- #1
Glenstr
- 76
- 33
Our carpool conversation this time of year usually involves the shortening daylight hours, which are quite noticeable given that we are between the 54th and 55th parallel. After each new year arrives we start watching the horizon as we're leaving work (at 5pm) waiting for the day when we start seeing the sunset again.
Having just been supplied an iphone recently, a couple of weeks ago I put a simple sunset/sunrise app on and was looking at times for our location. When the day came when we just caught the sunset as we were leaving, I opined that on exactly this many days on the other side of the solstice we should be seeing the exact same thing, so I looked up the Xth day past Dec 21 to see what the times were. It turns out that while the (length of) daylight hours are very close, there was quite a time shift-difference in the sunrise-sunsets, almost 1/2 hour if I recall.
Our (laypersons) opinion was that this must be because of the Earth's rotational wobble, and the further towards either pole one was the bigger the time shift would be.
Are we correct in this assumption? Also, is the wobble conisistent throughout Earth's orbit?, if so then next year should be the same scenario, correct?
Having just been supplied an iphone recently, a couple of weeks ago I put a simple sunset/sunrise app on and was looking at times for our location. When the day came when we just caught the sunset as we were leaving, I opined that on exactly this many days on the other side of the solstice we should be seeing the exact same thing, so I looked up the Xth day past Dec 21 to see what the times were. It turns out that while the (length of) daylight hours are very close, there was quite a time shift-difference in the sunrise-sunsets, almost 1/2 hour if I recall.
Our (laypersons) opinion was that this must be because of the Earth's rotational wobble, and the further towards either pole one was the bigger the time shift would be.
Are we correct in this assumption? Also, is the wobble conisistent throughout Earth's orbit?, if so then next year should be the same scenario, correct?