Polar Sunrise

On Wednesday, 21 September 2016 16:43:30 UTC+2, 1461 scribbled:

This annual spectacle ...... is the result of a turn Earth as opposed to the 'tilting' Earth.

Should we change the thread title to: "Tilting at Equinoxes?"

Get a stick!

"Turn Earth?"

Needs a cane!

Science would turn in its grave if 1461 was ever taken seriously.

Unlike the moon which keeps the same face to the Earth over the course of its monthly circuit, the Earth has a single annual surface rotation as a function of is orbital motion around the Sun. Watching Antarctica turn across the full sunlit face of the Earth is perhaps the easiest way to appreciate the orbital surface rotation and a great advance for humanity -

https://www.youtube.com/watch?v=CFrP6QfbC2g

Polar dawn at the South pole is a resulting a turning Earth parallel to the orbital plane and not a tilting Earth.

The only way to get rid of graffiti sprayed on top of the masterpieces of modern imaging is to renew that imaging.

Closing out this 6 month journey from polar daylight into polar twilight and from there into polar darkness lit up only by the reflected light of the moon until polar dawn turns into polar daylight has now emerged -

http://www.usap.gov/videoclipsandmaps/spwebcam.cfm

Ultimately it means that when daily rotation is subtracted the Earth will turn once in a direction parallel to the orbital plane to the Sun over the course of an orbital circuit.

This has been going on for many, many millions of years and it is humbling for those who realize the ease by which explaining the polar day/night cycle first is a point of departure for the cause of the seasons when it joins with daily rotation. It is now obvious with time lapse of the Earth from space so despite this forum ignoring the significance of the perspective it does attract people who see much more than others.

So, this thread is closed.

Gerald Kelleher wrote:
Closing out this 6 month journey from polar daylight into polar twilight
and from there into polar darkness lit up only by the reflected light of
the moon until polar dawn turns into polar daylight has now emerged -

http://www.usap.gov/videoclipsandmaps/spwebcam.cfm

Ultimately it means that when daily rotation is subtracted the Earth will
turn once in a direction parallel to the orbital plane to the Sun over
the course of an orbital circuit.

Exactly! That's why there are 366 and a quarter sidereal days in a year.
You've finally worked it out! Congratulations!

The cause of the seasons begins with the explanation of the polar day/night cycle which is split apart from the diurnal cycle due to daily rotation. The reduction of rotational speeds across latitudes from a maximum 1037.5 miles per hour to zero at the North and South poles leaves a separate rotation arising from the orbital motion of the Earth to account for why the Sun is in view and absent from view for 6 months at a time.

Where the dual surface rotations combine, one constant in speed and the other variable, people experiences the seasons and timekeepers note the inequality in the length of the natural noon cycle from one day to the next.

There is nothing to dislike and a lot to appreciate when contemporary imaging culture combines with human consideration -

https://www.youtube.com/watch?v=CFrP6QfbC2g

For many millions of years the dual rotations have gone on but this year is special for the ability of humans not only to watch these dual rotations combine but the ability to interpret them.