# Tag Info

### What type of abrasive grit was used to grind lenses for telescopes?

There is an entire article devoted to your query: From "Lens Making for Scientific Instrumentation in the Seventeenth Century" by Silvio A. Bedini (it is behind pay-wall), Appl. Opt. 5, 687-...
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### What type of abrasive grit was used to grind lenses for telescopes?

One of the early publications covering the topic is Pere Cherubin d'Orleans, La Dioptrique Oculaire, ou La Theorique, La Positive, et La Mechanique, de l'Oculaire Dioptrique en Toutes Ses Especes. ...
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### When did people notice the special shapes of snowflakes, and when did they start to study them?

There is a very nice site SnowCrystals.com run by Kenneth Libbrecht, a professor of physics at Caltech, which covers both physics and history, and hosts many captivating images, videos and more. ...
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### When was double-paned glass first invented and used for insulation?

lmgtfy google cache of mimivanderhave.com 1945 The first double-pane, insulated window was introduced That's without attribution; door and window claims From single to double pane windows… ...
• 2,535
Accepted

### What is the explanation of rope's strength in Galileo's Two New Sciences?

In this passage Galileo is explaining how a bundle of multiple short fibers twisted into a rope functions. He is analogizing a fiber in the bundle to a fiber held between fingers, and notes that it ...
• 69.5k
Accepted

### Who discovered anisotropic materials, and what were they studying?

It depends on what counts as "discovery". Interestingly, optical anisotropy was discovered before the elastic one, and the first anisotropic "material" modeled was... the luminiferous ether. ...
• 69.5k

### To what degree did ancient Egyptians use Cement Chemistry

Davidovits' theory appears to be moving slowly from fringe toward mainstream. Also the possibility of a mixed technique i.e. some carved stones along with cast blocks offers a compromise in the ...
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1 vote

### Was metallurgy of Zinc first started in India?

Zinc is principally known anciently from the production of brass which was widespread in the ancient world. The way that brass is made is that copper is combined with calamine (zinc oxide, a common ...
• 307
1 vote

### Early history of the phase concept in the physical sciences

The term phase' appears to have been coined by J. Willard Gibbs: `In considering the different homogeneous bodies which can be formed out of any set of component substances, it is convenient to have ...
• 11

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