Question about winter solstice

Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

On Jan 3, 8:48*pm, wrote:
Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

There are no real experts and most of what you will see is entirely
new to most people in this newsgroup so that you will have to figure
things out yourself to the best of your ability.It is a shame a
renowned educational institution has not picked up on the invaluable
resources of modern imaging but perhaps that will change shortly.

First things first.Get rid of the calendar system and strip everything
back to its barest form based on daily rotation and our orbital
motion around the central Sun.Here is a view of the Earth from space
showing what happens from Solstice to Equinox -

http://www.youtube.com/watch?v=nwTrYVBcx9s

The line separating daylight/darkness (otherwise known as the
'terminator' or 'circle of illumination') appears to pivot off the
Equator so that at the solstice,the distance between the geographical
North/South poles and the daylight/darkness line is at its greatest
while at the Equinox the line appears to split the geographical
rotational axis.What is happening is that as the Earth orbits the
Sun,there is a separate motion to daily rotation where the Earth
slowly turns with respect to the central Sun and while we do not have
a bird's eye view of this occuring on Earth we can borrow the unique
features from Uranus to carry the point and see the motion directly -

http://astro.berkeley.edu/~imke/Infr..._2001_2005.jpg

Most experience the greatest 'interpretation' difficulty here as the
sequence of images shows the specific way a planet turns with respect
to the central Sun while keeping the rotational pole (North/South)
pointing in the same direction in space.The best way to appreciate
this slow annual 360 degree motion is to take a look at how a
crankshaft pin keeps pointing in the same direction externally
(representing daily rotation) while the motion of the crank around the
shaft changes the orientation of the pin to the central central shaft
(orbital motion) -

http://www.youtube.com/watch?v=YV9WkQkUHZ4

In this,the International Year Of Astronomy,it is time for educational
institutions and those who deem themselves astronomers to pick up what
modern imaging dictates and until the time comes when genuine people
enjoy what goes into creating an Equinox and Solstice via the motions
of the Earth can your question be answered in a meaningful way.

Take it slowly,separate daily rotation from orbital motion and look
at each motion individually and then realize the effect of each
motion - daily rotation causes day/night and keeps the Earth pointing
to one direction in space -

http://www.youtube.com/watch?v=XTTDWhky9HY

Then there is orbital motion and the specific way the Earth orbits the
Sun where a given location will slowly turn through 360 degrees,not
from a point of the geographical axis but from a line at right angles
to the circle of illumination.You can see this again by looking at the
Uranus image where you can actually see Two 360 degree motions with
respect to the Sun -

http://hubblesite.org/newscenter/arc...999/11/video/b

May I remind others that if this year is to make an impact in
astronomy and a productive one then modern imaging has to come to the
forefront along with people capable of interpreting these images in an
open and honest way.To this end,it is not a matter of being correct
but who can provide a better explanation using images and analogies on
this very important question.

A slight correction:

The precession is caused by the earths tilt changing, not the orbit.
As far as I can research, the orbit is not changing measureably. I have
problems there, but I haven't found any more accurate information.

The tilt of the earth is changing on about a 26000 year cycle, so 5000 years
ago, the seasons would have been off by about 2 months,
if you used our present calendar, which was modified in 1583 to the tune of
11 days under pope Gregory.
2000 years ago, we only had 10 months, and there was a big gap in the Roman
calendar. (according to Wiki)
Then the politicos and religious heads got together, and changed it a half
dozen times or so to their convenience.

The solstices (?) and equinox (es?) would remain the same, but the seasons
will move!

wrote in message
...
Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

In article
,
wrote:

snip

Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

No. Consistency in the date of the Solstice depends on the accuracy of
our Gregorian calendar, in terms of its ability to match the tropical
year. The Julian calendar drifted WRT the seasons at a rate of about one
day every three centuries, but now the discrepancy between the tropical
year and the calendar year is a good order of magnitude smaller; it will
take more than three millennia to accumulate a one-day error.

