[Tom Bishop]

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).

I have shown several quotes in this thread which say that there are 365.24 Solar Days in a Solar Year.

I have also shown with the Recap post that the Solar Day must be connected to the Solar Year.

You have not yet provided the + ~6 hour solution.

A Sidrael Year is only different by the Solar Year by 20 minutes, and is not a solution. Why doesn't the Solar Day fit into the Solar Year?

[Stagiri]

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.

Solar noon is based on Earth's rotation, not its orbit (in contrary to equinoxes).

[Stagiri]

(...)
You have not yet provided the +6 hour solution.
(...)

It takes 365.24 solar days (i. e. time units are not defined by the tropical year and that do not fit exactly to one tropical year) to complete a tropical year.

[Bobby Shafto]

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

I wasn't addressing what you said about your own thoughts. I was addressing how you were mis-characterizing the explanations provided to you in your recap.

[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.

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.

Wrong. Once again. Solar Noon for a place on Earth happens after a set period of 24 hours (roughly). The movement of the Earth around the sun has no relation to a solar day (beyond the difference to a sidereal day). Why is Solar Noon moving? What is making Solar Noon move? Solar Noon is happening 24/7. Every second of every day somewhere is experiencing Solar Noon. From Equinox A to Equinox B, if location X was experiencing solar noon during A, it will not be in solar noon during B. Location Y will. What's wrong with that? Nothing says location X should be experiencing solar noon at B, if it was at A. If you think it is, explain exactly what you think is saying this should be the case.

[Bobby Shafto]

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.

Assuming solar noon was the start of the solar year, after 364.24 solar days, the last solar noon would have happened ~6 hours before the equinox. Thus, at equinox, solar noon is past. Solar noon didn't change. It still came and went as predicted.  The return to equinox after one solar year will not line up with solar noon, as you apparently expect it to. That's not the "geometry of the scene." The earth has rotated past solar noon by the time equinox arrives.

[Bobby Shafto]

I have also shown with the Recap post at the top that the Solar Day must be connected to the Solar Year.

This is the crux of the issue, right here. There's no hope of resolution if we don't understand why the "solar day must be connected to the solar year" in the whole integer way you expect, or if you don't understand that the relationship is fractional.

Without that being resolved, this is a merry-go-round.

[Bobby Shafto]

I have also shown with the Recap post at the top that the Solar Day must be connected to the Solar Year.

This is the crux of the issue, right here. There's no hope of resolution if we don't understand why the "solar day must be connected to the solar year" in the whole integer way you expect, or if you don't understand that the relationship is fractional.

Without that being resolved, this is a merry-go-round.

I'm getting off, unless I see an explanation from Tom why the earth's rotation relative to the sun (solar day) must be synchronized to the orbit around the sun (solar year), without any fractional variance.

[Devils Advocate]

This thread is the smoking gun that proves beyond reasonable doubt that Tom is just here for the banter, to wind up folks, to troll. The guys one of the finest examples of modern troll, he's led 14 pages here and it will still grow, his technique is sublime. I salute you Tom,   master of the mass debate!

[Tom Bishop]

Solar noon is based on Earth's rotation, not its orbit (in contrary to equinoxes).

Solar Noon is part of the Solar Day and Solar Time, which is period of the rotation of the sun around the earth.

The number of Solar Days and Solar Hours must fit into the Solar Year. See the Recap post. After 365.24 Solar Days the earth will be back at the September Equinox point. Solar Noon will be at a position that is + ~6 Hours. Solar Noon can't change.

(...)
You have not yet provided the +6 hour solution.
(...)

It takes 365.24 solar days (i. e. time units are not defined by the tropical year and that do not fit exactly to one tropical year) to complete a tropical year.

See https://encyclopedia2.thefreedictionary.com/tropical+year

Tropical Year

the time interval between two successive passages of the sun through the vernal equinox. The tropical year contains 365.242196 mean solar days.

It says right there that the Tropical Year, also known as the Solar Year, contains 365.24 Solar Days.

