The LHC is a discovery machine. It was not built to improve our material lives, but to understand the Universe in which we live. Its science goals are numerous, with three distinct types of experiment:
The ATLAS and CMS experiments in the LHC were designed to discover the Higgs boson and search for other high-mass unknown particles, such as dark matter.
The LHCb experiment exploits the vast production rate of b-quarks, where rare decays reveal deeper laws, especially in matter-antimatter symmetry.
For the Alice experiment we take time each year to collide lead atoms head on, and understand a new state of matter where quarks become free.
Over 1000 scientific papers have been published already, and each of these experiments has made new discoveries.
- It may take a while for anything of practical use to come out of the research that is being carried out at CERN but Professor Bill Murray says that the same has been the case with many great discoveries of the past including Einstein's general relativity
The LHC cost billions of Swiss Francs, spent over 20 years. The cost is similar to the London Olympics, and in many ways this is a good parallel: the Olympics inspire and enthuse, the bring together the countries of the world. The experiments at the LHC are often cited by young people deciding to study Physics at University as inspiring them to do so. A shortage of people trained in science is a problem many Governments are keen to solve.
Furthermore it is a wonderful example of the countries of the world working together on a common project – my experiment, ATLAS, has members from 38 countries: Many outside the European hosts including China, Mongolia, Morocco, South Africa, Colombia, Chile and many more. People are motivated by a common project and work together, forging closer ties between nations in the process.
There is always a possibility that the scientific discoveries may be put to use. We are learning the laws of nature, and understanding more of their implications. We do not foresee any use to them today – but neither could Einstein have predicted when he wrote down General relativity 100 years ago that we would navigate our cars using a GPS satellite system that relies on his theory to produce its accurate timing signals. If we do not learn what the laws are we can be certain that we cannot exploit them.
But in the meantime the spin-offs from this research are large. A well known example is the World Wide Web, which was invented at CERN to allow physicists around the world to collaborate better. The GDP impact of that single invention vastly outweighs the costs of the research that inspired it. A more direct impact of the fast particle detectors developed for LHC is a PET scanner which uses the readout developed for CMS to give much more precise imaging of cancer tumours than conventional scanners were able to, with lower dose to the patient. Thus yes, LHC helps cure cancer.