Quit making stuff up, Portugal!

I hope nobody objects if, for a change of pace, I'd do a little science blogging.

Little countries fight for everything they can get. It's why the Danish have never shut up about Hans Christian Andersen or Niels Bohr: because that's all they got.

Portugal is a country smaller than most, and if you read a Portuguese work on the history of aviation, they say it's one of theirs - Bartolomeu de Gusmão - who invented lighter than air travel first, in 1709, years before the Montgolfier Brothers (who happen to come from France, a big, important country).

Bartolomeu de Gusmão was a Jesuit that petitioned to King John of Portugal for the right to build a lighter than air craft. Plans still exist and can be seen: de Gusmão's drawings and design involved tubes that blow at a quilt.

In general, though, de Gusmão isn't considered to be the founder of lighter than air travel, because his machine was never built, it was never publicly demonstrated, and it's doubtful it would have worked at all.

Here's why: in science and engineering, there are only a finite number of ways something can be done because of physical laws. This is why, for instance, dolphins and sharks have similar body shapes despite the fact they're in no way related.

For lighter than air travel, any sort of craft would have to look more or less like a hot air balloon. No matter where it is invented and by whom, look more or less like the hot air balloon the Montgolfiers made. The reason for this is basic high school geometry: a sphere is the shape with the greatest volume and the lowest surface area. Likewise, the cabin would have to be far smaller than the gasbag, so that the gasbag could generate enough lift to carry it.

What's interesting is, de Gusmão's device resembles the helikite, another type of aerostat. Yet hot air below the kite surface itself doesn't generate lift. It needs a gasbag like any other aerostat.

To reward everybody for their patience, here's a picture of a hard guy with a body of pure iron:

(Suckers!)