Osler's Razor

Now this is a difficult question.

If the aliens are biological, we should send sick people around them, a la H.G. Wells' "War of the Worlds." Now, I know RRL will say that Wells was a dirty commie that was chummy with Lenin and we can't trust at hing he says, but any creature that knowingly exposes itself to an alien biosphere is too stupid to conquer us.

If, as is more likely, given the limitations of space travel, the aliens are mechanical, a good electromagnetic pulse would short-circuit even alien technology, because the wonderful thing about physics is that it is universal.

However, this neglects a very serious practical problem: the distances of space are frighteningly, shockingly large. It takes enormous amounts of mathematics, eningeering and logistics to get a plane from one side of the ocean to another. A spacefaring vessel capable of crossing from even the nearest possibly-inhabited star (26 light years) would need food, fuel and supplies for a 26-year voyage.

Even assuming that aliens developed technology faster than we did (an unlikely assumption), and had some sort of faster-than-light capability, the sheer amount of energy needed for such a voyage, not to mention the cost of a ship capable of making the voyage, would bankrupt an entire planet's economy for a single, one-way voyage. Such a ship, even if it made the trip, would be far too valuable to risk in a fight.

No, I am quite sure that if extraterrestrials ever show up at our door, it will be under the most dire and pressing of circumstances, because nothing else could push a spacefaring society to such extreme measures.
 

Space is big. Really big. You just won't believe how vastly hugely mindbogglingly big it is. I mean you may think it’s a long way down the road to the chemist, but that’s just peanuts to space.

"Even assuming that aliens developed technology faster than we did (an unlikely assumption)..."

Isn't the faulty assumption the idea that we all would've started at the same time? I agree that it would be silly to assume that aliens are smarter than us necessarily, or more capable of interstellar warfare, but what if they had a two thousand year head start? What if they had a two million year head start? Why should be assume that we all started developing as fully evolved beings at the same moment? Maybe the conditions of their planet were such that they evolved quicker. Maybe some cosmic event altered their history and caused quicker development. Maybe their planet has natural resources we can't even imagine, and that allows them to accomplish more.

"the sheer amount of energy needed for such a voyage, not to mention the cost of a ship capable of making the voyage, would bankrupt an entire planet's economy for a single, one-way voyage."

That is only true based on the resources humans have on earth, and the nature of our economy. But it is awfully shortsighted to assume that earth has every possible type of element that could possibly exist in the universe. I'm not saying it is possible that there are more elements and natural resources than what we are aware of, I'm saying it is a statistical certainty.

What should we do to prepare for aliens. Step one: we have to take space travel more seriously, invest heavily in NASA, and start talking about traveling to and colonizing at least the other planets in our vicinity. Step two: space weapons. Step three: wait for the little green men and open fire.
 

That's the problem with our limited data; as far as we know, the life cycle from formation of a solar system to development of intelligent life happens more or less at the same speed as ours did.

And I am fairly sure that any element we haven't yet found would be like those weirdo elements on the period table that only exist in labs: lots and lots of particles in the nucleus, making them inherently unstable and unusable as fuel.

No, nature, in its infinite bounty, has made the perfect fuel: hydrogen. Hydrogen fusion is so awesome it powers giant balls of incandescent fire in the sky for billions of years. That's the perfect source of energy... except putting a miniature sun at the heart of a ship has "danger, Will Robinson!" written all over it.

That said, I am all for investing in space, because eventually we will have to leave this poor little rock and start colonizing other planets. And yes, weapons will be necessary.

Also, I want, at some point in my life, to blow up Mercury with a Death Star.
 

This is an interesting question, Professor Osler. I appreciate the suggestions already given, but if we have any hope of surviving an (impending) attack by an extraterrestrial invasion force—undoubtedly led by the planet Xe (formerly Blackwater Worldwide)—we must reign in our wasteful use of tin and aluminum and initiate the AFMST (American Foilable Metals Strategic Reserve). It has long been known that the only effective method to rebuff an alien mind ray (also effective against the left-wing, “drive by” media) is to surround your head with a reflective foil—Reynolds Wrap® (non-stick) works best.
 

And if I may be so bold, if the need arises for a PMT Part III, I humbly suggest a discussion of the planned Sept. 11th Koran burning in Florida.

http://www.nytimes.com/2010/08/26/us/26gainesville.html?emc=eta1
 

I think the demon spawn would only get citizenship if they were "persons."
 

We need to elect a former fighter pilot as president--a former president who has the ability to inspire crowds with rousing speaches. Then, under his leadership, we would just need to find a drunk who is willing to fly a jet fighter into the engine-area (for lack of a better word)--you know, that big glowing blue thing in the middle of the ship--so that it is destroyed by its own fuel source. Without the support and protection of the mother ship, we can use red matter to destroy the individual fighters. If that doesn't work, we could all just buy a bunch of super soakers and spray them with water.
 

As a threshold matter, I would need evidence that extraterrestrials are "persons" within the meaning of the Fourteenth Amendment before proceeding to the merits.
 

Also,

Turtle force field...

And no intergalactic terrorist anchor babies (since apparently bizzaro conspiracy theories are what Baylor lawyers are supposed to produce... thanks for bringin' shame on the old alma mater, Gohmert).
 

I think a turtle fence would work.
Why?
It would be alien-proof.
How?
We would make it three feet high.