Wrap this around your mental astronomical-phenomena spindle and see if you can make of it more of a skein than a snarl:
Where I live on the west coast of the U.S.A., astronomical equinox is at 1:20AM Pacific Daylight Time on Wednesday 23 September 2015. The time from sunrise to sunset should be equal to the time from sunset to sunrise, right?
Doesn't work that way.
Wednesday actually has six more minutes of daylight than Friday. On Friday 25 September we actually get 12 hours zero minutes between sunrise and sunset.
Why?
First, the astronomical definition of equinox is at the moment the earth in its orbit around the sun crosses a particular point in reference to what astronomers call the fixed stars. We know that point wanders with respect to the earth's axis-wobble and the earth's elliptical orbit (precession of the equinox) -- ve-e-e-r-r-y s-slo-o-o-owly! But can it make a difference of a day or two?
Second, there's the spin of the earth. Does the spin, added to the round-the-sun motion, make a difference?
I admit I haven't done the research. But hey, give me some credit for finding the conundrum.
Showing posts with label equinox. Show all posts
Showing posts with label equinox. Show all posts
3/09/2013
Fixing the clocks
First let's talk solar astronomy.
At the equinoxes in the spring (20 March 2013 at 4:02AM Pacific Daylight Time) and fall (22 September 2013 at 1:44PM Pacific Daylight Time) the length of day is approximately equal to the length of night. That is where the name "equinox" comes from. The time of equinoxes has been observed, marked, and predicted since ancient times. The day of the month on which equinoxes fall in March or September can vary slightly, mostly because of because of leap years.
So. Let's talk about public policy. Suppose somebody decided it would be best for all within the polity to behave as though noon did not occur at noon. Suppose they decided that clock noon would need to occur an hour before solar noon. A law would decree that the clocks be adjusted an hour ahead. That way at clock noon the sun would still be in the morning half of the sky, but humans are remarkably flexible and life goes on.
And so it is.
Leaving aside the asininity of the policy itself, it can be done. It is not even as invasive and disruptive as many other things the ruling class decree.
Here's my question. It is a question of logical (or illogical) internal consistency.
If the clocks are moved forward for Daylight Savings Time less than two weeks before the vernal equinox, why (O! Dear God of the heavenly lights! Why?!) do they decree that we not move the clocks back for Standard Time, moving clock noon back to something more like solar noon, until SIX WEEKS AFTER THE AUTUMNAL EQUINOX???!!!
I'm sorry. Did I raise my voice?
Quite apart from the bad policy of Daylight Savings Time, what really grates my brain, what really distracts me, what really brings me almost to think that our ruling class have neither logic nor benefit in mind, is the inconsistency of the thing. At least the change should be made approximately "n" weeks before the vernal equinox and equally "n" weeks after the autumnal equinox.
Clearly that is too much to ask of our ruling class. The vast apparatus of their power is directed elsewhere. They are busy fixing men's souls. Fixing the clocks will have to wait.
At the equinoxes in the spring (20 March 2013 at 4:02AM Pacific Daylight Time) and fall (22 September 2013 at 1:44PM Pacific Daylight Time) the length of day is approximately equal to the length of night. That is where the name "equinox" comes from. The time of equinoxes has been observed, marked, and predicted since ancient times. The day of the month on which equinoxes fall in March or September can vary slightly, mostly because of because of leap years.
So. Let's talk about public policy. Suppose somebody decided it would be best for all within the polity to behave as though noon did not occur at noon. Suppose they decided that clock noon would need to occur an hour before solar noon. A law would decree that the clocks be adjusted an hour ahead. That way at clock noon the sun would still be in the morning half of the sky, but humans are remarkably flexible and life goes on.
And so it is.
Leaving aside the asininity of the policy itself, it can be done. It is not even as invasive and disruptive as many other things the ruling class decree.
Here's my question. It is a question of logical (or illogical) internal consistency.
If the clocks are moved forward for Daylight Savings Time less than two weeks before the vernal equinox, why (O! Dear God of the heavenly lights! Why?!) do they decree that we not move the clocks back for Standard Time, moving clock noon back to something more like solar noon, until SIX WEEKS AFTER THE AUTUMNAL EQUINOX???!!!
I'm sorry. Did I raise my voice?
Quite apart from the bad policy of Daylight Savings Time, what really grates my brain, what really distracts me, what really brings me almost to think that our ruling class have neither logic nor benefit in mind, is the inconsistency of the thing. At least the change should be made approximately "n" weeks before the vernal equinox and equally "n" weeks after the autumnal equinox.
Clearly that is too much to ask of our ruling class. The vast apparatus of their power is directed elsewhere. They are busy fixing men's souls. Fixing the clocks will have to wait.
Subscribe to:
Posts (Atom)