Search found 3 matches

by dkdowell
Thu Aug 26, 2004 11:47 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Green ring: Wavefront or debris feild? (8-26-04 APOD)
Replies: 0
Views: 24486

Green ring: Wavefront or debris feild? (8-26-04 APOD)

In the explanation for the August 26 APOD, the false-color green ring is estimated to be 10 light-years in diameter. Also, it states that light from the explosion first reached Earth just over 300 years ago. If the green ring represents the wavefront from the explosion, it must be moving very quickl...
by dkdowell
Thu Aug 26, 2004 10:49 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Orientation of planetary surfaces...
Replies: 3
Views: 34733

I'm sorry I didn't read this topic before starting "Backward Brain?". I see the reverse image consistently regardless of the direction of illumination. It happens most often when the light is low angle which is preferred because it highlights the relief. I've never met anyone with the same...
by dkdowell
Wed Aug 25, 2004 7:36 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Backward Brain?
Replies: 3
Views: 20856

Backward Brain?

Whenever I first look at a high quality photo of a cratered surface, or actually any photo of a surface with high relief and a low angle for the illumination (such as http://antwrp.gsfc.nasa.gov/apod/ap020627.html), my brain initially processes the image in reverse. That means that craters look like...