Search found 11 matches
- Mon Aug 05, 2013 9:33 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: 130 Years of Earth Surface Temperatures (2013 Jul 31)
- Replies: 183
- Views: 18817
Re: APOD: 130 Years of Earth Surface Temperatures (2013 Jul
On the other hand, more water vapor in the air is likely to cause more clouds to form. The presence of clouds dramatically increases Earth's overall albedo, reflecting a lot of the incoming sunlight back into space. Increased cloudiness would be expected to further reduce the amount of sunlight rea...
- Wed Jul 31, 2013 10:44 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: 130 Years of Earth Surface Temperatures (2013 Jul 31)
- Replies: 183
- Views: 18817
Re: APOD: 130 Years of Earth Surface Temperatures (2013 Jul
There really is no reasonable doubt that our CO2 emissions are the cause of the recent rapid warming. Unfortunately the science has become politicised, and there is a massive campaign to sow doubt in people's minds and to spread misinformation. These arguments have been refuted repeatedly, but they ...
- Wed Nov 18, 2009 12:25 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Dawn Before Nova (APOD 17 November 2009)
- Replies: 13
- Views: 1999
Re: Dawn Before Nova (APOD 17 November 2009)
According to the Wiki link, L5 is only stable if the ratio of M1/M2 is greater than 24.96. Not many binary stars have such a large mass ratio!
- Tue Nov 17, 2009 7:51 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Dawn Before Nova (APOD 17 November 2009)
- Replies: 13
- Views: 1999
Dawn Before Nova (APOD 17 November 2009)
The lighting in this painting is all wrong!
The crescent moons indicate the direction of the main light source, which should be where these two lines intersect. There is nothing there!
http://apod.nasa.gov/apod/ap091117.html
The crescent moons indicate the direction of the main light source, which should be where these two lines intersect. There is nothing there!
http://apod.nasa.gov/apod/ap091117.html
- Thu Aug 06, 2009 8:47 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
This shows how a light ray is affected by multiple reflection between two panes which are not quite parallel. Ray A goes straight through, ray B is reflected twice and appears to emanate from the left of the sun, ray C is reflected four times and will seem to come from even further to the left.
- Thu Aug 06, 2009 4:18 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
Here is the center of the image. The original image has been cropped at the bottom. You can tell because the height is less than two-thirds of the width. If you measure one-third of the width of the frame (=one half of the original height) from the middle of the top edge you will get a point mid-wa...
- Thu Aug 06, 2009 3:43 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
The second sun in Danamongden's photo is caused by internal reflection inside the camera, and is a common phenomenon. The reflection is exactly 180 degrees around the mid point of the frame.
- Wed Aug 05, 2009 3:49 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
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- Wed Aug 05, 2009 3:34 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
The displacement of the second image from the first is less than one degree. The two sheets of glass need to deviate by half this amount, ie roughly one part in 150. This is 1mm over 15cm, which is perfectly plausible for a short distance. The fact that the third image is closer to the second shows ...
- Tue Aug 04, 2009 7:41 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
@TheSciencePundit: I believe you are wrong on all of your points. I agree with DaveB that the clouds are different in front of each of the reflections. It may be hard to see from the first three, but 9810 has distinctly different clouds. It is not possible to say that, as the main image is severely...
- Tue Aug 04, 2009 7:46 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
- Replies: 338
- Views: 53663
Re: Cause of Triple Sunrise (APOD 2009 August 4)
I have also seen this effect when looking at the moon through double glazing. It explains the features of photographs perfectly - the fact that there are several images of decreasing intensity and equal spacing but unequal height, the different spacing in different photos, and the clouds in the same...