Most astronomers are fascinated by the history of their subject. Perhaps it’s not surprising, since a common way of teaching astronomy is to trace its historical development, from superstition to reason, and from ignorance to…well, a little less ignorance. And I confess I’m as susceptible to this fascination as anybody.
In 2009, the world’s astronomical community celebrated the International Year of Astronomy (IYA) to mark the four-hundredth anniversary of Galileo first turning a telescope on the night sky. ‘This was the beginning of modern instrumental astronomy, and a milestone in the history of evidence-based science’, ran the International Astronomical Union’s promotional blurb. Indeed, it was – but perhaps more unexpectedly, it was also the beginning of disputes concerning telescopes and what they might reveal. And such controversies continue, even today.
GALILEO’S CASE WAS CERTAINLY THE MOST EPOCH-MAKING as far as the course of science is concerned. The telescope he used was not his own invention, but had turned up in the hands of Dutch spectacle makers in the northern autumn of 1608. At least, that was when it appeared in the historical record; there’s evidence that the idea of using combinations of lenses or curved mirrors to magnify distant objects had been around for much longer – even if they had never quite made it to reality. Chaucer mentioned such things in his Canterbury Tales in the late 1300s, for example. It was intense diplomatic activity that finally brought the ‘far-seer’ out of the woodwork, however, with Spain and the Netherlands locked in difficult negotiations to halt the war they had been fighting for the previous 40 years. An enterprising spectacle maker by the name of Hans Lipperhey arrived at the seat of Dutch government in The Hague, seeking a patent for this useful piece of military hardware. But within three weeks, two other individuals had filed counterclaims for the invention, and the result was that no patents were awarded. The cat was out of the bag, and word of the invention spread rapidly.
By May 1609, the news had reached our man – Galileo di Vincenzo Bonaiuti de’ Galilei, the capable professor of mathematics in the University of Padua. His insight enabled him to formulate the optical prescription needed to make a telescope, and then perfect the lens-grinding process necessary to bring it to reality. In fact, he made at least four versions with successively higher magnifications, culminating in one that made distant objects appear 30 times larger. It was with this impressive instrument that he embarked on a spree of celestial discovery towards the end of 1609. Mountains on the Moon, congealed stars rather than congealed milk in the Milky Way, and most significantly, four satellites ‘flying about the star [sic] Jupiter…with wonderful swiftness’, rocketed Galileo to international fame when he published his findings in a little book in March 1610.
Sidereus nuncius – or Starry Messenger – is a truly fascinating read if you can get hold of one of the many translations from the original Latin that are now available. And it is beautifully illustrated with Galileo’s own depictions of the Moon, star clusters and the back and forth motion of Jupiter’s moons. While the book did not explicitly support Copernicus’s controversial theory that the Sun was at the centre of the Solar System (published by the great Polish astronomer nearly seven decades earlier), the moons of Jupiter clearly demonstrated that not everything revolved around Earth.
Towards the end of 1610, Galileo made another discovery. His telescope revealed that the planet Venus, which appears to the unaided eye only as a brilliant star in the morning or evening sky, actually displays phases like the Moon. With both its ‘full’ and ‘new’ phases occurring when Venus was close to the Sun in the sky, it had to be in orbit around the Sun, rather than Earth. Here was the seed of Copernicanism, which had already been planted in Galileo’s mind more than a decade earlier. But it was a dangerous idea, at odds with the teaching of the Holy Roman Church. That all-powerful body held to the Aristotelian (or Ptolemaic) view that Earth is at the centre of the Universe, and everything moves around it. And support of Copernicus’s view of the Solar System was one of the misdemeanours that had taken Giordano Bruno – ‘the mad priest of the Sun’ – to the stake in Rome’s Campo de’ Fiori on 17 February 1600.
