Pub Date : 2021-03-01DOI: 10.1093/OSO/9780197518571.003.0020
S. R. Wilk
Photographic color test cards having four rows of six squares include a six-square row that has six gradations of gray, including pure white and pure black at the ends. The intervening values are different manifestations of gray, going from lighter to darker. But how are the intervening values selected? What determines how “gray” they are? It turns out that they are not steps of equal change in transmission (or reflection, depending upon the type of chart), nor are they steps of equal change in optical density. The size of the gray “steps” are chosen on a somewhat different scale of values. Who came up with them, and how did they decide which values to use?
{"title":"Forty-Four Fewer Shades of Gray","authors":"S. R. Wilk","doi":"10.1093/OSO/9780197518571.003.0020","DOIUrl":"https://doi.org/10.1093/OSO/9780197518571.003.0020","url":null,"abstract":"Photographic color test cards having four rows of six squares include a six-square row that has six gradations of gray, including pure white and pure black at the ends. The intervening values are different manifestations of gray, going from lighter to darker. But how are the intervening values selected? What determines how “gray” they are? It turns out that they are not steps of equal change in transmission (or reflection, depending upon the type of chart), nor are they steps of equal change in optical density. The size of the gray “steps” are chosen on a somewhat different scale of values. Who came up with them, and how did they decide which values to use?","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127997360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-01DOI: 10.1093/OSO/9780197518571.003.0038
S. R. Wilk
3-D movies have gone through several waves of popularity. They have appeared several times in the 20th and 21st centuries, with new developments in technology enabling better effects with each new incarnation. Rotating discs, polarizing glasses, anaglyphic glasses, coupled polarizers and optical retarders, and the use of electro-optic shutters each provided small advantages over previous technology. But the basic idea is simple, and was used in the 19th century stereoscope—present each eye with an independent view from a different perspective so that the parallax enables the brain to fuse them into one stereoscopic image. Who invented the first 3D movies? The idea is much older than most people suspect, dating back to the very beginning of cinema.
{"title":"The First 3D Movies","authors":"S. R. Wilk","doi":"10.1093/OSO/9780197518571.003.0038","DOIUrl":"https://doi.org/10.1093/OSO/9780197518571.003.0038","url":null,"abstract":"3-D movies have gone through several waves of popularity. They have appeared several times in the 20th and 21st centuries, with new developments in technology enabling better effects with each new incarnation. Rotating discs, polarizing glasses, anaglyphic glasses, coupled polarizers and optical retarders, and the use of electro-optic shutters each provided small advantages over previous technology. But the basic idea is simple, and was used in the 19th century stereoscope—present each eye with an independent view from a different perspective so that the parallax enables the brain to fuse them into one stereoscopic image. Who invented the first 3D movies? The idea is much older than most people suspect, dating back to the very beginning of cinema.","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129064507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-01DOI: 10.1093/OSO/9780197518571.003.0016
S. R. Wilk
Candle flames have a warm, yellow color that is prized as nostalgic and romantic. But why is this the color of a standard candle flame? The usual explanation given is that the color is due to minute particles of soot that result from combustion of the candle wax, heated to incandescence, and emitting blackbody radiation. But this explanation cannot be correct. The shape of the emission spectrum is not that of a blackbody spectrum, and the peak occurs at much too short a wavelength, given the flame’s temperature. So what physical phenomenon does dictate the properties of the light from a candle?
{"title":"Why Are Candle Flames Yellow?","authors":"S. R. Wilk","doi":"10.1093/OSO/9780197518571.003.0016","DOIUrl":"https://doi.org/10.1093/OSO/9780197518571.003.0016","url":null,"abstract":"Candle flames have a warm, yellow color that is prized as nostalgic and romantic. But why is this the color of a standard candle flame? The usual explanation given is that the color is due to minute particles of soot that result from combustion of the candle wax, heated to incandescence, and emitting blackbody radiation. But this explanation cannot be correct. The shape of the emission spectrum is not that of a blackbody spectrum, and the peak occurs at much too short a wavelength, given the flame’s temperature. So what physical phenomenon does dictate the properties of the light from a candle?","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114227170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-01DOI: 10.1093/OSO/9780197518571.003.0027
S. R. Wilk
People have known of the effectiveness of sunlight in helping people recover from illness, and early work on bacteria showed that sunlight could indeed kill micro-organisms. The efficacy of sunlight as a germicidal agent was worked into sanitation designs from the turn of the century. Then it was learned that ultraviolet light with wavelengths shorter than those transmitted by the atmosphere were even more effective at killing germs. Recently SODIS—SOlar DISinfection of contaminated water, a very simple process that uses only ordinary sunlight and no shortwave rays—provides a surprisingly effective, low-tech method for killing harmful microorganisms in water. How can this possibly work?
