Flawlessly incomprehensible.

There is no reason it isn't achievable and many leading computer scientists support the idea. Acting ignorant to the idea is simply moronic. It's like saying we don't have nothing to worry because we'll never invent nuclear weapons. It's only a matter of time.

Here's some links for you. Read both pages and you'll see.

http://waitbutwhy.com/2015/01/artificial-intelligence-revolution-1.html

http://waitbutwhy.com/2015/01/artificial-intelligence-revolution-2.html

I think our biggest problem isn't/wont hinge on warfare but on artificial intelligence.

Once an A.I. reaches superintelligence the human race will either become extinct in a matter of months or we'll benefit and gain immortality.

If they are out there we should be able to see their technological prowess; harnessing their stars' energy etc. Of course the universe is such a vast place it would be certainly possible to have overlooked or just not seen them at all.