[Tom Bishop]

Lets Recap

I have several pages giving a rebuttal is that the Solar Day and Solar Time is unconnected to the Solar Year. There are 24 hours in a Solar Day and 356.24 Solar Days in a Solar Year. Where does the .24 come from? The argument I am hearing is that the two are "unconnected". There are posts with arguments that the two are "arbitrary" and the names Solar Day and Solar Year coincidental. Lets work with that.

The Solar Year is measured starting at the Equinox. It can be measured from elsewhere to get very slight variance, but starting from the Equinox is the standard definition. The Equinox is two points on the Earth's route around the Sun. The March Equinox and the September Equinox. The Equinox is defined as the point where the Equatorial Plane intersects the Ecliptic Plane.



The Equinox is the line that runs through the Earth-Sun System. Its an exact point on the earth's path around the sun.

Starting at point at the September Equinox and after one year when the Earth is again at the September Equinox the Solar Year will have accumulated 356.24 Solar Days.

But I am hearing that  the Solar Day and the Solar Year are "unconnected". The 24 Hour Solar Day will have accumulated almost 6 hours, according to that argument.

Consider if the September Equinox in the above illustration was at Solar Noon. Solar Noon is when the Sun is directly overhead.

After 1 Solar Year the new Solar Noon can't be at + ~6 Solar Hours. The earth has returned to its location on the orbit. The sun can't be pointing in a different direction. How does that work?

Solar Noon is when the sun is directly overhead of the local celestial meridian:

https://en.wikipedia.org/wiki/Noon

Solar noon is the time when the Sun appears to contact the local celestial meridian. This is when the Sun apparently reaches its highest point in the sky, at 12 noon apparent solar time. The local or clock time of solar noon depends on the longitude and date.

Meridian Illustration



The 24 hour Solar Time is, therefore, related to the Solar Year. They cannot be "arbitrary". This question is not answered by that argument.

[Curious Squirrel]

Lets Recap

I have several pages giving a rebuttal is that the Solar Day and Solar Time is unconnected to the Solar Year. There are 24 hours in a Solar Day and 356.24 Solar Days in a Solar Year. Where does the .24 come from? The argument I am hearing is that the two are "unconnected". There are posts with arguments that the two are "arbitrary" and the names Solar Day and Solar Year coincidental. Lets work with that.

The Solar Year is measured starting at the Equinox. It can be measured from elsewhere to get very slight variance, but from the Equinox is the standard definition. The Equinox is two points on the Earth's route around the Sun. The March Equinox and the September Equinox. The Equinox is defined as the point where the Sun's Equalatorial Plane intersects the Orbital Plane.



The Equinox is the line that runs through the Solar System. Its an exact point on the earth's path.

Starting at point at the September Equinox and after one year when the Earth is again at the September Equinox the Solar Year will have accumulated 356.24 Solar Days.

But I am hearing that  the Solar Day and the Solar Year are "unconnected". The 24 Hour Solar Day will have accumulated almost 6 hours, according to that argument.

Consider if the September Equinox in the above illustration was at Solar Noon. Solar Noon is when the Sun is directly overhead.

After 1 Solar Year the Solar Noon can't be Solar Noon plus 5+ Solar Hours. The sun would be pointing off into space. How does that work?

Solar Noon is when the sun is directly overhead of the local celestial meridian:

https://en.wikipedia.org/wiki/Noon

Solar noon is the time when the Sun appears to contact the local celestial meridian. This is when the Sun apparently reaches its highest point in the sky, at 12 noon apparent solar time. The local or clock time of solar noon depends on the longitude and date.

Meridian Illustration



The 24 hour Solar Time is, therefore, related to the Solar Year. They cannot be "arbitrary".

The equinox doesn't happen at the same time every year. Boom, mystery solved. That's what we've been telling you this whole time. If the September equinox of 2023 happens on the 20th, at solar noon local time, the September equinox of 2024 happens on the 20th at around 18:00 local time. It does not occur at solar noon year to year at any location on Earth, and it would be an extraordinary coincidence if it did.