In 1613, Galileo wrote a lengthy new book, Istoria e Dimostrazioni intorno alle Macchie Solari, usually known in English as Letters on Sunspots. Copiously illustrated with sketches of sunspots, explanatory drawings and, rather unexpectedly, diagrammatic predictions of the movements of Jupiter’s moons, the book challenges the Aristotelian idea of flawless perfection in the Sun, and lays down the gauntlet of Copernicanism. It is particularly critical of the work of a Jesuit astronomer, Christoph Scheiner, whose observations had led him to interpret sunspots as clusters of small bodies orbiting the Sun, thereby preserving its Aristotelian perfection. After all, Galileo had discovered objects randomly circulating around Jupiter, so why not invoke objects randomly circulating around the Sun to explain the mysterious spots? Ah, retorted Galileo in his Letters, the movement of Jupiter’s moons can be accurately predicted – hence the diagrams. The motion of the spots can’t, and must therefore be flaws in the solar surface itself.
Stirring up Scheiner was probably a mistake. It pitted the Jesuit community against Galileo, who was already feeling the heat from another adversary, a Dominican friar and committed Aristotelian by the name of Tommaso Caccini. It was Friar Caccini who, in March 1615, lodged a formal complaint about Galileo’s perceived impieties to the Holy Office, citing his Letters and other writings. By then, Galileo was firmly established in Florence, but he determined to travel to Rome to clear his name. However, his name was already before the Congregation for the Doctrine of the Faith – otherwise known as the Holy Roman Inquisition – which began its investigations towards the end of that year. A group of learned theologians, known as the Qualifiers, or Consultors, deliberated on the merits of a heliocentric (Sun-centred) model of the Solar System, and, on 24 February 1616, presented their report to the Inquisition.
They concluded unanimously that the idea of a static Sun is ‘foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture’. Likewise, the proposal that Earth moves around the Sun was given short shrift. The next day, Pope Paul V convened a meeting of his cardinals, and instructed one Robert Bellarmine to communicate the outcome to Galileo. This Cardinal Bellarmine did so in a meeting at his residence on 26 February, a meeting that turned out to be crucial in Galileo’s subsequent travails.
It’s understood that Bellarmine himself was not opposed to Copernicanism, so long as it was used merely as a device for calculation, and not as a representation of physical reality. But at this point in the narrative, things become fuzzy, as there are two versions of the meeting’s outcome. One is that Bellarmine instructed Galileo not to hold or to defend the Copernican claim of the Earth’s motion, warning him that if he failed to acquiesce, he would be imprisoned. This was Galileo’s impression, and he asked Bellarmine to confirm it with a letter, to squash rumours of his trial and condemnation – which Bellarmine did. It was a reasonably satisfactory outcome for Galileo, who, duly admonished, returned to his studies, hampered by the knowledge that he could not publish what he knew to be true, but would be spared the baleful glare of the Inquisition.
However, the other version includes a ‘Special Injunction’ by the Commissary General of the Holy Office, which ordered Galileo to abandon the Copernican model altogether, stating that he was ‘henceforth not to hold, teach, or defend it in any way whatever, either orally or in writing; otherwise the Holy Office would start proceedings against him’. Although Galileo’s signature is missing from the document, it goes on to state that he agreed to these terms, and undertook to obey them. Thus were the seeds of Galileo’s eventual downfall sown, for this injunction inexplicably vanished from the record for 16 years, surfacing (to Galileo’s surprise) on the eve of his trial in 1633.
IT IS ARGUABLE THAT GALILEO BROUGHT ABOUT HIS eventual trial himself by misjudging attitudes within the Church. On 6 August 1623, an old champion of his work by the name of Maffeo Barberini became Pope Urban VIII, and, in a series of audiences the following spring, Galileo discussed Copernicanism with a freedom that suggested the hypothesis might have found some acceptance. But that acceptance probably hinged on regarding the Copernican model merely as a tool for calculation rather than a representation of physical reality, in much the same way as Bellarmine had viewed it, thus avoiding contradicting the Scriptures. One of today’s foremost Galileo scholars, Maurice Finocchiaro of the University of Nevada, has suggested that this differed from Galileo’s view of what constitutes a hypothesis, which probably aligned more with the modern view – that it is an as-yet-unproven representation of a physical reality.
