Friday, March 21, 2008

How to destroy the Earth, parts 8 & 9

8. Meticulously and systematically deconstructed

You will need: a mass driver. A mass driver is a sort of oversized electromagnetic railgun, which was once proposed as a way of getting mined materials back from the Moon to Earth - basically, you just load it into the driver and fire it upwards in roughly the right direction. Your design should be powerful enough to hit escape velocity of 11 kilometres per second.

At a million tonnes of mass driven out of the Earth's gravity well per second, this would take 189,000,000 years. One mass driver would suffice, but ideally, lots (i.e. trillions) would be employed simultaneously. Alternatively you could use space elevators or conventional rockets.

Method: Basically, what we're going to do here is dig up the Earth, a big chunk at a time, and boost the whole lot of it into orbit. Yes. All six sextillion tonnes of it.

We will ignore atmospheric considerations. Compared with the extra energy needed to overcome air friction, it would be a relatively trivial step to completely burn away the Earth's atmosphere before beginning the process. Even with this done, however, this method would require a - let me emphasize this - titanic quantity of energy to carry out. Building a Dyson sphere ain't gonna cut it here. (Note: Actually, it would. But if you have the technology to build a Dyson sphere, why are you reading this?)

Earth's final resting place: Many tiny pieces, some dropped into the Sun, the remainder scattered across the rest of the Solar System.

Feasibility rating: 6/10. If we wanted to and were willing to devote resources to it, we could start this process RIGHT NOW. Indeed, what with all the gunk left in orbit, on the Moon and heading out into space, we already have done.

Source: this method arose when Joe Baldwin and I knocked our heads together by accident.

9. Pulverized by impact with blunt instrument

You will need: a big heavy rock, something with a bit of a swing to it... perhaps Mars.

Method: Essentially, anything can be destroyed if you hit it hard enough. ANYTHING. The concept is simple: find a really, really big asteroid or planet, accelerate it up to some dazzling speed, and smash it into Earth, preferably head-on but whatever you can manage. The result: an absolutely spectacular collision, resulting hopefully in Earth (and, most likely, our "cue ball" too) being pulverized out of existence - smashed into any number of large pieces which if the collision is hard enough should have enough energy to overcome their mutual gravity and drift away forever, never to coagulate back into a planet again.

A brief analysis of the size of the object required can be found here. Falling at the minimal impact velocity of 11 kilometres per second and assuming zero energy loss to heat and other energy forms, the cue ball would have to have roughly 60% of the mass of the Earth. Mars, the next planet out, "weighs" in at about 11% of Earth's mass, while Venus, the next planet in and also the nearest to Earth, has about 81%. Assuming that we would fire our cue ball into Earth at much greater than 11km/s (I'm thinking more like 50km/s), either of these would make great possibilities.

Obviously a smaller rock would do the job, you just need to fire it faster. Taking mass dilation into account, a 5,000,000,000,000-tonne asteroid at 90% of light speed would do just as well. See the Guide to moving Earth for useful information on manoeuvring big hunks of rock across interplanetary distances. For smaller chunks, there are more options - a Bussard Ramjet (scoop up interstellar hydrogen at the front and fire it out the back as propellant) is one of the most technically feasible as of right now. Of course, a run-up would be needed...

Earth's final resting place: a variety of roughly Moon-sized chunks of rock, scattered haphazardly across the greater Solar System.

Feasibility rating: 7/10. Pretty plausible.

Source: This method suggested by Andy Kirkpatrick

Comments: Earth is believed to have been hit by an object the size of Mars at some point in the distant past before its surface cooled. This titanic collision resulted in... the Moon.

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