MacDirectory Magazine

INTERVIEW The geometry, the speed of response, and the granularity of the detectors are studied with very accurate simulation programs that include the generation of any particles we know or we still don’t know, but that has been studied in detail with theoretical models and that we expect have a certain type of behavior. Whatever unknown particle or unknown matter will remain unknown forever if when coming to life, living and finally dying, it would not manifest itself in a way that we can measure. MA > So what type of detectors have you built for the Collider? BDG > We have built detectors able to measure any manifestation of the matter either directly (for example measuring known charged particles) or indirectly (for example measuring the missing energy by the “escape” of neutrinos). If we find quantities that we are unable to measure and there is a manifestation of this impossibility we will address the problem. MA > Are therespecific models to anticipate what you don’t know? BDG > Necessity drives inventions. There are models that foresee that the dark matter would produce photons when interacting with matters and our detector is able to detect photons and the possible particles from a photon decay. When a discovery is made it can go via a verification of something predicted by models, but also via unexpected phenomena. Our detectors are general enough to cope with any known phenomena. MA > Since you mentioned dark matter, what type of instruments were built in order to detect them? And how do you know if they will work? BDG > As in the case of dark matters, the search for supersymmetric particles is based on possible models that predict the decay of the particles in particles. The detector is built to reconstruct the complete history of each particle. If the collisions will produce particles never seen before we will reconstruct their history and compare with the known particle. Part of the history will also be the mass and the charge of that possible new particle and we will be able to understand from our models if that was a predicted particle of a completely new and not documented before situation. These challenges make our work every day more interesting. MA > It has been said that the collider is not strong enough to produce a black hole, but how can anyone be sure? BDG > The LHC produces beams of particles at a certain energy and every day the Earth and all planets and stars are continuously traversed by cosmic rays that have energies that span from few MeV to many TeV, even much higher than the energies produced at LHC. A black hole is the terminal stage of the life of a certain type of stars; during that phase all the matter composing the star collapses into a tiny space with high energy density. If such a phenomena would have been possible by the interaction of very energetic cosmic rays we would know; instead the Earth, the other solar system planets, and the stars are clearly still there without evidence of black hole occurrences. MA > Back in September 2008, the collider experienced a technical setback due to lack of adequate risk analysis. As a result the collider is now running at half power capacity. Can you elaborate on exactly what happened? BDG > In September 2008 what happened is what always happens for frontier technological advancements. Before the technical problems we had not imagined to need to measure resistances at the level of nano-Ohms (a billionth of a Ohm) with high level precision. MA > Now, can we talk a bit about Apple technology? I am curious to know when you first used Apple products and why. BDG > It was long ago, probably in 1985, that I used an Apple II for the first time. I can’t remember precisely if it was a II, or a IIe. One of my high school professors was a geologist and he had just bought a new instrument to measure shock waves propagating through the ground and establish the composition of the rocks. The instrument was storing all information on floppy disks and then he had an Apple II with an ad-hoc program for the analysis of the data. My professor wasn’t very good with computers, therefore he asked me to help with both the work on the ground and the data analysis. I still remember how different it was from MS- MacDirectory 123

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