OT: Seasons

In article <[email hidden]>, Paul Rooney <[email hidden]> writes

Quoted message said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I disagree. They are simplistic accounts written for children. Or Americans.

Bernard Hill Selkirk, Scotland

Paul Rooney said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I'm still trying to establish why the day is not symmetrical about noon. (Check sunrise/sunset times
if you don't believe me.) Anyone have an explanation or a relevant URL ?

--
No matter which side of the door the cat or dog is on, it's the wrong side.

Mail john rather than nospam...

In article <[email hidden]>, Sandy <[email hidden]> writes

Quoted message said:

Bernard Hill said:

In article <[email hidden]>, Paul Rooney <[email hidden]> writes

Quoted message said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I disagree. They are simplistic accounts written for children. Or Americans.

Bernard Hill Selkirk, Scotland

en.wikipedia.orgSummer SolsticeOpen ↗

" Please note that this midsummer is not the middle of summer, if summer is defined as the warm
time of year, because of delayed heating effect. Indeed, summer may be defined to begin with the
summer solstice."

en.wikipedia.orgSummerOpen ↗

"Summer is one of the four temperate seasons. Astronomically, it begins with the summer solstice
(around 21 June in the Northern hemisphere, and 21 December in the Southern hemisphere), and ends
with the autumn equinox (around 21 September in the Northern hemisphere and 21 March in the
Southern hemisphere). However, sometimes it is counted instead as the whole months of December,
January and February in the Southern hemisphere and June, July and August in the Northern
hemisphere."

bartleby.comsolstice.htmlOpen ↗

"[Lat.,=sun stands still], in astronomy, either of the two points on the ecliptic that lie midway
between the equinoxes (separated from them by an angular distance of 90°). At the solstices the
sun's apparent position on the celestial sphere reaches its greatest distance above or below the
celestial equator (see equatorial coordinate system), about 231/2° of arc. At the time of summer
solstice, about June 22, the sun is directly overhead at noon at the Tropic of Cancer (see
tropics). In the Northern Hemisphere the longest day and shortest night of the year occur on this
date, marking the beginning of summer. At winter solstice, about Dec. 22, the sun is overhead at
noon at the Tropic of Capricorn; this marks the beginning of winter in the Northern Hemisphere.
For several days before and after each solstice the sun appears to stand still in the sky, i.e.,
its noontime elevation does not seem to change from day to day."

By my reckoning there are only two seasons Winter and Summer. Winter from Sept. 21st to March 21st,
hence Dec. 21st being midwinter. Summer from March 21st to Sept. 21st, hence June 21st being
midsummer.

There is a lot of merit in that. But I merely fit in Spring and Autumn to take equal measures off
both neighbours.

Quoted message said:

The idea that Spring is when the flowers and buds open can't be right either, if it is then this is
Spring because I have roses budding and blooming in my garden, the snowdrops are beginning to come
up and some are showing buds, not far behind them will come the crocus'. It can't be when the seeds
germinate either because the weeds are still germinating and growing. Nature does it's own thing no
matter how man tries to regiment it
🙂

--
Don`t Worry, Be Happy

Sandy

Bernard Hill Selkirk, Scotland

In article <[email hidden]>, Paul Rooney <[email hidden]> writes

Quoted message said:

Bernard Hill said:

In article <[email hidden]>, Paul Rooney <[email hidden]> writes

Quoted message said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I disagree. They are simplistic accounts written for children. Or Americans.

I concluded that 'simplistic' was the only way of getting through to you.

There are plenty of English sites out there, as well as English dictionaries, which give the
astronomical definitions as I have quoted above.

Have you found a dictionary or reference book that gives the astronomical definitions that you are
claiming as correct?

I keep pointing out that the SOED says "midsummer" is "the period in the middle of summer,
especially the time around the summer solstice".

Looks conclusive to me.

You can't be serious in claiming that most of December is Autumn, or most of June is Spring!

Bernard Hill Selkirk, Scotland

In article <[email hidden]>, John Laird <nospam@laird-
towers.org.uk> writes

Quoted message said:

Paul Rooney said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I'm still trying to establish why the day is not symmetrical about noon. (Check sunrise/sunset
times if you don't believe me.) Anyone have an explanation or a relevant URL ?

It may well be symmetrical at Greenwich. However if you are further West for instance then the sun
rises *later* than at Greenwich and sets later.

Now Greenwich may not be symmetrical, but this shows that the day can't be symmetrical across the
whole of the time zone.

Bernard Hill Selkirk, Scotland

In article <[email hidden]>, Bernard Hill <[email hidden]> writes

Quoted message said:

I keep pointing out that the SOED says "midsummer" is "the period in the middle of summer,
especially the time around the summer solstice".

