The Hadron Collider

[Brainy]

Greetings

Many people have asked the question : will the LHC create a black hole that will destroy the earth ?

Answer : No. Nyet. Non. Nein.

<insert your language's version of "NO !" here>

With 110% certainty. Without the slightest bit of doubt.

Why ? Let's go through this step-by-step. Please forgive me in advance for the CAPITAL letters from time to time. And this is a long answer.

a) It is clear people have in mind "black holes" of the type theorized by astronomers. Though it is not 100% certain that any actually have been seen (really), almost all are sure they exist.

These black holes are ENORMOUSLY, INCREDIBLY, HUGE, DENSE stellar objects, MANY times more massive than our entire solar system resulting from the collapse of a gigantic star. They MUST be this massive in order to be able 'trap' light and 'suck in matter' and become 'black'. Our Sun, hugely larger than the Earth, is not nearly big enough to create a black hole.

So, it goes without saying that there is NOT enough energy COMBINED in our entire Solar System, never mind our little accelerator at the LHC, to create these kinds of black holes. Remember E=mc^2 ? We cannot now, and will never in our future, create an accelerator with enough energy E to create any new particle with mass m greater than a dozen or so _individual atoms_, vastly vastly smaller than the tiniest speck of dust on the computer screen in front of you.

So WHAT are the media talking about ?

b) Theoretical physicists have developed a really terrific theory called the "Standard Model' which explains everything we have seen so far in the subatomic world. and I mean everything. BUT ! it does NOT account for gravity. Gravity is handled by Einstein's General Theory, which is a completely different type of theory than the SM. The ultimate goal for theorists is to construct a theory which can explain BOTH the Standard Model, and Gravity within a single mathematical theory.

**Now, there are many, MANY attempts to construct such a theory - lots and lots of weird and wacky ideas around trying to come up with a solution. NOTE ! so far NOT ONE of these ideas has ANY basis in experimental fact. Zero. Nada. It is probably the toughest problem modern theorists are facing, and so they are trying very hard to come with an idea, any idea, that _might_ work.

Some theories have more exotic ideas than others. And not are "created equal", in other words, some ideas are weirder than others.

Now one particularly _unlikely_ idea is that there are 'higher dimensions' of space and time. One (remember, of _many_) theory states that there may be the remotest of remotest of chance that the LHC _might_ be able to create new types of particle related to these higher dimensions of space. Some marketing genius (I am joking) called some of these hypothetical new particles "quantum black holes". Perhaps to generate media interest in the wildly hypothetical idea of extra dimensions.

Well, did it ever generate interest ! BUT BUT BUT !, these new objects are NOT, repeat are NOT, the same as an astronomer's "black hole". They are something TOTALLY DIFFERENT, which would weigh the same as about a _half-dozen_ gold or lead atoms, and live less than a billionth of billionth of a second before decaying into other particles. It turns out to be very unfortunate that those theorists chose the name "quantum black hole".

OK, I think we can all agree that something weighing the same as a half-dozen atoms and living less than a billionth of a billionth of a second is not going to be 'sucking' anything into it. Never mind that it is hugely improbable that these things even exist in the first place.

We are safe.

So why the fuss ?

c) People in the media heard 'black hole', probably assumed it meant the same as the enormous astronomical objects in space, and thought: "if we make one of those, it'll destroy the earth !'.

But of course, the theory including higher dimension does NOT describe this type of black hole, and moreover, that theory was very very hypothetical, much more so than others.

Think about it : did any of the media reports you read refer to any credible scientific sources for their claim ? No, they didn't, because there aren't any. No, they always refer to 'critics', or 'some people say', or other vague phrases. This way wild media stories run away from reality.

Ah, you say, but you are just giving me a 'theory', which could be wrong.

d) NO ! As we speak, the earth is being bombarded by cosmic rays with energies MUCH MUCH HIGHER than the LHC, as has been doing so for billions of years. Even if you do not believe a word written above, you must agree that if the LHC could create a destructive black hole (worse than crazy !) then Nature will have done it already with cosmic rays. It hasn't. Not here, nor on the moon, nor on the Sun or any other cosmic body, all of which are being bombarded with extremely high energy cosmic rays.

Conclusion : there is absolutely nothing to worry about. This is an example of a media story gone crazy, kind of like Orson Welles' famous

"war of the World's" radio broadcast in 1938.

http://en.wikipedia.org/wiki/The_War..._Worlds_(radio)

If you would like a more technical explanation of why the LHC is safe, but still very readable, look here:

http://arxiv.org/abs/0806.3414

best regards,

Marcello

WHAT are YOU talking about............

[Daggers]

WHAT are YOU talking about............

I think he's just coming out to us that his real name is Marcelle.

[Nick]

I think he's just coming out to us that his real name is Marcelle.

That's a lovely name.

I may take him off 'block.'

(a bit later on though as I've first got to finish stubbing my toes repeatedly into a fire grate.)

[Daggers]

That's a lovely name.

I may take him off 'block.'

(a bit later on though as I've first got to finish stubbing my toes repeatedly into a fire grate.)

I bet I have more people on 'ignore' than you.

How many people have you got on 'ignore'?

[Finnegan]

I bet I have more people on 'ignore' than you.

How many people have you got on 'ignore'?

Pft, poser. You ain't hardcore at all. I even have MYSELF on ignore.

Yeah? How'd you like that?

[Father Ted]

Pft, poser. You ain't hardcore at all. I even have MYSELF on ignore.

Yeah? How'd you like that?

Not possible, you can't block a mod

[Daggers]

Not possible, you can't block a mod

You can if you use plasters on the screen

[Finnegan]

Not possible, you can't block a mod

That's what they said to Christopher Columbus, when he said the world was round.

But oh ho ho. Who had the last laugh, yeh?

You can if you use plasters on the screen

I've been known to erode most common adhesives.

[Daggers]

I've been known to erode most common adhesives.

Are you infering I'm common?

I'll have you know that I went to the same public school as the lead singer from Iron Maiden, Richard Dawkins and Hairy from Foxestalk.

Common?!

Pfft!

I'm more posh than Joanna Lumley at a tea party eating cucumber sandwiches with a glass of Pimms and some corgi dogs at Peterborough.

Oh yes.

[Finnegan]

It's not that I doubt your credentials as a snob.

I just don't think you're much of a bonding agent, frankly.

[DB11]

I didn't write that. I copy and pasted it.