Galileo’s drawing of the solar system. Florence, 1611. The exhibit Galileo and His Ingenious Discoveries, is previewed at the Perimeter Institute for Theoretical Physics on Feb. 4. The drawings mark a turning point in the history of astronomy because this is when Galileo demonstrated the existence of celestial bodies unknown to the ancients.Fred Lum/The Globe and Mail
As an astrophysicist, Alessandro De Angelis has spent a lifetime chasing the rare and sublime, including particles from the deep universe that are among the most energetic forms of matter known to science.
But across his long career, nothing beats the time he spent in a Florentine library where he handled some of the original observing notes written by Galileo Galilei, the Italian astronomer who became a pivotal figure in the scientific revolution some four centuries ago. “I could touch the real pages,” said De Angelis, who is a professor at the University of Padua, where Galileo himself taught mathematics between 1601 and 1610. “This was an incredible emotion – the smell, the consistency of the paper – you cannot imagine.”
Now replicas of some of those pages are on display for a brief stint at the Perimeter Institute for Theoretical Physics in Waterloo, Ont., where they are helping to kick off celebrations of the institute’s 25th anniversary later this fall.
As curator of the exhibition, De Angelis has spent hours poring over his intellectual predecessor’s writings, which he spoke about while in Waterloo for its North American debut last week. Produced in conjunction with the Galileo Museum in Florence, the exhibition opens a window on a crucial period in the astronomer’s life – after he became famous for turning his telescope onto the night sky, but before he was censured by the church and later tried and placed under house arrest for supporting the idea that the Earth circles the sun rather than the other way around.
It’s a rare historical sojourn for an institute where researchers spend their time working at the cutting edge of quantum science or striving to continue the breakthroughs of Einstein and other pioneers of modern physics. Galileo precedes today’s physicists by many generations, but his work underscores the interplay of intellect and observation that drives the field forward. He sits squarely within the 150-year period that separates Nicolaus Copernicus from Isaac Newton – a time in European history that marks the transition from the Renaissance to the Enlightenment. By making pragmatic use of emerging technologies to explore the unknown, he became the bridge builder to a new era.
Professor Alesandro De Angelis, astrophysicist and curator of an exhibit on Galileo. De Angelis is a professor at the University of Padua, where Galileo himself taught mathematics between 1601 and 1610.Fred Lum/The Globe and Mail
“The first thing that Galileo makes me think about – even before thinking about him as a physicist – is about curiosity, human curiosity,” said Marcela Carena, a theoretical physicist who last year became the Perimeter Institute’s fourth director. “He was trying to understand our place in this universe.”
He was also trying to advance his own circumstances, notes Mario Biagioli, an author and historian whose specialty lies at the intersection of science and intellectual property. In his 2006 book, Galileo’s Instruments of Credit: Telescopes, Images, Secrecy, Biagioli chronicles how Galileo, then a 46-year-old professor in Padua, parlayed his discoveries and technical achievements into a higher-status position in Florence under the patronage of the Medici, the ruling elite of the period.
In a passage that echoes the high-stakes competition playing out in the tech world today, Biagioli writes: “Galileo’s tactics shifted as rapidly as his circumstances. The fast pace of these changes (often measurable in weeks or months rather than years) required him to respond swiftly to the opportunities and risks posed by unforeseen inventions and discoveries, and to his opponents’ interventions.”
The Perimeter exhibition captures this in striking fashion, starting with Galileo’s observations of the four largest moons of Jupiter in January, 1610. It is a discovery that backyard stargazers can recreate for themselves this month with Jupiter currently riding high in the evening sky, forming a line with Saturn, Venus and Mars that stretches from southwest to east every night after dusk. (To find Jupiter in particular look high in the southern sky around 7 p.m., where the planet is positioned above the familiar winter constellation Orion.)
How to spot February’s planet parade
Four bright planets can be seen in evening skies across Canada this month. Look around 7 p.m. to see them stretched out in a line from southwest to east. Venus and Jupiter are the brightest, with Jupiter high in the south above the constellation Orion.
THE GLOBE AND MAIL, SOURCE: THESKYLIVE.COM
How to spot February’s planet parade
Four bright planets can be seen in evening skies across Canada this month. Look around 7 p.m. to see them stretched out in a line from southwest to east. Venus and Jupiter are the brightest, with Jupiter high in the south above the constellation Orion.
