C is for Collider

By Siobhan Fairgreaves

In this post, we will learn a little more about the world’s largest particle accelerator, the Large Hadron Collider (LHC).

Do you remember a few years ago when there was a lot of fuss about a black hole being created? I know there were a few nervous questions fired at our unfortunate science teacher that day.

Proton beams in the LHC can at least enjoy a few thousand trips through the scenic Alpine countryside before being annihilated | Image: CERN

The reason for all that fuss is situated 175 metres underground, on the border between France and Switzerland. The LHC is a circular tunnel with a diameter of 27 kilometres, where scientists and engineers are working to solve some of the big unanswered questions in physics.

But how does this machine work, and how is it going to help?

Well, as the name suggests, colliding is a pretty big part of the whole idea. This machine usually uses protons (the positive subatomic particle) but can sometimes use the whole nucleus of the material lead. Remember what they are? If not, we’ve already covered a bit about what protons are.

Naturally, it’s not as easy as just throwing them at each other and observing what happens. The particles are so small that the chance of getting a successful collision is described by the creators themselves as about as likely as “firing two needles 10 kilometres apart with such precision that they meet halfway.”

Hmmmm, not easy stuff then.

Rumour has it that to make sure the LHC’s superconducting electromagnets were cold enough, CERN hired a group of Canadians to touch them, and were only satisfied when they admitted “they’re pretty chilly, eh?” On a side note, you shouldn’t believe everything you read on the internet | Image: MaGIc2laNTern

To add to the complications, the particles must be going at almost the speed of light to have enough impact when (or if) they do collide for anything to happen. The Large Hadron Collider is designed to help speed up the particles using thousands of seriously strong magnets. These magnets actually have a pretty impressive name, officially they are superconducting electromagnets. There’s your dinner party lingo for the day!

With all that whizzing around and accelerating you’d imagine things are getting pretty hot down there, right? Well, no. Another complication arises. In order for the electromagnets to work they must be kept at -271.3 °C. That’s colder than outer space! In order to achieve this, a complicated cooling system is in place which uses liquid helium to keep things chilly.

I’m beginning to understand why this project is such a big deal.

But what is it all for?

Collision data for the Higgs event. When your raw data looks this cool, it’s not too hard to persuade anyone that your research is justified | Image: Lucas Taylor/ CERN

Well, sometimes science for science’s sake is a good enough reason to conduct an experiment. However when setting up that experiment cost an estimated ÂŁ6.2 billion and involves over 10,000 scientists and engineers in an international collaboration you need a slightly better excuse.

The team at the European Organisation for Nuclear Research (CERN) have certainly got more than one decent reason for this mammoth undertaking. They hope to answer some fundamental questions about the structure of space and time, to better understand forces which are part of our lives every day and even to discover brand new particles. In July 2012 the team announced the discovery of the Higgs boson, a particle which will now be studied intensively to help answer some of these big questions.

The Large Hadron Collider is at the forefront of some of the most profound scientific discoveries of our time and we should certainly stay tuned for more exciting discoveries. If you’re interested in finding out more visit the CERN website which even includes a virtual tour of the tunnel itself.

Until next time!

H is for Helium

By Jonathan Farrow from The Thoughtful Pharaoh

Say goodbye to foil floating hearts on Valentines, shimmering floating shamrocks on St. Patty’s, and the prospect of tying thousands of balloons to your house and abducting a neighbourhood boy scout.  The world’s Helium reserve is going to run out, and sooner than you might think.

Sorry Carl, but I'm not sure your pension is enough to pay for the 1.5 million cubic feet of helium required to lift your house and the abducted boy scout. Image by Walt Disney Pictures
Sorry Carl, but I’m not sure your pension is enough to pay for the 1.5 million cubic feet of helium required to lift your house and the abducted boy scout. Image by Walt Disney Pictures

Helium is the universe’s second most abundant element and we’ve never had real cause to worry about it before, so what has changed that we need to start hoarding Helium?  The short answer: the U.S. is selling off their strategic reserve and getting out of the Helium game, meaning prices are going to skyrocket as demand outstrips supply.

The longer answer begins with the fact that Helium has always been a non-renewable resource here on Earth.  It is produced underground by radioactive materials like Uranium and Thorium and then floats up into the atmosphere and out into space unless it gets trapped by natural gas in the Earth’s crust. Once the radioactive materials decay and release Helium, there is no putting it back.

Sometimes an alpha particle (aka Helium nucleus) just needs to spread its wings and fly!
Sometimes an alpha particle (aka Helium nucleus) just needs to spread its wings and fly!

When we extract this gas, we can collect the Helium and use it to fill party balloons, make our voices squeaky, pack fuel into rockets, or cool superconducting electromagnets to four degrees above absolute zero (-269C).

Why might we want to do that last one when the first three are so much fun, you might ask?  Magnetic Resonance Imaging (MRI) machines, the Large Hadron Collider (LHC), and other scientific Three Letter Initialisms (TLI) have advanced our understanding of the human body and its diseases, the universe and its composition, and have contributed to widespread confusion over the difference between “acronym” and “initialism”.

MRIs and the LHC capitalize on the unique properties of Helium: it is inert and has the lowest boiling point of any element, allowing it to bring the temperature of metals down enough to make them superconducting.  These more scientific uses of the substance have ballooned (pun kind of intended) in the past two decades, putting real pressure on producers.

One of the reasons why Helium demand is increasing and this awesome research about the sense of humour of dead fish happens                   Image by Jan Ainali

We don’t think of Helium as scarce, partially because of its perceived strategic value in the 1920s.  The U.S. felt that airships were the way of the future and so set up a government-owned strategic reserve in 1925.  Given that the only real demand on this stockpile was the occasional rocket test or airship, this reserve built up over 70 years.

The U.S. government has long dominated the world Helium market (in 2006, U.S. helium reserves accounted for two thirds of the world’s total) and has been gradually selling off reserves, keeping prices artificially low.  Maintaining the infrastructure to keep and distribute the gas isn’t cheap though, and the government wants out.

In 1996, Congress mandated the shutdown of the world’s largest (and only) strategic helium reserve by 2013.  This was delayed by a last-minute law passed by Congress which averted a dreaded “helium cliff” that would have seen MRIs go silent.  The new shut-down date is 2021.

Algeria and Qatar are trying to pick up the slack in time, but prices are rising by as much as a factor of 2.5 every year.  Some scientists think that before long, a simple Helium-filled party balloon will cost upwards of $100.

If Slate’s Nina Rastogi’s calculations about the number of balloons required to lift Carl’s house in Up are to be believed, that would put Carl’s Helium bill at nearly one billion dollars.  If there is going to be an Up 2, either someone’s going to have to be a billionaire, or they might just have to risk it with Hydrogen.

It's probably best for all involved if we just stay away from sequels.
It’s probably best for all involved if we just stay away from sequels.