(The Silence of Ancient Light, continued)
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The days and the nights passed, and if it were not for the desperation of their situation, Anna would have found the sailing nearly idyllic. The small trimaran performed brilliantly on the broad reach of their course, the skies remained clear and the tradewind constant. Occasionally a brief squall passed over, enough to keep their water jugs full, but not so much as to cause alarm. They had enough food if they were careful, though it became increasingly bland as they relied upon the salted fish and seaweed that Ca-Seti had thoughtfully left on board, supplemented with their own dwindling supply of prepackaged meal bars.
Ca-Tren continued to ask questions about the stars in the sky, and Anna tried to teach her the basics of astronomy and the structure of the galaxy. Ca-Tren struggled with the human names for the stars and constellations, and Anna wondered if she really grasped the distances involved or was just being agreeable. How does one teach the idea that light has a velocity to someone who has never before had to learn more than how or why their world has seasons? At least Li-Estl taught her students that their planet was a sphere and that it revolved around their sun, so thankfully Anna didn’t have to broach that particular subject, and Ca-Tren had been exposed to the idea that the stars in her sky were other suns, far away. Yet the speed of light remained a difficult concept.
If our boat could fly, could we sail to your world? Ca-Tren asked on one of these nights.
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(2,659 words; 10 min 38 sec reading time)
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If someone lights a fire in front of you, you see the fire instantly, right? Even if the fire is a mile away, assuming it’s large enough, your sense is that it takes no time for the light of that fire to reach your eyes. It could be many miles away, at the edge of the horizon, and it will seem this way to you. Of course, you’re an educated person, and you know from school or books you’ve read that the speed of light is not instantaneous, but it is very fast. In fact, it is so fast that to travel from a huge bonfire on the horizon, which for sake of argument we’ll call 20 km away, it takes a mere 67 microseconds to reach you, or 0.000067 seconds.
According to a 2017 MIT study, it takes 13 milliseconds (0.013) for the electrochemical signal to travel from the lens of your eye through your optic nerve and thalamus and finally reach your cerebral cortex, where your brain recognizes it as a visual signal. I’m sure you can do the math from here, but yes, that means that in the time it took for your brain to “see” the light already at your eye, additional photons from that same bonfire have traveled the 20 km to reach you 195 times. In fact, the only reason you see the light of that fire at all is because it continues to shine longer than 13 ms, as otherwise it would be so fast as to be unperceivable by you or I. This is beyond subliminal.
So, a civilization with no experience of anything beyond the surface of their world could be forgiven for not thinking of light as something that has to travel at all, but rather something which simply is.
In this circumstance, how would you begin to explain to someone from that civilization that the stars they see in the sky are not as they are, but as they were hundreds or even thousands of years ago?
This is where Anna begins as she attempts to instruct Ca-Tren in the nature of the galaxy around her.
Of course, such near-philosophical discussions are but a pleasant interlude, as Anna, Ca-Tren, Laxmi, and Jaci are about to arrive at the island housing the ancient base of the space elevator they have been seeing in the sky for months. What will they find upon arrival?
You’ll have to click that link and read on to find out.
As always, drop me a line and let me know what you think of the story so far!
header image credit: Enrique Meseguer / pixabay.com via Pixabay License
Matt Fraser 