Starship Asterisk*

It's impossible to tell if that light would reflect from the water at all because of the growth on the side of the river. A bit of choppiness on the river surface could obscure any reflection and perhaps the light was not on all images that comprised the composite. Look up "Cory Poole Photograp...

I see the constellation Corona Borealis and the meteor track doesn't seem to align in a way that it "radiated" from Perseus when I compare it with a star chart. Why is the photographer or anyone sure this is a Perseid?

"Sun Dogs" or parhelia are produced along with halos when the conditions produce ice crystals that orient themselves to the horizontal due to gravity. As usually seen, sun dogs are usually directly horizontal from the sun, when the sun is low in the sky. When they are observed higher in th...

Almost all atmospheric optical phenomena are described using Ray Optics. The APOD writers seem to like to think of these light rays as photon trajectories under which circumstances it sort of makes sense to refer to the secondary interference & diffraction phenomena as quantum effects. If this ...

I haven't figured out how to insert a quote from the previous comment. I'm not trying to quibble with how people want to think about optical effects but it's important to use terminology correctly. Therefore, in comments about and within a discussion about real science, I think terminology is import...

Sorry to repeat myself, but diffraction is a result of the wave nature of light, not the particle nature. I don't know why "standard practice" would now say that erroneous statements would be true. You get the interference that produces colors from the wave nature of light and you get the ...

Maybe someone can explain the term "quantum corona" in the text accompanying this APOD. The corona observed in this image (as is any such corona around the sun or moon) is produced by diffraction of light from small ice particles (sometimes water droplets but I assume not in this case) and...

It should be noted that there are many locations and times of the year when the ISS can be seen late at night and even all night long--depending on latitude. Lunar transits of the ISS occur about as often as solar transits but are not as frequently visible because there are times when the moon is ne...

This is an amazing image of the solar eclipse. Interesting that I have not seen it earlier. This image shows the part of the corona which is also seen as the zodiacal light. The bright bands streaming to the left "below" Regulus and to the right "below" Mars are components of thi...

The commenter, BjoernH, posting earlier has, in fact, a higher quality video posted at the link he provided. I couple of years ago I made a similar time lapse and image stack inspired by an image I saw long ago in an astronomy magazine. One interesting observation is that the "highway" app...