The seasonal relation affected by precession is not with the date, but
with the positions of the "fixed stars". Thousands of years from now
(assuming no calendar reforms) the Solstice will still occur in late
December, but the constellations visible at a given time of night on
that date will have shifted: where, for example, Orion is 'highlighted'
in this epoch, at some point in the future his place will be taken by
Cetus, which is currently best viewed a couple of months earlier in the
year.

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built?

"December" was invented only about two thousand years ago, so the easy
answer is "Of course not!"

That said, AFAIK the Egyptians used a solar calendar, and all such
(along with luni-solar ones like the Jewish or Chinese) are constructed
to keep step with the seasons rather than the stars. For a while the
Egyptians apparently used the heliacal rising of Sirius as a predictor
of the annual Nile floods, but precession eventually broke the
coincidence between these phenomena.

BTW the Egyptian pyramids are closer to five thousand years old than
seven thousand.

Does our calendar year (Jan-Dec) always mean summer solstice will
ALWAYS be in June and winter solstice ALWAYS in December?

For the foreseeable future, yes, and by design.

--
Odysseus

On Jan 3, 12:48*pm, wrote:
So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

No, because the year is defined in terms of the solstices and
equinoxes, not the constellations. Different stars may rise in
December due to precession, but the calendar is made to agree with the
tropical year so that the Winter Solstice will stay around the 22nd
and 23rd of December... so that we will always be likely to have a
white Christmas in the Northern Hemisphere... and so that Easter will
always be in the spring.

John Savard

wrote in message
...
Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

Ok, well, the first part of the problem is one of time-keeping rather than
seasons. If you look at the names of the months: Sept-, Oct-, Nov- and Dec-
are Latin prefixes for 7, 8, 9 and 10. July and August : Julius Caesar and
Augustus Caesar, men made into Roman deities. The calendar you are
familiar with is a very Roman calendar and would not have existed when
the pyramids were built.

http://www.astronomy.ohio-state.edu/.../calendar.html

Secondly, looking at the biblical text Genesis 5:27 states, "And all the
days of Methuselah
were nine hundred sixty and nine years: and he died"
If one assumes that the age of 969 indicates months instead of years
(indicating a mistranslation), Methuselah's age is calculated as 80.75 years
(969/12), which is a more realistic lifespan, but this requires that months
be in the modern twelfths of a year.
Now as you know, to fit 12 months into a year, some have 30 days
and some have 31 with Feb having 28 and 29 every fourth year and
11 days were "lost" when the switch from the Julian to the Gregorian
calendar was made - and that depended on where you lived because
Russia didn't switch until 1918.

So months are not really tied to the phases of the Moon, but they
were once for time-keeping purposes. The religious holiday of Easter
is still tied to the Moon, being the first Sunday after the first full moon
after the equinox.

As to precession, we have advance of perihelion and alignment with
Polaris to consider but I'm not going into that here.

On Jan 3, 10:26*pm, "Ralph" wrote:
A slight correction:

The precession is caused by the earths tilt changing, not the orbit.
As far as I can research, the orbit is not changing measureably. *I have
problems there, but I haven't found any more accurate information.


It is good that you see a problem insofar as the current description
of the Earth's orbital motion is an impossibility -

http://www.pfm.howard.edu/astronomy/...S/AACHCIT0.JPG

To keep daily rotational orientation (tilt) constantly pointing in one
direction in space over the course of an annual orbit,any given
location must turn slowly with respectto the central Sun just as
thoseimages of Uranus indicate -

http://astro.berkeley.edu/~imke/Infr..._2001_2005.jpg




The tilt of the earth is changing on about a 26000 year cycle, so 5000 years
ago, the seasons would have been off by about 2 months,
if you used our present calendar, which was modified in 1583 to the tune of
11 days under pope Gregory.
2000 years ago, we only had 10 months, and there was a big gap in the Roman
calendar. (according to Wiki)
Then the politicos and religious heads got together, and changed it a half
dozen times or so to their convenience.


