The Royal Society really needs to work on its history of the telescope

One would think that the Royal Society being one of the eldest, but not the eldest as they like to claim, scientific societies in Europe when presenting themselves as purveyors of the history of science, would take the trouble to get their facts right. If, however, one thought this, one would be wrong. Last week on the Internet the Royal Society was pushing a slide show, under their own name, on Google Arts and Culture on the history of the telescope in astronomy that in terms of historical accuracy is less than one, as a historian of science, nay of the telescope, might hope or indeed wish for.

The slide show in question is titled, Silent Harmony: astronomy at the Royal Society: Discover how innovation in telescopes and other optical instruments changed the way we see the universe. Following the title slide we have another general blurb slide but things then get serious on the history level, we get told under the heading, The new astronomy:

Galileo Portrait by Ottavio Leoni Source: Wikimedia Commons

Galileo Galilei (1564-1642) was the first to explore the solar system using a telescope. His work directly built on famous predecessors such as Nicolaus Copernicus (1473-1543) and Johannes Kepler (1571-1630), who set out to model a heliocentric universe – one in which the sun is at the centre of the universe – and theorise the motion of planets. 

Sometimes I tire slightly of repeating myself but once more into the breach dear friends, once more. Galileo was not the first to explore the solar system using a telescope. That honour goes to a man in London, you know London home of the Royal Society, Thomas Harriot (1560–1621).

Portrait often claimed to be Thomas Harriot (1602), which hangs in Oriel College, Oxford. Source: Wikimedia Commons

Also at the same time as Galileo was aiming his telescope at the heavens in Padua, Simon Marius (1573–1625) was doing the same in Ansbach in Franconia

Simon Marius Source: Wikimedia Commons

and Giovanni Paolo Lembo (1570–1618) and Odo van Maelcote (1572–1615) in Rome. Whilst Galileo was more than prepared to call himself a Copernican, he very strongly rejected or ignored the work of Johannes Kepler, so saying that his work directly built on that of Kepler is more than a simple distortion of history. To say that these three theorised the motion of planets is to say the least bizarre, all astronomical models whether heliocentric, geocentric or geo-heliocentric theorise the motion of planets that is a large part of what astronomy is. We are not finished with Signor Galileo:

Galileo’s Starry Messenger was the first published work to incorporate scientific observations made using a telescope.

The treatise contains descriptions of lunar landscapes, new stars in well-known constellations and the major satellites of Jupiter.

This is all correct, however because he was the first to publish people make the mistake of thinking he was the first or even the only one to make telescopic observations in 1609. Moving on, the next slide caption isn’t correct:

Galileo designed and built the most powerful telescope of his generation.

His own instrument, a thirty-power magnifier preserved at the Museo Galileo in Florence, served as model to other instrument-makers for many years.

I’m beginning to think that the Royal Society has got something against Thomas Harriot. Whilst Galileo did indeed build a thirty-power telescope it was not the most powerful telescope of his generation, Harriot built a fifty-power one. However, as in a Dutch telescope (convex objective/concave eyepiece) the field of vision diminishes with magnification the fifty-power telescope proved next to useless. Galileo’s own instrument did not serve as a model to other instrument-makers for many years that, is to put it mildly, total bullshit. Lots of people knew how to construct a simple Dutch telescope and did so without any reference to Galileo.

We skip a few slides and arrive at the most famous President of the Royal Society, Isaac Newton;

Portrait of Newton by Godfrey Kneller, 1689 Source: Wikimedia Commons

we get a picture of Newton’s reflecting telescope with the following caption:

Replica of Newton’s second reflecting telescope, which he presented to the Royal Society in 1672 Source: Wikimedia Commons

The Royal Society also owns a reflecting telescope made by Newton as a direct application of his theories on light and colour.

This statement is a best misleading and at worst simply wrong depending on how you interpret it. Newton’s theories on light and colour led him to the awareness that the coloured fringes visible on the images of the then normal refracting telescope were the result of chromatic aberration, i.e. the visible light being split up into the colour spectrum when passing through a spherical lenses. This discovery led him to developing a reflecting telescope because he believed falsely that creating an achromatic lens was impossible. It would be more than half a century before Chester Moore Hall invented the first achromatic lens. The principle of the reflecting telescope, which with a suitable mirror, does not suffer from chromatic aberration, had been known since antiquity and Newton was by no means the first to try and construct one. He was, however, the first to succeed in producing a functioning reflecting telescope. You can read an outline of the full history of the reflecting telescope here. Interestingly nobody succeeded in copying Newton’s achievements for the best part of fifty years, when John Hadley (1682–1784), another fellow of the Royal Society, who gets no mention in this slide show, finally succeeded in producing large scale functioning reflecting telescopes; Newton’s instrument was little more than a toy.

The instrument allowed him to make various observations conclusive with his theories on gravity.

This caption is just high-grade rubbish. Newton did not make any observations with this instrument that were in anyway connected with his theory of gravity, let alone conclusive with it.

There are, in the mean time, quite a few good books on the history of the telescope, I have most of them sitting on my book shelf and I’m sure some of them are in the Royal Society’s library, so why didn’t who ever put this slide show together consult them or simply ask an expert?