Encouraged by his meetings with Urban VIII, Galileo set about his next major task, a book that would compare the Earth-centred and Sun-centred models of the Solar System with particular regard to the phenomenon of tides on Earth. In fact, he was barking up the wrong tree, since the occurrence of tides doesn’t prove the motion of Earth. Nevertheless, other arguments in his book strongly supported the Sun-centred Copernican model – the phases of Venus, for example – and in its overall tenor, the book advocated the dangerously heretical Copernican view.
Galileo used the literary device of dialogue to present his arguments. Like his Letters on Sunspots, the book was written in the common language – Italian, rather than Latin – to give it a broader appeal. Its original title when he submitted it to the Church authorities for approval was Dialogue on the Ebb and Flow of the Sea. But this hinted that the real physical phenomenon of tidal motion was a consequence of the Copernican hypothesis, and so he was instructed to change it, along with some alterations the Pope had suggested to the text. So, early in 1632 – and with the imprimatur of the Inquisition – the book appeared under the title Dialogue by Galileo Galilei on the two Chief World Systems, Ptolemaic and Copernican.
For his protagonists, Galileo had invented three individuals, undoubtedly modelled on friends and enemies in his circle. Salviati was effectively Galileo’s mouthpiece, arguing for the Copernican position. Sagredo was an intelligent and impartial observer, supposedly from Venice, where tides are rather important. And Simplicio was an incompetent Aristotelian, clinging to the naïve view that Earth is stationary, and at the centre of the Solar System.
In the preface to the Dialogue, Galileo states that his choice of the name Simplicio was in homage to Simplicius of Cilicia, a distinguished 6th-century exponent of Aristotle’s views. But, of course, the name is also close to the word ‘simpleton’ in many European languages, including Italian. And to make matters worse for Galileo, the Aristotelian arguments that Urban VIII had asked him to include turned up in the words of the idiotic Simplicio. Bad move.
Predictably miffed, it was Urban VIII himself who referred the book to a special commission a few months after its publication, by which time it had already done rather well in the bookshops. Further sales were immediately prohibited. From there, Galileo’s path to the Inquisition was inevitable. A tribunal of ten cardinals made up the jury for his trial, which took place in Rome from April to June 1633. Galileo was interrogated, and confronted with the Special Injunction. In regard to that, Maurice Finocchiaro speculates that Galileo was actually framed. Perhaps his enemies had somehow stashed it away after his meeting with Bellarmine, only to produce it when it could do most harm to his case. Somewhere along the line, torture was mentioned. Not a nice thought, but then again, the Inquisition was not known for its niceness. Complexity, on the other hand, was something it relished, and the foregoing account of Galileo’s interaction with the Church really only scratches the surface of what took place in the lead-up to the trial.
ON 22 JUNE 1633, THE INQUISITION ANNOUNCED ITS verdict. Guilty – and the specific crime: suspicion of heresy. This is an offence with three levels of seriousness: strong, vehement and slight. Galileo’s accusers selected the intermediate level, but divided the heresy itself into two parts, each of which was addressed separately:
You…have rendered yourself according to this Holy Office vehemently suspected of heresy, namely
(1) having held and believed a doctrine which is false and contrary to the divine and Holy Scripture: that the Sun is the centre of the world and does not move from east to west, and the Earth moves and is not the centre of the world, and
(2) that [you] may hold and defend as probable an opinion after it has been declared and defined contrary to the Holy Scripture.
Galileo was duly sentenced:
With a sincere heart and unfeigned faith, in front of us you [must] abjure, curse, and detest the above-mentioned errors and heresies, and every other error and heresy contrary to the Catholic and Apostolic Church, in the manner and form we will prescribe to you.
Furthermore…we order that the book Dialogue by Galileo Galilei be prohibited by public edict.
We condemn you to formal imprisonment in this Holy Office at our pleasure.
It seems to be apocryphal that Galileo whispered the words eppur si muove (and yet it moves) after recanting his heresy. But it is certain that the sentence clipped Galileo’s wings for the remaining nine years of his life. Imprisoned first at Siena in central Tuscany, he was eventually sent home to Florence, where he lived under house arrest. As his sight failed, he returned to the studies he had carried out before his work in astronomy, effectively inventing the new discipline of dynamics.