[AATW]

I'm really hoping that Tom isn't thinking that the fact its 365.24 is in some way related to there being 24 hours a day 
For a start, 365.24 is rounding, according to:
https://www.timeanddate.com/astronomy/tropical-year.html

A tropical year, also known as a solar year, an astronomical year, or an equinoctial year, is, on average, approximately 365 days, 5 hours, 48 minutes and 45 seconds long (365.24219 days)

And secondly, the 24 hour day apparently comes from the ancient Egyptians who would not have had the ability to measure the length of a year that accurately.

I have no idea why anyone would think there would be any correlation between the time it takes a planet to orbit its star and the time it takes a planet to rotate on its axis. They are two completely separate motions.

[Tom Bishop]

The equinox doesn't happen at the same time every year. Boom, mystery solved.

That's not the answer to the question. That is the question I am asking. The Solar Day and the Solar Year that is based on the Equinox do not match up.

That's what we've been telling you this whole time. If the September equinox of 2023 happens on the 20th, at solar noon local time, the September equinox of 2024 happens on the 20th at around 18:00 local time. It does not occur at solar noon year to year at any location on Earth, and it would be an extraordinary coincidence if it did.

Furthermore, the equinox only moves at a rate measured in eons.

https://www.britannica.com/science/precession-of-the-equinoxes

Precession of the equinoxes, motion of the equinoxes along the ecliptic (the plane of Earth's orbit) caused by the cyclic precession of Earth's axis of rotation. ... Such a motion is called precession and consists of a cyclic wobbling in the orientation of Earth's axis of rotation with a period of 25,772 years.

[Tom Bishop]

I have no idea why anyone would think there would be any correlation between the time it takes a planet to orbit its star and the time it takes a planet to rotate on its axis. They are two completely separate motions.

The geometry of the scene shows you wrong. The time of Solar Noon when the earth returns to its position of the September Equinox can't be Solar Noon + 5+ Solar Hours. The sun and earth is in the same geometric position on the orbit. Solar Noon can't change.

[AATW]

Those diagrams are only representative. They are not exactly what happens.
The solstice and equinox dates aren't even the same each year

[Stagiri]

(...) Where does the .24 come from? (...)

You've calculated it yourself - it's because days don't fit exactly into one year.

(...) Furthermore, the equinox only moves at a rate measured in eons. (..)

Moreover, they also move by 6 hours each year.

[Curious Squirrel]

I have no idea why anyone would think there would be any correlation between the time it takes a planet to orbit its star and the time it takes a planet to rotate on its axis. They are two completely separate motions.

The geometry of the scene shows you wrong. The time of Solar Noon when the earth returns to its position of the September Equinox can't be Solar Noon + 5+ Solar Hours. The sun and earth is in the same geometric position on the orbit. Solar Noon can't change.

Incorrect. That's why the time of the equinox changes every year. I've lost what your problem is with this again. You keep repeating the same thing over and over and declaring it can't be true for some reason. Why? The Earth moves around the sun at X speed. The Earth rotates about it's own axis at Y speed. Why do you believe X and Y have any correlation to one another, such that an integer amount of Y's should happen in every X? There's none. Zero. Zilch. One is not dependent upon the other in any way. I don't understand how this concept is so difficult for you to grasp.

"The sun and earth is in the same geometric position on the orbit." This, is correct. Their spatial relationship to one another is the same each time the equinox happens.

"Solar Noon can't change." This is incorrect, and in fact a non-sequitur. Solar Noon has nothing whatsoever to do with the equinox.

[Bobby Shafto]

Lets Recap

I have several pages giving a rebuttal is that the Solar Day and Solar Time is unconnected to the Solar Year. There are 24 hours in a Solar Day and 356.24 Solar Days in a Solar Year. Where does the .24 come from? The argument I am hearing is that the two are "unconnected". There are posts with arguments that the two are "arbitrary" and the names Solar Day and Solar Year coincidental. Lets work with that.

I stopped reading here, and I haven't scrolled down to see if anyone else has responded.

