The Precession of Equinox

Equinox, often thought of as a specific day, is actually an exact moment when day and night are equal. With 86,400 seconds in a day, this precise astronomical event serves as a reminder of the incredible accuracy of Earth's diurnal rotation and celestial mechanics.

[keithheydenrych]

I was taught that it is an instantaneous event. I really enjoy Randalls teaching methods.

[izme]

Every moment has a moment on the approach it’s peak moment as well as the moment of it’s
Departure

[om-om-om.]

It's good to have a detailed understanding of the happenings with our Earth and relation to all.

Society has taught us to only look at the surface...

[robert-zjef]

Yes, its only a specific moment in time, yet, most of us regard that day, a few before and a few after as when daylight and dark are within a few minutes of being equal.

[williamhannah]

I am so fascinated by everything he says.

[gshefer]

Since the earth is constantly moving, The amount of "daytime" changes even during the day. But every year there are exactly two days, that the amount of "daytime" and "nighttime" are CLOSEST to equal. And those two days are different in most points on earth.

[jackpurlee]

Interesting stuff. I wish I could of been taught this stuff in school.but public school teachers are just in it for a check.

[wizengy]

You may also think that the winter solstice with the shortest day has either the earliest sunset or the latest sunrise. This is not true. Depending on the latitude, they can occur from over 6 weeks to a day away from the solstice point. The difference is greatest at the equator. The opposite occurs on the summer solstice.

[christelting]

I enjoy most of his planetary geology lectures. Very respectable. His switch up with engine exhaust cleanup and micro fusion throws me for a loop.

It's like watching following an auto repair person and then he starts content on home decorating. Not saying you can't have multiple interests... The micro fusion is kind of fringe, not that it isn't possible.

[Hal_McKinney]

I wonder how practical it would be if equinox was simply defined as 12:00pm noon every day?

[RanallAcquistapace]

Means 12 hours or 43100 seconds day and 12 hours or 43100 night.

[wirebrushproductions]

"It is an indefineably small moment." This from the guy who just defined it. I suspect he meant "an unveasurably small moment.
And he is also wrong. The more common meaning of the equinox is the day when the equinox occurs.

[James-plbu]

Sounds like your describing planks distance

[ejedijedi]

I think Reebok didnt market the pumps right,

[trueblu]

Did the Earth get knocked off its axis by a collision?

[johnschoen]

How long is the sunset or sunrise? The setting sun could be an hour of time, the sunrise happens when the first fiery beam breaks the horizon yet it takes app. 5 min for the full disk of the sun to be above the horizon, is it still sunrise?

[Tmanaz]

Indefinably small? Actually the word "point" is defined as infinitely small.

[John-sth]

Dude, you have banana bread stuck in your throat

[jam]

86, 400 seconds, the sun is 864, 000 mi in diameter, the moon is 2, 160 (times 4 is 8, 640)…crazy.

[leemcfarland]

He needs to read the definition of semantics. A point in time is how long? A day? An hour? A second? A millisecond? You can split hairs until there is no hair anymore.