In search of the Higgs Boson at the Large Hadron Collider

Imagine that you are lost at sea attempting to across the Atlantic Ocean. You are surrounded by hairy and hungry shipmates, and have no compass or friendly satellite navigation system with a celebrity voice. If you're lucky, you have a very basic chart.

What do you do? It may sound unnerving but this was the situation for most seafarers before the magnetic compass or concept of longitude came along. The Vikings in particular are well known for being successful sailors, perhaps even discovering the Americas before Columbus, thanks in part to their understanding that salt would preserve food for long journeys and to a simple but ingenious method of navigation.

Observing swell, wave size and direction, and most importantly the position of the Sun and stars, can ensure a ship's successful progress across the sea. However, navigating by the sky during either day or night would have been impossible when fog, cloud or the long polar twilights of the northern hemisphere obscured visibility. When this happened on a Viking voyage, a sunstone was held high to locate the sun and continue the journey.

This 'sunstone' has been identified as calcite crystal Researchers from Royal Society A

Over the years scientists have found many microbes which can survive in extremely hostile conditions; from those that live in highly acidic waters to those which make the frozen depths of the oceans their home. But now researchers from Oregon State University have discovered microbes in ice from natural caves deep within a volcanic mountain range that can tolerate conditi

On Tuesday 13 December 2011 scientists from the European Organization for Nuclear Research (CERN) held a press conference where researchers working at the Large Hadron Collider (LHC) announced that they might have glimpsed the elusive Higgs boson.

Tom Whyntie is a member of Imperial College London‘s High Energy Physics group. Tom currently works on the Compact Muon Solenoid experiment, one of the giant “digital cameras” photographing activity inside the LHC.

At school you are taught that atoms are made up of protons, neutrons and electrons; so what is the Higgs boson and where is it proposed to be?

Protons and neutrons are made up of even smaller particles called quarks. Together with electrons (and their ghostly "neutrino" cousins), these are what we think makes up matter – the stuff we're all made of.

Three fundamental forces – electromagnetism, the weak nuclear force and the strong nuclear force – hold it all together. But permeating everything is a sort of strange, quantum mud that sticks to some particles – giving them mass – but not to others. This is made up of Higgs bosons, and it's what we've been trying to find at CERN.

Who proposed that the Higgs boson existed?

Peter Higgs is popularly credited with suggesting that such a particle could explain how some particles get mass, but a few others had the same idea at around the same time –including Guralnik, Hagen and Kibble from Imperial College London.

Why is the Higgs boson so important?

Without it, nothing in our theories about how the Universe works at the smallest scale imaginable makes sense: we know particles have mass, and the best way of making sure that they do in equations is with the Higgs boson.

If it's not there, we have to go right back to the drawing board.

How have scientists been trying to find out whether the Higgs boson exists?

We smash protons together in our 27km-circumference underground tunnel at nearly the speed of light with the hope of creating Higgs bosons from high-energy collisions. If it exists, it would then disappear almost instantly, so we use cathedral-sized digital cameras to take "pictures" of the collisions and look for things that the Higgs boson might have left behind.

How long has it taken them to look for the Higgs so far?

The two experiments looking for the Higgs boson – CMS and ATLAS – took around twenty years to design, build and get running.

What do the latest results show? Have they found the Higgs Boson?

Both experiments have had a tantalizing glimpse of something that might be a Higgs boson – and importantly, it looks like the same thing – but we can't be sure.

What will the researchers do next to prove whether they have seen the Higgs boson or not?

Collect more data! The really important finding from [the recent] announcement is that we know the accelerator and the experiments are performing fantastically well. And with the same level of hard work from the thousands of scientists and engineers involved (and a bit of luck!) we should have an answer either way by the end of next year.

We can't wait!

ons similar to those found on Mars.

The microbes were discovered deep within the Cascade Mountains, a mountain range that stretches along the northwestern coast of America. They are closely related to other microbes commonly found on earth but, uniquely, they have the ability to tolerate near-freezing temperatures and very low oxygen levels, as well as being able to grow in the absence of organic food.

In these hostile conditions the microbe’s metabolism is driven by the oxidation of iron from olivine, a common volcanic mineral found in the surrounding rocks. According to the researchers who unearthed the microbes, this makes them capable of living on Mars.

have carried out experiments with calcite to demonstrate how the Vikings could have 'performed a precise navigation under different conditions… using absorbing dichroic crystals as polarizers to detect a hidden sun direction using the polarized skylight.'

The light emitted by the Sun is not polarized. The electromagnetic waves (including visible light) vibrate in all directions perpendicular to the direction in which they are traveling. However, when it reaches Earth's atmosphere light scatters and becomes polarized in a particular direction. A calcite crystal absorbs light at different rates, known as birefringence, becoming brighter and turning yellow when in the path of the Sun. After noting the position of the Sun when the sky was clear, if fog descended then holding up the calcite and observing when it brightened would show which direction was East and as such the way home. Spars of calcite have also been found on 16th century voyaging vessels, nearly 400 years after the Vikings, giving further weight to the theory of their use as navigational tools.

However, not everyone is convinced by this theory, partly because the 'voyaging season' was summer, when neither inclement weather nor polar twilight would have been a significant navigational issue. Additionally, when particularly overcast the sunstone and the polarization method would likely not have worked.

Glossary

Birefringence

Also known as double refraction, describes the splitting of a light ray in two when passed through certain substances.

Dichroic

A property attributed to some substances in reference to light traveling through them. They experience a varying absorption rate depending on the polarization of the light resulting in color change.