Large Hadron Collider: convince me to not be freaked out by this

I think there was a thread on the Large Hadron Collider a while ago, but I was just thinking about it last night for some reason and it got me pretty freaked out. I mean, the idea of the earth being destroyed by a black hole is not too appealing to me. OK, frankly, it’s terrifying - especially since I haven’t been around for very long and would like to at least experience a few more decades on earth before everything is annihilated. The idea of these scientists monkeying around with stuff that has the potential to destroy the world freaks me out big time, and it also seems extremely foolish and cold-hearted (although that’s a sentiment for another thread.)

What I want to know here is, how worried should I be about this? I know absolutely nothing about particle physics, so I don’t have the knowledge to make my own assessment of the situation. I am relying on the judgment of others, who do know about the topic, to reassure me that the Large Hadron Collider is safe.

So what’s your take on this? Does anyone with a good knowledge of the science behind this have anything to say that might ease my worries?

This is why getting your science from the popular press is a bad idea. Although there’s always a theoretical chance of such an event, there is no real chance of anything catastrophic happening. The probability of a long-lived black hole actually forming and consuming the Earth is so close to zero as to be virtually impossible. Of course, the news media likes to sensationalize the theoretical worst-case and make it sound like a likely event. It ain’t.

The energies involved translate into a mass too small to intelligently discuss.

Here’s a good previous thread

What exactly do you mean “too small to intelligently discuss?”

Also, why is this collider supposed to be any more dangerous or risky than the other collider which Wikipedia says has been up and running for a while without doing any harm? Is it that the other collider had no chance of creating a black hole?

Chronos had a good bit from the thread I linked

Basically, yes the LHC is very “powerful” but the energies involved, if they were completely converted to mass, would give a black hole with a diameter smaller than what we currently understand to be possible.

Let’s say this incredibly unlikely event actually happened… over what sort of timeframe would the effects unfold? Would we have time to get news crews out to see a huge giant hole in the earth (presuming the thing made for the earth’s core immediately)? Would we have time to put the idiots responsible in front of a firing squad? Or would there just be a giant sucking sound? Inquiring minds want to know.

So is a black hole which is smaller than what we understand to be possible not capable of destroying everything?

Most important bit first:
Cosmic rays hit the atmosphere at energies far higher than the LHC. Note that to date we’ve yet to be devoured by a rampaging black hole from the sky.

Second, a black hole is scary only if it’s around long enough to start munching on things like dryer lint, small dogs, or annoying telemarketers. The length of time a black hole is expected to last depends greatly on its mass. The lighter the black hole, the faster it effectively evaporates. Since the energies at the LHC could produce a mass equivalent of 10[sup]-23[/sup]kg the expected life time is so short as to not make any sense. If you want some sort of planet killing black hole, you’re going to need a MUCH bigger mass (and much higher energies).

So a small black hole could actually exist on Earth for a period of time without destroying the stuff around it? What’s the longest that it could exist before it destroyed everything?

We’re probably talking about fractions of a second that this thing would exist. There’s no way for it to destroy everything.

More like fractions of a picosecond.

And, by the way, a black hole isn’t some all-consuming gateway into Hell … it’s just a point gravitational source from which things can’t escape once they fall inside a specific radius. If nothing falls inside … then … well … everything is fine. Remember, if the Sun were turned into a black hole of the same mass, it wouldn’t suddenly suck the Earth down the drain, or anything. We’d continue to orbit the same as always. (Just much colder.)

OK, so say a black hole which was 2 feet in diameter suddenly appeared in Kentucky, and existed there for 10 minutes? Would I, in Indiana, be safe from it? How close do you have to be to the black hole for it to suck you in?

A black hole is not magic. It’s just a concentrated bit of mass. It will do exactly what the same mass in less concentrated form will do.

We live on a ball of fantastic mass. 5.9742 × 10[sup]24[/sup] kilograms. That’s 5,974,200,000,000,000,000,000,000 kilograms.

Yet a tiny magnet can make a pin jump up in the air against all that gravity pulling it down.

Now imagine a weight of 1 kilogram. How much gravity does that have? Nothing detectable by humans, as you know.

Now get down to the weight of a black hole created by the collider. It’s not a kilogram. It’s more like 0.0000000000000000000000001 kilograms. (Very approximately.) What can that amount do to attract other masses? Virtually nothing, even if it sits in your hand and tries to suck up the crumbs from your sandwich. But it doesn’t last very long. It vanishes in a million trillionth of a second.

Don’t worry. Don’t worry even for a million trillionth of a second.

I should have previewed. Nothing we can possibly imagine doing could create a 2 foot black hole. The entire mass of the earth would only make a 2 cm black hole.

How big would a black hole have to be to pose a threat to us?

The LHC is only going to be using a few particles, albeit accelerated to a large fraction of the speed of light, and thus hugely energetic, about 14 trillion electron volts (eV) is what the crowd in Switzerland are aiming for. The thing to bear in mind though is that the Earth is regularly hit by naturally occurring particles/rays/whatever of that energy, and occasionally by something of the order of a million trillion eV (the largest ever recorded appears to be roughly 10 billion trillion eV). To put that in perspective that’s about the same energy that a fast baseball pitch possesses - impressive for a tiny particle/ray/whatever, but hardly Earth-shattering.

Wanna bet? These guys built a torsion balance and measured the gravitational force exerted by a 740-gram mass.

Thanks for the knowledgeable responses everyone. I’m now a little bit less ignorant of particle physics, and a little less worried.

This bit from Wikipedia sounds kind of worrisome but also strangely awesome:

(Bolding mine.

I looked up the false vacuum entry and I’m pretty sure that if I could understand a word of it I would be scared shitless.