Tom,

I can appreciate if you feel kind of like you're being ganged up on, and I don't want to contribute to what might feel like a mob. I think we're all independently trying to explain to you the same thing, though maybe in different ways. And there's obviously history with some of you that is leading others to respond more caustically.

I, for one, don't like to discuss things that way. But I do wish I could help you work through the question, but your recap is not right, and you can't use that as a place from which to start to "work with."

You seem to expect something to be true that isn't.  These solar days, solar years, etc. are not "arbitrary." They aren't "unconnected." They're just not connected in a manner that you consider whole.

1 rotation of the earth with respect to the sun is a solar day. That's not arbitrary. It's 1. 1 day. 1 solar day.

1 orbit around the sun is a solar year. That's not arbitrary. It's 1. 1 year. 1 solar year.

The solar day happens 365 times in 1 solar year, but then there's a fractional period of rotation that must occur before the orbit of 1 solar year is complete. That's not arbitrary. It's measurable. It's "arbitrary" I suppose, but with good reason, that you might want to choose a starting point for measuring the year at an equinox or solstice. In this case, via convention (call it arbitrary) we use the vernal equinox. But the number of earth rotations (relative to the sun) during the length of that orbit to the next vernal equinox is not arbitrary. They happen naturally, are measurable, and the solar day doesn't line up with the solar year in a whole number. The earth reaches a point in its orbit around the sun a little before the vernal equinox when it completes its 365th solar day rotation.

That's where the extra time is coming from. The earth rotates a little more while it has to complete that orbit, returning to the point of the vernal equinox.

Calling things "arbitrary," "coincidental" and "unconnected" indicates you aren't absorbing what's being explained. Some things, like words or units of measurement might be "arbitrary" or based on something that is a matter of convenience or convention, but what we are measuring aren't. And you can't consider what's being measured as "unconnected" just because the way we measure doesn't use units that divide evenly as integers. Fractions are a way of life in the world.

I hope that helps. (If I'm redundant and someone else has already made that point, I apologize, but I hope you aren't being resistant just because you feel defensive or ganged up on.)

[Tumeni]

The equinox doesn't happen at the same time every year. Boom, mystery solved. That's what we've been telling you this whole time. If the September equinox of 2023 happens on the 20th, at solar noon local time, the September equinox of 2024 happens on the 20th at around 18:00 local time. It does not occur at solar noon year to year at any location on Earth, and it would be an extraordinary coincidence if it did.

AND, Tom, to go back to your diagram on the first page, it shows the equinoxes and solstices on two possible days in each instance.

Please consider why.

[Bobby Shafto]

Consider if the September Equinox in the above illustration was at Solar Noon. Solar Noon is when the Sun is directly overhead.

After 1 Solar Year the Solar Noon can't be Solar Noon plus 5+ Solar Hours. The sun would be pointing off into space. How does that work?

You're right. It can't. That's why the last solar noon (on the 365th day) happens before the end of the solar year. Those two moments don't coincide. If starting the measure of the solar year is at the equinox (you've chosen September instead of March, but whatever), that isn't at solar noon either (necessary; I mean it could be on rare occasions.)

Solar day doesn't have to start at solar noon either. You could pick any measurable moment of sun elevation and use that as a starting point. But the day is the amount of time to rotate and see the sun back at that point.

Similar with solar year. Doesn't have to start count at an equinox. It's just a good marking point. But the amount of time for the earth to complete its orbit to get back to that point, relative to the sun, is a solar year.

For illustration purposes, you can start the measure at solar noon and, for the sake of understanding, assume that is also the time of the vernal (Spring) equinox. Let the motions occur and at the next vernal equinox, it won't be solar noon. That's because that 365th solar noon happened earlier, before the equinox was reached. When the equinox is finally reached (completing the solar year), about 5.5 to 5.8 more hours will have elapsed because the earth kept rotating until vernal equinox.

[Bobby Shafto]

That's not the answer to the question. That is the question I am asking. The Solar Day and the Solar Year that is based on the Equinox do not match up.

