Stardate 20020716.1356

(On Screen): Brendan O'Neill, a professional writer who has been blogging for two months, offers we amateur writers some paternalistic pointers on how to turn our blogs into credible professional journals. (As if.) One observation in particular:

Then there are the over-long posts - 2000 words, when 400 words would have been fine. As Voltaire once wrote: 'The best way to be boring is to leave nothing out.' Blogging everything that comes into your head is a recipe for revealing nothing of substance about yourself or your views.

He'd probably be aghast at yesterday's post, where I wrote 3500 words about how to fight dragons with modern military hardware. I got done writing it and was a little surprised myself at how much I ended up saying, but I went back over it and couldn't find anything I felt like taking out, so said hell with it and posted the sucker, certain that my readers would all decide I was a loon.

Well, if so, then my readers all decided to be loony with me. (To heck with O'Neill; if I'm enjoying myself and my readers are, too, then that's good enough. Who cares about professional standards?) I've gotten about 30 letters from people commenting on various aspects of the problems involved, and though I had not intended to revisit the subject, some of it was just too good to pass up. So, once more into the breach, dear friends.

Probably the most important difference between birds and bats is feathers: birds got 'em, bats don't. A bird uses feathers to make a two-surface wing, like the ones we use on air craft. The top is rounded and air flows more rapidly over it, generating lift. As a result, birds can glide.

Bats can't. A bat wing is a membrane of skin stretched between extended phalange bones on the ends of its arms. The only way a bat can glide and generate lift is by having a steep angle of attack, which generates huge drag. So a bat has a terrible glide ratio, and if it stops flapping its wings for more than a couple of seconds, it will start to fall.

Bats are superb fliers, and some of them cover upwards of a hundred miles per night when foraging. But they flap their wings constantly when they're in the air.

Dragons don't have feathers (or at least, the ones in Reign of Fire don't) and their wings are like those of a bat. Though they may be shown gliding in the film (it's likely; it's a traditional poetic image) the reality is that like bats they'd have to be flapping at all times when in the air. That means that they'll be expending huge amounts of metabolic energy, just as bats do. We're talking about flying creatures which are whale-sized; several tons at least. With inefficient wings, the energy needed to stay airborne is going to be immense. That has several ramifications.

For one thing, these guys are going to be hot. Whenever they're in the air, they will always be quite hot relative to the ambient temperature. Not only are they expending immense amounts of energy just to stay up, because they're so huge they'll have a smaller surface area per volume than we do, because of a scaling principle called "cube-square". It's no wonder they breath fire; it's about the only way to really get rid of that much heat. It is unavoidable that their skin will glow very strongly in IR, especially the skin on the chest on top of the pectoral muscles.

That means they'll be extremely easy to pick out at night with FLIR and LANTIRN. It also means that heat-seeking guided missiles could be used against them. Galfant writes:

In 1970, I was going through a Navy Avionics course. As one of the demonstrations, they had an explosiveless Sidewinder in the classroom. All of its electronics were active as well as its guidance mechanism.

The instructor pick up a standard Navy issue 2-cell flashlight and turned it on. He swung the beam around to point at the Sidewinder, and the tracking head on the missile acquired a "lock". From that point, any movement of the flashlight cause the missile to track, and the guidance fins to move to steer the missile.

What is the infra-red signature of a 2-cell flashlight at 30 feet? Certainly less than the ball of flame from a dragons mouth.

And that was thirty years ago. The AIM-9 Sidewinder is the most successful and effective air-to-air missile in history, and since its introduction it's gone through many upgrades. Its current guidance package should have no difficulty at all locking on the heat signature of a dragon's body in flight. With a range of more than 10 miles, flying at Mach 2.5 (which means you can't hear it coming) and carrying a 10 Kg high explosive fragmentation warhead, it would make short work of a dragon. Both jets and helicopters carry them.

Neil writes:

Not to flog a dead horse, but I believe the Reign of Fire movie trailer has one of the characters mention something about the dragon population going from one to millions in a couple of years. With this magical reproduction cycle, they can lie low for a few years and then attack, overwhelming our defenses despite being knocked out of the sky routinely.

In other words, they breed like Kudzu. I don't buy it. What are they eating? If they're using as much energy as it seems they must, they will be voracious. Many bats have to consume their weight in food every couple of days, and a multi-ton dragon is going to have to spend most of its time cramming things into its mouth to survive at all.

If a million dragon eggs all hatch at the same time and stay together, shortly thereafter almost all of the baby dragons will be dead from starvation.

The only way they could possibly get that much food (no matter what they eat) is to spread out and forage, which means they wouldn't be lying low. They'd be discovered almost immediately, and then you'd get a massive baby-dragon hunt by ground forces and local hunters.

Quite a few people wrote in to confirm that modern radars detect anything solid no matter what it's made of. Aviation radars routinely pick up birds, for instance, and as I mentioned they use radar to watch cloud movements. Doppler radar is particularly good at this since it can much more easily identify moving objects.

Modern radar is so good at this, in fact, that it's too good. The radar screen doesn't usually show the raw data being returned because it would be too cluttered. Rather, the signal is heavily processed by computers to remove most everything that doesn't look like an aircraft.

The design of stealth jets such as the F-117 tries to reduce the radar signature as much as possible, but even more important is to reduce the consistent return to near zero. The purpose of the flat facets on the F-117 are to make it so that its reduced radar return "sparkles" like a gemstone; it will appear on radar, disappear, appear again somewhere else, and look like random fuzz. There isn't any continuity of trace which a round object would produce. But the radars are actually incredibly sensitive. Again, Galfant writes:

A popular misconception is that living tissue is invisible to radar. One of the problems they found in the F-117 was that the pilot's head was a large return. They had to coat the canopy windows with gold to ensure that radar would not pass through and be reflected by the pilot.

So the difficulty is that the pilot's skull would give a consistent return, albeit a small one. But that would be enough to permit the computers to figure out that it was hostile. Even if it's small, if it's moving 400 MPH, it's probably interesting.

And Joshua writes:

Most military radars can pick up cars, planes, birds, people, even inanimates. I watched a demo of a version of the E-3 Sentry radar that was modified for use in drug interdiction on a Lockheed P-3. We could see cars on the freeway 200 miles inland on an overwater flight 100 miles off the coast. Redirected, we could pick up bales of dropped drugs on radar to direct recovery efforts. Scary accurate and good radar. This is a detuned version of the P-3 frequency hopping radar, about 75% of the capability of the big rig on the E-3.

So you can forget about dragons hiding from radar. Not gonna happen.

Dragons would be easily detected at a distance with radar and close up with IR imaging equipment, and could be easily killed with guided standoff weapons or at closer range with gunfire. I don't believe those reproduction numbers so I don't believe they could saturate the defenses with raw numbers. I still put my money on the humans.