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Why do people not notice the equinox when it happens ?
Suggest not noticing the equinox corresponds with several modern cultural trends.Baluncore said:Why do people not notice the equinox when it happens ?
I'm near the equator this week, so nothing noteworthy happened/changed.Baluncore said:Why do people not notice the equinox when it happens ?
Nor is north or south marked in the landscape.snorkack said:Nor is due east or west marked in landscape.
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.
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.
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.
Why would we?Baluncore said:Why do people not notice the equinox when it happens ?
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 ?
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. But many people don't even notice when it's time to turn on their car headlamps,Drakkith said:Why would we?
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.
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.
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.
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.
I was actually wondering if anyone would notice the time stamp of a self-referential OP.Vanadium 50 said:Were we supposed to notice something at 3:52 exactly (or whenever it was)?
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.
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.
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.
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.