They don't match up as a whole number.  So what? I don't understand why you expect them to, especially after having it repeatedly explained why they don't.

1 solar year = 365.24 solar days.
The equinox is about 0.24 solar days later each year because they "don't match up" without the fraction. They match up well with the fraction.

We're all telling you why that is, but you keep claiming that's a problem or a question.

Furthermore, the equinox only moves at a rate measured in eons.

https://www.britannica.com/science/precession-of-the-equinoxes

Precession of the equinoxes, motion of the equinoxes along the ecliptic (the plane of Earth's orbit) caused by the cyclic precession of Earth's axis of rotation. ... Such a motion is called precession and consists of a cyclic wobbling in the orientation of Earth's axis of rotation with a period of 25,772 years.

I tried to tell you that that's a different influence on the motion, and it's much more marginal, so don't worry about it for trying to comprehend this other, much larger (relatively) variance that is the focus of your question.

Until the solar year/solar day relationship is understood, the precession affect will just add to the confusion. And it's way down in the weeds, astronomically, for the short time reference periods we've been focusing on.

[Bobby Shafto]

The geometry of the scene shows you wrong. The time of Solar Noon when the earth returns to its position of the September Equinox can't be Solar Noon + 5+ Solar Hours. The sun and earth is in the same geometric position on the orbit. Solar Noon can't change.

Until you can discard yourself of that incorrect premise, attempting to work through it with you is bound to be fruitless.

It's disappointing that that UNL animated illustration seems to have cemented your misunderstanding. That same Astronomy Department also has published this page on the Web. Maybe it will help you get over the rigid insistence that a starting marker to the solar day must line up with the starting marker to the solar year and the end of 1 solar year.
http://astro.unl.edu/naap/motion3/sidereal_synodic.html

[Tom Bishop]

Those diagrams are only representative. They are not exactly what happens.
The solstice and equinox dates aren't even the same each year

Solar Noon can't change. The question has not been answered.

(...) Where does the .24 come from? (...)

You've calculated it yourself - it's because days don't fit exactly into one year.

(...) Furthermore, the equinox only moves at a rate measured in eons. (..)

Moreover, they also move by 6 hours each year.

That is not the answer to the question. That was the question.

From your link (ignoring that is it from TimeandDate that has been discredited as a source on RET models, and also ignoring that it is displaying as PDT for me and on a 365 Day Gregorian Calendar, not Solar Time):

Year    March Equinox   
2013   Mar 20   4:01 am PDT
2014   Mar 20   9:57 am PDT    -- ~6 hr difference
2015   Mar 20   3:45 pm PDT    -- ~6 hr difference
2016   Mar 19   9:30 pm PDT    -- ~ -1 day + 6 hr difference
2017   Mar 20   3:28 am PDT    -- ~6 hr difference
2018   Mar 20   9:15 am PDT    -- ~6 hr difference
2019   Mar 20   2:58 pm PDT    -- ~6 hr difference

We already know that the Solar Year that is based on the equinox adds .24 hours to our local calendars and clocks which we must create innovative adjustment methods for (ie. Leap Year). That is what needs to be solved and reconciled with Solar Time that is based on a 24 hour solar clock.

Why doesn't Solar Noon move?

[Macarios]

That's not the answer to the question. That is the question I am asking. The Solar Day and the Solar Year that is based on the Equinox do not match up.

And I answered that question few times in this thread already.

Solar day is based on Earth's rotation towards Sun.
Calendar year is based on solar days.
We, humans count it for our needs.

Tropical year is not based on solar days.
Tropical year is based on Earth's orbital events and it is not calendar year.

EDIT:
I already placed analogy with propeller of the plane model revolving pole.
We count our calendar year by counting "rotations of the propeller" (days), and trying to adjust "counted sets of rotations" (calendar year) as close as possible to "number of revolutions" (tropical year).

[Stagiri]

Dear Mr. Bishop,
Just to make this situation clear, what exactly is your question?

