Intro to Particle Physics and a Couple of Field Trips

 

Bonjour!

Aujourd'hui we started the day with some insights into what CERN is.  Let's start with the name: Conseil Européen pour la Recherche Nucléaire.  Now this name is in English says the Council of European Nuclear research.  When it was first conceived in 1949 after the Second World War, groups of scientists from around Europe recognized that many bright minds had been lost of emigrated to the US.  This left them with a problem to solve.  How to bring science back to a war torn continent and how to get things started knowing that there was brand new science to be developed and learned from.  As nuclear science was demonstrated in a big way at the end of the war. To quote Olivander, "Terrible, yes, but great."  

Well the group worked together to find a spot and got some strong backers including Werner Heisenberg who signed the agreement for Germany.  Scientists from the twelve founding member states all signed in 1953 but it wasn't until 1954 that the countries from which they were sent accented to the concord and the group originally known as the Council became the Organization. However, the name CERN stays because OERN sounds stupid (according to Heisenberg himself).  

Throughout the next few years CERN worked to develop a working relationship with those original 12 nations but are now composed of 25 member states (the newest is Slovenia, where my new colleague Lenka is from and fun fact, where part of my family emigrated from as well) who pay yearly to cover more than 98% of the $1.4 billion budget.  There are other 12 other Associate member states and then the Observer states that include the US, Japan, the EU and UNESCO.  Russia was an observer, but was politely asked to get themselves in order before recommencing relationships.  Observer states tend to be ones that paid a large sum at one point to help build or contribute to a massive undertaking.  The US paid nearly $50 million to help build the LHC and the Russians had been helping since the beginning, at one point using refurbished Naval shells to supply the type of brass needed for an experiment here in Geneva.  

 Me and Lenka

After learning about CERN, we went for a trip to the Synchrocyclotron which was the first particle accelerator build in CERN.  The Synchrocyclotron was built in 1957, the very same year the Russians launched Sputnik and just 6 years after the first color TV.  If you look the personal calculator didn't show up until 1972 so all calculations were being performed by people or with calculators the size of buildings.

Timeline of CERN events and world events

 Here is the Synchrocyclotron in all its Glory! 

Enjoy the video showing how it works

Recognize here that only 3 years after the CERN organization was formed to do nuclear research, it has now moved on to smashing atoms into subnuclear pieces.  This is huge because at this point we have entered particle physics and left nuclear way, way behind.  So a rebrand of CERN might be:

International Collaboration

Education

Fundamental Research

New Technology

There we fixed OERN with something monstrous that vaguely uses the letters.

So on to our next adventure; we went to visit the ATLAS control room.  ATLAS is one of the experiments that live at CERN and use the LHC and the protons traveling at 99.9999991% the speed of light (c) to perform experiments and it...is...massive.  Here is a 1/3 scale model of the toroidal magnets that are in the ground at ATLAS.  This model had to be made to see if a magnet like this (which had never been made) would work 100 meters underground, so they build a model and it worked as expected, so they built the real ones.

For reference the blue bar is about one human tall (5'6'')

Because the beam is currently on and the experiment is running we were able to see the room but not much else, except this scale model made of Lego.

Control Room, manned 24/7 even when not functioning.

We will talk more about the make up of particle detectors tomorrow, but this entire set up fits INSIDE a set of toroidal magnets represented by the purple and orange tube looking things in the image behind me in this picture.  The magnets are there to keep the charged particles moving.  As charged particles enter the magnetic field, their path curves and then they hit detectors all around the experiment.  Where they hit and how hard tell the physicists what particles they caught.

We finished the day by meeting and listening to John Ellis who was a pioneer in the particle physics world.  He has done some great theorizing around supersymmetry which may help explain the missing matter in the universe (dark matter) which makes up nearly 27% of everything in the universe.  His work has been extensive here and he was able to give us a brief introduction to the ideas in particle physics. Mainly these points:

1. The standard model is the best thing we have right now, it looks like this:

The quarks are the purple bits, the leptons the green bits and the bosons the blue bits.  Quarks are held together and altered by gluons.  Photons control interactions between leptons and things called hadrons (made up of quarks) and W and Z is responsible for radioactivity.  That fancy orange one is called the Higgs boson and it's job is to give mass to matter.   He talked about how we started with just finding  that first elementary particle (the electron), then the first force carrier (the photon) and then little by little the table was filled from 1897 to 2012 when we confirmed the Higgs particle.

2. John gave us this analogy for how the Higgs works: 

Think of a Snowfield.  If a skier moves fast this is like particle without mass because the skier doesn't interact with the snow much, just slides right on by (e.g., photon or a particle of light it doesn't interact with the field of Higgs). 

Now consider a snowshoer who sinks into snow a bit so he moves slower and this is like a particle with mass who interacts weakly with the snow and it slows them a bit (e.g., electron or neutrino that interacts very weakly with the Higgs field).  

Lastly, a hiker sinks deep in the snow and so moves very slowly reacting with a whole bunch of snow and this is like a particle with large mass. (the top quark is the heaviest of the particles so it reacts most strongly with the Higgs).  

The Higgs is a snowflake in this scenario and the blanket of snow is the Higgs field.  This is the best analogy for this phenomenon that I have yet heard.

3. We don't know what is coming next.  The Higgs helps us understand where the mass comes from, but we don't know what is playing with the Higgs but not with photons (dark matter).  So now we look to the future and try to increase the energy in the LHC or maybe even build a new one, the FCC (Future Circular Collider which would increase the 27km ring of LHC to 91km and pass under lake Geneva and into  Annecy, France.

Bonne nuit!