Search found 71 matches
- Thu May 20, 2010 2:55 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M87: Elliptical Galaxy with Jet (2010 May 20)
- Replies: 37
- Views: 4941
Re: APOD: M87: Elliptical Galaxy with Jet (2010 May 20)
btw, here's my best guess of the relationship between the radio and visual images, conflating the radio images posted here: http://en.wikipedia.org/wiki/File:M87_VLA_VLBA_radio_astronomy.jpg http://seds.org/messier/more/m087_nrao.html http://www.handprint.com/HP/WCL/M87rad.jpg and this is just a gue...
- Thu May 20, 2010 2:36 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M87: Elliptical Galaxy with Jet (2010 May 20)
- Replies: 37
- Views: 4941
Re: APOD: M87: Elliptical Galaxy with Jet (2010 May 20)
what is the diffuse cloud of point light sources around the M87 galaxy? are they very faint stars in our galaxy whose luminance has been boosted by processing the contrast of the M87 image and the area around it? if not, at the virgo distance they would have to be dwarf galaxies or massive globular ...
- Tue Feb 02, 2010 1:48 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Mysterious Voynich Manuscript (2010 Jan 31)
- Replies: 238
- Views: 67094
Re: The Mysterious Voynich Manuscript (2010 Jan 31)
postscript ... carbon dating of the parchment means nothing other than the *earliest* date at which the *parchment* could be produced. parchment was regularly scraped, washed and reused in the period, as it was somewhat expensive to manufacture. this sometimes resulted in a *palimpsest*, if the prev...
- Mon Feb 01, 2010 12:54 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Mysterious Voynich Manuscript (2010 Jan 31)
- Replies: 238
- Views: 67094
Re: The Mysterious Voynich Manuscript (2010 Jan 31)
it's a hoax artifact. the circumstances under which it was sold, the superficial, almost hasty quality of the text and diagrams, the lack of any recognizable external domain for the illustrations, the lack of decipherable structure in the text (in an age of codebreaking computers and advanced lingui...
- Sat Jan 30, 2010 3:35 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Messier 88 (2010 Jan 30)
- Replies: 3
- Views: 2026
Re: Messier 88 (2010 Jan 30)
actually, messier wrote in 1784 that M88 was a "nebula without star", not "a spiral nebula without stars". the spiral form of galaxies wasn't resolved until William Herschel and Lord Rosse (William Parsons) observed galaxies with their 50" or 72" alt-az reflecting teles...
- Tue Jan 19, 2010 4:26 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Dark Sand Cascades on Mars (2010 Jan 19)
- Replies: 19
- Views: 5329
Re: Dark Sand Cascades on Mars (2010 Jan 19)
visually, probably the ugliest image ever posted on APOD.
- Sat Jan 09, 2010 3:55 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Andromeda Island Universe (2010 Jan 09)
- Replies: 10
- Views: 2165
Re: Andromeda Island Universe (2010 Jan 09)
this is a beautiful post. i've always felt dissatisfied with andromeda images -- the nucleus always seems overexposed, the arms seem crooked somehow, and all the galaxy stars get in the way -- but pugh got the balance of color and luminance just right. the spiral structure is clear, the nucleus isn'...
- Fri Dec 11, 2009 5:27 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: redshft, bbt, dm, de, et al (split from HUDF Infrared)
- Replies: 24
- Views: 4278
Re: redshft, bbt, dm, de, et al (split from HUDF Infrared)
What could stop expansion? Or slow it down? Or speed it up? the underlying cause of the expansion is unknown, so anything that might affect it cannot be talked about. Where is the new space time coming from? you seem to imagine space as a quantity, such as a quantity of matter, so that to increase ...
- Fri Dec 11, 2009 4:50 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: redshft, bbt, dm, de, et al (split from HUDF Infrared)
- Replies: 24
- Views: 4278
Re: redshft, bbt, dm, de, et al (split from HUDF Infrared)
Why do you keep asking these same questions, or ones so similar it makes no difference. Do you not like the answers? I hope you are not acting as a proxy for sputnick. He used to do the same thing. One more time, here's my version. bystander, i don't envy you your task, but i want to make a general...
