No, it’s not a prequel to a bizarre Peter Sellers movie.
I drive an economy car. Every time I get on the highway, I feel like a millipede trying to outrun a stampede of buffalo. My car’s only got a four-cylinder engine, and it seems like everybody else is driving an armored car with a jet engine strapped on. I’ve had to do a lot more highway driving than usual lately, and so I’ve been thinking about speed (and the lack thereof) a lot.
My drive covers about 20 miles of the most desolate highway in North Carolina. And, on one of those long, hot, dry sojourns, I started wondering just how fast I could possibly make the trip.
Einstein’s got me covered. Light (as far as we know) travels faster in a vacuum than anything else. If I could convert myself into photons, I could get where I’m going in 107 microseconds. Of course, if I could convert myself into photons and back, you can bet your ass I’d find something more interesting to do than drive on that ugly damn highway.
But since I’m stuck in a body made almost entirely out of matter (a major design oversight, if you ask me), I’m going to have to settle for a longer ride. Well, comparatively, at least.
The Cold War was a weird time. I’m glad I missed it. People who lived through it get a funny look in their eyes whenever you say “Cuban Missile Crisis.” Probably because we were about thirty minutes from an all-out deserts-turn-to-glowing-glass nuclear shootout. (Or maybe not. I’m not a historian. Leave me alone. I don’t even remember when the Gettysburg Address was.) But, scary as it was, the desire to place nuclear bombs in cities as fast as possible bred a lot of interesting technology. And the desire to stop people from rapidly placing nuclear bombs in cities bred even more interesting technology. Namely, the Sprint missile:
This chunky bastard was intended to be the United States’ last ditch anti-missile defense. If you didn’t manage to shoot the enemy ICBMs down with your atom-bomb-powered laser (look that one up…) or your regular antiballistic missiles, this thing would launch and use a neutron bomb to destroy the warhead before it could reach its target.
Of course, nuclear warheads hit the atmosphere going fast. We’re talking speeds that only astronauts and railguns ever achieve. And by the time they hit atmosphere, they’re already pretty near their target. So if you want to take them out then, you’ve gotta be fast. And dear God was the Sprint fast. Not only was it launched out of its silo by a piston driven by high explosives, but it accelerated at 100 gees. That’s 981 m/s^2. What does that look like? Well, it looks like this:
Apparently, that’s real-time footage. The Sprint could accelerate from launch speed to Mach 10 in seconds. That’s terrifying.
It was a really weird rocket, too. The composition of its propellant is still classified, but I’ve heard mention of nitrocellulose, which is pretty much cotton that’s been turned into gunpowder. Even weirder is how its first stage steered. You’ll note that the first stage doesn’t have any fins, and the fins on the second stage are tiny by rocket standards. That’s because the first stage was steered by injecting Freon into its four gas nozzles. Presumably, that’s because Freon is a fairly heavy gas, and would therefore increase the thrust of the nozzle in question while reducing its efficiency.
But to hell with all those technical details. Go watch the video again. People actually built a rocket that can do that. That’s terrifying.
If I was riding a Sprint missile down the highway, I could make the trip in something like 8 seconds. I believe Sprint could actually burn that long, so I’d still be accelerating when I got there, and I’d get to skip the most desolate stretch of highway outside of Nevada.
One problem: I’d be going eight times faster than a rifle bullet when I got there. And the skin of the missile would be white-hot from ram heating. And I’d be sitting on top of an armed neutron bomb. And I’d have scorched several hundred people to death on the road. And 100 gees would have turned me into a heap of bloody gelatin. Why did I say one problem? There’s lots of problems!
So I guess I’m not getting there on a Sprint missile. That works out, because apparently the program was eventually scrapped anyway.
Also sadly scrapped was the SR-71 Blackbird, a terrifying beauty of an airplane that may be one of the fastest planes ever built. It could easily reach Mach 3. Hey, if I’m gonna drive a boring highway, I’m gonna do it in style.
And I’m gonna do it in 4 minutes and 44 seconds. We humans really like to make pieces of metal move really fast. Probably because it’s AWESOME.