THE GLOBE AND MAIL, SOURCE: THESKYLIVE.COM
How to spot February’s planet parade
Four bright planets can be seen in evening skies across Canada this month. Look around 7 p.m. to see them stretched out in a line from southwest to east. Venus and Jupiter are the brightest, with Jupiter high in the south above the constellation Orion.
THE GLOBE AND MAIL, SOURCE: THESKYLIVE.COM
Even a small telescope or a good pair of binoculars is enough to reveal some tiny lights hovering beside Jupiter. As Galileo watched them night after night he was able to discern their separate orbits around the planet. The exhibition includes pages from Galileo’s log book where he records the moons’ shifting positions.
The drawings mark a turning point in the history of astronomy because this is when Galileo demonstrated the existence of celestial bodies unknown to the ancients. It was also a step toward heliocentrism – the idea that the planets revolve around the sun. While the moons of Jupiter don’t prove this idea is correct, they were evidence that the Aristotelian view adopted by the church – that everything in the sky revolves around Earth – was wrong.
But in the aftermath of the discovery Galileo was preoccupied with its possible practical applications. He realized the moons whirling around Jupiter in precise fashion amounted to a clock in the sky, visible to everyone on Earth. This led him to propose tools for observing the moons as a way to tell time and therefore calculate relative position at sea. In an era when mechanical clocks were not yet seaworthy, any possibility of allowing navigators to calculate exactly where they were when out of sight of land was a strategic advantage and a potential gold mine.
A replica of Galileo’s telescope.Fred Lum/The Globe and Mail
As a mechanical aid for converting observations into a local time, which could then be used to compute longitude, Galileo developed the “jovilabe.” The brass instrument included a wheel that mimicked Earth’s position relative to Jupiter and could be used to makes adjustments to predicted times of the moons’ regular disappearances behind the planet as it moved along its track through the heavens. While the mechanism does not explicitly purport to be a model of our solar system, it is doing just that. It works by allowing the observer on Earth to circle around a centre point that would be occupied by the sun.
A replica of the jovilabe is the centrepiece of the exhibition. Despite its ingenuity, Galileo was unable to persuade anyone to buy the technology, including the king of Spain, to whom he first offered it. A series of letters reveals the skepticism Galileo faced, including from an official tasked with evaluating his proposal and who doubted the moons of Jupiter even existed. One gets the distinct impression that the jovilabe was as difficult to grasp for some of Galileo’s potential backers as a quantum computer would be today.
“I’m not sure they understood fully how it works,” said De Angelis while pointing out various details of the mechanism. “Galileo thought that it could be used by a sailor – he was probably overestimating the capability of people.”
The exhibition opens a window on a crucial period in the astronomer’s life – after he became famous for turning his telescope onto the night sky, but before he was censured by the church for supporting the idea that the Earth circles the sun rather than the other way around.Fred Lum/The Globe and Mail
If the jovilabe was not a barrier to the practical use of Jupiter as a clock for mariners, the rest of the idea surely was. To make the scheme work, Galileo also envisioned that the sailor making the measurement would be wearing a helmet with a hinged visor to which a small telescope would be attached. This would allow the sailor to watch the moons being eclipsed by the planet. And to make such observations possible from the deck of a ship that was rocking back and forth with the waves, Galileo also thought the sailor should be sitting in a hemispherical container floating in a tub of oil that would maintain its level with respect to the horizon.
This was a technical leap too far for Galileo’s contemporaries, though Giovanni Cassini would later use the technique (minus the sailor floating in the tub) to produce the first accurate map of the coast of France. The underlying science would have a much greater impact, though, outlasting both Galileo and the church’s efforts to suppress him by laying the foundations for Newton and beyond.
It is the sort of longer view on innovation that Blackberry pioneer Mike Lazaridis said he had in mind when he founded Perimeter in 2000, with donations totalling more than $150-million dollars.
“All of physics is either impossible or trivial,” said Carena, referencing a quote by nuclear-physics pioneer Ernest Rutherford. ”The idea is that when we are trying to solve a problem, it’s superchallenging, until we get the answer and then it becomes trivial.”
Twenty-five years on, the quest for answers continues.
Galileo and His Ingenious Discoveries runs until Feb. 17.