And you have yet to quote the SOED definitions of "summer" - please do, all of them!

--

dscs.demon.co.ukdscs.demon.co.ukOpen ↗

In article <[email hidden]>, Paul Saunders <[email hidden]> writes

Quoted message said:

Sandy said:

By my reckoning there are only two seasons Winter and Summer. Winter from Sept. 21st to March
21st, hence Dec. 21st being midwinter. Summer from March 21st to Sept. 21st, hence June 21st
being midsummer.

In practice I agree. I often think in terms of the warm half of the year and the cold half, or the
light half and the dark half as the Celts used to define it.

To my mind, spring is merely the first half of summer and autumn the first half of winter. But they
have quite different characters. The period leading up to midsummer is a fresh clear warmth, devoid
of insects and tourists, while the late period is hot, hazy, swarming and generally [censored].

Amen to that!

Bernard Hill Selkirk, Scotland

Bernard Hill said:

In article <[email hidden]>, Paul Rooney <[email hidden]> writes

Quoted message said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I disagree. They are simplistic accounts written for children. Or Americans.

Bernard Hill Selkirk, Scotland

en.wikipedia.orgSummer SolsticeOpen ↗

" Please note that this midsummer is not the middle of summer, if summer is defined as the warm time
of year, because of delayed heating effect. Indeed, summer may be defined to begin with the summer
solstice."

en.wikipedia.orgSummerOpen ↗

"Summer is one of the four temperate seasons. Astronomically, it begins with the summer solstice
(around 21 June in the Northern hemisphere, and 21 December in the Southern hemisphere), and ends
with the autumn equinox (around 21 September in the Northern hemisphere and 21 March in the Southern
hemisphere). However, sometimes it is counted instead as the whole months of December, January and
February in the Southern hemisphere and June, July and August in the Northern hemisphere."

bartleby.comsolstice.htmlOpen ↗

"[Lat.,=sun stands still], in astronomy, either of the two points on the ecliptic that lie midway
between the equinoxes (separated from them by an angular distance of 90°). At the solstices the
sun's apparent position on the celestial sphere reaches its greatest distance above or below the
celestial equator (see equatorial coordinate system), about 231/2° of arc. At the time of summer
solstice, about June 22, the sun is directly overhead at noon at the Tropic of Cancer (see
tropics). In the Northern Hemisphere the longest day and shortest night of the year occur on this
date, marking the beginning of summer. At winter solstice, about Dec. 22, the sun is overhead at
noon at the Tropic of Capricorn; this marks the beginning of winter in the Northern Hemisphere. For
several days before and after each solstice the sun appears to stand still in the sky, i.e., its
noontime elevation does not seem to change from day to day."

By my reckoning there are only two seasons Winter and Summer. Winter from Sept. 21st to March 21st,
hence Dec. 21st being midwinter. Summer from March 21st to Sept. 21st, hence June 21st being
midsummer.

The idea that Spring is when the flowers and buds open can't be right either, if it is then this is
Spring because I have roses budding and blooming in my garden, the snowdrops are beginning to come
up and some are showing buds, not far behind them will come the crocus'. It can't be when the seeds
germinate either because the weeds are still germinating and growing. Nature does it's own thing no
matter how man tries to regiment it
🙂

--
Don`t Worry, Be Happy

Sandy
--

E-Mail:- [email hidden] Website:- ftscotland.co.ukftscotland.co.ukOpen ↗ IRC:- Sandyb in #rabble
uk3.arcnet.vapor.com Port:6667 #Rabble Channel Website:- ftscotland.co.ukrabbledOpen ↗
ICQ : 41266150

Bernard Hill said:

In article <[email hidden]>, Paul Rooney <[email hidden]> writes

Quoted message said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I disagree. They are simplistic accounts written for children. Or Americans.

I concluded that 'simplistic' was the only way of getting through to you.

There are plenty of English sites out there, as well as English dictionaries, which give the
astronomical definitions as I have quoted above.

Have you found a dictionary or reference book that gives the astronomical definitions that you are
claiming as correct?

--
Paul

My Lake District walking site (updated 29th September 2003): paulrooney.netfirms.compaulrooney.netfirms.comOpen ↗

Sandy said:

By my reckoning there are only two seasons Winter and Summer. Winter from Sept. 21st to March
21st, hence Dec. 21st being midwinter. Summer from March 21st to Sept. 21st, hence June 21st being
midsummer.

In practice I agree. I often think in terms of the warm half of the year and the cold half, or the
light half and the dark half as the Celts used to define it.

To my mind, spring is merely the first half of summer and autumn the first half of winter. But they
have quite different characters. The period leading up to midsummer is a fresh clear warmth, devoid
of insects and tourists, while the late period is hot, hazy, swarming and generally [censored].