- Thu Dec 10, 2009 4:23 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
- Replies: 23
- Views: 5171
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
checked in for an answer to my questions about variations in the galaxy population and optical "magnification" of deep space images. didn't see one ... is that a dead question or should i check back for a response?
- Thu Dec 10, 2009 4:24 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: redshft, bbt, dm, de, et al (split from HUDF Infrared)
- Replies: 24
- Views: 4278
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
as far as I know, nothing in the standard model requires a singularity. Expansion ... what causes it? We don't know. ... Dark matter? ... We can not directly observe it and, therefore, do not know what it is, but ... we can calculate how much of there needs to be. Call it whatever you want to, but ...
- Thu Dec 10, 2009 3:55 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: redshft, bbt, dm, de, et al (split from HUDF Infrared)
- Replies: 24
- Views: 4278
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
I thought the universe ceased to be opaque a few hundred thousand years after it began. So as I see it our remarkable point in history (though we've only occupied it recently) has lasted 13.3 billion years so far. Or does this lofty inspirational statement have a meaning I'm missing? save the sarca...
- Wed Dec 09, 2009 10:43 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
- Replies: 23
- Views: 5171
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
Of course, but I was thinking more about one that had come to a sort of stable state with the two cores still intact. occam recommends that you go with something simple until the data force you to contrive something more complicated. the image is pretty fuzzy, and the galaxies are pretty far away, ...
- Wed Dec 09, 2009 10:32 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: redshft, bbt, dm, de, et al (split from HUDF Infrared)
- Replies: 24
- Views: 4278
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
Dark Matter, Dark Energy? You can call them anything you want to, but you still have to account for their influence on the visible universe. Like it or not, the Lambda-Cold Dark Matter Model of Big Bang Cosmology remains as the best model to explain what we currently know about the universe. i comp...
- Wed Dec 09, 2009 9:53 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
- Replies: 23
- Views: 5171
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
Check this out. This is at the top of the deep field image. It's probably just two objects overlapping, but wouldn't it be interesting if there was a spiral galaxy with two distinct cores? Someone will probably come along and tell me it's not possible. colliding galaxies, galaxies fusing through mu...
- Wed Dec 09, 2009 9:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
- Replies: 23
- Views: 5171
Re: HUDF Infrared: Dawn of the Galaxies (2009 Dec 09)
i have two rather technical questions about deep space imagery in general. * galactic density. as we image galaxies farther back in time, we see the galactic distribution during those eras. presumably, at the distance of the microwave background, we see no galaxies, because they had not formed yet. ...
- Tue Aug 04, 2009 10:20 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: 52397
Re: Cause of Triple Sunrise (APOD 2009 August 4)
In the attached image, I took a flashlight and a scanner with two clear windows, much like a 2-pane window, and shined a flashlight through it and took a picture in the same orientation as the sun, window, and camera in the picture. What you will notice is the the reflected images go to the RIGHT, ...
- Tue Aug 04, 2009 9:52 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: 52397
Re: Cause of Triple Sunrise (APOD 2009 August 4)
From the glossary of the book "Color and light in nature" by D. Lynch and W. Livingston (Cambridge University Press, second edition, 2001), p.266: " multiple suns (moons) unexplained occurrences of multiple images of the sun". I would like to know what was in this book. Are they...
- Tue Aug 04, 2009 9:47 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: 52397
Re: Cause of Triple Sunrise (APOD 2009 August 4)
I would have to argue against the double-pane window arguments due to the cloud formations in the photo. If the multiple suns were an artifact of internal reflection, whether from the interior of the lens or from window panes, the additional suns would appear "on top" of the background an...
- Tue Aug 04, 2009 6:57 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: 52397
Re: Cause of Triple Sunrise (APOD 2009 August 4)
The reflection is 10% smaller. Does that rule out plate glass? no. i'd guess the glass is shatterproof, which means there is a layer of soft or flexible plastic between two sheets of glass. we don't know the optical properties of this layer, but the light imaging the reflection had to pass through ...
- Tue Aug 04, 2009 6:49 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: 52397
Re: Cause of Triple Sunrise (APOD 2009 August 4)
this is an internal reflection in multilayer architectural glass, either shatterproof or thermal layered, or both. the images are far too stable and invariant to be atmospheric, and the fact that the person was inside a room, rather than outdoors, pretty much clinches it. for this to be an atmospher...