Wednesday, July 4, 2012

What the Higgs Boson is all about

Higgs Boson Confirmed?


I am an aspiring "popular science writer."  I am a thinker / learner / teacher, not a scientist.  Scientists are the ones who actually make discoveries.  Unfortunately, they have a tendency to cloister themselves away in academia-land and spin jargon that only makes sense to each other.  Their elitism really makes no sense, because without communicating to a broader public, their scientific discoveries will die out!  Science often stirs the imagination of everyday people, who don't really quite understand what they are hearing.  Popular science writers are the translators and marketers.  As a kid, I was inspired by popular science authors such as Carl Sagan, Stephen Hawking, and James Gleick.  When I got to college, I got caught up in academic snobbery and looked down on the science writers.  Now I recognize their importance in society.  If we all wrote like academic papers or dusty old textbooks, we wouldn't be able to communicate scientific ideas, let alone what makes them interesting or important.  I will use this blog to keep up on my scientific writing for a general audience -- whether it can be called "popular" is up to you, LOL.

Today, we heard news about the discovery of the Higgs Boson or (*cringe*) the "God Particle."  It's phrases like this that are just plain bad press.  You take a concept that the public knows virtually nothing about, and then throw the word "God" in there, and suddenly every Joe Schmoe has a strong opinion about it.  Before too long, Yahoo Forums is a chaotic melee of religious-versus-science name-calling.  Let's all back up a step.  So what exactly is this Higgs Boson, and why is it making news today? 

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When I had just finished high school, I was selected to participate in a "Nerd Camp" (my name for it) at Fermi Lab in Illinois.  Fermi Lab's claim to fame is a large particle collider, directed by Nobel Prize-Winning physicist Leon Lederman.  At this program, we aspiring physicists learned about "particle physics," and got to observe some daily life goings-on for these scientists.

"Particles," or more particularly, "Fundamental Particles," are the very smallest units of matter, energy, and forces.  They're called fundamental because they are not made of smaller parts.  In science class, we all learned that each element, such as gold, is made of identical atoms, and that if you break apart an atom of gold, it's not gold anymore.  You could say that an atom is "fundamental" in a sense.  It's extremely small.  But even an atom is made of smaller parts, like protons, neutrons, and electrons.  An electron is a familiar example of a fundamental particle.  (Flowing ELECTRons make ELECTRicity).  It is not made of smaller parts. 

We learned at Nerd Camp that the fundamental particles are related to each other in predictable ways, much like the elements of chemistry can be organized into a periodic table.  The particles can be categorized into "fermions" (particles of matter) and "bosons" (force carriers).  There are a few dozen of them, mostly ending in the suffix -on.  Theoretically, all the workings of physics and chemistry can be explained by how these particles "interact" with each other.  For example, electrons and photons interact with each other all the time in chemical reactions, light, and heat transfer. 

There are two varieties of scientists in this field.  The theoretical physicists are the ones who try to figure this stuff out.  They spend their time making "models," like the Standard Model, to explain how the particles work.  Much of their work is based on fundamental principles such as conservation (some things, like energy, can never be created or destroyed), and their conclusions require very intensive math that even a Caltech math major like me doesn't know very well.  At that time of my life, I wanted to be a theoretical physicist when I grew up.  One of the most valuable lessons I learned at Nerd Camp is that becoming a theoretical physicist is no easier than becoming a movie star -- and they still don't make much money.

The other breed is the experimental physicist.  They're the ones who build laboratory experiments to test the theorists' ideas.  After all, these particles are extremely small.  Scientists were talking about atoms for decades before they could ever really "see" them in a microscope.  You really can't "see" particles directly in an everyday sense.  To see my cat, I turn on my light and let light particles (photons) bounce off of her into my eye.  If you shine a bunch of light at an electron, probably only one photon will hit it.  That collision will just knock the electron away, and you'll be lucky if you ever see that photon again.  If it did come back to your eye, would you really be "seeing" the electron?  Or just the ricocheting photon? 

So it requires elaborate, clever, and expensive experiments to confirm that the fundamental particles actually exist.  Experimental physicists have to devise ways to see them indirectly.  People have based their entire careers on the quest for fundamental particles that were hitherto only well-educated guesses by theoretical physicists.  Leon Lederman won the Nobel Prize for leading the first team to observe a "muon neutrino."  Over the last several decades, all particles predicted by the Standard Model were observed by experimentalists, except the elusive "Higgs Boson." 

I should explain that most of these particles are not free-floating, but hopelessly frozen together.  Maybe you've heard that a proton is actually made of three "quarks" and some "gluons" holding them together?  But those fundamental particles are bound together so tightly in a proton that there's pretty much no way of tearing them apart to look at them.  To do so, scientists have to smash them together at really high speeds (another way of saying really high temperatures).  The more massive the particle, the more difficult it is to isolate it.  And this Higgs Boson is really massive.  But the whole Standard Model depends on the existence of Higgs Bosons.  Scientists learned enough to be about 99% certain that the Standard Model is correct, but without actually observing Higgs Bosons, they really couldn't say for sure. 

Speaking of mass, the Higgs Boson plays a very unique role.  When it interacts with other particles, it gives them mass!  Yes, that's right.  The reason that the atoms in your body are "solid stuff" is because of Higgs Bosons and their mysterious energy fields!  (Frankly, I don't know the theory much more in-depth than that).  This is important not only because it completes the Standard Model, but because mass is linked to gravity -- and otherwise, the Standard Model does nothing to explain gravity.  The theory of gravity as it stands today is General Relativity, Einstein's brainchild.  Physicists feel that they won't really understand "everything" until they can find a missing link between gravity and particle physics.  The Higgs Boson plays a keystone role in the theory.  This "Theory of Everything" could provide physicists with the tools to understand the universe at the moment of the Big Bang.  So it is a mighty particle, in more ways than one.  Leon Lederman himself is sometimes credited / blamed with coining the phrase "God Particle."  Some say it was his publicist.  Whoever it was, he was being tongue-in-cheek.  No scientists believe that this particle is of God, from God, evidence for or against God, or anything like that.  It's just a fundamentally important fundamental particle. 

So hopefully I've given you a sense that today's discovery is indeed exciting -- and truly WHY it's exciting!

Like I said, I'm not a scientist.  If I got any facts wrong here, let me know!

-- SSF