Earliest sunset time on 12/12/12

Forum rules
Same as all HTUK forums, be courteous, polite and tolerant, remember everyone is entitled to an opinion, even if you don't agree with it ;)
Post Reply
User avatar
Dave Brown
Site Admin
Posts: 19742
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Earliest sunset time on 12/12/12

Post by Dave Brown »

Yes odd, but true :wink: Although the longest night is (21/22) 12/2012,the earliest sunset is today on 12th. From today sunset times get later, although the days are still shortening. Sun rise times continue to get later until 1st Jan. :wink:
Attachments
2012 Dec Canvey sun data.jpg
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
GoggleboxUK

Re: Earliest sunset time on 12/12/12

Post by GoggleboxUK »

icon_cheers The suns has turned the corner!

I do find this odd though, I would have thought it would be the winter solstice.
User avatar
The Codfather
Posts: 6436
Joined: Tue Sep 07, 2010 6:02 pm
Location: Darlington, C.O. Durham

Re: Earliest sunset time on 12/12/12

Post by The Codfather »

I wish it was fitted with a turbo
AKA - Martin

Wish list - Big Palms or Dicksonia antarctica's but open to anything really.....Cash Waiting !
RogerBacardy

Re: Earliest sunset time on 12/12/12

Post by RogerBacardy »

I believe it's because of the Earth's daily anti-clockwise rotation pushing against its anti-clockwise orbit of the sun, thus skewing the latest sunrise/ earliest sunset away from the actual winter solstice.

You'll notice that they're symmetrically pushed out by approx 10 days from the 21st.


edit - mistyped as I was working at the same time, honest!
Last edited by RogerBacardy on Wed Dec 12, 2012 6:18 pm, edited 1 time in total.
User avatar
Dave Brown
Site Admin
Posts: 19742
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: Earliest sunset time on 12/12/12

Post by Dave Brown »

RogerBacardy wrote:I believe it's because of the Earth's daily clockwise rotation pushing against its anti-clockwise orbit of the sun, thus skewing the latest sunrise/ earliest sunset away from the actual winter solstice.

You'll notice that they're symmetrically pushed out by approx 10 days from the 21st.
It's clockwise viewed from the south pole, anticlockwise from the north pole. Where do they reference rotation from ?
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
Conifers
Posts: 13147
Joined: Sat Jun 20, 2009 2:11 pm
Location: Northumbs

Re: Earliest sunset time on 12/12/12

Post by Conifers »

It's because the Earth's orbit is an ellipse, not a perfect circle. This means the Earth moves faster at some points of its orbit than others; at the moment it is running slightly ahead of its equivalent circular-orbit position, so sunrise and sunset times are pushed slightly backward.
User avatar
Dave Brown
Site Admin
Posts: 19742
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: Earliest sunset time on 12/12/12

Post by Dave Brown »

Conifers wrote:It's because the Earth's orbit is an ellipse, not a perfect circle. This means the Earth moves faster at some points of its orbit than others; at the moment it is running slightly ahead of its equivalent circular-orbit position, so sunrise and sunset times are pushed slightly backward.
I notice that we are getting closer to the sun looking at the chart so, am assuming that is the faster/flatter part of the orbit.
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
Conifers
Posts: 13147
Joined: Sat Jun 20, 2009 2:11 pm
Location: Northumbs

Re: Earliest sunset time on 12/12/12

Post by Conifers »

Dave Brown wrote:
Conifers wrote:It's because the Earth's orbit is an ellipse, not a perfect circle. This means the Earth moves faster at some points of its orbit than others; at the moment it is running slightly ahead of its equivalent circular-orbit position, so sunrise and sunset times are pushed slightly backward.
I notice that we are getting closer to the sun looking at the chart so, am assuming that is the faster/flatter part of the orbit.
Yep, that's right. Perihelion (closest to the sun) is on 4 January.
GoggleboxUK

Re: Earliest sunset time on 12/12/12

Post by GoggleboxUK »

So it's what's known as Procession then?
Conifers
Posts: 13147
Joined: Sat Jun 20, 2009 2:11 pm
Location: Northumbs

Re: Earliest sunset time on 12/12/12

Post by Conifers »

GoggleboxUK wrote:So it's what's known as Procession then?
Nope - that's different, the slow movement of the Earth's polar axis in a circle, takes about 26,000 years. See more here.
Post Reply