Talk:Telescope

Subsection waiting for rewrite

Telescopes as research tools

Zik (2001) notes that before the telescope scientific observation relied on instruments such as Heron's diopter, Levi Ben Gershom's cross-staff, Egnatio Danti's torqvetto astronomico, Tycho's quadrant, Galileo's geometric military compass, and Kepler's ecliptic instrument. At the beginning of the 17th century, however, it was unclear how an instrument such as the telescope could be employed to acquire new information and expand knowledge about the world. To exploit the telescope as a device for astronomical observations Galileo had to establish that telescopic images are not optical defects, imperfections in the eye of the observer, or illusions caused by lenses; and develop procedures for systematically handling errors that may occur during observation and measurement and methods of processing data. Galileo made it clear that in order to measure and interpret natural phenomena accurately, a suitable method and instrument would need to be developed. Historians of science explore the linkage established by Galileo among theory, method, and instrument, in his case the telescope. Although the telescope was not invented through science, Galileo used optics to employ a theory-laden instrument for bridging the gulf between picture and scientific language, between drawing and reporting physical facts, and between merely sketching the world and actually describing it.

Tele versus Telo

Hi Ro. In the article you edited "tele" saying that it is a word in its own right. We have looked and need a reference for this. I can not come up with any. I have reinserted telo (τηλó) but let me know if you come up with the exact word source and we'll change it to tele.--Thomas Simmons 01:04, 23 March 2008 (CDT)

Digges story

The Digges story goes back a long time but mainstream scholarlship rejects the claims, see Fred Watson, Stargazer: The Life and Times of the Telescope (2006) online reference p. 40; and Vincent Ilardi, Renaissance Vision from Spectacles to Telescopes (2006) online refernce p. 213

A leading historian of astronomy Westfall does NOT mention any telescope in his article on Digges, nor does his biographer Stephem Johnston, who in fact rejects such claims; there is "no evidence" for it Johnston says. No one ever says he saw such a telescope; son Thomas mentions an arrangement of lenses used to magnify objects on earth. Thomas who was an astronomer and senior military person never again mentioned the telescope and never used one or tried to get one built, which is astonishing if he indeed had one at one point during his father's lifetime. The son's statement that the father saw "at seven miles what had been doon at that instant in private places" is too incredible to believe. The son also claims "ye shall discerne any trifle, or read any letter there lying open, especially if the sunne beames come unto it, as plainly as if you were corporally present, although it be distante from you as farre as eye can discrye" which was quite impossible and strongly suggests he never used or invented a telescope. Of course science is a social interaction and claims of secret discoveries are very heavily discounted by historians. Richard Jensen 03:23, 23 March 2008 (CDT)

A leading historian? Mainstream? Send me copies of the sources mentioned above. I do not feel like spending my hard earned cash with Amazon dot Com everytime some one says that the British historians are unqualified to talk about British history. Sorry but I have placed good sources there. It would be appropriate to simply offer the counter arguments. The sources mentioned that do provide the story about the Diggeses involvement are not rumour, they exist. The position one may take from the available sources is in fact better than many of the events we ascribe to, say, the Romans, e,g, the entire events at Adrianople. Look at the mention Vesto Slipher gets for his research in spectral shift and the expansion of the universe yet his papers were published as far back as 1913. Consider how many times John Michell is mentioned when anyone talks about the theoretical underpinnings of black holes yet Cavendish did in fact read his paper to the Royal in the 18th century--Cavendish for pity's sake.

Most importantly, such sweeping deletions and revisions are to be discussed here. If you feel a balance is needed then write one and well discuss this. That is CZ policy. Please bear this in mind. --Thomas Simmons 04:14, 23 March 2008 (CDT)

To wit: Gilbert E Satterthwaite, Department of Physics, Imperial College, London SW7 2BH, UK; Colin Alistair Ronan, Science writer and lecturer. Author of The Cambridge Illustrated History of the World's Science. --Thomas Simmons 04:49, 23 March 2008 (CDT)

Digges myth and proposed compromise

Jensen: The idea that Digges invented a telescope is a vastly exaggerated myth that the consensus of recent scholars reject.

Please click on these 2006 book references and read their rejection of the myth. Fred Watson, Stargazer: The Life and Times of the Telescope (2006) online reference p. 40; and Vincent Ilardi, Renaissance Vision from Spectacles to Telescopes (2006) online refernce p. 213 re: Sorry but I have placed good sources there. The sources reject the myth. Thus Westfall, a leading scholar, says Digges invented an astrolabe and never mentions a telescope.