Planetary comparisons between Earth and Uranus determine exactly what
affect 'tilt' represents in respect to the seasons.A rotational
inclination like the Earth generates Equatorial-like conditions while
the daily rotational inclination of Uranus generates polar-like
qualities in seasonal patterns however 'tilt' does not cause the
seasons,the specifics of orbital dynamics cause seasonal changes.

Too many people are getting cut to pieces trying to mesh the
complexities of human devised civil timekeeping with structural
astronomical principles and especially by trying to dump everything
into 'tilt' which is,after all,just the daily rotational orientation
of the Earth.Clarity to the subject in future will rely on an accurate
description of both daily rotation,orbital motion and how both
interact with each other to generate seasonal variations of daylight/
darkness and then move on to more complex issues like precession.




The solstices (?) and equinox (es?) would remain the same, but the seasons
will move!


That is an impossible conclusion.

Solstices and Equinoxes are definite astronomical points based on the
relationship in distance between the circle of illumination and the
geographical axis and therefore the seasons ( in terms of seasonal
daylight/darkness asymmetries)always follow.

The solution is to split civil timekeeping away from structural
astronomical reasoning and recognize that although the calendar system
is a remarkable convenience,it is close to being useless for
referencing daily rotation and annualorbital motion,how these motions
interat with each other and their effects on the seasons,climate and
so on.



wrote in message

...



Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!- Hide quoted text -

- Show quoted text -

wrote in message
...
Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

"Odysseus" gave an essentially correct answer. The Gregorian calendar
reform pretty much fixed the problem of seasonal drift wrt calendar date,
and the average year length (leap years every four years EXCEPT when century
years are divisible by 400) is very close to the current mean tropical year
length (365.2425 vs 365.2422 days). In about 3000 years, the accumulated
error will amount to a full day.

The calendar is designed to keep the equinox and solstice dates constant.

Without the Gregorian Reform we would now be celebrating Christmas on
January 6th (?) (which is still the case for Eastern Orthodox
celebrations--they never accepted the Gregorian Reform for religious
purposes).

However, at present the perihelion is only about 2 weeks from the winter
solstice, and the aphelion is in early July. Due to 26,000-year precession
of the equinoxes, this will change gradually so that c. 13,000 years from
now the winter solstice would coincide with aphelion. This may mean colder
winters in the northern hemisphere, and shorter, hotter summers. There is
also a perihelion advance of the orbit due to the gravitation of other
planets, so 11-12,000 years is closer to the date when this will happen, if
I recall the numbers at all correctly.

There are also very much longer variations in ellipticity of Earth's orbit
that have an influence on the occurrence of ice ages, etc.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On Jan 3, 2:48 pm, wrote:
Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

The Egyptians had a 12 month calendar, but the Roman calendar with
months called June and December wasn't invented for a few more
millenia.

On Jan 4, 11:02*am, "Mike Dworetsky"
wrote:
wrote in message

...





Hello group,

I was kinda pondering this question in my mind for a while, but I hope
someone learned here can put this to rest for me
Due to precession of the equinox (I think somewhat of 50 arcseconds
per year?) the first point of aries always goes backwards on the
ecliptic. So now I'm thinking does that mean that the winter solstice
will fall in a different month from December if we travelled many
hundreds or few thousands of years either backwards or forward in
time?

In our times, it seems to be on December 21st/22nd every year, but
would this have been the case say around 5,000 BC when the pyramids
were being built? Does our calendar year (Jan-Dec) always mean summer
solstice will ALWAYS be in June and winter solstice ALWAYS in
December?

Well I sure would appreciate your correction for me non-expert!

"Odysseus" gave an essentially correct answer. *The Gregorian calendar
reform pretty much fixed the problem of seasonal drift wrt calendar date,
and the average year length (leap years every four years EXCEPT when century
years are divisible by 400) is very close to the current mean tropical year
length (365.2425 vs 365.2422 days). *In about 3000 years, the accumulated
error will amount to a full day.


