Given the resources available on Earth, can we erect a colossal cage to envelope the entire planet?


  1. must covers the entire globe in a single non breaking element.
  2. brave any kinds of weather conditions; even the perfect storm.
  3. resist all magnitudes of tremors and earthquakes.
  4. must not be at or below sea levels.
  5. any holes should not be large enough for Ceres to pass through.
  6. must not crumble under its own weight.
  7. hold in place for at least 10 years.


  • Art, a testimony of human's imagination and ambition.
  • $\begingroup$ At what altitude? Space-based, or just a metal grid on stilts? $\endgroup$
    – Rex Kerr
    Mar 30, 2015 at 12:28
  • $\begingroup$ @RexKerr any altitude any material as long as it covers the surface of Earth like a net. $\endgroup$
    – user6760
    Mar 30, 2015 at 12:32
  • $\begingroup$ How tough does it need to be? $\endgroup$
    – Rex Kerr
    Mar 30, 2015 at 12:35
  • $\begingroup$ @RexKerr 2 conditions only: (1) hold for at least many decades preferably 10 years or more (2) brave any weather conditions even resisting perfect storm that is all I'll even accept holographic projection as long as it must covers the entire globe. $\endgroup$
    – user6760
    Mar 30, 2015 at 12:46
  • 4
    $\begingroup$ This might be easier to answer if you gave more context of why you wanted it/what you are trying to achieve $\endgroup$
    – Tim B
    Mar 30, 2015 at 12:55

3 Answers 3


I would say it is possible, but unlikely.

To build it outside the atmosphere of earth would be nigh impossible, as you would have to either source all of the materials from the planet and send them up into space, or get extraterrestrial materials and bring them back.

Either way it would have to be assembled in space, as you could not really part build the structure to assemble once it is in space in any reasonable capacity, and it would be too difficult to manufacture it once it is up there. So that option is out.

If it was within the atmosphere of earth, it would have to be held up by a structure, as outlined in the points here.

Therefore you would need every country and environmentalist to agree that it was in the best interests of the planet, as it would mean having giant structures sticking out of the ground within every country and ocean around the world.

Assuming geopolitical stability, second would be sourcing the materials. I would suggest carbon nanotubes, as they are very strong, can be very thin and there is plenty of carbon on Earth that can be refined. You again would need every country to contribute to sourcing the materials for this one.

Thirdly is the motion of Tectonic Plates. You cannot just have unmoving pillars going straight up all over the planet, as any movement in Uganda would affect the overall structure in Canada (Butterfly Effect). This would mean moving parts, so whilst the overall structure would be constant it could not be rigid.

You could have a hollow pipes-within-pipes kind of design. This would not only allow movement but also help assembly. You could not build a single constant shape, because it needs to be bigger than the Earth, so you wouldn't be able to. This then avoids the structural weaknesses you would generally find at the joints where separate pieces are attached together.

In terms of shape, I would suggest possibly tracking the lines of latitude/longitude. Kind of gives things a cagey look already.

As for weather, we have structures now that can withstand tornadoes/hurricanes, so it would be feasible. But considering it is right across the Earth, it would need to at least need to be maintained. Particularly if it needs to stand for a decade.

This again takes into consideration every country in the world allowing access to the structure from their territory.

Then again, there is always the second way that you could Cage Earth.


There is already a net of sorts encircling the globe. The Internet.

Just kidding...kind of. My first thought was to use laser beams. You could have laser stations around the globe, pointed heavenward at an angle, such that somewhere the laser beam will intersect another beam perpendicularly. If you could see the laser beams from space, the resulting cage would look...spiky all over the earth.

My second thought was to use existing manmade satellites already in orbit (about 1,000 active satellites; 3,600 total). You'd probably need to send up more for this...each satellite shoots a laser at the next closest satellite, forming a net. Plus side: it could also double as an early warning system...for example, when extra-terrestrials come to attack Earth with their cloaked ships, we'd know about it when they break the laser net.

My third thought was that you could use a combination of lasers stationed on earth, pointing at satellites in space. The resulting mesh of lasers should envelope the entire earth. While you're at it, why not encode digital information in the beam? Sounds somewhat like how satellites are used today anyways...

  • $\begingroup$ 's nice thinking out of the box I really like it. $\endgroup$
    – user6760
    Mar 30, 2015 at 16:06
  • $\begingroup$ Lasers can't penetrate clouds, so they wouldn't be independent of weather if not up in space. $\endgroup$
    – Oldcat
    Mar 30, 2015 at 18:43

There is not enough ressources on Earth. You need an external source of material or else you will have to go below the Earth's crust and that bring a lot of over problems.


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