{"title":"The Best Disinfectant","authors":"S. R. Wilk","doi":"10.1093/OSO/9780197518571.003.0027","DOIUrl":"https://doi.org/10.1093/OSO/9780197518571.003.0027","url":null,"abstract":"People have known of the effectiveness of sunlight in helping people recover from illness, and early work on bacteria showed that sunlight could indeed kill micro-organisms. The efficacy of sunlight as a germicidal agent was worked into sanitation designs from the turn of the century. Then it was learned that ultraviolet light with wavelengths shorter than those transmitted by the atmosphere were even more effective at killing germs. Recently SODIS—SOlar DISinfection of contaminated water, a very simple process that uses only ordinary sunlight and no shortwave rays—provides a surprisingly effective, low-tech method for killing harmful microorganisms in water. How can this possibly work?","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"61 16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116479941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1093/oso/9780197518571.003.0005
S. R. Wilk
For centuries Great Britain could rely upon its position as an island nation to keep a barrier between them and any invaders from continental Europe. They cultivated a large and powerful navy to maintain control of the waterways, and this and good fortune enabled them to withstand or discourage attacks from Spain, France, and Germany. But with the development of aircraft at the beginning of the 20th century, potential invaders had a way to project force to the islands without having to go by sea, and a method of detecting any such attacks had to be found so that they could be targeted. Before radar had been developed, one method was to use huge hemispherical cavities to concentrate faint noises onto a microphone placed near the focus. Many of these were constructed, carved out of stone, or cast in concrete, and, being large and robust, most of them still exist.
{"title":"Acoustic Mirrors","authors":"S. R. Wilk","doi":"10.1093/oso/9780197518571.003.0005","DOIUrl":"https://doi.org/10.1093/oso/9780197518571.003.0005","url":null,"abstract":"For centuries Great Britain could rely upon its position as an island nation to keep a barrier between them and any invaders from continental Europe. They cultivated a large and powerful navy to maintain control of the waterways, and this and good fortune enabled them to withstand or discourage attacks from Spain, France, and Germany. But with the development of aircraft at the beginning of the 20th century, potential invaders had a way to project force to the islands without having to go by sea, and a method of detecting any such attacks had to be found so that they could be targeted. Before radar had been developed, one method was to use huge hemispherical cavities to concentrate faint noises onto a microphone placed near the focus. Many of these were constructed, carved out of stone, or cast in concrete, and, being large and robust, most of them still exist.","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115282452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1093/oso/9780197518571.003.0023
Stephen R. Wilk
Several writers in the 19th century, including Florence Nightingale, recorded their impressions of a rainbow-like phenomenon seen in the desert, and assumed to be caused, not by droplets of rain, but by grains of sand. Is it, in fact, possible for spherical grains of sand to exist in a great enough quantity for thisd, for the relatively heavy sand to be lofted into the air, and to be transparent enough to produce what we have to call a “sandbow”? Speculation centered around “oolitic” sand that nucleates around organic matter and is naturally rounded, but which is translucent, rather than transparent.
{"title":"The Sandbow","authors":"Stephen R. Wilk","doi":"10.1093/oso/9780197518571.003.0023","DOIUrl":"https://doi.org/10.1093/oso/9780197518571.003.0023","url":null,"abstract":"Several writers in the 19th century, including Florence Nightingale, recorded their impressions of a rainbow-like phenomenon seen in the desert, and assumed to be caused, not by droplets of rain, but by grains of sand. Is it, in fact, possible for spherical grains of sand to exist in a great enough quantity for thisd, for the relatively heavy sand to be lofted into the air, and to be transparent enough to produce what we have to call a “sandbow”? Speculation centered around “oolitic” sand that nucleates around organic matter and is naturally rounded, but which is translucent, rather than transparent.","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133494592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1093/oso/9780197518571.003.0014
Stephen R. Wilk
The Book of Genesis famously opens with God ordering “Let there be Light!” as the first step in the Creation. This stands in contrast to most of the creation myths of other cultures, which do not begin with the creation of light. What is the significance of this? Is it meant to be taken literally (so that God can see what He is doing and Creation is visible to all), or metaphorically (that is, is light meant to stand for Knowledge, Wisdom, or Understanding)? Do any other cultures also start things off with the creation of light?
