A picture with a zoom effect shows graphic traces of proton-proton collision events measured at the Large Hadron Collider in 2011. Credit:AFP In that experiment, the world's largest particle accelerator smashed protons together at energy levels of eight tera-electron volts. After two years of maintenance, the 27-kilometre circular accelerator is being turned up to 11 and is ready to rumble again for LHC: Season Two. This time, scientists are cranking up the proton beams to energy levels 62 per cent higher than when the Higgs boson was found. And at 13 tera-electron volts they aren't exactly sure what they'll find. On Wednesday, particle physicists at CERN, near Geneva, Switzerland, will start receiving data from particle collisions at 13 TeV. (An electron volt is the amount of energy gained by the charge on an electron passing through the electronic potential difference of one volt. A "tera" electron volt is 1,000,000,000,000 electron volts. Energy levels are explained at the CERN website.) After the dizzy heights of finding the Higgs boson, often erroneously named the "God particle", can physicists blow our minds again?

The Large Hadron Collider is used to smash fast-moving particles into one another. The answer is, most probably. This time scientists will be looking further into the Higgs boson and for evidence of other fundamental sub-atomic particles. It is also hoped that these high energy collisions will let us peer into the mysterious world of dark matter. Other areas of research include "super-symmetry" that scientists hope will help find evidence of dark matter and unify particle physics with theories of gravity. British scientist Peter Higgs, whose theoretical work predicted the Higgs boson. Credit:AFP Australian scientists are involved in the ATLAS project that brings together 3000 physicists in 38 countries. Australia's involvement is led by Professor Geoff Taylor at the University of Melbourne. The "Sydney node" director is Associate Professor Kevin Varvell.

Professor Taylor told Fairfax Media that the "LHC Run Two" opens up "another period of discovery, potentially for the detection of much heavier particles". A worker on a bike inside the tunnel of the Large Hadron Collider near Geneva. Credit:AFP He said that the first months of this new phase would involve an "intense search for new particles". Any found within the framework of supersymmetry theory - which predicts much heavier fundamental particles - could be firm possibilities for dark matter candidates. Professor Taylor said that, as the intensity of the collisions increases over months and statistical data improves, Australian scientists will look further at the properties of the Higgs boson. Professor Geoff Taylor leads Australia's contribution to research at CERN. Credit:Angela Wylie

A PhD student at the University of Sydney, Curtis Black, is eagerly awaiting the outcome of LHC: Run Two. His research uses data from Run One to see if the Higgs boson detected in 2011 is the same as the boson predicted in the Standard Model. By looking at the behaviour of what is essentially a heavier, short-lived electron known as the tau lepton (produced by Higgs boson decay), Mr Black compares experimental data with predictive theory. If the tau lepton acts as predicted it will further confirm the validity of the Standard Model. If not, it will need to be adjusted. Data from Run Two will further build on that knowledge. Curtis Black, who is studying properties of the Higgs boson using data from the Large Hadron Collider. So how does it work? All atoms - carbon, oxygen, plutonium, etc - consist of subatomic particles: protons, electrons and neutrons. Protons and neutrons themselves are made up of even smaller and more exotic particles: quarks. Then there is the world of muons, gluons and leptons.

Quarks are held together by a strong nuclear force, which is 39 orders of magnitude stronger than gravity. To transform these fundamental particles to see how they work, scientists need to smash them with massive amounts of energy. And that's what the LHC does. Beams of protons are accelerated using superconductors in a near perfect vacuum at temperatures colder than deep space and close to the speed of light: about 300,000 kilometres a second. Detectors pick up the debris from those collisions. Scientists will pore over the data streams from these collisions for months before coming to any tentative findings, so watch this space. You can follow CERN's live blog here.

Dark matter Scientists now know that the atoms that make up the stuff we can see (such as stars, butterflies, asteroids, toasters, clouds and humans), account for less than 5 per cent of the universe's mass. That leaves a lot of other stuff about which we know almost nothing. About 27 per cent of the universe is dark matter and the rest - about 68 per cent - is dark energy. Some scientists hope that collisions in the Large Hadron Collider will give us some evidence of dark matter, which has never before been detected. Higgs boson and exotic particles Some theories predict a whole other bunch of particles that don't interact with the known fundamental forces (gravity, electromagnetism, strong and weak nuclear forces), but nonetheless have mass, courtesy of the Higgs boson. It is expected that some of these particles will pop up in the data from LHC: Season Two.

Fifth, sixth and higher dimensions Seriously? Some theoretical physicists reckon there are more dimensions in heaven and earth than are dreamt of in most people's philosophy. For example, gravity is so much weaker than other fundamental forces (electromagnetism and nuclear forces). Why? Some believe that gravity's full effect can only be detected at higher dimensions. Some experiments at the LHC will try to find heavier fundamental particles - and even mini-black holes - that provide evidence for these ideas. If they're found, prepare to have your mind blown. Antimatter Not the work of science fiction, antimatter exists. There are electrons with a negative charge and anti-electrons (positrons) with a positive charge. When matter and anti-matter meet, they annihilate each other, creating energy in line with Einstein's famous E=mc² equation. But don't worry, there isn't nearly as much anti-matter as cosmological models predict. According to those theories, equal amounts of matter and antimatter should have been created at the Big Bang. But there is much, much more matter than anti-matter. Experiments at the LHC will try to find out why.