The Large Hadron Collider

After my now world famous first journal, this one has a lot to live up to.

This, is The Ultimate Book of Dinosaurs:

It's the first book that I ever read all the way through on my own. I pretty much memorised it at the age of 7, repeating the information within to every single girl I saw in an attempt to impress them. (Little did I know that you have to make it all the way to University before you can really get into the "Dinosaur Factoids" market. But trust me, once you're there, you're there.)

Ladies.

I've always had a thing for giving people information. I love to tell people things that they enjoy knowing. I love the look on a person's face as you explain to them that the Lockheed Martin SR71 Blackbird is not only the sexiest plane ever designed,

Ladies

but is also faster than the missiles people used to use to try and shoot it down. It's faster than the rotation of the earth, meaning that on the 22nd of December, 1964, Robert J. Gilliard, Lockheed's chief test pilot at the time, was the first living thing in the history of our planet, to watch the Sun rise in the west.

So that's what I do all day. I sit around with people, annoying them with a constant stream of irrelevant but (I think) fascinating information until eventually one of them is something they care about. And when I'm not doing that, I'm on the internet, learning more things about our Universe.

The best facts are always the superlatives. That's why people loved the Jumbo Jet. For years it was the biggest, and the heaviest, and most powerful, and the most recognisable, and the most complicated plane in the world.

So, imagine my utter astonishment and glee when last year, I was given the opportunity to visit CERN, in Switzerland. And imagine my face when, since the Large Hadron Collider was, at the time, shut down for upgrades, we could go down into the CMS detector cavern.

Ladies

That detector behind me is 50 feet across. It weighs 12,500 tonnes. It creates a magnetic field of 4 Tesla to analyse the particles. If you're not familiar with magnetic fields, you may not realise how strong that is, but to put it in some sort of perspective, the electromagnet that generates that field uses electricity at the same rate as the entire city of Geneva. Luckily, it's only on for nano-seconds at a time, or the already ridiculous power bill would bankrupt the EU faster than Greece (3 year old economics reference, HAR HAR HAR).

But we were talking about superlatives, so let's get them out of the way:

The Large Hadron Collider, is in short, the Biggest, Hottest, Coldest, Fastest, Most Complicated, Most Energetic and Most Empty machine, ever made.

Let me explain some of that. Specifically I think you might be having trouble with "Hot", "Cold" and "Empty". The impact site of the protons have been conservatively estimated to be at around 1.5*10^12 degrees Kelvin. Which looks like this: 1,500,000,000,000 degrees Kelvin or 2,700,000,000,000 Fahrenheit (If for some deranged reason you like your temperature scale based on ammonia and horse blood.) That's not just the hottest place on earth, it's roughly 100,000 times hotter than the core of the sun. The only places in the universe that even come close are relativistic particle jets emitted from supermassive black holes.

Now, see that long greyish bar behind my shoulder going right through the middle? That's the collider. It's about 8 inches across, and inside it is the highest quality vacuum inside a piece of machinery ever made. it is cooled by liquid helium, a fabulous substance which we will talk about another day. But the combination of almost complete vacuum and the coldest liquid possible, the temperature is within groping distance of absolute zero. It's inner temperature during operation is 1.9K. That's cold. That's beyond the human understanding of what cold even is. 

And finally, the emptiness. The vacuum in the beam chamber is of the order of 10 times lower pressure, than interplanetary space. To find a place with less stuff in it than that, you would almost certainly have to leave our solar system. Now, there are vacuum experiments which are emptier, and cooling experiments which are colder. But those temperatures and pressures are not components of a machine, they are the end goals, the products. The fact that these details in the LHC are merely tools to be used makes them far more impressive, in my opinion.

Enough with the Top Trumps. It's time for some actual science!

Well, not really. Since science is actually maths, and even the infinitesimal portion of this branch of particle physics which I'm familiar with is much too complicated to put here, what we'll be doing is clearing up some things about what the LHC is actually for.

The first thing everyone knows about the LHC is that it was built to find the Higgs Boson. So let's talk about that. In order to do that, we have to start with a cup of coffee.

My cup of coffee, to be exact. That equation up there describes the standard model. In theory, if you knew all those values and the equation were true, it would explain all known physical phenomena except for gravity (hence the quest for a Unified Theory). The top line describes the nature of electromagnetic, weak nuclear and strong nuclear fields, 3 of the 4 fundamental forces. Line two describes the way the fundamental particles interact with these forces. Line 3 is a description of how these particles gain their masses from the Higgs Boson, and line 4 explains the Higgs Field and the mechanism by which the Higgs field produces these bosons.

Physicists are very familiar with the first two lines. They've been researched thousands of times all around the world, and indeed, using astonomy, they've been investigated all around the universe. But the third and fourth lines are a challenge. We've never been able to achieve the sort of energy levels where particles like the Higgs Boson are formed, until the LHC. It was built to test those last two lines.

They are mathematical objects. Demonstrated numerically for decades, and now we've finally been able to check line 3. It is now accepted by the particle physics community that line 3 is indeed correct. Any field needs a particle in order to interact with other particles, so this is hugely impressive evidence of the Higgs Field. 

However, right now the LHC is running at 7 TerraElectronVolts (TeV) which isn't high enough to verify that last line. So I guess it's lucky that it's so far only been running at about 47% of it's full capacity. With plans to have full 14TeV tests by 2015, and billions of Euros worth of upgrades already planned to take it far beyond even that, the clues to our Universe's inner working are going to become clearer and clearer.

I'll certainly write more about the LHC and CERN some other time, but this is long enough for now.

This has been an Empircal Opinions journal, allow me to play you out: