tag:blogger.com,1999:blog-1840985738235902482.post4165857058077541561..comments2024-03-27T07:14:48.488-04:00Comments on John the Math Guy: Flat paint is not flatJohn Seymourhttp://www.blogger.com/profile/11350487038873935295noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-1840985738235902482.post-73732194271543742132012-09-25T00:31:06.541-04:002012-09-25T00:31:06.541-04:00Time on a heatset web is much more costly than ink...Time on a heatset web is much more costly than ink. (a total guess, knowing that cost is usually the determining factor over quality)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-58676006908287915292012-07-05T11:03:42.496-04:002012-07-05T11:03:42.496-04:00As for those darn flocculating extenders... One th...As for those darn flocculating extenders... One thing I have pondered about heatset presses... In order to maximize the amount of product out the door, the press guy tries to run the press as fast as possible, which means he needs to run the dryer at a higher temp. Doing that, he spends more money on natural gas, but (it seems to me) he also loses gloss. This means he needs to run more ink to get the same density.<br /><br />I wonder how big this effect is. What are the hidden costs of running faster?John Seymourhttps://www.blogger.com/profile/11350487038873935295noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-87123500983239959022012-07-05T11:02:52.284-04:002012-07-05T11:02:52.284-04:00This comment has been removed by the author.John Seymourhttps://www.blogger.com/profile/11350487038873935295noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-80575654606480732582012-07-05T10:55:57.382-04:002012-07-05T10:55:57.382-04:00I love the comments! Thank you, Unknown. (Althoug...I love the comments! Thank you, Unknown. (Although I suspect you are not quote unknown to me. I think I recognize the lion by his paw.)<br /><br />You are correct that I have given too much credit to Ptolemy. He merely characterized the effect of Snell's law, and fit a quadratic to it. He did not analyze this from first principles, apply a trig function, or go beyond measurements of refraction in water.<br /><br />Thanks for the info on ibn Sahl. I had not yet met the guy in my studies on applied math history.<br /><br />You're right. Fresnel's law is not required when understanding Fresnel lenses. <br /><br />I hope you don't think less of me for sometimes favoring "cool" over "useful". :)John Seymourhttps://www.blogger.com/profile/11350487038873935295noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-84898409950991914182012-07-05T00:02:13.773-04:002012-07-05T00:02:13.773-04:00Perhaps next time you will give more attention to ...Perhaps next time you will give more attention to the instructions from the coatings chemist concerning the reaction temperature required for his polymer resin to form a conformal coating instead of floculating the extenders and pooling a layer of unpigmented polymer at the surface of the coating.<br /><br />Also those in optics prefer the term metrology or metrological to mensuration, even though optics is highly dependent on geometry we prefer to reserve the term mensuration for the practice of measurement in geometric mathematics.Unknownhttps://www.blogger.com/profile/03791815228024493846noreply@blogger.comtag:blogger.com,1999:blog-1840985738235902482.post-13947813186509767052012-07-04T23:43:33.306-04:002012-07-04T23:43:33.306-04:00Actually what we call Snell's law was not accu...Actually what we call Snell's law was not accurately derived ny Ptolemy but by Ibn Sahl in 984 (Rashed, Roshdi (1990). "A pioneer in anaclastics: Ibn Sahl on burning mirrors and lenses". Isis 81 (3): 464–491. DOI:10.1086/355456.)<br /><br />While you may consider Fresnel's law way cooler it is far less useful. Snell is used to undepin most ray tracing programs use to design focusing devices in all kinds of modern optoelectronic devices. Fresnel not required.<br /><br />Fresnel lenses have nothing in common with the law assigned to his name.Unknownhttps://www.blogger.com/profile/03791815228024493846noreply@blogger.com