TL 3 telescopes and microscopes

[Tom Mazanec]

Could a TL 3 culture develop these two inventions?

[Anthony]

Originally Posted by Tom Mazanec

Could a TL 3 culture develop these two inventions?

Maybe, but not as a single invention? You need lens grinding and polishing to exist and be inexpensive enough for experimentation to be viable, at which point sufficient experimentation (it took about three centuries historically) can get you to simple microscopes and telescopes.

[ravenfish]

Historically, convex lenses for eyeglasses appeared at late TL3 (Roger Bacon makes comments that seem to refer to them, and they were certainly in existence, albeit as an exotic curiosity, by the early 1300s), so it is not entirely implausible that someone could notice a few centuries early how to employ them to magnify far-off objects. Bear in mind that clear glass is itself a mid-to-late TL3 invention, so, barring expensive and difficult-to-work-with transparent crystals, there's a limit to how early you can push lens-based technology.

[whswhs]

Rudyard Kipling has a story about that: "The Eye of Allah" (http://www.telelib.com/authors/K/Kip...its/index.html).

I haven't researched the history of optics in depth, but I have the impression that early TL4 optics had enough problems with the quality of glass for lenses that using optical devices was a strain. I expect TL3 lenses would have been even worse.

[Turhan's Bey Company]

Originally Posted by whswhs

I have the impression that early TL4 optics had enough problems with the quality of glass for lenses that using optical devices was a strain. I expect TL3 lenses would have been even worse.

This is consonant with what I know (and, obGURPS, what we wrote in Low Tech, p. 42). There are enough little tiny subtle things that have to be right that consistently making such things is TL4, but at TL3 society advanced in optics isn't out of the question the way a TL3 society with CD players would be.

[Anthony]

Originally Posted by whswhs

I haven't researched the history of optics in depth, but I have the impression that early TL4 optics had enough problems with the quality of glass for lenses that using optical devices was a strain.

Even with good glass, you're not realistically going to deal with chromatic aberration before TL 5 (you need to have the concept, then you need the materials and production quality to compensate).

[Willy]

Can be possible. In TL 3 medieval europe you had lens grinders and a basic knowledge of how to use glasses to correct eyesight. The idea that a lens grinder is just by accident holding 2 lenses in the right distance from each other and looks though is very possible. In the east telescopes were far ealier known as in europe.

A microscope is also feasible, but needs a way more glad accidents to happen. All the basic technologys are there, but combining them into a working tool is quite another matter.

Remember that lens grinding was much earlier done the vikings polished there sun stones, and may just have tried any clear material for a similar effect.

[whswhs]

Originally Posted by Willy

Can be possible. In TL 3 medieval europe you had lens grinders and a basic knowledge of how to use glasses to correct eyesight. The idea that a lens grinder is just by accident holding 2 lenses in the right distance from each other and looks though is very possible. In the east telescopes were far ealier known as in europe.

I’ve not heard of this. Can you point me at a source?

[Willy]

Originally Posted by whswhs

I’ve not heard of this. Can you point me at a source?

The problem is the lens grinding in the medieval was to a lenght written in a german reenactment magazine, with a 8 sources list of further reading, all german of course. This mag is recommended enough not to write BS. Got lucky and found the right mag in a shelf. It´s Karfunkel Nr. 62 Page51 ff, the list of sources sadly all german, the magazine is from 2006 Februar/März ( german month name ) I will send you a PM if wished with a short abstract of the topic and in the articel are pictures depicting people wearing glasses: 1352 a Kardinal signing something on a fresco in the monastery of San Nicole', and the circumcission christy on a altar picture in the St Jakobs church in Rothenburg ob der Tauber from 1466. The pictures / frescos may be found on the web.

The sun stones came from a TV science programm called Terra X, if I remind correctly a sun stone is mentioned in a monastery inventory list around the year 900, the vikings used them historically longer. Same goes for telescopes from another book read a decade ago. I wouldn´t even know where to search exactly for the right book / episode.

Hope this helped you a bit.

[whswhs]

What I was hoping for was specifically something on Chinese optical technology. The other things I was aware of.