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.
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.
Courtesy : http://cosmiclog.msnbc.msn.com/_news/2012/07/03/12547980-the-higgs-boson-made-simple?lite