The variation between years is very small.

Solar/Tropical Year Variation

See https://en.wikipedia.org/wiki/Tropical_year

Mean time interval between equinoxes

As already mentioned, there is some choice in the length of the tropical year depending on the point of reference that one selects. But during the period when return of the Sun to a chosen longitude was the method in use by astronomers, one of the equinoxes was usually chosen because it was easier to detect when it occurred. When tropical year measurements from several successive years are compared, variations are found which are due to nutation, and to the planetary perturbations acting on the Sun. Meeus & Savoie (1992, p. 41) provided the following examples of intervals between northward equinoxes:

	days	hours	min	s
1985–1986	365	5	48	58
1986–1987	365	5	49	15
1987–1988	365	5	46	38
1988–1989	365	5	49	42
1989–1990	365	5	51	06

    Until the beginning of the 19th century, the length of the tropical year was found by comparing equinox dates that were separated by many years; this approach yielded the mean tropical year (Meeus & Savoie 1992, p. 42).

The variation between the years does not account for those hours.

I have also shown with the Recap post at the top that the Solar Day must be connected to the Solar Year.

This is the crux of the issue, right here. There's no hope of resolution if we don't understand why the "solar day must be connected to the solar year" in the whole integer way you expect, or if you don't understand that the relationship is fractional.

Without that being resolved, this is a merry-go-round.

I'm getting off, unless I see an explanation from Tom why the earth's rotation relative to the sun (solar day) must be synchronized to the orbit around the sun (solar year), without any fractional variance.

This was explained. See the Recap Post. The Sun is back in its position in its path around the sun. Solar Noon can't change.

The Sidrael Year only has a difference of 20 minutes from the Solar Year.

See http://astro.unl.edu/naap/motion3/sidereal_synodic.html

the sidereal year is about 20 minutes longer than the tropical year.

Not a solution to the number of Solar Days in a Solar Year.

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.

Assuming solar noon was the start of the solar year, after 364.24 solar days, the last solar noon would have happened ~6 hours before the equinox. Thus, at equinox, solar noon is past. Solar noon didn't change. It still came and went as predicted.  The return to equinox after one solar year will not line up with solar noon, as you apparently expect it to. That's not the "geometry of the scene." The earth has rotated past solar noon by the time equinox arrives.

You say "The earth has rotated past solar noon by the time equinox arrives."

Solar Time is based on the sun moving over the earth along a local celestial meridian. If the earth has rotated past Solar Noon after a Solar Year, then the Solar Noon has as well. The Solar Day does not fit into the Solar Year.

[Tom Bishop]

This topic is getting a little stale now. There is still no answer. Nothing new.

Lets go back to the Equation of Time. Maybe this is an answer for this.

http://nfo.edu/solarday.htm

Timekeeping on Earth is loosely based on the position of the Sun in the sky. Apparent solar time is the time like a Sundial would tell, where local noon is when the Sun would be directly to the South. However the length of the apparent solar day is not constant throughout the year because of two contributing factors. To account for these varitions the solar day is averaged so all the days of the year will be of equal length. Mean solar time is the time that clocks display. The difference between apparent solar time and mean solar time is called the equation of time.

From https://en.wikipedia.org/wiki/Equation_of_time

The equation of time describes the discrepancy between two kinds of solar time. The word equation is used in the medieval sense of "reconcile a difference". The two times that differ are the apparent solar time, which directly tracks the diurnal motion of the Sun, and mean solar time, which tracks a theoretical mean Sun with noons 24 hours apart. Apparent solar time can be obtained by measurement of the current position (hour angle) of the Sun, as indicated (with limited accuracy) by a sundial. Mean solar time, for the same place, would be the time indicated by a steady clock set so that over the year its differences from apparent solar time would resolve to zero

The equation of time is this difference, which is cyclical and does not accumulate from year to year.

It seems that this is not the answer to this problem either. Starting from a point in the year, after one year, any seconds added will be subtracted, giving no extra time.

