Manchester marks Rutherford centenary
- 10 August 2011
- From the section Science & Environment
Manchester is hosting a series of events to mark the centenary of a paper by Ernest Rutherford that changed the way we looked at the world and Universe around us.
In 1911, Rutherford, described as the father of nuclear physics, presented his research to the Manchester Literary and Philosophical Society, which - for the first time - described a "planetary structure" of atoms, one that we still recognise today.
"Before Rutherford, people had thought about atoms as an amorphous lump, the "plum pudding model" we sometimes hear about," explained Catherine Rushmore, science curator at Mosi (Museum of Science and Industry).
"Rutherford pulled together all of the research that had been happening and realised that atomic structure had a really dense nucleus, which was positively charged, with negatively charged electrons circulating a long way away.
"It is almost like the Solar System, where we have the Sun in the middle and planets circulating around it," she told BBC News.
"This visualisation moved things forward so much, and took physics and chemistry in directions that had not really been open to us before."
Until the end of October, Mosi is hosting an exhibition that celebrates the pioneering work of Rutherford, much of which was carried out while he was the Langworthy Professor of Physics at the University of Manchester.
Visitors will be able to see a range of exhibits, some of which have not been on public display before. Among the highlights are Rutherford's writing desk; a draft manuscript of his famous 1911 paper, including notes and amendments he had made; personal correspondence with fellow scientists and lab notebooks.
Sean Freeman, the organiser of the University of Manchester's Rutherford Centennial Conference on Nuclear Physics, explained why Ernest Rutherford is deemed to have been such a pivotal figure in modern physics.
"He found out that the mass of an atom is mainly concentrated in a tiny, tiny little speck right in the middle - which was later called the atomic nucleus," he told BBC News.
"He discovered the atomic nucleus, which helped sort out people's models of atoms, but - if you like - it started off the whole field of nuclear physics."
In a profile of Ernest Rutherford, Chemistry World magazine's Mike Sutton explained that his model for the structure of an atom was largely shaped when he supervised one experiment.
The test involved firing the "alpha particles" - which were not yet known to be the nuclei of helium atoms - at a sheet of gold foil. The scientists found to their surprise that a few of the particles changed direction quite radically.
"Rutherford realised that any alpha particle deflected through such a wide angle must have bounced off another positively charged body," he explained.
"But, since most alpha particles passed straight through the foil, such collisions were clearly rare. He concluded that most of an atom's mass was concentrated in a small positively charged nucleus, surrounded by a cloud of negatively charged electrons which occupied much more space."
Professor Freeman said there was a lot of fundamental curiosity-driven science that had been done in nuclear physics, and it was still continuing.
"The main part of this centennial conference is to celebrate the fundamental curiosity-driven science that Rutherford started off," he said.
He highlighted some of the high-level sessions that will be presenting findings at the gathering: "There are people who will be talking about the latest results from heavy ion collisions at the Large Hadron Collider - that is really hot off the press.
"There are going to be people talking about the nuclear reactions that power energy production in stars, supernovas and explosions in the Universe. There is also going to be a lot of discussion about the structure and novel decay processes of atomic nuclei."
Professor Freeman added that as well as the fundamental side of nuclear physics, the legacy of Rutherford's work could be found in day-to-day life.
"If you want the simplest example possible, everybody has smoke alarms in their homes today - that includes a very, very weak radioactive source which a detector looks at.
"Normally, when everything is OK, the detector measures alpha particles from that source.
"However, when there is a fire, smoke gets in the way and the alpha particles cannot get to the detector and that is what causes the alarm to go off.
"There are 101 applications of radioactivity and nuclear physics that have grown out of the work Rutherford initiated in Manchester 100 years ago."
On Monday, a Royal Society of Chemistry Chemical Landmark Award plaque was unveilled in honour of Ernest Rutherford's work in chemistry, as well as nuclear physics.
The Mosi exhibition was opened by Mary Fowler, Lord Rutherford's great-granddaugher and professor of geophysics, who decribed the scientific pioneer as a "superb leader".
"He was one of the founders of the modern scientific PhD degree, and during his career in Montreal, Manchester and Cambridge had many research students and colleagues, who came from as far away as India, Japan, Russia and Africa," she told BBC News.
"They won numbers of Nobel prizes and revolutionised physics around the world. Some of his research students, including his first, were women something that was very unusual in those days."
She added that her great-grandfather was the "greatest experimental physicist since Archimedes".
"He had the good fortune to work with theoretical friends such as Bohr and Einstein, themselves equals to Newton and Aristotle.
"Together, they and their students remade the world. But, perhaps most important, throughout he retained his humanity and the simple goodness of a plain New Zealand farmer."