Science a GoGo's Home Page Forums General Discussion Not-Quite-Science Forum Is Planetary Defense Necessary?

I came across this site for the first time when I googled this link:

http://www.scienceagogo.com/news/alien_invasion.shtml

after seeing a reference to the book elsewhere. So here's my first post. Hi y'all!

My first thought is that movie-style alien invasion is probably even sillier than it sounds to the man-in-the-street. I'm willing to admit that it's conceivable that there are aliens out there who might not like us. Also conceivable that they might have the technological capability to do bad things to us in a way that they could afford.

But I can't see any reason for them to mount a classic alien invasion of us. If they just hate us, better to use weapons of mass destruction against which we'd have no defense. A rain of nuclear weapons (or a more advanced equivalent) on our major cities wouldn't make us extinct, but it would (followed up by selective pummelings on anywhere civilization seemed to be coming back) put us back at the level of cavemen who couldn't possibly be any danger. They could send a starship around every century or so for a follow-on bombing. This would do nicely if they were motivated by paranoia that we might somehow become a threat to them.

If they wanted the planet's ecosystem intact, or wanted us truly wiped out to the last woman because of extreme xenophobia, a human-specific biological weapons (which they presumably would be easily capable of engineering if they had affordable interstellar travel) blitz would do us in. Someone published a short story based on this idea in Analog magazine when I was a teenager, I believe the title was "The Screwfly Solution".

The only reason I can possibly think of for them to want to invade us and conquer and rule us would be if they felt the need for slaves, and I would think a race advanced enough for star travel would have an easier way to get reasonably intelligent things for slaves--Building Jetsons-style robots, or grafting electronic or genetic intelligence boosters onto their indigenous primates perhaps. If they couldn't do that, I'd expect them to be able to do slave raids (I don't consider aliens attacking us for slaves to be likely at all, it's just the least-unlikely scenario I can think of, so I'm going into a lot of detail about it). Grabbing airliners or steamships out of the sky/sea, swooping down and grabbing the population of isolated towns, etc. would work. And they could breed their own once they had a breeding stock, that would be much more trainable than wild-caught slaves. Alternately, they could send in James Bond-style agents (probably captive-bred humans) to quietly take over the government for them and somehow make humans available for export.

I've spent a lot of time picking the above apart, but it just seems to me that I can't imagine aliens coming to Earth the way human invaders move into neighboring countries.

I invite comment.

Welcome.


I think a planetary defense system for objects is probably necessary. But I don't think we need it for aliens.

I'm with scape on this one, I thought this thread was going to cover possible threats from NEA's. Aliens? If they're coming, and they're malevolent, we would have as much chance as Krill standing up to a Whale.

Anyone willing to expend their brain power attempting to design a means of thwarting an alien invasion must surely have a rational motive, e.g., making a bob or two in the bermuda triangle/pseudoscience market. Either that, or their internet connection is down

Advanced technology doesn't necessarily mean advanced "moral" compasses...just look around the world today. It would all come down to how such a technologically advanced civilizations belief system (religion) is set up. As for the means to attack us, I would think nudging an object or two from the asteroid belt into our orbit might do the trick.

pathfinder: "Advanced technology doesn't necessarily mean advanced "moral" compasses"

That's true, it doesn't - not necessarily, anyway - but I agree with the view, expressed by many including Carl Sagan, that if a species has survived its own high technology for many millenia, then it's not unreasonable to suppose that it's because its ethical nature has allowed it to do so.

And how old would an ET technology be? It's unlikely to be precisely the same as ours, since we've just 'this moment' become technological. On the cosmological time scale of billions of years, I think it would be very odd indeed if the ET age of technology had not begun at least several million years ago. That's several million years of surviving the potential for self-destruction. Good credentials for wisdom and compassion, I would say.

The rampant destructiveness of our own species may well destroy our global civilisation very soon. The threat that we pose to our own existence is vastly greater than that posed by an ETI. Martin Rees, in his book Our Final Hour*** gives us a 50/50 chance of getting throught the next century.

So, I would say that rather that expend enormous effort, and waste precious time, on a useless system of defence against a non-existent threat from ET, we should focus the resources on other ways to prevent our extinction.

*** Full title "Our Final Hour: A Scientist's Warning: How Terror, Error, and Environmental Disaster Threaten Humankind's Future In This Century - On Earth and Beyond."

http://en.wikipedia.org/wiki/Our_Final_Hour

I'd agree that advanced technology (including a civilization that has survived long enough to develop it) suggests an advanced moral compass, but whose morality is it? The morality may not include consideration for aborigines, especially of some freaky alien species (which in this case means us).

Shakespeare was a pretty moral guy, but his contemporaries did nasty things to American Indians (who admittedly were often doing nasty things back) and engaged in the slave trade. Indians and Africans weren't given good moral consideration in that ethos. Humans might rate the same way in an alien's ethos.

I agree with redewenur.

rede, that's a common theme in Sci-Fi, that, when Man's intellect exceeds his wisdom, we are doomed to oblivion.

I used to laugh at that stuff, "Worlds In Collision", the "Grey Goo Scenario" and so on. But now, seeing the leaps and bounds that we've made in just my own short time here, I must admit, I'm not laughing anymore.

Yes, I agree with redewenur, in that if a culture has been able to survive it's technology for awhile (millienia) then they probably are not out there with the goal to conquer others. What of those cultures who gain technology faster than they gain wisdom?
All they are needing is the ability for interstellar travel. While we haven't reached that stage yet, how far off might we be?
100yrs?200? 500? Will we be a benevolent culture by then? I think more of what the consequences might be if an alien culture mirrored, say, the Nazi's, or ancient Rome. Then they might be predisposed to use such technology once they develop it.
However, I still don't think we need to worry and fret, because there is also, most probably, much more peacefully advanced cultures who would intercede on some level to prevent this.
I imagine this protection to take the form of them saying " Hey, you guys seem to think you can take what you want, but if you do we would consider you a possible threat. And so we might have to do what we need to protect ourselves and those under our protection".

About thirty years ago I read a novel by Olaf Stapledon called Starmaker. It was first published 70yrs ago. Anyone interested in these NQS threads would no doubt enjoy it as much as I did. I think I'll read it again sometime.

http://www.bbc.co.uk/dna/mysciencefictionlife/A17390694
http://en.wikipedia.org/wiki/Star_Maker

Also by Stapledon: Last and First Men (the first sci-fi I ever read, back in '61!)
http://en.wikipedia.org/wiki/Last_and_First_Men

To a greater extent than most sci-fi, whilst these novels have no pretensions of holding true to science, they are an impressive commentary on the nature and spirit of mankind.

(Yes, I know I could have posted this in 'Science Fiction', but these novels have a lot to say about this topic)