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Daylight Saving Time



 
 
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  #1  
Old October 29th 17, 10:20 AM posted to sci.astro.amateur
Gerald Kelleher
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Default Daylight Saving Time

As usual I have to explain something most are uncomfortable with while knowing all too well that others can't do it because of some silly allegiance to mistakes made centuries ago.

The 24 hour weekday is anchored in noon when the observer is midway to either side of the circle of illumination or ,in geocentric terms, the Sun crosses the observer's meridian. The milestones of each weekday rotation are sunrise, noon, sunset and midnight so that on the September Equinox the Sun rises at 6 AM and sets at roughly 6 PM. Because of DST, sunrise is at 7 AM while Sunset is at 7 PM so this period is the artificial setup.

The creation of the average 24 hour day is also anchored to noon along with the same principles which create the daily milestones of sunrise, noon ect.. The Equation of Time is the facility by which we get the 24 hour day which allows for the flexibility of DST among others things.

  #2  
Old October 29th 17, 02:50 PM posted to sci.astro.amateur
Quadibloc
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Default Daylight Saving Time

Daylight Saving Time is an inconvenience to observational astronomy, since it is
one more thing to keep track of and avoid making mistakes with when reporting the
times of astronomical events.

It is used by governments as the most convenient way to get everyone to get up, go
to school or to work, and watch their favorite television programs an hour
earlier, so as to minimize electrical power consumption. Everyone knows it is
artificial, and has nothing to do with the real time of day, however one might
express that concept.

John Savard
  #3  
Old October 29th 17, 08:45 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Daylight Saving Time

The Equation of Time and therefore the 24 hour weekday is anchored in the noon observation so Huygens, in his description of how to use the sunrise/sunset references allowed for a centering process for natural noon -

" In the morning then, when the Sun is just half above the Horizon, note, what hour, min. and sec. the Watch points at, if it be going; if not, set it a going, and put the Indexes, at what hour, min. and sec. you please. Let them goe till Sun-set, and when the Body of the Sun is just half under the Horizon, see, what hour, min. and sec. the Indexes of the Watch point at, and note them too; and reckon, how many houres &c. are Pass'd by the Watch between the one and the other: which is done by adding to the Evening-Observation the hours, &c. that the morning-Observation wanted of 12. or 24. in case the Hour-hand hath in the mean time pass'd that hour once or twice; otherwise the difference only gives the time. Then take the half of that number, and add it to the hours, &c. of the morning-Observation, and you shall have the hours, &c. which the Watch did show, when the Sun was in the South; whereunto add the Aequation in the Table belonging to that day, and note the summe." Huygens

https://adcs.home.xs4all.nl/Huygens/06/kort-E.html

The equalizing of the length of daylight either side of noon from sunrise to sunset is just a normal consequence of one rotation and likewise the length of darkness either side of midnight from sunset to sunrise is an extension of the four milestones of one rotation (sunrise, noon, sunset and midnight).






  #4  
Old October 30th 17, 12:20 AM posted to sci.astro.amateur
Mike Collins[_4_]
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Default Daylight Saving Time

Quadibloc wrote:
Daylight Saving Time is an inconvenience to observational astronomy, since it is
one more thing to keep track of and avoid making mistakes with when reporting the
times of astronomical events.

It is used by governments as the most convenient way to get everyone to get up, go
to school or to work, and watch their favorite television programs an hour
earlier, so as to minimize electrical power consumption. Everyone knows it is
artificial, and has nothing to do with the real time of day, however one might
express that concept.

John Savard


It’s just a successful confidence trick. Imagine the uproar if the
government decreed that everyone should get up an hour earlier in spring.
Yet we meekly acquiesce when they put the clock forward,


  #5  
Old October 30th 17, 12:11 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Daylight Saving Time

Just goes to show how nobody really appreciates what happens when timekeeping meets the body clock in terms of the planet's rotation. When I explain this somewhere else, most find it easy enough whereas others will still feel uncomfortable with the explanation. At all times the principles are anchored in the Lat/Long system and the fact that rotation is anchored in noon which means that this period is the most natural to the body and its daily rhythms -

https://learn.pharmacy.unc.edu/insom...ical_clock.png


The intellectual rednecks who attempt to imply one more rotation than weekdays in a year or the recent rubbish of a slowing rotation based on spurious nonsense would rather become ill in the mind than accept what their bodies are telling them.