{"title":"Fiat Lux!","authors":"Stephen R. Wilk","doi":"10.1093/oso/9780197518571.003.0014","DOIUrl":"https://doi.org/10.1093/oso/9780197518571.003.0014","url":null,"abstract":"The Book of Genesis famously opens with God ordering “Let there be Light!” as the first step in the Creation. This stands in contrast to most of the creation myths of other cultures, which do not begin with the creation of light. What is the significance of this? Is it meant to be taken literally (so that God can see what He is doing and Creation is visible to all), or metaphorically (that is, is light meant to stand for Knowledge, Wisdom, or Understanding)? Do any other cultures also start things off with the creation of light?","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"257 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116015957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1093/oso/9780197518571.003.0015
S. R. Wilk
In order to compare the output from the different light sources that became available in the nineteenth century, the measurement of light was codified., One of the reference standards that was selected was the light from a spermaceti candle of a specified composition and size, made in a specified fasion and burning at a precise rate. But the spermaceti used to fabricate the candle is the natural product of non-domesticated animals living in the wild. It therefore ought to be expected to have great variation in its own composition. How did the governing bodies settle on a spermaceti candle, and why did they continue to use it?
{"title":"Not Worth the Candle","authors":"S. R. Wilk","doi":"10.1093/oso/9780197518571.003.0015","DOIUrl":"https://doi.org/10.1093/oso/9780197518571.003.0015","url":null,"abstract":"In order to compare the output from the different light sources that became available in the nineteenth century, the measurement of light was codified., One of the reference standards that was selected was the light from a spermaceti candle of a specified composition and size, made in a specified fasion and burning at a precise rate. But the spermaceti used to fabricate the candle is the natural product of non-domesticated animals living in the wild. It therefore ought to be expected to have great variation in its own composition. How did the governing bodies settle on a spermaceti candle, and why did they continue to use it?","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129091972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1093/oso/9780197518571.003.0002
S. R. Wilk
If you ask a search engine, “Who invented the black light?,” odds are very good that the answer you will receive is “Dr. William H. Byler in 1935.” But, in fact, Dr. Byler never claimed to have invented the long-wave ultraviolet light, no such invention is recorded in any of his papers or patents, and what is certainly what we today call the “blacklight” was invented over fifteen years earlier. So who really did invent it, and how did Byler’s name and date get on it? We look into the history and development of the ultraviolet lamp and at the work of Dr. Byler.
{"title":"Who Invented the Black Light?","authors":"S. R. Wilk","doi":"10.1093/oso/9780197518571.003.0002","DOIUrl":"https://doi.org/10.1093/oso/9780197518571.003.0002","url":null,"abstract":"If you ask a search engine, “Who invented the black light?,” odds are very good that the answer you will receive is “Dr. William H. Byler in 1935.” But, in fact, Dr. Byler never claimed to have invented the long-wave ultraviolet light, no such invention is recorded in any of his papers or patents, and what is certainly what we today call the “blacklight” was invented over fifteen years earlier. So who really did invent it, and how did Byler’s name and date get on it? We look into the history and development of the ultraviolet lamp and at the work of Dr. Byler.","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134358741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1093/oso/9780197518571.003.0022
S. R. Wilk
Many interference phenomena that are seen in the natural world are characterized by alternating bands of pinkish-purple and aqua colors. These can be seen in oil films, soap bubbles, interference from scratches, supernumerary rainbows, glories, and other places where multiple orders of interference are present and the light source is broad band white light. It was such a clear manifestation of a common optical effect that it was very early on incorporated into computer simulation software. The effect also shows up in many basic optics experiments, such as on the edges of single-slit interference patterns. Why does white light multiple-order interference tend to produce aqua and pink colors?
{"title":"Preppy Physics","authors":"S. R. Wilk","doi":"10.1093/oso/9780197518571.003.0022","DOIUrl":"https://doi.org/10.1093/oso/9780197518571.003.0022","url":null,"abstract":"Many interference phenomena that are seen in the natural world are characterized by alternating bands of pinkish-purple and aqua colors. These can be seen in oil films, soap bubbles, interference from scratches, supernumerary rainbows, glories, and other places where multiple orders of interference are present and the light source is broad band white light. It was such a clear manifestation of a common optical effect that it was very early on incorporated into computer simulation software. The effect also shows up in many basic optics experiments, such as on the edges of single-slit interference patterns. Why does white light multiple-order interference tend to produce aqua and pink colors?","PeriodicalId":211028,"journal":{"name":"Sandbows and Black Lights","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122303078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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