fields singing their songs to each other under the swiss countryside

Last night a ten year old asked what particle physics is.  I've given a number of descriptions over the years, but I think this one captures the spirit and maybe even a bit of the physics.

 

Physicists like to figure out what's going on deep inside something.   If you're studying things smaller than atoms it turns out the best technique for looking at the smallest bits of nature is to slam bits of matter together in particle accelerators.  The example that you've probably heard about is the Large Hadron Collider in Switzerland and France.  It's about seventeen miles around and accelerates protons to nearly the speed of light in bunches that move clockwise and counterclockwise through the machine. At a few spots these "beams" of bunched protons collide.  That's where the fun begins.

 

I've already mislead you a bit..  a proton is one of the building blocks - protons, neutrons and electrons - of the elements  Protons (and neutrons) are really composite particles made up of three quarks and some indeterminate number of gluons.  The inside of a proton is mostly empty.  Think of the quarks and gluons as a gas -- they interaction with each other exerting forces on each other and their surroundings defining  the proton and giving it a size much larger than themselves.    When most people visualize this, they think in terms of what we're used to thinking of - little balls perhaps.   That turns out not to be the case, so hang in there for awhile.

 

We have these bunches of protons whizzing around at nearly the speed of light coming together in places.  but the beams are huge in diameter compared to the protons which, in turn, are huge compared to the quarks and gluons.  The protons don't collide in the way that a bat collides with a ball or anything we're used to.  Instead they sing to each other.¹

 

You see they are really songs themselves - a vibration in something we call a field.  If they're close enough and loud enough the other particle can respond.  Mostly they just talk to each other, but sometimes if their songs are loud and clear enough and at just the right pitch that they pluck a field in the Universe in just that place in space and time.  The field sings it's response and new particles are produced.  These new bits matter have their own songs, masses, charges, momentums and other things physicists care deeply about and mostly rush away from the area,  Some of them don't make it far and pluck other fields,.  For the smallest fraction of a second a bit of the Universe underneath the Swiss countryside erupts into a symphony of new harmonies.

 

The collision regions are surrounded by particle detectors which measure everything that can be measured about these particle and then, using enormous amounts of computation, the physicists reconstruct the fields and their songs at specific notes.

 

We're pretty good at understanding the Universe at low and medium pitches...  but the higher pitches require faster and faster protons -- more and more energy to pluck those fields.

 

The odd thing is, at a very fundamental level, we're really just a massive collection of the plucking of certain fields.  It's music all the way down.

 

_________-

¹  Here I take a bit of license - it's more accurate than the model you probably think of, but going in deeper takes a lot of math.

 

 

Comments

[Jheri]

I so love this Steve! We’ve talked about fields and how particles are just excitations in them, but such a nice way of saying it!

I have a bad cold, but this picked me up:)

[Gregg Vesonder]

Nicely done Steve. The science here is so beautiful.

[steve]

Thanks.. it bothers me how inaccurate most of the descriptions aimed at non-physicists are. I take a lot of license, but I think this is closer to reality