Paul
--
wildwales.fsnet.co.ukoctober.htmlOpen ↗
wilderness-wales.co.ukwilderness-wales.co.ukOpen ↗
photosig.comuserphotosOpen ↗

On Wed, 24 Dec 2003 17:17:42 +0000, Bernard Hill <[email hidden]>

Quoted message said:

In article <[email hidden]>, John Laird <nospam@laird-
towers.org.uk> writes

Quoted message said:

Paul Rooney said:

scienceworld.wolfram.comSeasons.htmlOpen ↗
curious.astro.cornell.eduquestion.phpOpen ↗

Nuff said.

I'm still trying to establish why the day is not symmetrical about noon. (Check sunrise/sunset
times if you don't believe me.) Anyone have an explanation or a relevant URL ?

It may well be symmetrical at Greenwich. However if you are further West for instance then the sun
rises *later* than at Greenwich and sets later.

Now Greenwich may not be symmetrical, but this shows that the day can't be symmetrical across the
whole of the time zone.

I would expect that to be a relatively constant shift (everything a few minutes later for places
west of Greenwich, for example). Pierre's post referred me to some sites which explain the
differences between clock time and sun time (ie. why the sun is not at its highest at noon).

--
Success is just a matter of luck. Ask any failure.

Mail john rather than nospam...

In article <[email hidden]>, John Laird <nospam@laird-
towers.org.uk> writes

Quoted message said:

I'm still trying to establish why the day is not symmetrical about noon. (Check sunrise/sunset
times if you don't believe me.) Anyone have an explanation or a relevant URL ?

The Earth spins around its axis at a (very, very, very, nearly) constant rate. This results in a
sidereal day (e.g. between 2 occurrences of Sirius passing due south) of constant length (a little
under 24 hours). Because of the motion of the Earth about the Sun, the solar day is longer (the mean
solar day is 24 hours). Because the eccentricity of the Earth's orbit is non-zero (i.e. it is non-
circular) and hence its angular velocity about the sun is variable, the length of the solar day
oscillates with a period of one year; hence local true noon varies from local mean noon.

Also local mean noon differs from clock noon, unless one is on the meridian from the clock time is
taken for that time zone. Most of Britain is west of the Greenwich meridian, and therefore noon is
delayed for seconds to minutes compared with Greenwich noon.
--
Stewart Robert Hinsley

In article <[email hidden]>, Paul Saunders <[email hidden]> writes

Quoted message said:

John Laird wrote:

Bernard Hill said:

Quoted message said:

It may well be symmetrical at Greenwich.

No, it isn't.

Quoted message said:

I would expect that to be a relatively constant shift (everything a few minutes later for places
west of Greenwich, for example).

The time zone shift is constant I believe. Each degree is equal to four minutes of time (15 degrees
= 1 hour). Since I live roughly 4 degrees west of Greenwich, sunrise, midday and sunset occur 16
minutes later (the 4 degree line also runs through Snowdonia incidentally).

Quoted message said:

Pierre's post referred me to some sites which explain the differences between clock time and sun
time (ie. why the sun is not at its highest at noon).

The equation of time means that there's an additional variation on top of this which can be as much
as +/-16m at certain times of the year (I thought I'd seen variations up to 25 minutes but I can't
be sure offhand). Combined with the time zone difference that means that midday for me can range
from 12:00 to 12:32 (add an hour for summer time of course).

That's the harder (more complex) explanation. The simpler explanation is that it can't be symmetric
right through a time zone because of the time zone shift.

I'm very pleased you quote 16 minutes. Many many years ago (about 1970) I was involved in a project
which sought to make an accurate sundial. I was the mathematician and was exceedingly pleased with
myself when proved by 3D geometry and the earth's elliptical orbit that the dial could be out by 16
minutes. But I never heard it verified until now.

I'd forgotten I'd ever done that :-)

Quoted message said:

There's an excellent little programme called Anno Domini which tells you the current equation of
time and the time of the Sun's "transit" (i.e. midday), in addition to loads of other useful
calendar related data (sunrise, moonrise, moon phases etc. for any location) I'm still using a very
old version but I've just checked and it's been considerably upgraded since I last looked. Time to
get the new version methinks. I recommend this program. anno-domini.netanno-domini.netOpen ↗

Paul
--
wildwales.fsnet.co.ukoctober.htmlOpen ↗ wilderness-wales.co.ukwilderness-wales.co.ukOpen ↗
photosig.comuserphotosOpen ↗

Bernard Hill Selkirk, Scotland

In article <[email hidden]>, Bernard Hill <[email hidden]> writes

Quoted message said:

That's the harder (more complex) explanation. The simpler explanation is that it can't be symmetric
right through a time zone because of the time zone shift.

