Stephen Hawking Is Terrified Of An Alien Invasion, And The Reason Makes Nothing But Sense

[NickB79]

12. You're assuming they behave like humans with regard to resources

Given massive resources, humans have repeatedly shown their willingness to consume those resources until they are almost gone.

We HAD massive reserves of oil at the beginning of the 20th century; then we invented automobiles, plastics, etc and burned through it rapidly.

We HAD massive reserves of fertile soils and ground water; then we invented modern farming methods and aquifer drilling and used it up rapidly.

At every step in our development, we've taken what should be thousands of years of resources and found new ways to use them up at a blinding pace. Who knows what an alien race might do with their technology and resources?

Invent a warp drive that can move a massive ship between planets, but requires an entire planet be consumed for energy with every use? Oh well, there are MILLIONS of planets, right?

And that doesn't even take into account their potential population growth. Do they reproduce slowly and deliberately control their numbers, or do they breed fast? Do they have some type of religion or philosophy that encourages large numbers of offspring?

AND you're assuming the aliens are even biological. For all we know, they could have replaced themselves (or been replaced against their will) by machines: http://io9.com/how-self-replicating-spacecraft-could-take-over-the-gal-1463732482

The strength of Von Neumann's idea lies in the brute efficiency of exponential growth. Given enough time and patience, a single self-replicating probe (SRP) could produce millions upon millions of offspring; it would be like a massive bubble expanding outward into the Galaxy. Theoretically, these probes could occupy all four corners of the Milky Way in as little as half a million years – even if each probe were to travel at an average cruising speed of one tenth the speed of light (though, as I'll describe later, more recent estimates place it at 10 million years, which is still an incredibly short amount of time cosmologically speaking).

The fact is, we simply don't KNOW how an alien race would treat our species, and all opinions need to be considered until we have more evidence either way.