Notes for Em

Time lapse of lightfoil in motion.I’m going to have to become some sort of physicist. Damn. I hate math.

No, actually, I don’t; I’m just a pathetic mathematician. Or, more accurately, not a mathematician at all. But that’s beside the point. Except, damn. I’m going to have to become some sort of physicist.

I suppose I shouldn’t be surprised. Some of the questions my brother and I asked thirty years ago probably astounded my father the way my daughter can absolutely befuddle me. “What,” she asked, not too long ago, “is a solar sail?”

Seven, by the way. Now eight.

Of course I told her about this far-flung idea of using a laser to push a spacecraft, and how the vessel could reach speeds near light. You know, stuff from fifteen years ago.

But I had no idea.

A BBC article brings me up to speed with lightfoil, which is a cool word despite the fact that no superhero will ever use it as a name:

Just as air causes lift on the wings of an aeroplane, light can do the same trick, researchers have said.

The effect, first shown in simulations, was proven by showing it in action on tiny glass rods.

Like the aerofoil concept of wings, the approach, published in Nature Photonics, works by making use of the radiation pressure of light.

The results are of interest for steering “solar sails”, a spacecraft propulsion based on the same force.

Each photon – or packet of light – carries its own momentum, and this “lightfoil” works by gathering the momentum of light as it passes through a material.

This radiation pressure has been considered as a fuel-free source of propulsion for long-distance space missions; a “solar sail” gathering up the momentum of the Sun’s rays can get a spacecraft up to a significant fraction of the speed of light.

But until now, no one thought to use the pressure in an analogue of an aerofoil, said Grover Swarzlander of the Rochester Institute of Technology (RIT).

And the nifty links for related stories tells me that Japan has succssfully deployed a solar sail:

Japanese scientists are celebrating the successful deployment of their solar sail, Ikaros.

The Ikaros sail deploys.The 200-sq-m (2,100-sq-ft) membrane is attached to a small disc-shaped spacecraft that was put in orbit last month by an H-IIA rocket.

Ikaros will demonstrate the principle of using sunlight as a simple and efficient means of propulsion.

The technique has long been touted as a way of moving spacecraft around the Solar System using no chemical fuels.

The mission team will be watching to see if Ikaros produces a measurable acceleration, and how well its systems are able to steer the craft through space.

The Japan Aerospace Exploration Agency (Jaxa) said in a statement that its scientists and engineers had begun to deploy the solar sail on 3 June (JST).

On 10 June, Jaxa said, confirmation was received that the sail had expanded successfully. Some thin-film solar cells embedded in the membrane were even generating power, it added.

I had no idea. At first I was simply amused that my daughter and her peers knew about the idea of solar sails. Let this be a lessson on what happens when you stop checking in on really cool things.

Speaking of really cool things, did you know there is a “Cool Stuff Theory of Literature?

The Cool Stuff Theory of Literature states that all literature consists of whatever the writer thinks is cool, and the reader will enjoy the work to the degree that the reader and writer agree about what’s cool — and this functions all the way from the external trappings to deepest level of theme and to the way the writer uses words. I came up with it when I had to do an interview for Locus and hadn’t enough sleep the night before, so I had to invent something interesting to say. Its Godfather is Gene Wolfe and some advice he gave a writer when judging a writing contest. I heard the advice and it got me to thinking. Most of the things Mr. Wolfe says get me to thinking. Why aren’t you interviewing him?

Science and its advocates.I mention it because there ought to be some similar scientific principle. After all, sure it’s fascinating that things like lightfoil exist, but just how is it going to make money? That is the great question. We’re a long way from science fiction. Sure, there’s more technology in a Ford Focus than the moonshot, but we don’t have FTL, and there are no stargates, and solar sails still mean a five-year trip to Centauri—sometime in the next two hundred years.

Where are the damn hovercars? You know, when I was a kid, there was this guy who came on That’s Incredible, or Real People, or something like that, showing off his newly-designed laundry machine. The thing didn’t use detergent. Soundwaves, apparently, knocked the dirt out of the clothes.

Legend says Colgate-Palmolive bought the idea.

I have no idea what ever happened to it.

Twenty years ago, we heard rumors of hydrogen cars. Most lately, a peteroleum company advert resurrected the idea. But it’s never coming; there’s no money in it.

That is to say, nobody has figured out how to maximize its profitability compared to other potential models including biofuels.

What is the business model for the future solar sail development? I can’t wait to see what crazy applications people invent for lightfoil in the meantime.

It’s absolutely, insanely, almost paradoxically cool that humans can do this sort of thing, but that isn’t worth a thing in the marketplace.

Maybe I don’t have to become a physicist. Maybe I just have to pay attention. And, who knows? Maybe my daughter will grow up to be a solar sail designer. Or, maybe, she’ll figure out how to monetize the whole scheme and make a bazillion dollars while rescuing the human species from itself.

I mean, cool, yeah, but what’s it actually worth?

And what does it say of us if that’s a viable question?

(Image credits: BBC, JAXA/BBC,

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