Every year the team of editors at Science selects ten scientific accomplishments to highlight as some the most notable advances of the year. I very much enjoyed reading about them, so I indulged myself in making a summary of it for my first post of the year. (And if you’re not that much into science, you probably do not know what Science is. To give you an idea, I’ll just say it’s a highly renowned international scientific journal that haunts the publishing fantasies of many a researcher.)
Breakthrough of the year: the Higgs boson
If you have not heard of the Higgs boson, you must have spent the whole of July 2012 at the beach, resolutely shunning all types of media (good for you). After researchers from the European particle physics laboratory (CERN) working with the Large Hadron Collider (LHC) in Switzerland announced on the 4th of July that they had detected a particle appearing to be the Higgs boson, there was a flurry of media activity celebrating the discovery.
The existence of the Higgs boson was hypothesized in 1964 by Peter Higgs to complete the standard model, a theory that mathematically describes the particles that make up ordinary matter (electrons, quarks, neutrinos and others) and their interactions (electromagnetic, weak and strong nuclear forces). The problem was that the standard model seemed to be a theory of massless particles. That’s where the Higgs boson came in. Mass is not an intrinsic property of matter, but emerges from the interaction of fundamental particles with the “Higgs field”, made up of Higgs bosons. The more a particle moving in the Higgs field interacts with the Higgs bosons, the more it is slowed down and the heavier it appears.
Proving the existence of the Higgs boson is no small feat. Although it was predicted in the sixties, tremendous technological advances were required to reach a set-up that would allow its detection. This was achieved by the LHC, a 27-kilometer-long ring in which particles are accelerated close to the speed of light and eventually smash into one another, generating an array of other particles that are analyzed by the LHC two particle detectors, ATLAS and CMS (and let’s not forget the human power behind all this: for each detector, a team of about 3000 members).
When theoretical physicists predicted the existence of the Higgs boson, they also described its properties, for example the rates at which it should decay into five different combinations of other particles. The Higgs boson exists only for an infinitesimal fraction of a second, so the only way to identify it is to detect the particles that are generated by its decay. That’s what researchers at CERN have been doing, analyzing massive amounts of data coming out of the two LHC detectors, until they finally identified with a high degree of certitude a new particle that fitted the description of the Higgs boson.
Although the discovery of the Higgs boson was celebrated as the final missing piece to the standard model of fundamental particles and forces, theoretical physicists are not out of work yet. For one thing, the standard model describes all fundamental particles and three of the four fundamental forces (electromagnetic force, weak nuclear force and strong nuclear force), but fails to incorporate the fourth fundamental force, the force of gravity. Also, the Higgs boson does not directly shed light on what makes up dark matter, which constitutes 23% of the universe (on the positive side, knowing the mass of the Higgs boson will limit the possibilities as to the properties of the particles making up dark matter).
So, for all the fans of the TV show The Big Bang Theory, no need to worry, there’s still lots to do for the few real-life Sheldons out there!
– a new method to sequence ancient DNA to the same degree of high resolution as that obtained for DNA from living people (and subsequent sequencing of the genome of a Denisovan, an archaic human that lived in Siberia at least 50,000 years ago)
– a new genome engineering tool, called TALEN (transcription activator-like effector nuclease), that cuts DNA in specific places, allowing the precise targeting and modification of a gene
– the completion of a decade-long project, called ENCODE (Encyclopedia of DNA Elements), that looked at how active our DNA is, biochemically speaking, and generated data that will be useful for researchers trying to understand how the expression of genes is controlled and how it may be linked to disease
– the successful use of a brain-machine interface by paralyzed human patients to execute complex movements by manipulating a robotic arm with their thoughts
– and: the production of fertile oocytes (egg cells) from mouse embryonic stem cells, the fantastic landing of the Curiosity rover on Mars, the use of x-ray lasers to determine the structure of proteins, and finally, advances in particle physics involving neutrinos and Majorana fermions that are well beyond my modest understanding of particle physics and that I will therefore not mention in more details!
If you are curious about all these scientific advances, check out the Science special issue “Breakthrough of the year 2012” (21 December 2012 vol 338, issue 6114, pages 1497-1676).