Sadly, I don’t have access to an SR-71. And, after some failed science experiments, when people see me around jet fuel, they start to twitch and back away. So perhaps I should stick to more mundane transportation. But I really hate the highway in question, so I want to spend as little time on it as possible. So I guess I’ll just break the speed limit (and probably my car) the whole way.
I may or may not have confirmed (in another unwise science experiment I may or may not have performed) that a 2007 Toyota Yaris can reach something between 105 and 110 miles an hour. Maybe the car felt like it was about to lift off the ground, and maybe I was sweating so much at the end that I needed two showers, but it can do it. So if I managed to maintain 105 mph the entire trip (weaving like a madman the whole time and praying to every deity ever worshipped that my tires didn’t fling themselves apart), I could make the trip in 11 minutes and 26 seconds. Unfortunately, speed’s probably not going to help me escape from the three dozen police cars I’ll have on my tail by then, but I’m sure the cops will understand that I did it for science.
But police give me funny looks, too, so perhaps I should slow down a bit. Perhaps I should just walk. I can walk at 3 miles an hour (I’ve got long legs). Although, I’m not entirely convinced that I could walk that fast for the 6 hours and 40 minutes that would require. I live in North Carolina, for crying out loud! It’s hot out there!
I think I’ll hitch a ride. I don’t think those Iditarod huskies would put up with the summers down here, so I’m going to need to find another animal. You know what? I’ve always liked snails. They’re like living snot. They’re like land squids. They’re little aliens that everybody just ignores. And their genitals come out of the sides of their heads. What’s not to like? So I’m going to hitch myself up a few thousand snails and have them pull me to my destination. I’ll be there some time next year, because the snails will need 136 days to pull me there. And that’s only if they don’t happen to notice all the tasty dandelions on the side of the road.
Because my car is economical but not exactly sporty, when I’m driving, I often think about ion engines. Ion engines hardly provide any thrust. The ion engine on the amazing Dawn spacecraft (which is currently orbiting Ceres, getting great pictures but not doing a lot to explain what the hell those weird white spots are) maxes out at 92 milli-Newtons. In terrestrial terms, that’s about the same as the Earth’s-surface weight of a coin, a pencil, or an empty soda can. It would take Dawn, weighing in at 1,240 kilograms fully-fueled, several seconds before it was outrunning a glacier.
But ion engines can do something more muscular engines can’t: fire for a very, very long time. Dawn’s been thrusting on and off since 2007. Its engine still runs fine, and there’s still some xenon in the tanks. It’s changed its velocity more than any other spacecraft ever built, and it’s done all that with only 425 kilograms of xenon propellant. To put that in perspective, 425 kilograms of gasoline takes up a volume of 156 gallons or 590 liters. That’s just over 14 times the fuel capacity of my car, but it would fit just fine in a tractor-trailer’s fuel tank (and would also destroy the truck, since they run on diesel; there’s a reason I’m not a trucker). That’s not a lot of fuel, and Dawn has traveled a ridiculous distance, so the mileage is amazing.
But that mileage comes at a price: the ridiculously low acceleration, which is in the neighborhood of 74 microns per second per second. If we pretend for a second that ion engines worked in air (or that somebody very kindly built me a twenty-mile-long vacuum tunnel; get on that, Boeing: my birthday’s only 11 months away!), then Dawn could make the trip in 8 hours and 11 minutes. And there wouldn’t be any police on my tail when I got there, since I’d only be going 5 miles an hour. Joggers and all but the laziest bicyclists would be whizzing past me. But to hell with them–they don’t have a stylish space-age ion-engine probe to ride on.
Between the snails and the ion engine, I’ve gotten to my destination about as slowly as possible. But there’s one more way I could get there, and for that, I wouldn’t even have to move. All I’d have to do is create a new subduction fault right in front of my destination. After that, all I need to do is wait. A lot. This isn’t a crowded-post-office kind of wait. It isn’t even a bad-day-at-the-DMV kind of wait. Hell, it’s not even a might-as-well-build-a-house kind of wait. If I traveled that accursed highway at the speed of continental drift, we’re talking about a “hopefully my descendants won’t evolve into a different species by the time they get there” kind of wait. Specifically, 340,000 years.
You know what? The commute doesn’t sound quite so terrible now…