If it helps, I have several methods of computing the Sun's position at varying degrees of accuracy/complexity, and some sundial code at https://www.celestialprogramming.com/
Not really anything in there regarding the sundial. I'm guessing that was put in there metaphorically for clickbait reasons.
Knowing quite a bit about sundials I was genuinely curious about how that would work, as a typical (horizontal) sundial doesn't have enough information to make a calendar. It's a time of day device, rather than a time of year device. You could teach the model about the Equation of Time or the Sun's declination, but it wouldn't need the sundial at that point. There are sundials like a spider sundial, or nodus sundial, that encode date information too. But there's overlap/ambiguity between the two solstices as the sun goes from highest to lowest, then back to its highest declination. Leap years also add some challenges too. There are various ways to deal with those, but I think you can see why I was curious how producing a calendar from a sundial would work (without giving it some other information that makes the sundial unecessary).
There are a handful of Earth centered, geocentric standard reference frames. The most used today is the Geocentric Celestial Reference System (GCRS). It should be obvious that if you want to compute where to point a telescope, a transformation of coordinates will involve a step through such a coordinate system. GPS is it's own system, but there are transformations to and from the GCRS and GPS frames. Which one makes sense depends a lot on your application.
I guess I must be. Where did he "point out the difference between new and used"? All I see is "But newsflash: used is different than new", then the explicit declaration 'you can't say "Tiny PCs are cheaper than Raspberry Pis" based on used pricing versus new.'.
I actually unsubscribed from Jeff's channel after he published that video. Anyone claiming the lack of a used RPi market means we have to ignore the used market for everything else is just an idiot. I'm going to compare the two no matter how much it bothers the fanboys.
Have to say my experience differs from what most here have had. Mostly I just saw no improvement over using Google.
It still returned lots of results that were paywalled, lots of results with more ads than content, results that didn't contain words I put in quotes. Apparently there's options to filter out certain sites, but it's pretty pointless if there are so many that the task is impossible to do manually.
I've been using Duck Duck Go for a while. Can't say it's better, I even have the occasional search where ddg doesn't return results and revert to Google which does.
At least of the people who've been on the debates, the motive is quite clearly money. They all have apps, merch, blogs, or Youtube Channels they make money from.
Not sure "fascinating" is the word I'd use. While there might be some people that are genuinely confused, the flat Earthers that I've seen debate people who went on the Final Experiment are nothing more than pathological liars.
When prominent flat Earthers heard about and were invited to participate in the Final Experiment, none of them were excited that the globers would finally see the Sun isn't up for 24 hours. They attacked the flat Earthers that did agree to go. All of the globers bought new equipment with their own money and sought out experiments to do and record. The flat Earthers were essentially dead weight, none of them actually planed to record a sunset.
Atmospheric refraction does not matter for this method as it is not based on the time of sunset. Yes, the actual sunset occurs later than the observed sunset, but the relationship between the reflection and the observed position of the Sun remains the same. So, the only difference is you're observing the relationship at a slightly different time than when it actually occurred geometrically.
The current coordinate system is based on extremely distant radio sources. Ground based scopes found some bright galactic sources which GAIA aligned to, and is measuring everything relative to those. And now GAIA is the defining source of the ICRS for optical observations.
The goal of the keogram is to give a quick overview of sky conditions so you can see if there were clouds, aurora, or other interesting activity. No information is discarded, as the user keeps all of the data, the keogram is just a way of identifying which pictures might have something interesting.
The year long keogram presents even less data, as it's just the centerline of the keogram for each day. So, essentially just the center pixel of each image. Still gives a good overview of what the sky conditions were like throughout the year.
You get so many respondents, you can give them all different combinations. Each race you disregard the losers, and when the population gets low enough you might miss a race, you just say "hey, I predicted x races, call Bob to confirm".
I was reading a book from the early 1900's, and it referenced using computers to calculate some complex algorithms. Threw me for a loop, and I finally realized the author was talking about people. Apparently it was a thing to send long computations to a room/building full of people and get the answer back.
You don't have to look far to find one language naming itself to associate itself with another language it isn't really related to. E.g. C# has very little in common with C. But, ironically, it's popularity likely played a role in the naming of J#. Not to mention all the flavors of BASIC that resemble virtually nothing like the original.
Stealing isn't just a legal concept, it also applies (among others) in a social context where you "steal someone's joke" or "steal someone's girlfriend".
With open source the social contract is that you're going to contribute to the project if it's a substantial part of your business.
To be USFC/FIDE legal, the board has to size with the pieces. Even though it's not likely to be used in a tournament, it would just look odd being sized differently.
A spherical cuttoff limit is also not how the human eye sees. Light can travel from any distance to reach your eye. The view frustrum is an optimization, and there will always be cases where it fails.
[Warning: bad joke ahead]
Every day at noon a soldier fired a cannon to signal it was noon. A guy was curious as to how he knew when to fire the cannon. So he asked the soldier, who told him "the guy in the guard station gives me a signal, and I fire the canon". He asks the guy in the guard station how he knows when to signal, "I use the clock on the wall, a guy comes and sets it occasionally". He finds the guy who sets the clock and asks him how he knows what time it is, "I sync my watch to the clock in the town square, then set that clock from my watch". So he finds the guy who sets the town square clock and asks how he knows what time to set it to. "Oh, I just sync it to the noon cannon".
One situation that already uses two doubles, which you may already be familiar with, is the International Astronomical Union's Standards of Fundamental Astronomy library. It uses two doubles for the date in order to be able to be able to have pico/nano second precision over thousands of years. Of course the algorithms aren't precise to that level over thousands of years, but you still need the ability to specify it to that level during the time periods they are that accurate for.
I've had that same one for a long time, and am pretty happy with it. But I would recommend shopping around and watching some reviews. Things may have changed.
One thing to consider is the light. I was never happy with the light on this scope, and instead use a different flexible desk lamp. Most of the ones mounted to the scope have pretty short stems, and can't be positioned to shine from the front, or very low to the side.