The Trinity College Science Safari is a free walking tour that takes the visitor on a journey through 400 years of science in Ireland, relating some strange but true stories along the way
TRINITY COLLEGE Dublin (TCD) is surely Ireland’s most ingenious quarter. For more than 400 years – longer than any other Irish institution – it has been a centre of ideas, discovery and innovation, in philosophy and the natural sciences, in engineering and mathematics. No surprise, then, that the college can lay claim to a host of intriguing and unusual stories, from the date of the Creation to the man who split the atom. In terms of artefacts, there’s a fascinating model of the engine that electrified the 20th century, and a gem of a museum in an attic that is Dublin’s loveliest yet least-known.
Trinity’s rich heritage also includes a myriad of interesting inventions and discoveries, such as the first commercial nicotine patch, an early technique for colour photography, and some 19th-century mathematics that are now important in computer graphics.
Although we in Ireland are better at celebrating our writers and artists than our scientists and engineers, Trinity has long been proud of its scientific tradition. When I have led occasional walking tours around “ingenious Dublin”, the college has always been welcoming and accommodating.
Now, a new trail (see panel), for TCD’s faculty of engineering, mathematics and science, brings this rich history to a wider audience. The recorded commentary lasts an hour, and takes the listener around the campus, visiting a couple of research buildings en route where you can even hear the “sound of science” at work. From the 20 stories featured in the trail, below are a few favourites.
The date of Creation, 4004 BC
The man who famously calculated the age of the earth by counting all the generations in the Old Testament was a Dubliner, James Ussher (1581-1656), one of the first students to attend Trinity College in the 1590s.
This philosopher-scientist, later archbishop of Armagh, studied numerous Egyptian and Hebrew texts, analysed how ancient calendars were calculated, and concluded that the world began on October 23rd, 4004 BC. He also calculated dates for other events, among them the Great Flood, in 2348 BC.
Many people laugh at Ussher’s work, yet it was a tremendous feat of scholarship, using all the available evidence. Other scholars across Europe were doing similar computations and contested Ussher’s calculations, although most were agreed that the Earth was about 5,600 years old.
The reason Ussher’s chronology is so well known is that his was chosen for use in printed English bibles. Accorded the same respect as the Scriptures, it was widely accepted until the late 1800s. On his death, Ussher’s extensive library was given to TCD, forming the nucleus of what is now the country’s greatest library.
The humane hangman’s drop
Hanging was never meant to kill a condemned person, merely render them unconscious before drawing and quartering them. When drawing and quartering was dropped, executioners would merely hang someone, but from a short rope that was never enough to break their neck. The poor victim would slowly strangle, their agonies adding to the spectacle for the watching crowd. Until a TCD geology professor realised that it didn’t have to be so.
Rev Samuel Haughton (1820-1897), from a noted Carlow Quaker family, had degrees in geology and medicine. Arguably his greatest contribution, however, was to campaign for a more humane execution.
After numerous experiments with weights, Haughton calculated the drop needed to break someone’s neck and kill them quickly and more humanely – for somebody weighing 160lbs (72.5kg), for example, a 14ft (4.2m) drop was needed.
Like Ussher before him, he also calculated an age for the Earth; based on sedimentation and cooling rates, Haughton calculated that the planet was 2.5 billion years old. But being firmly anti-Darwin, he revised the figure down to a more conservative 100 million.
Offaly’s inventive genius
The first effective radiation therapy for cancer was developed around 1910 by a brilliant polymath from Co Offaly, John Joly. A professor of geology at TCD, he was one of the founding fathers of geophysics, and his many inventions include the steam calorimeter and an early technique for colour photography.
Cancer treatments then relied on radium, which was extremely expensive, highly radioactive, pretty unsafe, and fairly ineffective. Joly’s insight was to use the radioactive radon gas given off by the radium, rather than the radium itself. Working with Dublin cancer expert Walter Stevenson, Joly collected the radon gas in sealed needles, so that it could be injected into tumours. The dose could be controlled, and delivered directly to a tumour, and the gas could percolate through the tumour, making it very effective. The technique was also safer and, because the radium source could be reused, it was significantly cheaper, and it came to be known around the world as “the Dublin method”.
The engine that electrified the world
We would probably be using gas-powered fridges, radios and other appliances today, if it wasn’t for the steam turbine, invented in 1884 by another Offaly genius, Charles Parsons. More powerful, more efficient, smoother and quieter than traditional steam engines, the turbine made electricity generation more effective, revolutionising industry and even naval warfare.
Parsons learned his early engineering at home in Birr Castle, where his father, the third earl, built the world’s largest telescope in 1845. Steam engines then used steam to move pistons, consumed vast amounts of coal, and wasted a lot of energy. Parsons’s innovation was to have the steam turn a rotor with a fan of turbine blades. By controlling the steam release from the boiler, he could harness most of the energy, connecting the turbine to a generator that produced electricity.
Power stations around the world still use Parsons’s steam turbine to generate electricity. A demonstration model of his turbine, built in 1885, is on display in TCD’s school of engineering.
The man who split the atom
Ireland can boast four Nobel prizes in literature but just one in science: Ernest Walton (1903-1995) shared the physics prize in 1951 for splitting the atom, work that ushered in the era of nuclear power.
It was 1932 when this young Irish PhD student was working in Cambridge with his collaborator, John Cockcroft. Sitting underneath a particle accelerator he had built, Walton saw “scintillations” when an atom was split and energy released.
Cockcroft and Walton’s brilliant experiment smashed a high-energy particle into a lithium atom, creating an unstable atom-particle combo that quickly disintegrated into two helium atoms, releasing energy in the process. They converted matter into energy, as predicted by Einstein’s equation, E=mc2. The result made headlines around the world.
Walton, from Dungarvan in Co Waterford, had studied physics at Trinity, and in 1934 he returned, later becoming professor of physics. Today, a plaque on the department commemorates his contribution to science.
Where did prehistoric cows come from?
This may seem an esoteric question – but the answer turned out to be surprisingly practical. For years, archaeologists, farmers and scientists believed that modern European cattle were descended from animals domesticated about 10,000 years ago in the near east.
But research at TCD over the last decade or so has rewritten the cattle history book. Using something akin to genetic fingerprinting techniques, scientists here discovered that cattle were domesticated twice, producing two very different types of cow.
“Humped” African cattle were indeed domesticated about 10,000 years ago, but Indian cattle emerged separately, about 7,000 years ago in what is now Pakistan. And modern European cattle are all descended from these Pakistani animals. That might seem removed from modern life, but, thanks to all the cattle genetic fingerprints, the TCD scientists had enough information to develop a genetic test to trace beef. The result is an award-winning company, IdentiGen, that now offers a genetic meat-tracing service to supermarkets across Europe and North America.
TIME TRAVELS
The Trinity College Science Safari is a free walking trail that spans the full 400 years of TCD’s history, with podcast commentary by Mary Mulvihill. Full details, complete with summaries and images, a map and brochure that you can print, and all the audio (MP3) files, are at tcd.ie/visitors/sciencesafari.
Allow 90 minutes to walk the full route. The interiors are usually open only on weekdays (9am-5pm; groups by appointment).