Although the Inquisition issued an edict forbidding the publication of his books, Galileo succeeded in bringing out one more, Discourses and Mathematical Demonstrations Relating to Two New Sciences, which was published in 1638 in the Protestant Netherlands. And, by the time of his death on 8 January 1642 at the age of 77, he had paved the way for Newton to develop his universal theory of gravitation. But it took another three and a half centuries – until November 1992 – for the Vatican to declare that Galileo had been right.
THE COMPLEX LEGAL TRAVAILS GALILEO EXPERIENCED were a direct consequence of his pioneering work with the newly invented telescope. Ideas that he knew to be true went against the accepted dogma of the age, and landed him uncomfortably in the spotlight of bigoted accusers. It was the first time a telescope had led to perceived breaches of the law – but far from the last. Throughout its 400-year history, the telescope has been the focus of some epic legal battles. Its evolution in the hands of gifted but sometimes unusual people has frequently thrust it into the centre of disputes, often as a result of technical developments – but sometimes quite unrelated.
Take, for example, the case of Richard Reeve, a London-based instrument-maker who produced the finest telescopes and microscopes available in Britain in the mid-1600s. By then, a number of improvements had been made to Galileo’s telescope design. It was still a tube with a lens at either end, but the eyepiece lens – the one nearer the eye – had become a magnifying glass rather than the diminishing (concave) lens used by Galileo, an improvement that widened the field of view and rendered observation less like looking through a drinking straw. Yes, it turned the image upside down, but that was a minor detail for astronomy. And telescopes had become longer – very much longer, in fact. That was to counter a defect of 17th-century lenses that made them not only refract the incoming light to form an image, but also disperse it into rainbow spectrum colours, so that stars and planets seemed awash with coloured fringes.
Richard Reeve was a masterly optician, producing telescopes up to 18 metres long that provided high magnification with minimal false colour. They were used by the leading scientists of the time, including Robert Hooke, Robert Boyle and Christopher Wren – not to mention the rich and famous such as the diarist Samuel Pepys, who bought Reeve’s instruments for both himself and his noble patrons. But Reeve apparently had a temper. In 1664, in a letter to Boyle, Robert Hooke wrote:
Perhaps you may have heard of it: if not, in short, he [Reeve] has between chance and anger, killed his wife, who died of a wound she received by a knife flung out of his hand, on Saturday last. The jury found it manslaughter, and he had all his goods seized on; and it is thought it may go hard with him.
And at first it did, despite a subsequent note from Hooke that ‘he now hopes that he will be able to get off, only it will cost him some money’. But what eventually transpired was a direct result of Reeve’s skill as a telescope-maker. A few years earlier, he had made a 10.7-metre-long telescope for no less a personage than the king – the newly restored Charles II. And the king had been delighted with it. Could there be a connection between his delight and the royal pardon that was bestowed on Reeve some six months after his wife’s death? It seems certain there was. The case was discharged, but it appears that it did, indeed, cost him a lot of money. The debt he incurred to his brother John, for example, is noted in John’s will.
It was the eventual solution of the problem of spurious colour in telescope lenses – technically known as ‘chromatic aberration’ – that led to a much bigger legal spat in the annals of the telescope. The great Isaac Newton had declared the problem insoluble and turned his attention to the idea of using a dished mirror rather than a lens as the main image-forming component – the so-called ‘objective’. That led to the first successful reflecting telescope, which he constructed in 1668. But a handful of individuals over ensuing decades wondered whether Newton might have been mistaken in abandoning the idea of colour-free lens telescopes. And the person who finally solved the problem in the early 1730s was not a scientist at all, but a barrister.
Chester Moor Hall worked at the Inner Temple, one of the four Inns of Court of the English judiciary. And he had an unusual hobby – the study of optics. After some experimentation, he devised a telescope objective that had two separate component lenses made of different types of glass. The idea worked, resulting in a lens that was ‘achromatic’, or free from spurious colour. Being a barrister, however, Moor Hall had no immediate use for his invention and, rather than patenting it, he simply passed it over to a couple of London telescope-makers he knew. But, unbelievably, after a few trials, they set it aside. Perhaps this newfangled telescope lens was just too hard to make, but the result was that for over two decades, the achromatic lens languished in obscurity.
