Aren't these particle physicists building replicators? That's just science fiction!
One of the most interesting piece of equipment used in the famous TV series ''Star trek'' is the replicator: a machine capable of transforming pure energy into any form of matter, be it a simple rock or a cup of Earl Grey tea. One might use the word "Electricity-to-matter" converter for these appliences - but this expression would also fit the particle accelerators of modern physics.
These machines accelerates tiny particles, which then collide. As we can understand in terms of quantum field theory, which is the combination of both quantum mechanics and special relativity, such collisions can create new particles - Einstein's famous relation ''E=mc²'' plays a role. It's even possible to deliberately ''order'' certain particles, if one correctly tunes the momenta of the colliding beams. Entire experiments (like Belle in Japan) are focused on investigating such special situations.
Nontheless, of course we are far from fiction - the actual, ''visible'' utility of particle physics lies in different areas.
Gain of knowledge
The main aim is of course science itself: We are trying to understand, how our environment, our entire universe work. Of course we can discern much by simply looking around - but what if we look more closely? Do we understand the details?
Take electricity as an example. It had been investigated for centuries, before any invention had been made, which could be used in all day's life. But a detailed understanding of the conductivity of metals was even not possible before the advent of quantum mechanics in the first half of the 20. century. This development allowed us to understand the famous ''band structure'' of solid states - and all of a sudden the semi conductor transistor was possible, which is used in every micro chip today. Such world changing inventions cannot be planned. They are the product of the entire accumulated knowledge of mankind.
New methods of cancer treatment
Specifically, accelerator technology, as it is being used in high energy physics, has already lead to new developents in medical treatments. The commonly used methods of radiotherapy use photons to damage tumor cells. This method is excellent for most applications, however it suffers from the fact that photons are easily capable to penetrate tissue. Thus, not only the tumor but also healthy tissue might be damaged. In some cases, this damage surpasses the gain.
In case of hadron therapy (or particle therapy) a small particle accelerator is used to shot protons or carbon nuclei at the tumor. The advantage of this method is that these particles are not influenced by matter very strongly - until they get bogged down in a certain depth, which can be calculated very accurately. There they then may destroy tumor cells.
Facilities using this approach are already in operation in Germany. In Austria the "MedAustron" facility is being constructed near Wiener Neustadt, in close collaboration with technitians from CERN. MedAustron will be equiped with state of the art technology and after going operational in 2014 it will help to treat near incurable cases of cancer - and research and developent in this area continues at CERN as you read this.
Detection methods like the PET scan
Further medial applications can be found in the connection with the large detectors in particle physics, like the CMS experiment. For example the PET scan.
In 1928, Paul Dirac postulated the existance of a ''sister particle'' of the electron - the positron, the first anti-particle. Its existance was confirmed within a few years and knowledge about antimatter grew swiftly. Beginning with the 1950s, an interesting idea came up: If one could manage to create these positrons within a patients body, it would collide with one of the many electrons inside the tissue and emit exactly two phtons. This is a rather weak, but extremely sharp and well defined signal. If one could then manage to measure these photons accurately, one could create a detailed picture of inaccessable tissue.
Detection of photons is one of the main duties of the detectors used in particle physics. Scintillator crystals are able to deliver the required signals - also in case of the PET scan. This method helps finding tumor cells, but even depression can be seen, since it changes the brains chemistry.
At CERN, the experience gained with construction of the large experiments is used to further improve the tools and components used in medical diagnostics. Among other things, several theses by austrian PhD students have contributed to this efford.
Education and transfer of knowledge
One of CERN's main aims is education of young scientists. Students from all member states are offered the opportunity to see and learn the newest developments first hand. They can even contribute themselves - summer student programs, master diploma and PhD theses open the door to work in this exciting environment.
Thanks to the efforts of the Austrian secretary of science at that time, as well as many austrian physicists at CERN, a dedicated PhD student program was initiated in 1995. Since then, about 150 theses have been completed, investigating all the aspects available at CERN.
These experiences, obtained in direct cooperations with the leading experts of the world in these fields, have been transfered back to Austria all those years. This is a transfer of technology and knowledge on the highest level.
Economic issues
During the ten years of construction of the LHC, contracts amount to about 73 million Euros have been closed with austrian enterprises. This represents about 70 percent of the austrian contributions and is in line with the numbers reached by the Federal Republic of Germany.
Additionally, contracts with such high profile contractors like CERN greatly increase the reputation and competitveness of the participants. Independent studies have shown that for each Euro, which was directly received from the contracts with CERN, three more have be earned by follow-up orders.
In conclusion, one can only state that Austria was an important part within CERN and in return benefited greatly from this cooperation.
For our german-speaking visitors: If you like, you can also take a look at a video, where we try to discuss the question ''What's in there for me?''.