[Bobby Shafto]

You say "The earth has rotated past solar noon by the time equinox arrives."

Solar Time is based on the sun moving over the earth along a local celestial meridian. If the earth has rotated past Solar Noon after a Solar Year, then the Solar Noon has as well. The Solar Day does not fit into the Solar Year.

If by "doesn't fit" you mean there can't be a fractional solar day in a solar year, you're absolutely right. But if you do accept that a fraction of a solar day is possible, then it does "fit." 365.24 solar days fit into a solar year. The "extra time" is what makes it "fit."

Now, can you provide some "explanation...why the earth's rotation relative to the sun (solar day) must be synchronized to the orbit around the sun (solar year), without any fractional variance," else it "doesn't fit?"

[Tom Bishop]

You say "The earth has rotated past solar noon by the time equinox arrives."

Solar Time is based on the sun moving over the earth along a local celestial meridian. If the earth has rotated past Solar Noon after a Solar Year, then the Solar Noon has as well. The Solar Day does not fit into the Solar Year.

If by "doesn't fit" you mean there can't be a fractional solar day in a solar year, you're absolutely right. But if you do accept that a fraction of a solar day is possible, then it does "fit." 365.24 solar days fit into a solar year. The "extra time" is what makes it "fit."

Now, can you provide some "explanation...why the earth's rotation relative to the sun (solar day) must be synchronized to the orbit around the sun (solar year), without any fractional variance," else it "doesn't fit?"

Read through the Recap post please.

After 1 Solar Year starting on the September Equinox the earth will return to the same place on the Earth-Sun orbit. The 24 Hour Solar Clock will not be in sync. This is a problem. The Sun did not change position in the Earth-Sun system. If the start point were Solar Noon, we can't have Solar Noon now + ~6 hours at the end point.

[Bobby Shafto]

Read through the Recap post please.

After 1 Solar Year starting on the September Equinox the earth will return to the same place on the Earth-Sun orbit. The 24 Hour Solar Clock will not be in sync. This is a problem. The Sun did not change position in the Earth-Sun system. If the start point were Solar Noon, we can't have Solar Noon now + ~6 hours at the end point.

I can read it a million times and it still restates the error.

Solar year and the solar day clock not being in sync is not a problem.
If the start point of the solar year is solar noon, we CAN (and will) have the end point of that solar year ~6 hours after the last solar noon. The new solar year start point is then ~6 hours after solar noon and after another solar year, THAT endp point will be ~12 hours after the last solar noon, and so on. What you seem to want is for each new solar year to be able to start at solar noon. But that's not possible. The timing of equinox (which is how we mark the start and end of the solar year for reasons of ease of measurement) is not synchronized with the timing of solar noon (which is also an indexing convention related to ease of measurement.)

Solar days and solar years not being in sync is not the problem you think it is.
Solar year is vernal equinox to vernal equinox (or autumnal if you prefer), measuring 1 orbital cycle.
Solar day is solar noon to solar noon (or some other indexing point of the solar day if you prefer, measuring 1 rotational cycle.
There is no reason for them to be synchronized. There's no reason to believe it's a problem if they are not.
I would actually be quite fascinated by the situation if they were.

[Bobby Shafto]

I'm pretty sure that's it, especially since you keep referring us back to your recap. You seem to believe that the solar year can only start at solar noon. If we haven't reached the equinox by the time of the 365th solar noon, then there must be a problem because the subsequent solar year can't start except at solar noon. In other words, if you start the clock with both orbit and rotation synchronized, you think he's new cycle of the orbit must start synchronized with the rotation.

That's a fallacy.

If I'm restating your position incorrectly, tell me; in which case my question surfaces again as to why you think solar year and solar day must be synchronized in a whole number ratio. If the earth's rotation and the earth's orbit of the sun were toothed gears with a ratio of 365:1, then yeah. I'd consider it a problem if they weren't in sync after 1 cycle of the orbital gear.