That isn't right. The solar time may be offset but the day and night are the same length as
elsewhere at the same latitude in the time zone. There is a time shift associated with the change of
longitude but that just shifts the sunrise, sunset, zenith etc. times.

--

dscs.demon.co.ukdscs.demon.co.ukOpen ↗

[email hidden]> writes

Quoted message said:

In article <[email hidden]>, Bernard Hill <[email hidden]> writes

Quoted message said:

That's the harder (more complex) explanation. The simpler explanation is that it can't be
symmetric right through a time zone because of the time zone shift.

That isn't right. The solar time may be offset but the day and night are the same length as
elsewhere at the same latitude in the time zone. There is a time shift associated with the change
of longitude but that just shifts the sunrise, sunset, zenith etc. times.

The question I replied to was not about length of night but the time of sunrise and sunset. The OP
wanted to know why sunrise/set are not symmetric about midnight/midday. As I say, the simple
answer is that it varies across the time zone with as the sun rises at different times across the
time zone.

Bernard Hill Selkirk, Scotland

In article <[email hidden]>, Bernard Hill <[email hidden]> writes

Quoted message said:

[email hidden]> writes

Quoted message said:

In article <[email hidden]>, Bernard Hill <[email hidden]> writes

Quoted message said:

That's the harder (more complex) explanation. The simpler explanation is that it can't be
symmetric right through a time zone because of the time zone shift.

That isn't right. The solar time may be offset but the day and night are the same length as
elsewhere at the same latitude in the time zone. There is a time shift associated with the change
of longitude but that just shifts the sunrise, sunset, zenith etc. times.

The question I replied to was not about length of night but the time of sunrise and sunset. The OP
wanted to know why sunrise/set are not symmetric about midnight/midday. As I say, the simple
answer is that it varies across the time zone with as the sun rises at different times across the
time zone.

Bernard Hill Selkirk, Scotland

Ooops, mea culpa. Sorry Bernard.

--

dscs.demon.co.ukdscs.demon.co.ukOpen ↗

John Laird wrote:

Bernard Hill said:

Quoted message said:

It may well be symmetrical at Greenwich.

No, it isn't.

Quoted message said:

I would expect that to be a relatively constant shift (everything a few minutes later for places
west of Greenwich, for example).

The time zone shift is constant I believe. Each degree is equal to four minutes of time (15 degrees
= 1 hour). Since I live roughly 4 degrees west of Greenwich, sunrise, midday and sunset occur 16
minutes later (the 4 degree line also runs through Snowdonia incidentally).

Quoted message said:

Pierre's post referred me to some sites which explain the differences between clock time and sun
time (ie. why the sun is not at its highest at noon).

The equation of time means that there's an additional variation on top of this which can be as much
as +/-16m at certain times of the year (I thought I'd seen variations up to 25 minutes but I can't
be sure offhand). Combined with the time zone difference that means that midday for me can range
from 12:00 to 12:32 (add an hour for summer time of course).

There's an excellent little programme called Anno Domini which tells you the current equation of
time and the time of the Sun's "transit" (i.e. midday), in addition to loads of other useful
calendar related data (sunrise, moonrise, moon phases etc. for any location) I'm still using a very
old version but I've just checked and it's been considerably upgraded since I last looked. Time to
get the new version methinks. I recommend this program. anno-domini.netanno-domini.netOpen ↗

Paul
--
wildwales.fsnet.co.ukoctober.htmlOpen ↗
wilderness-wales.co.ukwilderness-wales.co.ukOpen ↗
photosig.comuserphotosOpen ↗

Bernard Hill said:

That's the harder (more complex) explanation. The simpler explanation is that it can't be
symmetric right through a time zone because of the time zone shift.

I'm very pleased you quote 16 minutes. Many many years ago (about
1970) I was involved in a project which sought to make an accurate sundial. I was the
mathematician and was exceedingly pleased with myself when proved by 3D geometry and the
earth's elliptical orbit that the dial could be out by 16 minutes. But I never heard it
verified until now.

Good for you.

By the way, I forgot to mention, you know I said that Anno Domini can tell you the equation of time
and the true time of midday (anno-domini.netanno-domini.netOpen ↗), well what I often do each time I go
camping is to synchronise the second time on my Dual Time watch to match true midday, so I then have
"Solar Time" on my watch, where midday really is the middle of the day. I find this is more
practical when I'm away from civilisation for a few days, especially in summer when "Civ" time is
way off reality.

For one thing, it makes it far easier to estimate the angle of the sun's rays at any given time of
day, useful for photography.

Paul
--
wildwales.fsnet.co.ukoctober.htmlOpen ↗
wilderness-wales.co.ukwilderness-wales.co.ukOpen ↗
photosig.comuserphotosOpen ↗