Issue #4 of Jonathan Hickman’s sublime space opera Infinity dropped this week (although our reviewer Jordan didn’t enjoy it quite as much) and the situation on Earth is dire.

Invasion forces of the omnicidal alien Thanos fill our streets and choke the sky. Of course this isn’t the first time our planet has been targeted by extraterrestrial ne’er-do-wells in fiction; such attacks from beyond the stars are natural atomic age sequels to the simpler, old-timey disaster movies. But do we in the real world also need to worry? Could interstellar forces ever make it here? And if so, what would they want?

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A frighteningly gorgeous page from Infinity #2 reminds us to watch the skies.


It’s the Journey, not the Destination


Hopping between planetary systems is not an easy task.

As freelance writer Robert Shaeffer points out in the May/June 2013 edition of Skeptical Inquirer, three oft-overlooked studies from the ‘60s put a pretty succinct kibosh on the idea’s feasibility. The most persuasive paper may be “Radioastronomy and Communication through Space,” by Edward M. Purcell, which calculates that even a perfectly efficient nuclear fusion generator would require a fuel payload over A BILLION TIMES the mass of the spaceship to even approach light speed, which would be necessary if you want to really get anywhere. If you try something more exotic and use antimatter (ignoring how difficult it is to manufacture and store), you can knock that down to a more reasonable 14:1 ratio.

matter-antimatter
Could matter-antimatter annihilation be the key to space travel?

That’s if you don’t want to stop. Decelerating enough so you could actually end your journey would cost you another 15 times that much fuel. Not to mention that despite our casual use of the word “vacuum,” interstellar space is still littered with a couple hundred hydrogen atoms per cubic foot, particles that become hull-destroying daggers at extreme speeds. Space-spanning aliens would have to come up with some pretty impressive shielding that we haven’t yet conceived to protect themselves en route.

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Maybe that’s why they’re always crashing?

Well, if traveling THROUGH space is so goddamn difficult, why not just skip it? Some interpretations of general relativity suppose shortcuts across the vastness dubbed “wormholes,” bridges between distant locations that have themselves become a sci-fi staple. The reality is while a neat idea, the things have never been observed, and theory predicts they’d be infinitesimally small and unstable. Besides, why would there be one just around the corner from a would-be conquering civilization? Given how huge the universe really is, odds are you’d still have to go ahead and invent long-distance space travel just to get to a wormhole!

wormhole

Even if the Deep Space Nine guys were lucky enough to find a wormhole, they’d have to blow it up to a useable size through currently inconceivable methods. And you’d still have no way of controlling where it ends.


They Come in Peace


Stephen Hawking has famously remarked that we shouldn’t go deliberately broadcasting our existence to the cosmos, as anyone who might notice and show up on our doorstep would probably treat us like the Europeans did the Indians upon “discovering” the Americas. Considering that interstellar spaceflight is all but impossible, though, anybody who’s actually capable probably doesn’t have plundering and imperialism on their minds. They’ve already built one of these…

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New Avengers #4

Tony Stark brainstormed it as a weapon, but the original idea behind the Dyson Sphere, named for theoretical physicist Freeman Dyson, is to harness all the energy from a local star, eliminating the need to go foraging for resources. Constructing one of those, or a more practical “Dyson Swarm,” has gotta be easier and more sensible than jaunting across the galaxy just to strip-mine. A crafty enough civilization could expand to the stars next door (still closer than we’d be), or even use an array to harness the dizzyingly fast rotation rates of black holes. So you shouldn’t expect there to be a whole lot of interplanetary piracy going on out there.

dyson_swarm

If Stark were really smart, he’d opt for a more fragmented Dyson Swarm (pictured above) instead of the sphere. Wouldn’t have to shell out for as many Shi’ar contractors.

But what if the aliens ran out of food, or ruined their own planet? Could they view Earth as a blue-hued bed and breakfast, with us on the menu? I doubt they’d have to go looking for snacks; even we can grow some meat on a hook. And searching the spaceways for a new home would be way more difficult than just terraforming another world in your own system. If there weren’t any others nearby that were habitable, as crazy as it sounds, it would still likely be less of a technological hardship to just MOVE one into a suitable position.

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Or just give that guy a call.

Really, if extraterrestrials had any desire to visit Earth, it would probably be for the same reasons some us spend our lives scrutinizing the folds in rocks or the ear bones of fish. Scientific curiosity. Science and technology are often unfairly conflated, but it’s presumably true that you can’t have the latter without the former, so any sufficiently advanced civilization must have that itch to find things out. I still wouldn’t worry too much about big-headed grey guys with unlicensed medical equipment, though. If we figured out it’s a lot easier to stay home and let the probe do all the work, it’s probably cosmic common knowledge.

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The Mars Curiosity Rover is aptly named, and similar devices are likely the exploratory method of choice for any inquisitive civilization.

Hey, I’ll be attending New York Comic Con this coming Sunday, sitting in at Mike Kingston’s Headlocked booth (#1278)! Except for when I’m at the World Science Festival panel! Come say hi!