RE: The thread being discussed Equation of TimeRE: New Question The link has a real nice representation EOT
HI Group, The link in the message from clar...@aol.com below has this link on the page also An Intrinsic Representation of the Equation of Time - 2014-2017 - a .pdf file. This example is for Greenwich - contact me (ke...@karney.com) for a version for your own locality and the Nodebox 1.9.7 python code - Flame EoT.py I would like to include the graph of EOT in a sundial I did email the author above and was wondering if perhaps the mathematics behind it had been included in a Delta Cad Marco I could make use of. I hope the author Kevin Karney does reply with the graph. Ray Rochester NY USA N043.18550, W077.59415 From: clar...@aol.com To: rkell...@comcast.net, sundial@uni-koeln.de Cc: Date: Fri, 27 Jan 2017 12:13:05 -0500 Subject: Re: Looking for minutes and seconds correction for whole year, for Equation of Time plaque Thanks Bob and everyone else for their input. The EQT really does change way into the future. I am leaning towards Kevin Karney website: http://www.precisedirections.co.uk/Sundials/index.html using a “Victorian EOT” table adding or subtracting minutes. I could set it into the future 2050 and after that I am sure I will not be around or if the sundial is still standing. Thanks, Ken Clark Elizabethtown, PA --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Why we should reform the Calendar
A bit off topic, but I enjoyed this quite a lot! https://youtu.be/EcMTHr3TqA0 Dan --- https://lists.uni-koeln.de/mailman/listinfo/sundial
RE: Why we should reform the Calendar
Hear, hear!! From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Dan-George Uza Sent: Saturday, January 28, 2017 12:38 PM To: sundial@uni-koeln.de Subject: Why we should reform the Calendar A bit off topic, but I enjoyed this quite a lot! https://youtu.be/EcMTHr3TqA0 Dan --- https://lists.uni-koeln.de/mailman/listinfo/sundial
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Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die eigentliche Nachricht steht dadurch in einem Anhang. This message was wrapped to be DMARC compliant. The actual message text is therefore in an attachment.--- Begin Message --- Jack thanks for the feedback, I appreciate it. Simon Sent from Yahoo Mail on Android On Thu, Jan 26, 2017 at 23:12, Jack Aubert wrote: HI Simon, I like to use the “time of solar transit” version of the EOT from your spreadsheet because I can never remember with any confidence if I am correcting the watch or the dial. Jack Aubert From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Simon Wheaton Smith Sent: Wednesday, January 25, 2017 8:08 PM To: Kenneth R clark Cc: sundial@uni-koeln.de Subject: Re: Looking for minutes and seconds correction for whole year for Equation of Time plaque Last email from me today... here is the 4 year EOT from my main book Simon On Wed, Jan 25, 2017 at 5:21 PM, Kenneth R clark wrote: I had an error message from AOL Sorry for no subject line and my files were not sent. Let me retry with this account. Hi everyone, I am working on my Equation of Time plaque for my aluminum cross sundial. All the instructions and graphics and EQT will be on an 8 ½” diameter ½” aluminum plate. I do not want to use the standard graph found on many sundials but instead a chart for the whole year, mins and secs, to add or subtract total correction to get watch time. I do not have much room for detailed instructions. I looked at difference sources for the chart and would like to verify the most accurate times to use the four year leap year cycle for a church at 40.1526N, 76.6038W. I have looked at the Solar Noon calculator, Sonne and Shadows-(cannot input decimal degrees?) Are there other sources or spreadsheet programs? I like to convey that sundials are accurate. I envision that a person will wait till the shadow is on a line and the person will know what time it is suppose to be even though this type of sundial may not be design for precision. I made a quick drawing. There will be some type of sun image at the top and a logo at the bottom for the location. The chart in the center is from another project that I did just to see how it would look and if the printing is large enough to read. I would have to change the inputs to standard time for the whole year. I have also attached a picture of the sundial. I just want to know if I am using the right times and would appreciate any comments or suggestions. Thanks very much Ken Clark Elizabethtown, PA --- https://lists.uni-koeln.de/mailman/listinfo/sundial -- Simon Wheaton-Smith www.illustratingshadows.com Phoenix, AZ W 112.1, N 33.5 --- End Message --- --- https://lists.uni-koeln.de/mailman/listinfo/sundial
What is the Real Time?