It was a silk-weaver turned optician by the name of John Dollond who eventually rediscovered the idea, with a little help from an elderly jobbing optician who had made lenses for Chester Moor Hall back in the 1730s. In 1758, Dollond published an account of his experiments in the Royal Society’s prestigious journal Philosophical Transactions. Then, urged on by his business-minded son, Peter, the elder Dollond successfully applied for a patent on the achromatic lens, allowing his company to flourish as the only legal manufacturer of optical instruments using it. Dollond’s colour-free telescopes became the sensation of the age, with patrons including everyone from kings to Astronomers Royal, and unexpected luminaries such as President Thomas Jefferson and Mozart’s father, Leopold – who was a noted amateur astronomer.
But other opticians in London were not impressed. They became aware that Chester Moor Hall had first invented the achromatic lens, and moved to challenge the Dollond patent. In a class action in 1764, thirty-five members of the Worshipful Company of Spectacle Makers petitioned the Privy Council to annul the patent, but were unsuccessful. Others simply ignored it, and produced achromatic telescopes of their own. But by then, John Dollond had died and Peter was the sole owner, taking a hard line on patent infringement. Several court cases ensued, including the case of Dollond vs. James Champneys of Cornhill, London, in which the Chief Justice of the Court of Common Pleas, Lord Camden, noted with regard to Moor Hall’s invention that ‘…it is not the person who locks his invention in his scrutoire who ought to profit by a patent for such invention, but he who brings it forth for the benefit of the public’. Champneys and many others wound up paying crippling damages and royalties that quickly sent them bankrupt, while the Dollond company went from strength to strength. Until 2015, the name could still be seen in the British high street optical chain of Dollond and Aitchison, a company that lives on today under the Boots Opticians brand name.
A CENTURY AFTER CHESTER MOOR HALL’S EXPERIMENTS, the achromatic lens again became the centre of a legal dispute. This time, however, it involved two of the highest profile figures in British astronomy. In 1829, Sir James South and the Reverend Richard Sheepshanks became founding president and secretary of what was soon renamed the Royal Astronomical Society. The problem with these two strong-minded individuals was they had differing views on almost everything, and frankly despised each other. Their animosity boiled over in legal proceedings after South had purchased an exquisite 30-centimetre-diameter achromatic lens from a noted French optician, with the aim of pursuing his studies of double stars. This was the largest telescope lens in Britain at the time, and South hired a well-respected instrument-maker, Edward Troughton, to build the telescope to house it. Things did not go well and, in 1832, after two and a half years of work, South wrote to Troughton, accusing him of delivering ‘a useless pile’. Well out of pocket, Troughton took legal action against South, hiring a certain lawyer who was also a mathematical genius and an ordained minister in the Church of England: one Richard Sheepshanks.
Six years of legal wrangling followed, but in 1838, matters were resolved in Troughton’s favour. Sadly, he had died three years earlier, but his company was awarded £1470 in costs against Sir James South. This tipped South over the edge, and no doubt Sheepshanks’ involvement in the case enraged him far more than the financial loss. In 1839, he took to the unfinished telescope with an axe, putting up posters all over London advertising the sale of its dismal remnants, and decrying Troughton, Sheepshanks and their accomplices (who included no less a personage than the Astronomer Royal). And he repeated the exercise with the remaining bits and pieces in 1843.
The feud between South and Sheepshanks raged on for another decade until Richard Sheepshanks passed away in 1855. But that wasn’t quite the end of it, as South took a verbal swipe at the Royal Astronomical Society’s glowing obituary for his old enemy. The saddest part of the story is that the magnificent French lens never realised its full potential. By the time it was finally mounted in a telescope, at the University of Dublin’s Dunsink Observatory in 1863, it was a small instrument by the standards of the day. It’s still used for amateur astronomy and teaching.
