Tag Archives: electron

The Constancy of the Heavens — Verified Anew

This is a post about constancy and inconstancy, one of my favorite topics.  And about how alcohol can make you smarter.

There are many quantities that we call “constants of nature”.  Of course, anything we call a “constant” is merely something that, empirically, appears to be constant, to the extent we can measure it.  Everything we know comes from observation and experiment, and our knowledge is always limited by how good our measurements are.

We have pretty good evidence that a number of basic physical quantities are pretty much constant.  A lot of evidence comes from the constancy of the colors of light waves (i.e. the frequencies of waves of electromagnetic radiation) that are emitted by different types of atoms, which appear to be very much the same from day to day and year to year and even across billions of years (neat trick! will describe that another time), and from here to the next country and on to the moon and to the sun and across our galaxy to distant galaxies.  For example, if the electron mass changed very much over time and place, or if the strength of the electromagnetic force varied, then atoms, and the precise colors they emit, would also change.  Since we haven’t ever detected such an effect, it makes sense to think of the electron mass and the electromagnetic force’s strength as constants of nature.

But they’re not necessarily exactly constant.  One can always imagine they vary slowly enough across time or place that we wouldn’t have noticed it yet, with our current experimental technology.  So it makes sense to look at very distant places and measure whatever we can to seek signs that maybe, just maybe, some of the constants actually vary after all.

[I wrote a paper in 2001 with Paul Langacker and Gino Segre about this subject (Calmet and Fritzsch had a similar one).  This followed the observational claims of this paper (now thought false) suggesting the strength of electromagnetism varies across the universe and/or with time.  A lot of what follows in this post is based on what I learned writing that old paper.]

Suppose they did vary?  Well, the discovery of any variation whatsoever, in any quantity, would be a bombshell, and it would open up a door to an entirely new area of scientific research.  Once one quantity were known to vary, it would be much more plausible that others vary too.  For instance, if the electron mass varies, why not the W particle’s mass, which affects the strength of the weak nuclear force, and thereby radioactivity rates and the properties of supernovas?  If the electromagnetic force strength varies, why not that of the strong nuclear force?  There would be interest in understanding whether the variation is over space, over time, or both.  Is it continuous and slow, or does it occur in jumps?  One can imagine dozens of new experiments that would be proposed to study these questions — and the answers might reveal relations among the laws and “constants” of nature that we are currently completely unaware of, as well as giving us new insights into the history of the universe.

So it would be a very big deal.  [Though I should note it would also be puzzling: even small variations in these constants would naively lead to large variations in the "dark energy" (i.e. cosmological "constant") of the universe, which would potentially make the universe very inhomogeneous.  However, we don't understand dark energy, so this expectation might be too naive.] Since there’s no story about it on the front page of the New York Times, you can already guess that no variation’s been found.  But a nice new measurement’s been done. Continue reading

Why The Electron Can’t Have a Mass Without the Higgs Field

After a hiatus for a hurricane and a trip to a conference in Asia, I am adding one more article to my series on How the Higgs Field Works, following my series of articles on Fields and Particles. (These sets of articles require a little math and physics background, the sort you’d get in your first few months of a beginning university or pre-university physics class.  I’m still thinking about how to structure a similar set of articles that require no math or physics; that’s much harder, of course!)

The first article in the series explained the basic Idea behind how the Higgs field works. Then came an article about why and how the Higgs field becomes non-zero, and a third concerning how the Higgs particle arises as the quantum of waves that oscillate around the non-zero value of the Higgs field.  The new article tries to clarify why there’s no alternative to introducing a Higgs field, explaining that it’s otherwise impossible to reconcile two apparently contradictory features of our world: a mass for the electron (and many other types of known particles) and the properties of the weak nuclear force.

This article contains the most elaborate equations and concepts that I’ve had to introduce to my readers, so it won’t be suitable for everyone (though it still only requires some first-year physics/math.)  But on the other hand, it seems necessary for me to write it, since it’s the only place that I’ve explained not only why the Higgs field can give mass to the known particles, but why it (or something very much like it) must do so.

(Note that in these articles I’m mainly concentrating on the simplest type of Higgs, the Standard Model Higgs field and particle.  However, most of the basic concepts in these articles apply even for more complicated cases.)