, a transcendental ‘spacetime’ opera. His occasional forays beyond the local stellar neighborhood persuade him that sightseeing is often best enjoyed from the vehicle of one’s own imagination.