WHILE WE MAY SMILE AT THE LIKES OF SOUTH AND Sheepshanks, there is really nothing funny about the legal disputes that sometimes surround telescopes today. As we noted in chapter 2, modern optical telescopes are major international collaborations, located on high mountain-tops where atmospheric conditions are superbly matched to astronomers’ requirements. Since the early 20th century, reflecting telescopes equipped with large dished mirrors have overtaken lens telescopes as the instruments of choice, simply because mirrors can be made bigger. And in astronomy, size is everything, to maximise the light gathered from faint objects in deep space. Today’s biggest telescopes have mirrors 8 to 10 metres in diameter, sometimes made of a single piece of high-tech glass, but often composed of interlocking hexagonal segments held in perfect alignment by computer-controlled fingers. They are known generically as ‘very large telescopes’ and indeed, among the most productive of them is a quartet of 8.2-metre instruments operated in northern Chile by the European Southern Observatory (ESO), known collectively as the VLT.
But we are now on the brink of a new generation of ELTs, or extremely large telescopes, with mirrors 20 metres or more in diameter. And they have brought to a head some serious legal issues surrounding their construction. In fact, what is happening today was foreshadowed during the 1990s, when the University of Arizona embarked on constructing an international optical observatory on Mount Graham in the south of the state. This tree-covered 3200-metre peak is home to the endangered Mount Graham Red Squirrel and, to the discomfort of astronomers (who are by nature environmentalists), a highly publicised legal challenge took place.
The dispute of astronomers vs. conservationists quickly escalated to incorporate the question of the mountain-top’s traditional ownership. Like other peaks in the Pinaleño Mountains, Mount Graham is a sacred site for the San Carlos Apache people. After years of protests and legal wrangling, a compromise was eventually reached with the Apache Tribal Council, and construction of the observatory was approved by an Act of the US Congress, with the proviso that an independent census of the squirrel population should be carried out. The biggest telescope on the mountain, the 2 × 8.4-metre Large Binocular Telescope, was eventually built between 1998 and 2004, coinciding initially with an unexpected peak in squirrel numbers, but now seeing numbers similar to those before the site was developed for astronomy.
Aside from environmental issues, the clear lesson from this episode is that the mountain peaks favoured by astronomers for their giant telescopes are often deeply significant for the indigenous people of the area. And of the three ELTs currently under development, one is now embroiled in a conflict whose outcome is difficult to foresee. This is the TMT, or Thirty Meter Telescope project, whose multinational proponents expect the telescope to be built on land managed by the University of Hawaii on the 4200-metre summit of Mauna Kea on Hawaii’s Big Island. (The other two ELTs are in the southern hemisphere, by the way, and already under construction on sites in northern Chile. They are ESO’s 39-metre European ELT and the 23-metre Giant Magellan Telescope, both of which have the approval of indigenous authorities.)
In fact, development on Mauna Kea has been controversial since the first astronomical facilities were built there in the late 1960s. The summit area is sacred in native Hawaiian religion, and is visible from virtually the whole island. Today, there are 12 separate facilities on the mountain, reflecting its status as the northern hemisphere’s best site for optical astronomy. However, the thirteenth – the giant TMT – will be enclosed in the most visible structure by far, and has triggered unprecedented protest. In October 2018, after seven years of controversy, the Supreme Court of Hawaii approved construction of the telescope, and that is legally where things stand today. However, a public forum in March 2019 drew bitter criticism from the local community, with the University of Hawaii being accused of ‘50 years of mismanagement’, and the Native Hawaiian Legal Corporation wondering what has become of the spirit of aloha in the dispute.
In a conflict that seems light years from Galileo’s trial, there are no winners over this sensitive issue. Astronomers clearly want to respect the traditional culture of Hawaii, but are jealous of the superb conditions that nature has dealt them on Mauna Kea. The best that can be hoped for is a compromise that will probably involve decommissioning some existing facilities as a gesture of goodwill, and perhaps a review of the site’s management structure. As someone who has cherished the pristine skies of Mauna Kea since my first visits there 40 years ago, I sympathise with all parties in the dispute. I’ll be watching developments with interest.