But there's not. They are "synced" to a ratio of ~365.24:1 though. There's no reason I know of why that ratio exists, but they are. So at the end of 1 orbital cycle, the rotation gear will have turned a fraction more than it would have in a 365:1 ratio system.

[douglips]

This appears to be the misunderstanding on your recap post:

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:

Yes, solar noon can be any amount of time later, just for a different meridian.

If you stand even 100 feet to the West of new, your solar noon is slightly later than mine.

It is always solar noon somewhere.

The sun isn't pointing anywhere different, the Earth is.

[Bobby Shafto]

Solar noon is a local phenomenon. The length of the solar day is global.

It is always solar noon somewhere, so the equinox happens at solar noon for someone, just not the same person/meridian every year.

Does this help?

It might help Tom to distinguish it that way.

Looking up times for the next two autumnal equinoxes, 2018 occurs 01:53 UTC on Sep 23. A year later, in 2019, it occurs 07:41 UTC.

Estimating using 15° of longitude per (solar) hour, that means that in 2018, solar noon at the time of autumnal equinox will be somewhere near 150°E meridian. But in 2019, solar noon at the time of autumnal equinox will be somewhere near the 70°E meridian. 

The 365th solar noon will have passed those on the 150° meridian because the earth hasn't reached the autumnal equinox yet. It will take another 5 hrs and 48 mins to get there. Meanwhile, the earth will keep rotating with respect to the sun and the solar noon line will keep moving west for that amount of time until...equinox.

(My meridians might be off. I'm sure there's a calculator that can figure what longitude the sun is at given UTC, but I don't have a link handy. The point ought to be made, though.)

[Tom Bishop]

This appears to be the misunderstanding on your recap post:

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:

Yes, solar noon can be any amount of time later, just for a different meridian.

If you stand even 100 feet to the West of new, your solar noon is slightly later than mine.

It is always solar noon somewhere.

The sun isn't pointing anywhere different, the Earth is.

I am comparing the 24 Hour Clock in Solar Time to the 365.24 Solar Days per Solar Year.

Sidereal Time, the time in comparison to the stars, which is the time of rotation the earth "really" moves at isn't even being discussed in this.

The difference between the Sidrael Year and the Solar Year is only 20 minutes a year anyway, and does not account for this.

[Tom Bishop]

I'm pretty sure that's it, especially since you keep referring us back to your recap. You seem to believe that the solar year can only start at solar noon. If we haven't reached the equinox by the time of the 365th solar noon, then there must be a problem because the subsequent solar year can't start except at solar noon. In other words, if you start the clock with both orbit and rotation synchronized, you think he's new cycle of the orbit must start synchronized with the rotation.

That's a fallacy.

If I'm restating your position incorrectly, tell me; in which case my question surfaces again as to why you think solar year and solar day must be synchronized in a whole number ratio. If the earth's rotation and the earth's orbit of the sun were toothed gears with a ratio of 365:1, then yeah. I'd consider it a problem if they weren't in sync after 1 cycle of the orbital gear.

But there's not. They are "synced" to a ratio of ~365.24:1 though. There's no reason I know of why that ratio exists, but they are. So at the end of 1 orbital cycle, the rotation gear will have turned a fraction more than it would have in a 365:1 ratio system.

You, like douglips, seem to think that the "true" rotation of the earth has something to do with this. We are not even talking about the "true" rotation of the earth. The "true" rotation of the earth, Sidrael Time, which is gauged in relation to the movement of the stars, could be rotating at 902.76 rotations in a Solar Day, and the definitions of Sidrael changed to reflect as much. The stars can be moving at any rate, and if you want to consider them to be fixed stars and that it is really the earth that is moving that rate of 902.76 rotations in a Solar Day, then sure.

The Solar Clock would still be defined by the rate the Sun (Sol) is moving around the earth, and, will still maintain, no matter how fast the stars moved or if they even existed at all, one rotation around the earth in one Solar Day.

[Bobby Shafto]

What?

I've long since moved past sidereal day reference frame.