Current location:	Nuberhouse
Current mood:	sleepy
Current music:	An Earth-shattering KaBOOM!

How not to glass a planet
I saw the latest Star Trek today. It's a good movie, though it suffers from the problem that their giant planet killing machine sucks. Their plan looks like this:


Step 1) Drill hole to center of the planet.
Step 2) Drop small black hole into center of the planet.
Step 3) Laugh manically while the planet implodes.

The first step fails, as the planet's radius is a bit over 3,000km, all solid rock that gets denser as you go down. By the time you reach anywhere near the center the hole would have collapsed, repeatedly. You might be able to reach the center of the planet, but it would take you a lot longer than 10 minutes.
Also, if you had a planet with a gooey liquid center then all the goop oozes out and the crust collapses well before you hit the center, and everyone dies before step 3 of the plan.
Note: if your going to try this anyway, drill down through the north or south pole, as planets aren't true spheres and it's a little shorter from the poles.

Step 2 is problematic, as small black holes don't suck matter in that fast. The planet would implode, but it would take a while, and that is if the black hole didn't evaporate first from Hawking radiation. Plus you don't even need to fire it into the center of the planet, if you lob it lazily into the planet it'll wander into the center in it's own time.

Step 3 is better, but still wrong. see as the matter gets sucked into the event horizon of the black hole it gets compacted, undergoes fusion and releases radiation. As the planet still over the black hole is opaque to the radiation, the radiation piles up. eventually the force of the radiation overcome the force exerted by the planet above it, and the whole thing explodes. This is what happens in some supernovas.
Of course everyone is dead by this point, but still there is nothing worse than a wrong, mad scientist.

If you want to destroy a planet, your best bet is a bunch of big bombs. Nukes will work, but fancy Sci-fi bombs are usually cooler. Drop them onto the planet, watch as everyone dies of radiation and fucked up weather, then next time someone gives you lip point to the charred cinder and ask them if they want to be next.
A giant gamma ray or xray laser would also work, sweep it over the planet and watch as people cook and plants wilt. Though that would require a lot of power, and bombs might be better.
Marvin the Martian knows his stuff.