[Bobby Shafto]

Are you saying that the Astronomy Department at the University of Nebraska-Lincoln got Round Earth Astronomy wrong, and that you know better than them?

Their simulation is clearly showing that Solar Time is related to the Equinoxes and Solstices of the year. It is not arbitrary. The sun needs to return to its same position above the earth after 1 year.

Think of that animation like this animation of a flat earth model.
https://imgur.com/r/educationalgifs/D7aOXVA

Should I use that animation to work out things like azimuth of the sun at sunset from San Diego at the equinox?
http://oi66.tinypic.com/213iz6f.jpg
And if the azimuth of the sun is not what that animation predicts, should I reject the flat earth model?

I read you elsewhere tell someone that animation (or others like it) are visualizations. They convey the concept, but aren't intended to be accurate.

Same with that simple animation you showed that isn't synchronized to any actual time, can't be used for predicting or comparing to actual truth data (time/date) and doesn't even bother to illustrate the very aspect of the "extra time" that you are interested in. But that's because it's just a visualization. A fancy cartoon to help explain the relationship of sidereal days with solar days.

Unfortunately, it's reinforced a notion that a solar day (solar noon) must line up always with the solar year (equinox) or else something's wrong with the globe/solar model. If you are sincere in wanting to find resolution to what you see as a problem with solar noon in round earth theory, you need to break through that incorrect concept that "The sun needs to return to its same position above the earth after 1 year."

[Curious Squirrel]

Why doesn't Solar Noon move?

Why doesn't what move? Your question is a nonsense question here Tom. If this is what you're attempting to ask, you will need to explain what exactly it is that you mean.

I had more to say about Timeanddate, but it's not conducive to the discussion, just as your dishonest ramblings aren't conducive. Stick to the topic, and see if you can be clear with what exactly your issue is, because after this sentence it seems your issue is complete nonsense.

[Bobby Shafto]

Solar Noon can't change...Why doesn't Solar Noon move?

You started with "solar noon can't change" and then ended asking "why doesn't solar noon move?"

Solar noon is one moment out of a solar day. Solar noon doesn't care about the equinox or where the earth is in its orbit or how the ecliptic plane is oriented. As long as the earth is spinning, solar noon will come around again and again, as will any other demarcation point in the solar day. 

Even if the earth didn't orbit the sun at all but somehow just hung above the sun in one spot, you'd still have solar days if the earth is rotating making the sun appear to rise to a solar noon.

Solar noon can't change? Sure. As long as your clock is tied to the sun and the rotation of earth is constant, solar noon will be solar noon always. When the sun is at its highest elevation.

But if you tie your clock to, say, the stars? Then solar noon isn't always at the same time. It's still solar noon, but it's happening at a different sidereal time each day.

Right? But we're talking about a solar day clock, so yeah. Solar noon is constant.

So, why doesn't it move then if the solar year doesn't "match?" Why should it? Why would you expect it to? The solar year is not based on the rotation of the earth. It's based on the orbit of the earth around the sun. It's a different cyclical motion: one "inside" of the other.

They match up and are relateable fractionally, but you can have orbit without rotation and rotation without orbit (well, at least temporarily). In the sun/earth case, we have 365 and a fraction rotations for every orbit. This fraction won't change the timing of solar noon. But it will change how we relate the marking of the new solar year to the timing of a solar day.

You've got to remember your reference frames and understand the relationships between them, else you will create conundrums that don't really exist.

[Tom Bishop]

Calling things "arbitrary," "coincidental" and "unconnected" indicates you aren't absorbing what's being explained.

I said that it can't be arbitrarily connected. Read the post again. This indicates that you are not really absorbing this content.

Why doesn't Solar Noon move?

Why doesn't what move? Your question is a nonsense question here Tom. If this is what you're attempting to ask, you will need to explain what exactly it is that you mean.

Solar Noon is based on a 24 hour Solar Day. After 364.24 days Solar Noon should have moved ~6 Hours. The geometry of the scene when the earth returns to the September Equinox point shows that Solar Noon is not in that place.