Light and luminosity at CERN

‘Light as luminosity’ is the theme of the CERN celebrations on the occasion of the International Year of Light and Light-based Technologies (IYL 2015). CERN will organize a series of public events, which will be broadcasted online,through the year. Follow the upcoming events here.

CERN IYL 2015 campaign picture representing the particle collisions in an LHC detector.  Credits: CERN

CERN IYL 2015 campaign picture representing the particle collisions in an LHC detector. Credits: CERN

Why CERN is celebrating the International Year of Light?

At CERN, light is linked to luminosity and the High Luminosity Large Hadron Collider (LHC) project plays an important part in it.

Light is the means with which we can see and can reach reality. Over 100 years ago, Einstein discovered that light waves behave like particles. Just 90 years ago, Louis de Broglie put forward the unimaginable idea that a particle can behave like a wave, with a wavelength inversely proportional to its momentum. This completed the particle–wave duality initiated by Albert Einstein in his annus mirabilis, when he realized that waves behave like particles and introduced the concept of light quanta, the photons.

In particle accelerators we provide such a huge amount of energy that the wave associated to each particle becomes a wave with which we can see in finer detail. In this way, particle accelerators can generate the finest “light”.

But light is only a means, a bridge between reality and our minds, where the image is formed and vision occurs. Indeed the light generated by the Large Hadron Collider at CERN would be useless without “eyes” – the LHC detectors that collect the collision events to record the detail illuminated by the light. As with the eyes, the collected information is then transmitted to the mind for image formation. At the LHC, the computers, the physics theory, the brains of the experimentalists and theoretical physicists – all of these form the “mind” where the wonderful images of, for example, the Higgs boson, are formed and, finally, known. Exactly as with sight, some signals (most of them, in fact) are first treated “unconsciously” (by the trigger) and only a selected part is treated consciously on a longer time scale.

Now the LHC is restarting and we will be able to generate light almost as twice as fine, thanks to the 13TeV collision energy. Moreover, the High-Luminosity LHC project is already on the starting blocks to be ready 10 years from now. Why high luminosity? Just as in a room where we might ask for more light to investigate finer details and measure the properties of objects more precisely, with the LHC we are planning to increase luminosity by a factor of five (instantaneous) or 10 (integrated) to make more precise measurements and so extend our sight, i.e., the physics reach of the collider and the detectors.

Projection of the IYL 2015 logo on the Globe of Science and Innovation, one of CERN’s symbols. Credit: CERN

Projection of the IYL 2015 logo on the Globe of Science and Innovation, one of CERN’s symbols. Credit: CERN

The inauguration event was held on 4 February 2015 with first public talk on “Light and Luminosity, from Einstein to LHC”. The event kicked-off with a spectacular projection of the IYL 2015, CERN and High Luminosity LHC logos on the Globe of Science and Innovation, one of CERN’s symbols. You can re-watch the webcast here and find more photos here. The event was attended by more than 200 people and another 300 followed via live webcast.

Additionally, this year’s Researchers’ Night at CERN (under an EU-supported project, POPSCIENCE) will be celebrated on 25 September, and it will be themed around light in physics and … poetry!

More Information

On HL-LHC: High Luminosity Large Hadron Collider:
Seeing is believing:
On why increasing the energy:

LucioRossiLucio Rossi is the leader of the High Luminosity LHC, with a project budget of about 1 billion CHF. He became Professor of Experimental Physics at the University of Milan. He worked on a Superconducting Cyclotron and he has been responsible of the first LHC dipole prototype for CERN. In 2001 he joined CERN to lead the construction of Magnets & Superconductors for the LHC Project, the largest scientific instruments with a budget of more than 1.5 billion CHF. Rossi has received the IEEE Council of SuperConductivity Award for scientific accomplishment in 2007, and has been nominated IEEE-CSC Distinguished Lecture for Superconductivity for 2013. In 2013 he has been elevated to the grade of IEEE Fellow.

He is active in public outreach: he is founding member from 1985 of “Euresis”, an association for the promotion of scientific culture established in Milan, organizing public Science Exposition, and he gives 10-15 talks per year to general public on science and on relation between Science and Technology, Certainty and Truth.


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