Tag Archives: waves

Creating a New Particle from the Annihilation of Two Others

[Long silence should be over for now; personal issues had to take precedence for a little while.]

Back to building up articles on how the Higgs field works! As part of the necessary background, I’ve added another general article on how particles and fields interact with each other to my series on Particles and Fields (with a little math — first-year university level.)

This one explains, among other things, how a small modification of the equations of motion for fields allows two particles of one type to annihilate and create a third one of a different type.  Examples of such phenomena include the collision and annihilation of a quark and an antiquark to form a Z particle, or the collision and annihilation of two gluons to form a Higgs particle. Particle decay is often just the time-reversed process.

Moreover, similar modifications of the equations are essential in allowing the Higgs field to give mass to other particles.

So this is one of the most important articles, and one of the most sophisticated, to appear on this website so far.  Although there are a couple of animations to help you visualize what is going on, to understand the text you will want to have read the other articles in the Particles and Fields series first.

Two Major Steps Forward

Apologies to those who’ve been asking questions: I’ve been away from the website for a few days (family matters) and have not been able to keep up with comments.  I will try to catch up over the coming day or two.

But I do have two pieces of good news.

First, I gave a public lecture over the weekend, on-line, called “The Quest for the Higgs”, which I believe many of my readers will find at the right level.  Because of some technical difficulties with the sound recording, I didn’t immediately recommend that you listen; but those problems are now fixed and the sound is pretty good.  The audio is to be found here at BlogTalkRadio, through the Virtually Speaking Science series; on that website, there’s a link to the slides accompanying the talk, or you can just click here to get them.  [Note the slides are under copyright; please ask permission before reproducing or using ideas you find therein.] 

Second, the long-awaited final article in the series on Particles and Fields (with a little math) has arrived.

  1. Ball on a Spring (Classical)
  2. Ball on a Spring (Quantum)
  3. Waves (Classical Form)
  4. Waves (Classical Equation of Motion)
  5. Waves (Quantum)
  6. Fields
  7. Particles are Quanta (new!)

As a bonus, you can then find out what the key technical difference is between bosons and fermions (the consequences of this difference are described, without technicalities, here.)

Next month: a series of articles on How the Higgs Field Works.

What Fields Are (& a Public Talk Saturday)

To the five articles in my very-slightly-mathy series on Fields and Particles [sorry, the non-mathy series will be probably appear a couple of months from now] I have now added a 6th:

  1. Ball on a Spring (Classical)
  2. Ball on a Spring (Quantum)
  3. Waves (Classical Form)
  4. Waves (Classical Equation of Motion)
  5. Waves (Quantum)
  6. Fields (new!)
  7. Particles (coming next week)

Meanwhile, I remind you that I’m giving a talk on-line, about The Quest for the Higgs Particle. No math required there. (Saturday, September 8th, 1 p.m. New York time/10 a.m. Pacific, through the MICA Popular Talks series, held online at the Large Auditorium on StellaNova, Second Life.  You’ll need a Second Life viewer to watch it live.  Should you miss it, both the audio and the slides will be posted later for you to look at.)  And also, if you missed my colleague Sean Carroll being interviewed about his new book and the science behind the Higgs Discovery, an opportunity I recommended to you yesterday, all is not lost; you can hear it here.

The Quantum Wave

If you’ve just gotten back from vacation, perhaps after days or weeks seeking the perfect wave, well, what a treat awaits! So much reading to do, about such interesting things. I’m writing a set of articles, intended for the reader who has once-upon-a-time seen beginning physics (what we in the U.S. would call “freshman physics”, or even a good “advanced placement physics” course pre-university) with the goal of explaining what fields and particles are. Five of the seven or eight articles are done; four appeared over the last two weeks, and now there’s a new one:

  1. Ball on a Spring (Classical)
  2. Ball on a Spring (Quantum)
  3. Waves (Classical Form)
  4. Waves (Classical Equation of Motion)
  5. Waves (Quantum)the new one.

After this: an article on Fields, and then one on Particles, and maybe one more with some follow-up information.  And then, with this set complete, I’ll move on to another series of articles, about how the Higgs field works…

After Springs, Waves

On Monday I started a series of articles to explain particles and fields, aimed at those who’ve had a little bit of physics in their past (perhaps a semester or two just before or just at the beginning level at a university), and containing a very little amount of math.

I first brought you the story of the ball on a spring, both the classical [i.e. pre-quantum] version from the 1700s and the quantum version from the early 1900s.

Now it’s time to turn to waves. This is the longest subject I’ll have to cover, I think, so I split even the pre-quantum story of waves up into two parts, one aimed at getting the right formula for describing a wave, and the other at getting the right equation of motion for which that formula is a solution. If you’ve had first-year physics you’ve seen most of this, but there’s a twist toward the very end that is probably novel — you’ll see a wave equation you’ll probably recognize, but also one that, quite possibly, you haven’t seen before.

A Little Math; A Lot of Physics

One of my current goals is to explain how the Higgs field works to anyone who’s learned a bit of physics at the beginning-university or advanced pre-university level. As a step toward the goal, I am creating a set of pages that explain how fields work, why quantum mechanics implies that sufficiently simple fields have particles, and which aspect of a field’s behavior determines the masses of its particles.  You will find that knowing a little physics and a little math is helpful.

[I’m afraid that most of you who never had a beginning physics class at all will have to be patient. It’s an even greater challenge for me to explain the Higgs field to someone who’s allergic to math, or hasn’t had much math yet; I’m hoping my current efforts will help me see how surmount that challenge.  But meanwhile you might like to read my Higgs FAQ and my popular article on Why the Higgs Particle Matters.]

The first step is to remember how a ball on a spring works — one of the first things one learns in any physics class — and then learn a little bit about how quantum mechanics changes the answer — one of the first things one learns in a quantum mechanics class.  This is where the concept of a “quantum” first makes its appearance in physics.  Those articles are now ready for you to look at.  The next step [waves, both without and with quantum mechanics] will follow over the coming week.

Note: I’ve included, for the first time on this website, some animated gifs among the figures.  These should animate when you click on them.  I know they need improvement; over the next day I’ll be trying to make them faster to load and run.  Please be patient and let them load; but do let me know if you can’t make them work at all, and if so, what browser and hardware you’re using.  Update: they should be much faster now.