The LHC, the Higgs Boson, and Everything
April 18, 2013
About a month ago, confirmation of one of the most important scientific discoveries of all time was announced. A massive international effort conducted by the European Organization for Nuclear Research (CERN) with its Large Hadron Collider (LHC) had created and detected the Higgs boson. Billions of euros, petabytes of data, and thousands of scientists, engineers, and technicians were required to find this subatomic particle, so obviously someone thought its discovery was a high priority. For the public at large, however, the news registered as a mere blip. So why doesn’t the fulfillment of the quest for the Higgs boson register on the public consciousness like the fulfillment of the quest to put human beings on the Moon, an endeavor of similar cost and scale?
Many would argue that the theoretical work that predicted the Higgs boson is based on very complex mathematical concepts and a bizarre submicroscopic quantum world that behaves very strangely compared to the large scale world we inhabit. However, one could also argue that the "rocket science" needed to put Neil Armstrong and Buzz Aldrin safely on the ground in the Sea of Tranquility is based on mathematics and complex engineering problems equally opaque to laypeople.
I would argue that one big reason is that one can’t see the Higgs boson. Not only is it smaller than an atom, it rapidly decays into other particles. In fact, the discovery really amounts to identifying the predicted decay particles with complex detector devices. Compare the following image with the lead image for this blog post. Which do you find more compelling? While the spray of Higgs decay particles above may have a certain aesthetic beauty, it hardly compares to a PERSON STANDING ON THE SURFACE OF THE MOON.
To make matters worse, the conditions required to produce a Higgs boson are so extreme that it is unlikely that any foreseeable technology will be based on exploiting Higgs bosons. We may not be able to see electrons or atomic nuclei, but at least we use devices based on exploiting their bizarre quantum mechanical properties all the time. You’re reading this blog on one such device right now. However, you are also using the World Wide Web developed by Tim Berners-Lee at CERN as a way to share particle physics data. So, just as with the space program, spinoff technologies can affect our lives in ways beyond simply knowing the mass of a Higgs boson or the chemical composition of a moon rock.
But why do scientists care about the Higgs boson? The theoretical framework of our understanding of nature at its most basic level, the Standard Model of particle physics, had a major problem: it couldn’t account for the fact that some particles have mass and others don’t. Decades of theory developed by countless physicists might have been in vain, and an entirely new model of particle physics would have to be developed to take the Standard Model’s place.
Enter the Higgs field, a field that permeates space and interacts with certain particles to create mass. This rescued the Standard Model, but no one knew if the Higgs field and its associated boson were actually real or simply a mathematically convenient way to make the data fit expectations. The fact that the Higgs boson does exist with the observed properties (such as its mass and decay processes) seen at the LHC means that the Standard Model is in fact on the right track.
So now we’re home free, right? Not exactly. The Higgs boson solves the mass problem (and by doing so many other associated questions such as the range of the weak nuclear force), but there are still some things the Standard Model can't explain. First, why is the gravitational force so much weaker than the three other fundamental forces? This is where theoretical constructs like supersymmetry, microscopic extra dimensions, loop quantum gravity, and string theory come into play in an attempt to create a “Theory of Everything.” And what about dark matter and dark energy, the stuff we can't see but that we now know makes up 96% of the mass/energy of the universe?
While scientists at the LHC will continue to gather data on the Higgs boson, these further questions will now come under scrutiny there. The search for superparticles predicted by supersymmetry, the nature of dark matter, and methods of experimentally testing the predictions of string theory and extra dimensions are all major areas of future research at the LHC. We are now entering a new era of fundamental physics, so perhaps none of our models are correct and something entirely new and exciting awaits us.
In the final analysis, perhaps it all boils down to the words of the late Richard Feynman, who built much of the framework of the Standard Model, who said it’s really just "the pleasure of finding things out." Even if we can’t personally understand the math, or see a picture of a subatomic particle, or benefit from some direct technological application, we can know that humanity is coming ever closer to a complete understanding of the physical laws of the universe.
Suspecting that the answer is 42,
Image credit: “CMS: Simulated Higgs to two jets and two electrons” by CERN, “Aldrin Apollo 11 original” NASA photo AS11-40-5903