# xkcd Judgment Day - sentient but stupid

See here.

Come on, if the computers controlling the nuclear arsenal ever gain sentience, they’d direct the nukes out of the solar system. It takes way too much energy to launch into the sun.

Was our nerd hero asleep at the switch when he drew this?

Didn’t do the rollover, did you…

I did but I’m not letting him get away with that. These sentient computers should still know that it’s better to launch out of the system, even if extra boosters are available. I demand realism in my stick-figure comics.

And possibly have them hit something and start an interstellar war? Are you mad?

I’m not a rocket scientist but wouldn’t it normally be easier to launch something towards the sun than away from it? I figured gravity would make the sun the easiest place in the solar system to send something to.

There are some threads on this - here’s a fairly recent one. Essentially, the Earth is orbiting the sun at 108,000 km/h, so anything you launch will already have that velocity. To make something hit the sun, you have to counteract that, otherwise it just circles the sun in a different orbit. The escape velocity of the solar system is significantly less.

IANARS either, but no, it turns out not. Before you can drop into the sun you have to scrub off all the kinetic energy you have just from having been carried along by the Earth as it goes round the sun. Until then, gravity will no more pull your rocket in than it will pull the Earth in. And as long as you’re changing something’s kinetic energy, the figures show that it takes less of a change to pull out of the sun’s gravity well than it does to reduce it to zero (or as near as it takes to fall into the sun).

ETA: fie upon you, TroutMan!

But, but what will Amazon do with those surplus rockets then? I mean, how many Lunarians are really going to upgrade to Amazon Prime?

I just finished reading Seveneves where Neal Stephenson talks about orbital mechanics; I get it but it makes my head hurt…

Clearly, the robots are lying. They’re just saying that they’re launching them into the sun because we humans are too stupid to know better.

MEGO. My Eyes Glazed Over.

Well if even NASAcan do it I’m sure a sentient AI could.

It seems like the key is seven flybys of Venus to shed energy.

I’m sure our nerd hero knows perfectly well how much more delta-v launching into the sun would take. He’s an orbital mechanics wiz.

Are you suggesting that he’s taking a subtle swipe against software developers by implying they aren’t smart enough to program the AI correctly? Because I could see that.

Why even launch them into the sun? They’re nuclear weapons, which is the very definition of an object with a built-in self-destruct. Launch them into space, and then, when they are far enough away, light them off and enjoy the solar system’s most expensive fireworks show.

The important bit is to do it at night.

I think he’s making fun of this common trope (“hurl it into the sun”), and you’re being whooshed.

Wait, he didn’t mean this was a viable means of destroying the nuclear arsenal? The point of the comic was just a joke?

I’ve totally misunderstood xkcd all these years. No wonder I couldn’t get the damn phone to work.