Nobel Prizes 2013 – the Lowdown
October: a month of pumpkins, non-sensible costumes and a fresh crop of Nobel Prizewinning scientists. Let’s see who the guys are (and they are all guys….just saying) who’ve earned the most prestigious prize in science.
Physics – Boson bonanza
The choice of Physics Prize winner was a popular one – Peter Higgs and Francois Englert. In 1964 these men independently came up with the idea of a field which permeates the entire universe and is responsible for giving particles mass, and therefore the ability to move slower than the speed of light. This field was predicted to occasionally manifest as a particle, and in July 2012 the existence of the particle was announced (to an accepted statistical likelihood). This particle is of course the Higgs boson.
The amount of mass a fundamental particle has can now be thought of as the degree to which it is affected by the Higgs field. Imagine a field of deep virgin snow – this is the Higgs field. Birds flying overhead are like massless photons, flying fast with no concern with getting bogged down in the field. A lithe skier would be like an electron, only lightly interacting and not much slowed by it, so she only has a small amount of mass. A fat man in wellies would be like a quark (core component of protons and neutrons) – heavily affected by the field and given lots of mass as a result.
And now for the humour portion of the blogpost.
A Higgs boson walks into a Catholic Church. The preacher comes up to him and says “you can’t come in here – you call yourself the God particle, that’s sacrilegious. The particle looks at the preacher and says “well if you don’t allow the Higgs boson, how do you have mass?” (Source)
Here ends the humour portion of the blogpost.
Physiology or Medicine – molecular traffic wardens
I was pretty pleased with the news of the Physiology / Medicine prize because I recalled the name of one of the scientists discussed in my third year lectures (with the same sad smugness I get if I actually know something off of University Challenge). Or maybe I just remembered the moustache.
Cells may be called “the building blocks of life”, but it’s a bit more complicated than that. Every cell is like a miniature city, generating its own products and tightly regulating imports, exports and transports of molecules to get them exactly where they need to be at the right time.
Around the 1970s it was known that molecular cargo in a cell was packaged inside small spheres called vesicles, but it was a mystery how any given vesicle “knew” where to go and when. To help work out what genes might be responsible, Randy Schekman used baker’s yeast cells, which are compartmentalised like our own. He created a wide variety of random mutants, and looked to see where the traffic jams were. If a cell was found clogged up with vesicles, it must have acquired a mutation in a gene vital for regulating the cellular highways. These came to be known as Sec proteins.
James Rothman tried a different tactic entirely. Rather than changing the process in living cells, he managed to recreate it in a test-tube – no life needed. Achieving in vitro reconstitutions is so helpful because it whittles a desperately complex system down to the bare bones. He found the proteins responsible for fusing the vesicles to the cell membrane, allowing the contents to be released into the outer environment only if the right combination of proteins comes into contact. He called these SNAREs.
Nerve cells use vesicles to pass on signals to other nerve cells. They have to be very precise about timing, so these vesicles full of neurotransmitter and packed up against the far end of the cell ready to be released at a moment’s notice. The “release NOW” message is given by a flood of calcium ions, and Thomas Sudhof’s work uncovered the proteins which responded to calcium’s message and burst the vesicle open, spilling the contents outside the cell where the neighbouring nerve cell awaits it.
It’s pretty amazing how all this happens without any intelligent foreman overseeing and controlling where stuff goes. Life is amazing <3
Chemistry – seeking hotter models
The Chemistry Prize was also shared between three men: Martin Karplus, Michael Levitt and Arieh Warshel. Their contribution to science has been in the development of better modelling of complex chemical reactions. Modelling is incredibly helpful because individual reactions are both incredibly small and incredibly fast – too fast to measure. You “teach” a program the chemistry and physics you understand, give it a starting point and see what it comes up with. Test the outcome in real-life, use the results to improve your model and you have a lovely cycle of knowledge gain.
However, there are two possible varieties of physics you can use, each with their own advantages. Classical/Newtonian physics works at the level of atoms or groups of atoms, is quick and simple to run but falls short of mapping the fine details of reactions. Quantum physics accounts for the intricacies (read: downright weirdness) of the subatomic universe, but modelling at this level requires vastly powerful computers due to the sheer amount of data being processed. It seemed for a long time like the two options could never be used harmoniously.
What these men did was find a way of integrating classical and quantum modelling software such that the “business end” is modelled with the quantum-level capabilities, and the less-affected outer parts of the molecules are mapped using classical physics which doesn’t need accuracy.
So this can actually be seen as more of an computing/IT achievement, but the implications for chemistry and engineering (we could have amazingly efficient solar cells if they better mimicked natural photosynthesis) are astounding.