Why do people not notice the equinox when it happens?
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Stonehenge is too big to carry around in your pocket?
My Dad always used to go into work the day after summer solstice, assume his best bluff Yorkshireman manner, and observe "well, evenin's are drawin' in".
My Dad always used to go into work the day after summer solstice, assume his best bluff Yorkshireman manner, and observe "well, evenin's are drawin' in".
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Suggest not noticing the equinox corresponds with several modern cultural trends.Baluncore said:Why do people not notice the equinox when it happens ?
People not engaged in agriculture generally do not pay close attention to change in the seasons. Aside from some wardrobe differences, people in temperate climates seem to ignore the seasonal changes indicated by the equinox. In northern areas where winter still requires attention to the outdoors, traditional festivals may mark the equinox but with scant observation of the underlying astronomical events.
Areas that change clocks forward and backwards in accord with longer days and shorter nights do so by government agreements with little notice of the actual equinox. Perhaps more ancient cultures with longer historical perspectives retain more interest.
This leads to a second reason. Modern life greatly reduces the significance of folklore, tradition and religion. Observing the equinox changes from a vital factor in our daily lives to nostalgia for a receding past rooted in the movements of earth and sun. Autumn post-harvest festivals and Spring planting rituals become largely symbolic holidays with only passing references -- fallen leaves, large cauldrons, 'Easter' eggs and tiny chicks -- to the equinox.
A third reason considers global trade and relative abundance of food with little regard for the local or regional growing season. Why pay attention to equinox when produce from north, south and equatorial regions obviates the necessity of observing this change?
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I'm near the equator this week, so nothing noteworthy happened/changed.Baluncore said:Why do people not notice the equinox when it happens ?
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Equality of day and night length takes exact measurement of time, and biologic clock is not so exact. Nor is due east or west marked in landscape.
Solstices are more conspicuous.
Solstices are more conspicuous.
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Nor is north or south marked in the landscape.snorkack said:Nor is due east or west marked in landscape.
What have east and west got to do with the equinox?
The few days around any solstice are all very similar. The exact day of the solstice is hard to determine without precision measurements. Near the solstice, sunrise and sunset, are according to the clock drifting together in the same direction, due to the equation of time, shown by the horizontal parts of the analemma curve.snorkack said:Solstices are more conspicuous.
The sweep of the Earth's equatorial plane through the centre of the Sun, on the March equinox, is an instant in time that forms the cardinal reference for sidereal time.
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At equinox, sun rises due east and sets due west.Baluncore said:Nor is north or south marked in the landscape.
What have east and west got to do with the equinox?
This requires using a precise clock - set to run on mean time.Baluncore said:The few days around any solstice are all very similar. The exact day of the solstice is hard to determine without precision measurements. Near the solstice, sunrise and sunset, are according to the clock drifting together in the same direction, due to the equation of time, shown by the horizontal parts of the analemma curve.
Alternately you might track the exact location of sunrise and sunset against horizon markers.
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That assumes I am at sea, not in the mountains.snorkack said:This requires using a precise clock - set to run on mean time.
Alternately you might track the exact location of sunrise and sunset against horizon markers.
I could measure the declination of the Sun at midday with a sextant. On the equinox, the declination will be equal to my latitude, and the declination is changing at the maximum rate per day.
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How many people even "notice" sunrise or sunset? The light level changes very slowly and you'd need to be looking very carefully at the Sun and the horizon (which is a really bad idea as your eyes would suffer). Even though the day length is changing at its fastest around the equinox, it's still pretty slow and local conditions and topography would affect any casual measurement.Baluncore said:Why do people not notice the equinox when it happens ?
There's also the fact that, at the instant of the actual equinox, the Sun could be anywhere in its path over any given location.
How many "people" do you know who own and can drive one of them?Baluncore said:I could measure the declination of the Sun at midday with a sextant.
I just read this - Nuff Said.Drakkith said:Why would we?
However - there are some people in the world who are very aware of this stuff and they are the ones who are in charge of slotting leap seconds into our time standards.
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They must have retired. We have not had a leap second in 7 years. Leap second insertion is proposed to end by 2035. Maybe will get a leap minute every century.sophiecentaur said:However - there are some people in the world who are very aware of this stuff and they are the ones who are in charge of slotting leap seconds into our time standards.
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Assuming that you have and can use sextant - and know your latitude.Baluncore said:I could measure the declination of the Sun at midday with a sextant. On the equinox, the declination will be equal to my latitude, and the declination is changing at the maximum rate per day.
Day length you need to measure against clock, and your biological one is imprecise. Local conditions and topography will affect measuring the place where Sun rises or sets, but when the point is not on featureless sea and the viewpoint is fixed, then the point of sunrise or sunset may be followed against objects on horizon like trees, roofs etc.sophiecentaur said:How many people even "notice" sunrise or sunset? The light level changes very slowly and you'd need to be looking very carefully at the Sun and the horizon (which is a really bad idea as your eyes would suffer). Even though the day length is changing at its fastest around the equinox, it's still pretty slow and local conditions and topography would affect any casual measurement.
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As it happens, I can spot sunset over most of its march across the West and I do know that it goes down amongst some familiar trees around this time. But I needed to know some side information to be sure it's the equinox.snorkack said:then the point of sunrise or sunset may be followed against objects on horizon like trees, roofs etc.
