Search found 21 matches
- Sat Dec 05, 2015 2:02 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
A word of clarification is in order. I say again: All posters are correct. I see no errors of logic in any statement by any poster throughout this thread. Consider the following: 1. Two sprinters begin a race running side-by-side. One begins to move in reverse motion to the other, yet continues forw...
- Fri Dec 04, 2015 1:17 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
True: You would need to travel to L.A. in less than three hours for the sun to appear to move in reverse.
True: Travel to L.A. in six hours. The sun will appear to move in reverse.
True: Travel to L.A. in six hours. The sun will appear to move in reverse.
- Fri Dec 04, 2015 1:13 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Very well, let's start over:
Leave Tampa at noon and travel to L.A. in six hours. Measure at each location. The sun will appear to move in reverse.
Leave Tampa at noon and travel to L.A. in six hours. Measure at each location. The sun will appear to move in reverse.
- Fri Dec 04, 2015 1:07 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Yes, it will move in reverse.
Agreed: You would need to travel to L.A. in less than three hours for the sun to appear to move in reverse.
Agreed: You would need to travel to L.A. in less than three hours for the sun to appear to move in reverse.
- Fri Dec 04, 2015 12:57 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Very well: Leave Tampa at noon and travel to L.A. in six hours. Measure at each location. The sun will appear to move in reverse.
(P.S. Notice carefully the title of this thread.)
(P.S. Notice carefully the title of this thread.)
- Fri Dec 04, 2015 12:48 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Granted: Leave Tampa at noon and travel to L.A. in six hours. Measure at each location. The sun will appear to descend.
Absolutely correct: If (and only if) the vehicle travels faster than the earth's rotation will the sun appear to descend.
This is the problem.
Absolutely correct: If (and only if) the vehicle travels faster than the earth's rotation will the sun appear to descend.
This is the problem.
- Fri Dec 04, 2015 12:34 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
The vehicle for the trip does not matter. It may be a plane, a train, a car, or walk. (Suppose one can walk to L.A. in six hours.) The observation method is simple: Measure the altitude of the sun in Tampa. Measure in New Orleans. Measure in Dallas. Measure in Phoenix. Measure in L.A. The altitude o...
- Thu Dec 03, 2015 10:41 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Yes, to all posters: Your comments are correct. But there is a subtle problem that is being missed to which I seek explanation: The sun is lower in the sky in L.A. than Tampa upon trip completion. Therefore the sun must descend during the trip. However, yes, the aircraft's speed is less than the ear...
- Thu Dec 03, 2015 10:21 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Yes, thanks, Geckzilla. I had to install Adobe Flash and that planetarium seemed to work. Now assuming I used the planetarium correctly, the sun appears lower in the sky in L.A. than it appears in Tampa at the same moment. Therefore during travel to L.A. from Tampa, the sun will appear to descend in...
- Thu Dec 03, 2015 9:48 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Re: Reverse sun motion
Misunderstanding: I was not clear enough:
Upon arrival in L.A., will the sun appear lower in the sky or the same as the sun appears in Tampa at the same moment? (Need Stellarium to verify.)
Upon arrival in L.A., will the sun appear lower in the sky or the same as the sun appears in Tampa at the same moment? (Need Stellarium to verify.)
- Thu Dec 03, 2015 9:20 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Reverse sun motion
- Replies: 27
- Views: 3314
Reverse sun motion
If I had Stellarium I could answer my own questions:
If I leave Tampa at sunrise and arrive in Los Angeles six hours later, will the sun appear lower in the sky or the same in L.A.?
If I leave Tampa at sunrise and arrive in Los Angeles six hours later, will the sun appear lower in the sky or the same in L.A.?
- Sun Nov 29, 2015 3:31 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Moon orientation across sky
- Replies: 8
- Views: 1490
Re: Moon orientation across sky
All I need is Stellarium. I need to see nine pictures: three during rise, three during change, three during set. In each pic I simply use the grid to check orientation.
- Sun Nov 29, 2015 1:58 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Moon orientation across sky
- Replies: 8
- Views: 1490
Re: Moon orientation across sky
P.S. I'm not looking for an explanation of the phenomenon, but rather a verification of the phenomenon. I am not yet able to download Stellarium, because I do not have a graphics card in my computer. I need someone to verify that the moon does, when observed with the naked eye, appear to rise fixed,...
- Sun Nov 29, 2015 12:21 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Moon orientation across sky
- Replies: 8
- Views: 1490
Re: Moon orientation across sky
Wait a minute: Clearly that moon in the video does not appear to rotate as it rises. And the same with the naked eye.
- Sat Nov 28, 2015 9:01 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perigee's Full Moon (2013 Jun 22)
- Replies: 21
- Views: 3400
Re: APOD: Perigee's Full Moon (2013 Jun 22)
Chris, what program did you use for that Athens picture? I am trying to download Stellarium but I like the grid in your program.
- Sat Nov 28, 2015 8:41 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Moon orientation across sky
- Replies: 8
- Views: 1490
Moon orientation across sky
Correct or incorrect:
The moon rises in a fixed orientation, and near the top of its ascent, it appears to rotate ninety degrees, and after rotating, it descends in a fixed orientation. It does not continuously appear to rotate from rise to set.
https://www.youtube.com/watch?v=0ARs3JCxYEo
The moon rises in a fixed orientation, and near the top of its ascent, it appears to rotate ninety degrees, and after rotating, it descends in a fixed orientation. It does not continuously appear to rotate from rise to set.
https://www.youtube.com/watch?v=0ARs3JCxYEo
- Sat Nov 28, 2015 4:49 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perigee's Full Moon (2013 Jun 22)
- Replies: 21
- Views: 3400
Re: Moon orientation
Correction: It is closer to a forty-five-degree shift between the dates and not ninety. Azimuth may very well be the cause.
Can you show the orientation diagram from Athens for 4 October 2009? Where did you get that grid diagram?
Can you show the orientation diagram from Athens for 4 October 2009? Where did you get that grid diagram?
- Sat Nov 28, 2015 4:33 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perigee's Full Moon (2013 Jun 22)
- Replies: 21
- Views: 3400
Re: Moon orientation
Yes, I think the difference in latitude would be negligible and would not cause nearly a ninety-degree shift in appearance. As to date, you may be right. We see nearly a ninety-degree difference in orientation between 22 June and 4 October. If azimuth is the cause of the shift, this would likewise i...
- Sat Nov 28, 2015 3:45 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perigee's Full Moon (2013 Jun 22)
- Replies: 21
- Views: 3400
Re: Moon orientation
No, the apparent angle between the Moon's features and the horizon changes smoothly with latitude. But the compared image is from Greece: http://twanight.org/newTWAN/photos.asp?ID=3002197 (Technical question: How did you insert the Athens image directly into your post? I tried to use the Img tool b...
- Sat Nov 28, 2015 3:34 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perigee's Full Moon (2013 Jun 22)
- Replies: 21
- Views: 3400
Re: Moon orientation
Greetings, Chris: 1. First, apologies: This is my first post. I should have put this topic under the existing thread for 22 June 2013. I find no "delete" button, however. 2. If I am not mistaken, the moon's face is generally fixed at rise when seen from any location in the northern hemisph...
- Sat Nov 28, 2015 3:00 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perigee's Full Moon (2013 Jun 22)
- Replies: 21
- Views: 3400
Moon orientation
The moon is not oriented correctly in this picture:
http://apod.nasa.gov/apod/ap130622.html
http://apod.nasa.gov/apod/ap130622.html