You got that backwards,the calendar system drifts against the seasons
and that is why the 24 hour day is added every 4th year to reset the
annual cycle to the human devised 24 hour day cycle and its 365/366
day calendar outrigger.The annual orbital cycle is calculated using
the human devised equable 24 hour cycle giving 365 days 5 hours 49
minutes so our astronomical timekeeping ancestors took the fraction of
days and linked it to the nearest equable day which happens to be
every 4th year.

I know all too well why you and your colleagues constantly make
mistakes when dealing with structural astronomy or the practicalities
of civil timekeeping and most of it emerges from the inability to
recognize that the 24 hour day is a human devised principle -

"Here take notice, that the Sun or the Earth passeth the 12. Signes,
or makes an entire revolution in the Ecliptick in 365 days, 5 hours 49
min. or there about, and that those days, reckon'd from noon to noon,
are of different lenghts; as is known to all that are vers'd in
Astronomy. Now between the longest and the shortest of those days, a
day may be taken of such a length, as 365 such days, 5. hours &c. (the
same numbers as before) make up, or are equall to that revolution: And
this is call'd the Equal or Mean day, according to which the Watches
are to be set; and therefore the Hour or Minute shew'd by the Watches,
though they be perfectly Iust and equal, must needs differ almost
continually from those that are shew'd by the Sun, or are reckon'd
according to its Motion. But this Difference is regular, and is
otherwise call'd the Aequation, "

http://www.xs4all.nl/~adcs/Huygens/06/kort-E.html

Empricists have convinced themselves that they can fit the daily and
orbital cycle into the 365/366 day calendar system and this is where
they get into a horrible situation when providing descriptions for
the seasons and the motions/orientations of the planet.


The calendar is designed to keep the equinox and solstice dates constant.


The magnificence of the calendar is designed to create a 365/366 day
system out of the annual orbital cycle of 365 days 5 hours 49 minutes
and it is about time some people learned how to split civil
timekeeping away from purely astronomical principles such as Solstice/
Equinox.



Without the Gregorian Reform we would now be celebrating Christmas on
January 6th (?) (which is still the case for Eastern Orthodox
celebrations--they never accepted the Gregorian Reform for religious
purposes).


The people who resolved civil timekeeping problems centuries based on
further refinements to the leap day adjustment made every 4th year
would be puzzled beyond belief at what contemporaries are doing with
the 'leap second' correction.I would love to speak with genuine people
at a reasonably competent level about great matters differentiating
civil timekeeping systems from structural astronomical principles but
unfortunately all I come in contact with is bluffinglike you are just
doing.


However, at present the perihelion is only about 2 weeks from the winter
solstice, and the aphelion is in early July. *Due to 26,000-year precession
of the equinoxes, this will change gradually so that c. 13,000 years from
now the winter solstice would coincide with aphelion.

A solstice is an event where the distance between the geographical
pole and the circle of illumination is at its greatest,it will occur
regardless of the calendar system and how men try to fit the motions
of the Earth into the calendar system and until somebody who can
actually interpret modern imaging,other than myself, and assign proper
cause and effect basedon the motions of the Earth then your
calendrically driven conclusion is worthless -

http://www.youtube.com/watch?v=nwTrYVBcx9s



*This may mean colder
winters in the northern hemisphere, and shorter, hotter summers. *There is
also a perihelion advance of the orbit due to the gravitation of other
planets, so 11-12,000 years is closer to the date when this will happen, if
I recall the numbers at all correctly.

There are also very much longer variations in ellipticity of Earth's orbit
that have an influence on the occurrence of ice ages, etc.


The people drawing conclusions regarding climate change are far more
frightening than climate change itself for they display no interest in
grasping just how poor their understanding of basic astronomical
principles of annual seasonal variations actually is.


--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

All this is very complex but in some ways most of it can be
streamlined by extracting civil timekeeping from structural
astronomy.Nobody wants to talk and they sure as hell do not want to
listen,all the same,when modern imaging provides most of the details
and people still can't interpret the data then it is no longer a
problem of astronomy or climate,it is a human created problem based on
the inability of people to reason properly based on physical
considerations.