This wall around the Earth would be made tall enough to keep any "illegal" aliens from reaching Earth from those more unsavory zones out there. We can't have just anyone (or thing) entering freely and availing themselves of free healthcare and government cheese. It should be transparent to let sunlight through of course.
-- sqeaketh the wheel, May 07 2011

Fictionally baked http://emergentmath...uum-bag-spaceballs/
Reason to MFD this Idea: Not an original idea by the author. [Vernon, May 09 2011]

Tall enough to be a Dyson sphere, perhaps.
-- tatterdemalion, May 07 2011


Those aliens can really hop fences what with their FTL drives and all.
-- DIYMatt, May 07 2011


FTL, schpTL! What is needed to discourage fence hoppers is a moat. One could make it out of the VanAllen belt.
-- bungston, May 08 2011


We're not trying to keep them out, they're trying to keep us in.
-- jaksplat, May 09 2011


Does this mean we'll have to evict Tom Cruise and Charlie Sheen before we build it?
-- infidel, May 09 2011


Can we do that anyway?
-- tatterdemalion, May 09 2011


This could rapidly turn into a list, I fear.
-- infidel, May 09 2011


Maybe we can draft an Escher-esque design, sort of like a Möbius fence, so when the alien invaders try to enter Earth orbit, they'll actually be leaving.
-- Canuck, May 09 2011


How are you going to stop wormhole tunneling under the fence?

But it's a good idea. We were wondering when you'd get fed up of the Vulcans sneaking in, stealing all your pens and leaving wire coathangers behind.

They may be intensely logical, but they enjoy a good laugh as much as any other species. Notorious practical jokers.
-- 8th of 7, May 09 2011


and the socks! don't forget all the missing socks! Someone has to put a stop to it.
-- dentworth, May 09 2011


How do you know you aren't ?

<having planted seed of paranoia, sneaks away sniggering>
-- 8th of 7, May 09 2011


Doesn't space junk fulfill exactly this purpose already?
-- DrBob, May 09 2011


Dyson sphere or Dyson Ball? Which would be more appropriate in the vaccuum of space?
-- RayfordSteele, May 09 2011


//Which would be more appropriate in the vaccuum of space?//
sp. "Which vacuum would be more appropriate in space"
-- AbsintheWithoutLeave, May 09 2011


// How are you going to stop wormhole tunneling under the fence? //

Now that I think of it, the whole point of saying it should be 'tall' was (or should have been) to avoid just that scenario. Assuming that wormholes allow one to go 'around' a spherical barrier by moving 'over' it in the fourth dimension, we need to make it 'tall' in that dimension to prevent that. For those not immediately thinking 'Flatland' at this moment, imagine beings living in a 2D plane who think they can protect their country by simply making a circular barrier round it. The aliens (clever lot) simply hop over it in the third dimension. According to the 'idea' (not fictionally baked by Mel Brooks), we need a Frickin' Tall Fence in the 4th dimension.
-- sqeaketh the wheel, May 09 2011


As [DrBob] pointed out... space junk. To add more we just have to gather up all of the screws left over after fixing computers, cars and motorcycles (There are always a few) and launching them into near earth orbit. Hitting one at speeds as low as Mach 25 could ruin your whole day... unless you already have a Whipple Shield on your space hotrod.
-- infidel, May 10 2011



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