By their very nature, those discoveries that most change the way we think about nature cannot be anticipated
This was Douglas Osheroff’s claim at the start of his lecture on Wednesday morning, where he promised to tell the young researchers at Lindau “how advances in science are made”.
In his talk Osheroff offered five things that scientists should keep in mind if they want make a discovery. One example that Osheroff used to illustrate these points was the discovery of cosmic microwave background (CMB) radiation by Arno Penzias and Robert Wilson. It earned them the Nobel Prize in Physics in 1978, and provided evidence for an expanding universe that started with a big bang.
Penzias and Wilson were both working at Bell Laboratories on radio astronomy when they discovered the CMB. “Penzias had convinced AT&T to allow him and Wilson to use this very elegant piece of high tech machinery to look at the radiation coming in from outer space,” says Osheroff. The antenna they used was originally developed in order to test the feasibility of satellite communications and had one of the quietist receivers of its day. It is important to use the best equipment available, says Osheroff. But you should also make sure that you don’t reinvent the wheel. You should borrow technology where you can, says Osheroff.
Your best bet to find something new and possibly unexpected is to look in an unexplored region of the physical landscape, And remember that failure might be an invitation to try something new. Looking at their data, Penzias and Wilson saw what they thought was noise, evenly spread across the sky. So they tried to find the source of it, eventually climbing up into the antenna itself. There they found some pigeons roosting. “Always check your experiment for pigeon nests before starting,” said Osheroff – not one of the most widely applicable pieces of advice from his talk, but perhaps worth bearing in mind in some very specific situations.
In Wilson's own words from his Nobel lecture:
A pair of pigeons was roosting up in the small part of the horn where it enters the warm cab. They had covered the inside with a white material familiar to all city dwellers. We evicted the pigeons and cleaned up their mess, but obtained only a small reduction in antenna temperature.
You should be aware of subtle unexplained behaviour – don’t just dismiss it, says Osheroff, as his final piece of advice. When, even after clearing out the pigeons and their droppings, Penzias and Wilson failed to eliminate the roughly 3 Kelvin background radiation they were measuring, they did not decide to dismiss it as noise and just recalibrate their instruments. They figured out, with the help of theorists including Jim Peebles, and went on to win the Nobel.
“You have to trick nature to give up its secrets,” concludes Osheroff. “It’s a fun game to play.”
How to discover a Higgs boson
Wednesday morning’s sessions at Lindau were somewhat overshadowed by the announcement from CERN of a new particle that looks a lot like a Higgs boson – a discovery that has been anticipated for a long time. Of course the Higgs result is not what Osheroff talked about in his session on scientific advances. But plenty of what he said applies here too.
In making their discovery, scientists at CERN had to push the boundaries of particle accelerator technology. Describing the process of working on a programme like that of the LHC, CMS experiment spokesperson Joe Incandela, said: “We go into the [LHC] programme with a goal for physics, but we don’t necessary have the technology yet.”
But, though they developed some new technology, they didn’t re-invent the wheel, or in this case, the tunnel: the LHC is housed in the same tunnel that was used by LEP, the Large Electron-Positron collider that was at CERN before the LHC was.
High-energy particle physics moves forwards by increasing the energy at the detectors. Last year CERN made the decision to step up its energy from 7 TeV to 8 TeV. It created more work for the scientists there because they had to run lots of simulations again, said George Smoot at the afternoon panel on CERN at Lindau. But they thought the extra reach it would give them was worth it. “It was a risk,” says Smoot, who was not involved in the research. “But it paid off.”
And scientists at CERN are looking where no-one has been able to before. “We’re reaching into the fabric of the universe in a way we’ve never done before,” said Incandela at the press conference from CERN. “We’ve completed one part of the story and we’re on the frontier now. We’re way out on the edge of understanding. It’s exploration.”
As ever, this scientific discovery would be more exciting if it turns out not be exactly what we expect. “The Standard Model is not complete,” says Fabiola Gianotti, spokesperson for the ATLAS collaboration. “I hope the picture will be much more complicated than what we see today. I would be delighted if this was not a Standard Model Higgs boson.”
From 1st to 6th July I'll be at the Lindau Nobel Laureates Meeting in Germany as part of the Lindau blog team. You can read my posts here or on the Lindau blog.