The article cites Johnson (Digges main biographer) who rejects the claim. Johnson in Oxford Dictionary of National Biography (2004): On the basis of comments by his son, occasional claims have been made that Digges devised a reflecting telescope; there is no evidence that his reported optical experimentation led to a working instrument for astronomical observation, but it seems likely that he did indeed use a rather unwieldy lens–mirror combination for terrestrial viewing.

The Gilbert E. Satterthwaite book on astronomy appeared in 1971 and hardly reflects current scholarship.

The only support comes from Colin A. Ronan who died in 1995 and he came to that idea late in life (1991). His article was not refereed and is based entitely on conjecture. In his 1967 book on English astronomy Ronan mentions Leonard Digges only in passing with no mention of these supposed inventions. see page 30

As for balance, while I think one sentence will do I nevertheless do have a compromise solution as follows:

Compromise statement by Jensen: Leonard Digges (?1515-?1559)was an English mathematician and architect who was the first in England to describe the altazimuth theodolitede. On the basis of much later comments by his son, some writers have claimed Digges might have devised a reflecting telescope. Apart from a brief few sentences by his son there is no independent evidence that he invented a working telescope for astronomical observation; it seems likely that he did indeed use a rather unwieldy lens–mirror combination for terrestrial viewing. His son Thomas, who was active in astronomy never claims to have used his father's supposed telescope; no one else claims to have seen it. +

Thomas in 1571 recalled how his father had observed things with "Perspective glasses" on numerous occasions from a considerable distance and with witnesses present: The father "sundrie Times hath by proportionall Glasses duly situate in convenient angles, not onely discovered things farre off, read letters, numbered peeces of money with the very coyne and superscription thereof, cast by some of his freends of purpose uppon Downes in open fields, but also at seven miles declared what had been doon at that instant in private places." +

Colin Ronan and Gilbert Satterthwaite built a working telescope in 2002 from a description found in a report on military and naval inventions, written in 1578 by William Bourne. It comprised a convex lens at the front and a curved mirror at the back, and gave an inverted image magnified 11x. There is no evidence that Bourne himself ever built the proposed telescope. +

end of compromise text Richard Jensen 05:13, 23 March 2008 (CDT)

Telescopes

Noel wrote:

The following comment which in part discusses the substantive content might better have been posted in Talk:Telescope, where future authors/editors can find it more easily. J. Noel Chiappa 11:26, 23 March 2008 (CDT)

CZ can't be making claims that are rejected by most scholars. Notable the Digges story. Please argue it out on the telescope-talk page first; CZ does not allow for the kind of reverting-wars that mar Wikipedia Richard Jensen 04:05, 23 March 2008 (CDT)

Unbelievable. Most scholars? Someone took a survey and that has been made public? Let's be specific and stick to facts here. You have made massive deletions without consultation, dismissed sources that are employed by the Imperial College and or have written well known works in the field for Cambridge U. Press and then misrepresent the very sources that half-heartedly pronounce who is and who is not mainstream.

To quote one of these mainstream sources From Fred Watson (2006) Stargazer:The life and times of the telescope

"From Pantometria and from writings of another Elizabethan mathematicians, William Bourne (also a contemporary of Thomas Digges), it is clear that the instrument described by the two Diggeses incorporated a dished mirror though probably unlike the modern reflecting telescope. . . .

But what might be called mainstream scholarship upholds an opposing view, namely that the first practical reflecting telescope was constructed by Issac Newton in 1668."

I sum up: Given the difficulty in making an adequate mirror to provide the sort of resolution that Thomas Digges asserts in his words in the Pantometria, it is unlikely that a practical instrument was built by Thomas Digges simply because the technological skill would have most probably been beyond the efforts of the 16th century.

This is no where near a whole-hearted a denunciation of the Diggeses earlier purported in the rationale for the huge deletions nor does the information presented from the source, Colin Ronan, make any pretense to extraordinary accomplishments. The deed was done and the fine instruments we see today had to wait for another time. That sums it up. Issac Newton did not invent the telescope, Galileo did not, Lipperhey did not and it would not be surprising to hear than neither were the Diggeses the first to sort this one out. In fact, there is some possibility that Caesar, to use Watson as a source here, was able to see from afar as well. Galileo is reported to have built his own instruments from a mere traveler's description and was able to see well enough to draw rather detailed views of the lunar aspects.

Furthermore Watson denounces Thomas Digges' claims about his father's powers of resolution. And Watson admits that a mirror is technically much harder to produce than a lens--yet Galileo did make a refractive telescope that had sufficient resolution within one lifetime from Thos. Digges with far less preparation--but Leonard and Thomas could not?

The information offered by Watson certainly makes for a balanced and informed perspective even though it is very possible that he is constructing a straw man to deconstruct but the deletions were wholly unnecessary and well outside the CZ community norm.--Thomas Simmons 05:49, 23 March 2008 (CDT)