“So what we have set up here is a light source.” Will’s dad pointed to an instrument that looked like a projector. “And here we have a prism, and a spectrometer,” he said, pointing to a large metal box with a small video screen with two rows of knobs and switches. On the back of the box was an opening that faced the projector. “The hardest part of the setup is to get all the instruments, lenses, prisms, and mirrors mounted on this table,” he patted a large metal table that had slots and holes machined into it in a regular pattern. “And last, but not least, we need to calibrate the whole she-bang. We do that with these.” He held up a box that had a bunch of slides in it. “These are super-accurate filters. Each slide only passes a narrow spectrum of light. This is how we know our spectrometer is reading things correctly.”
He turned on the projector and a beam of white light came out. The light went through a prism mounted on the table and some of the light split out onto a small screen that had been mounted at a right angle to the prism, and a rainbow appeared on the screen. Another beam of light came straight out of the other side of the prism and went into the hole on the side of the spectrometer.
“So look carefully at what happens when I put this filter over the lens.” His dad slid a piece of dark glass into a slot in the projector. The white beam went away.
Will said, “You blocked the light.”
His dad smiled and said, “No! Take a look at the screen!” And there on the screen was a single line of bright red light. All the other colors of the rainbow were gone. “You see, this filter blocks all colors of light except red! In fact, this filter passes only a very specific wavelength of light and we will use it to calibrate the spectrometer and make sure it is reading correctly.”
His dad busied himself with checking the readings on the spectrometer and fiddling with the switches and knobs to adjust the readings so they matched the filter. Will looked at the box of little glass slides. They all had labels like “810 nanometers.”
“So what do all these numbers mean?”
“Those,” said his dad, “Are the wavelengths of the light that the filter lets through. They are measured in nanometers—one billionth of a meter.”
“So light is a wave? Like a water wave?” asked Will.
“Mmmm, sort of. Definitely a wave but a little more complicated than that. I will explain it to you sometime. But a wavelength relates directly to color! And color is what we are interested in, or rather the color of a color that we cannot see . . . but we can see!” said his dad, cryptically.
“You’re talking about vox, right?” asked Will.
“That’s right. The light that you and I can ‘see’, or rather ‘hear through our eyes’ is what vox oculis is. Our eyes are sensitive to light that other people are not sensitive to. Specifically, infrared light. Now, you know this already because of our sensitivity to remote controls on TVs and radios and such. That annoying high pitch sound is caused by the infrared emitters on the remote controls. That is one of the reasons we gave you the glasses that you and Rose wear at school.”
Will and his sister each had glasses with a special clear coating on the lenses. When they were at school, putting on the glasses made it possible for them to concentrate. Without them, the crowded classrooms and hallways were distracting with all the chiss everywhere. And some rooms had fluorescent lamps that buzzed in their head like crazy if they didn’t wear the glasses. Wearing glasses was not unusual at school, and these glasses looked just like everyone else’s so they weren’t out of place, and they sure helped Will and Rose a lot in school. It made them feel normal, so much so that they took the glasses for granted.
“Dad, did you have glasses when you were in school?”
“Yes, we did,” said his dad. “Your mother and me both had regular glasses, and they helped, but they weren’t nearly as good as the ones you have now. You know how you can ‘hear’ through a window, but how it is quieter?”
Will knew of course. Sometimes it felt like a superpower—being able to “hear” vox through glass.
“Well, that’s about all the glasses did, make it a little quieter—except correct my nearsightedness, of course. The worst thing about it for your mother and I in those days was the fluorescent lights. The ones they have now are much better. I would just spend a lot of time with my eyes closed or squinting a lot when I was in the classroom. Kids thought I was a squinty-eyed nerd.”
“Wow. I just kind of assumed that you would have had glasses like ours. So where did our glasses come from?” asked Will.
“I invented the coating on them! Now do you have an idea of why I became a scientist? And do you ever wonder why your mother became a psychiatrist?”
