I See Double! The Birefringence or Double Refraction of Calcite

[caption id="attachment_8638" align="alignright" width="440"] Image splitting by a calcite crystal.[/caption] Refraction? Yes. But double refraction?? A number of phenomena produce double vision. I personally suffer a degree of double vision. It was caused by pressure damage to my 6th optic nerve. The pressure resulted from a tumor on my pituitary gland. One of the most interesting sources of double vision is caused by the splitting of an image by a calcite crystal. Almost transparent, calcite is a form of calcium carbonate. The phenomenon is birefringence or double refraction. Image Splitting Property Most science loving non-scientists use the term double refraction. Refraction is the bending of light as it leaves one medium to enter another. This bending alters the course the light would have taken if there was no change in…
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Important Differences between Lime and Limestone

[caption id="attachment_7743" align="alignright" width="480"] Lime stripes on football field.[/caption] I feel certain everyone has heard, whether in the realm of gardening or in the realm of sports, the words lime and limestone. Perhaps without even consciously thinking of it, these two words have been considered by many to be synonymous. Yet they are by no means synonymous. Lime Lime is used in delineating the zones and yard lines of a football field. Lime is a fine white powder. It is occasionally spread thinly over lawns as well. What is lime chemically speaking? It is calcium oxide, chemical formula CaO. By slaking lime with water, one obtains, naturally, slaked lime! Slaked lime has the chemical formula Ca(OH)2. The slaking of lime is written, in shorthand, CaO + H2O → Ca(OH)2 +…
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