Wednesday, December 8, 2010

Spaceships and seaships.

The sci-fi genre takes a lot of flak for comparing space travel to seamanship. While most of this is just overworked humorists looking for something to rib, a few people take it as actual criticism. Unfortunately, this is pretty unfair.

Now, just for openers, remember the name: spaceship. The word “ship” is right there, its impossible to say without evoking visions of watercraft. While man’s earliest spaceships were more like capsules, and the current vehicles resemble airplanes, there is every reason to believe the future of space travel will have a lot more in common with ships than it will with airplanes.

I think the first thing critics fail to realize, is that ships are literally the only thing on the planet currently to which authors can draw a parallel. The comparisons stem not from laziness on the part of writers, but from an honest attempt to describe something in terms readers can understand.

A second very important point is that some things just work. We’ve had very large ocean-going vessels for nearly a century now, ships large enough to easily get lost on, and the kind of vessels that our first interstellar spacecraft will probably resemble. How do people avoid getting lost on ships? Do they just have maps, carefully memorized section numbers? No, they have a much simpler system based on the nautical directions.

Take a tour of the U.S.S. Midway, a aircraft carrier come maritime museum permanently moored in San Diego, California. As soon as you step bellow decks, you’ll probably find yourself almost instantly disoriented. After a handful of twists and turns, just figuring out which direction you’re facing becomes a challenge.

Fortunately, about halfway through the tour, a kindly retired petty officer will explain to you how you get around on one of these ships, and basically any ship in the United States Navy. The giant ribs of the ship’s hull are numbered from the front(bow) to the back(stern) of the ship. Each number is also labeled with which side of the ship you are on, S for starboard, P for Port(starboard and port being right and left, respectively). So if you see that you are standing beside the number 34P, you know you are 34 sections from the bow, on the port(left) side. Once you get a feel for this system, it becomes very easy to visualize where inside the ship you are, and thus navigate. Remember, there are no windows below decks on an aircraft carrier, and there won’t be on spaceships.

This system works very well(though perhaps not exactly as I just described, its been a while since my last trip to the Midway), and in all honesty, it is very likely we will use a similar system if and when we take to the stars.

Consider, if you will, our two most prevalent science fiction franchises: Star Wars and Star Trek. The vehicles use artificial gravity, with a very clear up and down, multiple decks, and ships with distinct fronts, backs, tops, and bottoms. While many critics argue that this is not necessary in space, I submit that it IS necessary for human sanity.

We humans are born into gravity. We live our entire lives with ups and downs to contend with, lefts and rights. And unless there is some element of the technology that makes this impossible, we will build our spacecraft around those concepts. We are trained whole lives to think in those terms, our language requires it. If humans are ever to conquer space, we will do so by making it familiar.

Who is going to design the first large spaceships? Well, who’s designed them already? In the late 1950s to early 1960s, a top-secret government program called Project Orion(not to be confused with the more current Constellation program) worked on the concept of spaceships propelled by the explosive force of atomic bombs. While these ships were initially intended to explore our solar system, Freeman Dyson(yes, THAT Freeman Dyson, and you thought he was just a writer) posited that anti-matter catalyzed atomic detonations could propel the ships up to 80% of the speed of light—a velocity able to reach nearby star systems in a reasonable amount of time.

So basically, the Orioneers designed the first interstellar starships. What did they study to base their designs on? Coca-cola bottling plants and navy ships. The engine room, one scientist posited, would have far more in common with those of naval ships than with spacecraft of the time.

Now, one key difference is that Orion would have to spin to simulate gravity, but the example still stands: the only people in history to design an interstellar spaceship for real planned on making it like an oceangoing vessel.

Then there’s the basic physics to contend with. A lot of critics tend to argue that “there’s no reason for spaceships to be ‘ship’-shaped” that is, long and narrow. Since “space is empty” ships can be whatever shape we want. The common flying saucer, for example. There are many things wrong with this, but let’s start with the first mistake: space is not empty. By describing it as a ‘vacuum’ we tend to give that misinterpretation to people who have not actually bothered to learn about it. Space is full of little things, particles mostly, gasses, tiny rocks, and lots more. It’s extremely thinly-spread, but it is by no means “empty”. Once you get beyond the heliopause and into the interstellar medium, it gets a might bit thicker. Because of this, a cigar-shaped ship will be far more efficient at pushing through space than, say, a saucer, or any other shape you care to name.

Not only that, but spaceships still can’t be whatever shape we want, just because they’re ‘in space’. A whole lot of any vehicle’s design is determined by it’s engines. Spaceships are pretty likely to be mostly engine, and those engines are probably going to be long and narrow.

You’re probably wondering why I just made such a bold statement. Ok, let me explain. Right now, the most promising concept on the table for interstellar propulsion is something we’ve already been seeing in science fiction for decades: the notion of a ram-scoop. The idea is to put a big intake on the front of the ship, and as it flies through space, it will gather up material from the interstellar medium(which, as I mentioned above, is not empty). This material will then be used as fuel to push the ship forward. The process will, almost invariably, involve laying the engine out in a long, narrow, straight line. It’s science!

So spaceships will, very realistically, have a great deal in common with modern seagoing ships. Nautical terms will continue to be used, mostly because the naval tradition will still be carried out.

Right now, realistically, we don’t even have any ideas on the table for how we’re going to communicate faster than the speed of light. We’ve got all sorts of notions on how to travel faster than it, and plenty of really good ideas on how to at least get going pretty close to it, but instantaneous communication between solar systems is, for the time being, a head-scratcher.

This is another reason why authors frequently liken space travel to sea travel. When humanity finally does reach the stars, our first brave reach will be very similar to the golden age of sale. Ships will depart, amid much fanfare and celebration, destined for far-off systems. They will not return for years, or even decades, and during that time, we will not know anything about their fate.

We don’t know yet what names will join the ranks of such heroes as Erik the Red, Sir Francis Drake, James Cook, or Ferdinand Magellan. They may be born already(in fact I’m pretty sure one of them was on my robotics team) or they may still be generations off. But someday there will be new explorers, and they will touch the stars.

So do not fault science fiction writers for likening space travel to sea travel. The fact is: they’re the ones who are right. The reality is that star travel will be a lot like sailing. The journeys will be slow, they will be hard. Brave men and women will make them, and we will move ever closer to the elusive goal of catching the sun. That last part’s a reference to The World Set Free, in case you’re confused.

1 comment:

  1. Dear Rick:

    Good arguments. If I ever write a space-travel story I shall take these into account.

    – Siddharth.


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