Will stopped to think. Of course—his dad became a scientist because he wanted to find out how vox works. “So mom became a psychiatrist because . . . she wanted to know why people reacted funny to her?”
“Not exactly funny—harassed and bullied her is more like it,” his dad said.
Will had a hard time picturing anyone bullying his mother. It seemed like everyone was her friend, and she was so calm and poised all the time.
“I know. Hard to imagine your mom being bullied, eh?” He looked sidelong at Will.
“Did I leak just now?” voxed Will.
“No, but your face gave you away. You can read people by more than chiss, you know.” His father turned back to what he was working on.
So his mother was the same way, as abnormal as he felt, only she tried to find out why it made her so different from other people and why people reacted to her the way they did by studying psychiatry.
He thought about Blue and her world. She did not have glasses of any kind. For her vox is ‘on’ all the time unless she closes her eyes. She didn’t have a scientist father to make special glasses or a psychiatrist mother to explain people’s behavior. All she had was the ability to close her eyes or hole up in her room, and act distant and aloof, and answer in short sentences.
“You see, son, there isn’t a lot of science about our family trait. I decided there should be some, even if it is only for our benefit. Along the way I discovered that there is a lot of neat science that has nothing to do with vox, so it was a win-win decision for me.”
“So what have you discovered so far? I mean besides the coating on the glasses?” asked Will.
“Ah!” said his dad. “A very great deal,” “And yet not very much!” “So let’s start with what you know. You do know that the coating on the glasses helps, but do you know why it helps?”
“Well, you said we are sensitive to light that isn’t visible, right?” said Will.
“Go on,” said his dad, nodding.
“So is it a filter, like the filters you are putting in the projector, here?”
“Exactly!”
“And so this setup you have here, you are using that to test different filters?” asked Will.
“Yes! And no. Yes, because I do use this setup for that, but no, because I am using it for a different test today. Today and for the next few weeks, I want to test light sources! I told you that our eyes are sensitive to certain wavelengths of light that others are not, BUT, where does that light come from?”
Will thought it was a stupid question because his dad knew very well that somehow their eyes were the source. “Well,” said Will, “It comes from our eyes somehow—I always thought it was reflections like with dogs and cats.”
“Ah, no, it can’t be reflections. We can vox in complete darkness, even infrared darkness. Now with dogs and cats and other nocturnal animals, that actually is reflection—animals have a lining in their eye that reflects light back through their retina. That’s what allows them to see in low light. But even animals can’t see in complete darkness. The reflective lining is called ‘tapetum lucidum.’ It literally means ‘bright tapestry.’”
“But we don’t have that tap . . . tapetum . . .”
“Tapetum lucidum. That’s right,” said his dad. “But what I am quite sure of is that we have a lining in our eyes like tapetum lucidum. Only instead of reflecting light, our lining glows!”
“Glows!” said Will. “Like a firefly . . . only in infrared?”
“Well, that was my first guess, but I eliminated that right away. There are some deep-sea fishes that can glow in infrared and ultraviolet colors, but that’s a chemical reaction and not fast enough to vox. There are however other ways of generating infrared light and evolution has always proven to be more clever than we are. Science, in fact, is a very humbling discipline in which we are constantly amazed at the genius of nature and evolution.”
“So just how do we generate this light?” asked Will. He was starting to get interested and impatient for the answer. He also was getting exasperated by his dad’s drawn-out explanations. But his dad finally got to the point.
“I don’t know!” He smiled broadly.
“You don’t know? Doesn’t anyone know?”
“No, that’s what is so exciting—that’s what we are setting up to work on now. We can be the first ones to discover it. That’s what makes science so cool!” He clapped his hands and danced around as if he had just won the lottery.
Will’s dad often got a little over-excited when talking about science. When he got this animated, Will worried that his dad might be just a little bit insane. Problem was, Will was starting to get a little excited about it, too.