Most of these issues are new and barely touched.
  #6  
Old October 30th 17, 05:53 PM posted to sci.astro.amateur
palsing[_2_]
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Default Daylight Saving Time

Gerald wrote;

Most of these issues are new and barely touched.


All of these issues are well understood and have been for a very, very long time. You are just late to the dance, and so far you have not even learned to waltz, let alone do the lambada...
  #7  
Old October 30th 17, 08:21 PM posted to sci.astro.amateur
Gerald Kelleher
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Default Daylight Saving Time

On Monday, October 30, 2017 at 4:53:49 PM UTC, palsing wrote:
Gerald wrote;

Most of these issues are new and barely touched.


All of these issues are well understood and have been for a very, very long time.


How I wish that were so. The foundations of timekeeping have been presented in its entirety including the orbital benchmark which defines the proportion of rotations to one orbital circuit, the proportion of rotations to four orbital circuits and the additional refinement of rotations per orbital circuits known through the precession of the equinoxes insofar as the same framework and observations works for more general to more detailed proportions of rotations to orbital circuits.

A good start is DST which demonstrates how the rotation of the Earth is anchored to noon.


  #8  
Old November 4th 17, 06:40 AM posted to sci.astro.amateur
RichA[_1_]
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Default Daylight Saving Time

Daylight saving is garbage and should be done away with. It's not 1880 and we aren't all frigging farmers.

  #9  
Old November 4th 17, 07:40 AM posted to sci.astro.amateur
Gerald Kelleher
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Posts: 1,551
Default Daylight Saving Time

It seems that playing fast and loose with the English language or even torturing it comes at a price as followers of the early 20th century theorists have lost the capacity to put the back and forth motions of the planets and satellites around the parent Sun or parent planet using the normal language of motion to the left or to the right.

The rule of thumb is that a planet or a satellite, as we see it from Earth, moves from left to right in front of the parent object and from right to left as it travels behind it. This restores context after to losing it to RA/Dec modelling.

This response mostly belongs in the other thread however this thread and so many other are connected within a larger and more expansive narrative. It is fitting that the effect of daily rotation in isolation brings the Sun into view each weekday hence the 24 hour cycle as an average is anchored in natural noon whereas the orbital motion of the Earth anchors the annual cycle with the first seasonal appearance of a star. It generates the inviolate proportion of days/rotations to years/orbital cycles in such a way as a format can be created based on a continuous stream of rotations.

DST is perhaps unnecessary from an astronomical standpoint but it only makes sense in how it alters the relationship of timekeeping to daily rotation and orbital motion in two ways.
  #10  
Old November 4th 17, 12:51 PM posted to sci.astro.amateur
Mike Collins[_4_]
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Default Daylight Saving Time

Gerald Kelleher wrote:
It seems that playing fast and loose with the English language or even
torturing it comes at a price as followers of the early 20th century
theorists have lost the capacity to put the back and forth motions of the
planets and satellites around the parent Sun or parent planet using the
normal language of motion to the left or to the right.

The rule of thumb is that a planet or a satellite, as we see it from
Earth, moves from left to right in front of the parent object and from
right to left as it travels behind it. This restores context after to
losing it to RA/Dec modelling.


Except in the Southern Hemisphere. Herodotus knew this and described it in
his account of the voyages of Phoenicians


“Libya is washed on all sides by the sea except where it joins Asia, as was
first demonstrated, so far as our knowledge goes, by the Egyptian king
Necho, who, after calling off the construction of the canal between the
Nile and the Arabian gulf, sent out a fleet manned by a Phoenician crew
with orders to sail west about and return to Egypt and the Mediterranean by
way of the Straits of Gibraltar. The Phoenicians sailed from the Arabian
gulf into the southern ocean, and every autumn put in at some convenient
spot on the Libyan coast, sowed a patch of ground, and waited for next
year's harvest. Then, having got in their grain, they put to sea again, and
after two full years rounded the Pillars of Heracles in the course of the
third, and returned to Egypt. These men made a statement which I do not
myself believe, though others may, to the effect that as they sailed on a
westerly course round the southern end of Libya, they had the sun on their
right - to northward of them. This is how Libya was first discovered by
sea.”



 




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