I also notice it going down further and further towards Nine Ashes ) WNW of us. But, where it gets there, it's a sign that Autumn will be there soon. A very Eeyore take on things and time is accelerating for me.
But, for heaven's sake, I'm supposed to be keen on Astro matters so I am not an ordinary "people". No one else in our house sees it all like that.
An Amillary compass can tell you when the equinox occurs because it supplies its own ephemeris information if it's been set up correctly. But, around the equinox, the band that goes over the top gets in the way of forming shadows after 6pm etc.. I am making one at the moment and I soon realised that it could only be easy if I only use a semicircular scale.
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Since the early calendars , the intervals between necessary fudges have been longer and longer. I was amused to learn that the Gregorian calendar took about 300 years before GB (not wanting to do what a pope recommended) adopted it. By that time, calendars were drifting apart in an embarrassing way.Baluncore said:They must have retired. We have not had a leap second in 7 years. Leap second insertion is proposed to end by 2035. Maybe will get a leap minute every century.
The finer the error, the longer it takes to reveal itself.
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Were we supposed to notice something at 3:52 exactly (or whenever it was)?
Or were we supposed to notice exactly 12.00000 hours of daylight - which didn;t happen?
Or were we supposed to notice exactly 12.00000 hours of daylight - which didn;t happen?
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You were far too subtle for all of us linear thinkers.Baluncore said:I was actually wondering if anyone would notice the time stamp of a self-referential OP.
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If you're really close to the equator, you've got no shadows/minimal shadows of vertical posts/poles at local noon. That's something.russ_watters said:I'm near the equator this week, so nothing noteworthy happened/changed.
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You forgot to insert the condition "and if you're an enthusiast" in there. Solstices are much more 'noticeable' because they're associated with yearly ceremonies and they're publicised.collinsmark said:If you're really close to the equator, you've got no shadows/minimal shadows of vertical posts/poles at local noon. That's something.
The people who notice equinoxes are those who manage boats in shallow waters. Six months is a long time to wait to re-float your boat if you forgot you beached it at an equinoctial spring high tide so you keep account of these things.
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It's true that it can be important to be aware of the tidal range around that time of year, but spring tides depend on the moon phase so the highest tide around the equinox will typically be a few days before or after the equinox itself. And the effect is further modulated by the fact that the moon's orbit is not exactly aligned with the ecliptic, and by local tidal effects, so I think those people are more likely to be looking carefully at their local tide tables rather than being particularly aware of the date of the equinox.sophiecentaur said:The people who notice equinoxes are those who manage boats in shallow waters. Six months is a long time to wait to re-float your boat if you forgot you beached it at an equinoctial spring high tide so you keep account of these things.
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@Jonathan Scott this is all very nerdy stuff and there is no end to how deep one can go into it. However, boating folk are all very aware of Equinox time, to a level that your average man in the street can only feel bemused.
The sailors I know (cruising not dinghy racing) are all very much aware of when they're to expect the tide to allow them to do things and they use the term "equinox" frequently in their clubroom chats. But you are right that it's the tables that tell them precise dates and times.
Actual times are affected by both Sun and Moon positions and also location. At any particular mooring / port, the high and lows of spring tides tend to occur at around the same times of day, each time they come around. It tends to be the lows that can really getcha and can cause great embarrassment (even danger sometimes).
The sailors I know (cruising not dinghy racing) are all very much aware of when they're to expect the tide to allow them to do things and they use the term "equinox" frequently in their clubroom chats. But you are right that it's the tables that tell them precise dates and times.
Actual times are affected by both Sun and Moon positions and also location. At any particular mooring / port, the high and lows of spring tides tend to occur at around the same times of day, each time they come around. It tends to be the lows that can really getcha and can cause great embarrassment (even danger sometimes).
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Something like that.Baluncore said:They must have retired. We have not had a leap second in 7 years. Leap second insertion is proposed to end by 2035. Maybe will get a leap minute every century.
The earth was what, slowing down in rotation and then it has sped up recently. A un-leap second would have to subtracted to adjust the time keeping.
And adding in these seconds really balls up the works for all the facilities keeping their atomic clock in sync.
Don't even mention the governments and industries that find it a pain in the ( clock ) works to keep up with all the time changes.
So someone proclaimed no more second by second changes - when the earth rotation and atomic clocks get too out of sync, such as a minute someone in the future can worry about it.
And everyone clapped and cheered, and said right on. That makes whole lot of sense.
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As they say: "Equinox - it's a nightmare"
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People who were taught Latin by Mr Jones, and othersBaluncore said:Who are they ?
The 1950s was great for a wide education (and a sore backside).
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I live near the equator. I once told someone that in other latitudes the days change length. She was amazed.
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The things that people just don't know are amazing. But that goes for all of us. I keep having to remind myself not to be smug about it - 'cos my subset of non-knowledge is huge.Hornbein said:I live near the equator. I once told someone that in other latitudes the days change length. She was amazed.
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That was a great pickup line.Hornbein said:I live near the equator. I once told someone that in other latitudes the days change length. She was amazed.
I had forgotten how equinoxious the tropics could be.
Daylight variation in Bali: The longest days have about 12.5 hours of daylight in June/July, while the shortest days have about 11.75 hours in December/January.
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