An episode of the BBC World Service program "CrowdScience". A couple of inaccuracies/exaggerations but worth a listen. "It sounds like a simple question – what is the time? But look closer and you realise time is a slippery concept that scientists still do not fully understand. Even though we now have atomic clocks that can keep time to one second in 15 billion years, this astonishing level of accuracy may not be enough. The complexity of computer-controlled systems, such as high-frequency financial trading or self-driving cars which rely on the pinpoint accuracy of GPS, could in future require clocks that are even more accurate to ensure everything runs ‘on time’. "But what does that even mean? As Anand Jagatia discovers, time is a very strange thing. He visits the origins of modern time-keeping at the Royal Observatory in Greenwich and meets scientists at the National Physical Laboratory who have been counting and labelling every second since the 1950s. He meets Demetrios Matsakis, the man who defined time and visits the real-life ‘Time Lords’, at the International Bureau of Weights and Measures (BIPM) in Paris to find out how they co-ordinate the world’s time and why the leap second is ‘dangerous’." http://www.bbc.co.uk/programmes/p04q778b -- Richard Langley - | Richard B. LangleyE-mail: l...@unb.ca | | Geodetic Research Laboratory Web: http://gge.unb.ca | | Dept. of Geodesy and Geomatics EngineeringPhone:+1 506 453-5142 | | University of New Brunswick Fax: +1 506 453-4943 | | Fredericton, N.B., Canada E3B 5A3| |Fredericton? Where's that? See: http://www.fredericton.ca/ | - --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Why we should reform the Calendar
I don't think it's really off-topic, because, with sundials, we're interested in the EqT, which is given in terms of the calendar's dates. Though Gorman is a comedian, he's obviously given the matter some serious consideration, and I perceive some serious interest in calendar-reform. But I have a few disagreements with his proposal: *1. Blank Days:* Gorman proposes a "fixed calendar", a calendar that will be the same for every year. I have no objection to that. After all, so far as we know (except for each year setting a new record for increasing global warming) what we can expect from each year, nature-wise, is really the same. So, why should two successive years have different calendars, with different dates having different days-of-the-week? So far so good. There are two ways proposed for achieving a fixed calendar: *1. Blank Days:* A fixed calendar must have a number of days that's a multiple of 7, That's what enables each calendar to start on the same day of the week, allowing every date to have a day-of-the-week that doesn't change from year to year. So Gorman would make one of the 365 days a "blank day", a day that isn't a day of the week. Then the days-of-thes-week would resume after that day. so the year would have only 364 days that are days of the week. That being a multiple of 7, each year will start on the same day of the week, as desired. Problem: I'm sorry, but it doesn't make any sense for the day after a Saturday to be anything other than a Sunday. ...or for there to be an intervening day between a Saturday & a Sunday. Speaking for myself, I completely reject "blank-days". And I'm not the only one. Elizabeth Achellis, over several decades, up to around 1955, proposed a fixed calendar with blank-days. The League of Nations, and later the U.N. were giving serious consideration to it, and it might have been accepted, except for the strong opposition to the blank-days, A compromise was offered to Achellis: A leap-week (described in the next section below), to achieve a fixed calendar. She wouldn't accept that compromise, and her proposal was indefinitely tabled around 1955, and never got anywhere since. You could say that the blank-days were the Achilles' heel of Achellis' calendar proposal. *Leap-Week:* So a 364 day common (non-leap) year achieves a fixed calendar, because 364 is divisible by 7. What about the 365th day? Well, we could deal with it the same way we deal with the fact that the 365 day year is shorter than the 365.24217 day Mean Tropical Year (MTY)...by occasionally lengthening a year, to periodically compensate for the length-mismatch. So we'd deal with the short common year just as we do now. So, what we do is have a 364-day common year, and (by using a leap-year rule that I'll talk about later), when that 364-day common year gets about half a week out-of-step with the seasons, we add a leapweek, to set that displacement back. Gorman didn't talk about the leapyear-system, and we can presume that he meant to use the existing Gregorian leapyear system, which would be fine, for a leapday calendar such as he proposes. But for a leapweek calendar, which is what I (and many others) propose, a new leapyear system is required. No problem. I'll get to that after I discuss my disagreements with Gorman's proposal. Summary: A fixed calendar should be achieved via a leapweek, instead of by blank-days. If Achellis had agreed to that, we might be using her calendar right now. *2. Thirteen Months:* Really, the only reason for a reform calendar to have months, is for continuity & familiarity with our current Roman-Gregorian Calendar. For example, Elizabeth Achellis's *World Calendar *had, in each quarter, months with the following lengths: 31,30,30. Having 12 months, with 30 or 30 or 31 days, means that the calendar is familiar, looks familiar, and it means that the dates in the new calendar have really the same seasonal meaning as the dates in the old calendar. Achellis' 31,30,30 quarters achieves that. But there are other proposals of a calendar with 30,30,31 quarters. The advantage?: 1. The 30,30,31 calendar's months' start-days never differ by more than a day, from those of our current Roman months, when both month-systems start on the same day. Achellis' 31,30,30 quarter system can differ by at least twice as much. 2. The 30,30,31 quarters divide the weekdays most equally between the months of the quarter. So, if you're going to have months at all (and that's for continuity & familiarity), then you want 12 months, of 30 & 31 days. Preferably the 30,30,31 quarters. With 13 months of 28 days, the dates wouldn't have anything like the seasonal meaning that they do now. Continuity, familiarity, and the justification for having months at all, would be lost. The 30,30,31 quarter system is an improvement over our current Roman months, because the months are much more uniform. That allows much meaningful & accurate monthly statistics. But suppose you want something m