So what's the Higgs boson, and why are
people spending billions of dollars to find that god-danged subatomic particle?
I've rounded up a variety of resources aimed at showing you why the hunt for
the Higgs is a big deal.
First, a little context: The Higgs
particle, and its associated field, were hypothesized back in the 1960s by
British physicist Peter Higgs and others to fill a weird gap in the Standard
Model, one of physics' most successful theories. The model as it stood had no
mechanism to explain why some particles are massless (such as the photon, which
is the quantum bit for light and other types of electromagnetic radiation),
while other particles have varying degrees of mass (such as the W and Z bosons,
which play a part in the weak nuclear force). By rights, all particles should
be without mass and zipping around freely.
The Higgs mechanism sets up a field that
interacts with particles to endow them with mass, and the Higgs boson is the
particle associated with that field — just as photons are associated with an
electromagnetic field. For more than four decades, physicists have assumed that
the Higgs field existed, but found no experimental evidence for it. It requires
a super-powerful particle smasher such as the Large Hadron Collider to produce
energies high enough to knock a Higgs boson into existence under controlled
conditions.
But the heavy particles created in a
collider exist for just an instant before they decay into lighter particles.
The LHC's physicists have been looking for particular patterns in the spray of
particles that match what they'd expect to see from the decay of the Higgs
boson. They've collected data for roughly a quadrillion proton-on-proton
collisions, and on Wednesday they'll announce the status of the Higgs search
based on those conclusions. (Tune in the webcast.)
The teams at the LHC's ATLAS and CMS
detectors are likely to say they're pretty sure they see a new type of particle
with Higgs-like characteristics, but will need more time to nail down those
characteristics completely. If that's the case, physicists can then go on to
find out if the Higgs mechanism works exactly the way they expected it to, or
whether there are unexpected twists. Some of the theories about how the
universe is put together are pretty far-out — for example, suggesting that
there are several dimensions in space that we can't perceive directly, or that
there are huge troops of subatomic particles that we haven't yet discovered.
Following the tracks left behind by the Higgs could reveal whether there's any
truth to those theories.
Analogies, please!
For decades, experts have been trying to
come up with analogies to illustrate how the Higgs mechanism works. One of the
best-known was proposed in 1993 by David Miller, a physicist at University
College London. Imagine looking down from a balcony in a ballroom, watching a
cocktail party below. When just plain folks try to go from one end of the room
to the other, they can walk through easily, with no resistance from the party
crowd. But when a celebrity like Justin Bieber shows up, other partygoers press
around him so tightly that he can hardly move ... and once he moves, the crowd
moves with him in such a way that the whole group is harder to stop.
The partygoers are like Higgs bosons, the
just plain folks are like massless particles, and Bieber is like a massive Z
boson.
The Guardian's Ian Sample demonstrates a
variant of this analogy in a 4.5-minute video: Imagine a tray with ping-pong
balls scattered on it. The balls roll freely around the empty tray. But then,
if you spread a layer of sugar over the tray, the balls sitting on the piled-up
sugar don't roll so easily. The grains of sugar introduce a kind of inertial
"drag," and that's the kind of effect that the Higgs field supposedly
has on particles with mass.
In a 60-second shot of science written for
Symmetry magazine, Howard Haber of the University of California at Santa Cruz
uses a livelier comparison to a high-speed bullet plowing through a vat of
molasses.
What good is it?
Particle physicists try to avoid
forecasting the applications of an experimental advance before the actual
advance is confirmed, but in the past, advances on a par with the discovery of
the Higgs boson have had lots of beneficial applications, and some that are
more questionable. The rise of nuclear power and nuclear weaponry is a prime
example of that double-edged sword.
The discovery of antimatter is what made
medical PET scanning possible, and antimatter propulsion could eventually play
a part in interstellar travel, just like on "Star Trek." Particle
accelerators have opened the way to medical treatments such as proton eye
therapy — as well as advances in materials science, thanks to neutron
scattering.
It's conceivable that the discoveries made
at the Large Hadron Collider will eventually point to new sources of energy,
Michio Kaku, a physicist at City College of New York, told me during a
discussion of the LHC's promise and peril. And if the discovery of the Higgs
leads to fresh insights into the fabric of the universe, it's conceivable that
we could take advantage of the as-yet-unknown weave of that fabric for
communication or transportation. Who knows? Maybe this is how "Star
Trek" gets its start.
Visualizing the Higgs
If one picture can be worth a thousand
words, how much are six videos worth? Here are half a dozen videos that delve
more deeply into the Higgs boson and its significance. Be sure to tune in
CERN's webcast starting at 3 a.m. ET for the latest revelations.
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