How to Destroy the World

We currently possess the technology to completely and utterly destroy the Earth. I'm not talking about that worn-out old cliché of "Let's set off all the nuclear bombs on the face of the planet. That'll destroy everything!" That's the first (incorrect) idea most people have when someone mentions destroying the Earth. I'm not just talking about destroying all life on the planet Earth, I'm not even talking about destroying everything on the surface of the planet Earth, either of which is the only thing you could hope to do by setting off a bunch of nuclear weapons, and probably neither, in actuality. I'm talking about a complete and utter eradication of everything that currently exists as something you can point at and say, "That's Earth."

It wouldn't be easy, and it would probably have to be done covertly, I can't think of too many people out there who could drum up serious grassroots support for this kind of project, but it could be done, with today's technology, and at a reasonable cost. (Reasonable to someone who wants to totally annihilate the entire planet, of course. Perhaps not so reasonable to someone who only wants to annoy his/her neighbor.)

My solution is lacking in some specific technical details, because I'm not an Engineer or Physicist and my knowledge of orbital dynamics is rather limited, but here, in several simple steps, is how to do it:

1. Construct a huge balloon. I'm talking in the thousands of miles in diameter, although size is not necessarily too important. The bigger the balloon, the faster the destruction. It also need not necessarily be too airtight. Some kind of rubberized fabric would probably be ideal. (A huge Spandex sphere comes to mind…)
2. Launch the entire thing into orbit. Here's where it gets a little hairy. What we need to do is place the balloon into an orbit where it is tidally locked between the Earth and Sun so that the balloon is also rotationally locked between the Earth and Sun. In other words, the Earth, Sun and balloon should be points of a rigid triangle, and the balloon should also face the same position relative to the Earth and Sun. Possibly the leading or trailing Trojan points in Earth's orbit would be appropriate, but if we leave it there, there's all kinds of other junk that's also been picked up to wreck our balloon. Ideally we want an orbit that leaves it locked into place between the Earth and Sun with no other floating space junk to knock it out of orbit.
3. Once it's in an appropriate orbit, Inflate the balloon. Since we're in a vacuum, we don't need a lot of whatever gas it is we're using for full inflation. It also won't need to stay inflated for very long, hence the laxity on being airtight. (This is an easy step.)
4. Once the balloon is inflated, start it rotating along one axis. Attach small thruster units or something. We can't have a lot of acceleration because we don't want to deform the balloon during this stage. (The idea is to use centrifugal force to stretch the balloon to a certain paraboloid shape. Further details in a bit. I don't want to give too much away yet.)
5. Once we have it rotating, coat the outside of it with a hard shell. Something like a quick-drying Styrofoam or something. We want it to retain its shape when we stop it rotating.
6. Stop the balloon from rotating. We can be a little more rough with it now that its been hardened.
7. Cut the balloon in half. This is probably the most dangerous part of the plan, as whatever we used to inflate it will come out very quickly in the vacuum of space and try to thrust the balloon off on some vector. Probably the best solution is to create some kind of puncture 180 degrees apart along the centerline so that thrust from escaping gas from either side of the balloon cancel each other out.
8. Once we have the two halves, coat the insides of each half with something reflective. Mylar or maybe sublimate silver or nickel onto the surface like creating telescope mirrors, or something like that.
9. Once we have the two mirrored hemispheres, position them so that the focal point of the reflection is on the Earth's surface. Of course, what we want to reflect into that focal point is sunlight.

The basic idea is to create two, huge parabolic mirrors that we can place into orbit around the Earth that will reflect sunlight to a focal point that we place on the Earth's surface. We need the artificial satellite to always face the Earth, and also stay in position relative to the Earth and Sun so that the focal point doesn't wander off of the Earth's surface as one or another of the bodies involved rotates or revolves or orbits or anything else.

What this accomplishes, should, I hope, be obvious by now. If you've ever taken a magnifying glass to an anthill, you're looking at a similar concept here, except instead of a 4" magnifying glass, you've got a parabolic mirror thousands of miles in diameter, (well, two, actually. We can either keep one as a spare, or place them both in orbit and get double the exposure!) and instead of an anthill, you've got the Earth. Crackle-crackle.

The two major technical points that I'm not sure on are:

1. Where do we orbit the mirrors so that the requirements of staying in position and rotation relative to both the Earth and Sun are met?
2. How fast do we spin the balloon when we "harden" it so that the proper parabolic shape is created to cause the focal point to be at the position of the Earth when the mirror is in orbit in the location that is determined by (a), above. (Centrifugal force to create the shape is an elegant idea, but may not be practical. It may be that we might simply have to create the mirrors in orbit.)

Another additional idea, suggested by a someone whose name I don't remember, from MIT or Cornell or some other place like that, is that if we place the focal point on the trailing edge of rotation (If the Earth is rotating clockwise, and our balloon is orbiting along a line that we extend from Twelve O'clock through Six O'clock, the trailing edge of rotation is Nine O'clock) then some of the outgassing of molten rock and water vapor and atmosphere that has turned into plasma, and all those other nice things will reach escape velocity. In essence, we will be using the vaporization of the Earth itself to act as a jet engine that will increase its own rotational speed, causing all kinds of other nasty tectonic destruction along the way.

We'll probably need to put some sort of control mechanism on the orbiting mirrors so that as the Earth reduces its mass into a trail of rock vapor and gasses in a ring 93 million miles from the Sun, and therefore also reduces its diameter, we can continue to keep the focal point aimed at the surface.

Also, orbital dynamics will change as the Earth loses mass. As it loses mass, but retains its orbital speed, it will begin to increase the size of its orbit. Eventually, it might just wander off into the asteroid belt, or, if we're very lucky, it could smack into Jupiter and be completely subsumed by the gas giant.

And that, kids, is how to destroy the earth using today's technology.

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