Paul Davies pondered just that.
http://www.nytimes.com/2013/11/19/opini ... .html?_r=0
Search found 304 matches
- Mon Nov 25, 2013 6:52 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Kepler 78b: Earth Sized Planet... (2013 Nov 05)
- Replies: 190
- Views: 132188
- Sun Nov 17, 2013 5:54 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Magnificent Tail of Comet McNaught (2013 Nov 17)
- Replies: 28
- Views: 5566
Re: APOD: The Magnificent Tail of Comet McNaught (2013 Nov 1
Its quite an interesting fuzzy.Beyond wrote:Even though I'm no Astronomer, I would say that the tail, in "just the tail" link, is rather un-bright, although it does show up well against the background.
- Sat Nov 16, 2013 3:48 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Active Comet ISON (2013 Nov 16)
- Replies: 27
- Views: 11585
Re: APOD: Active Comet ISON (2013 Nov 16)
NGC4697jimbo48 wrote:There are several faint galaxies in the background.
Anybody know the designation of the bright galaxy below the comet in the frame?
- Sat Nov 16, 2013 12:57 pm
- Forum: Open Space: Discuss Anything
- Topic: Stream of Stuff
- Replies: 780
- Views: 397654
Re: The Universal Word
Ann wrote: So when we greet our first alien, maybe we should use that little word common to us all - a resounding Huh???
Ann
Click to play embedded YouTube video.
- Fri Nov 15, 2013 1:47 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Flash Spectrum of the Sun (2013 Nov 15)
- Replies: 31
- Views: 5908
Re: APOD: The Flash Spectrum of the Sun (2013 Nov 15)
I noticed that.geckzilla wrote:Yup, I've been through multiple lists of those. The list doesn't always match up with the descriptions for HubbleSite releases.
- Fri Nov 15, 2013 1:30 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: The Flash Spectrum of the Sun (2013 Nov 15)
- Replies: 31
- Views: 5908
Re: APOD: The Flash Spectrum of the Sun (2013 Nov 15)
I am pretty confused about filters and H-alpha and NII. When I look at Hubble images a lot of times H-alpha will come through the 658 filter and NII through the 656, yet both are called H-alpha filters. Sometimes they look very similar and other times they are quite different, which is really surpr...
- Thu Nov 14, 2013 2:13 am
- Forum: Open Space: Discuss Anything
- Topic: 3.48 billion years old life
- Replies: 23
- Views: 1964
Re: 3.48 billion years old life
http://en.wikipedia.org/wiki/Late_Heavy_Bombardment Of particular interest, Manfred Schidlowski argued in 1979 that the carbon isotopic ratios of some sedimentary rocks found in Greenland were a relic of organic matter. There was much debate over the precise dating of the rocks, with Schidlowski su...
- Sat Nov 09, 2013 4:33 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Comet Lovejoy with M44 (2013 Nov 09)
- Replies: 27
- Views: 3948
Re: APOD: Comet Lovejoy with M44 (2013 Nov 09)
It looks like it could be a single exposure tracking on the comet, which would mean a one shot color camera. :?: Looking at Damian's other comet pictures, I'm betting on the monochrome 6303 camera with a stack of several minute long luminance exposures and a short RGB sequence. If this was a single...
- Sat Nov 09, 2013 4:21 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Comet Lovejoy with M44 (2013 Nov 09)
- Replies: 27
- Views: 3948
Re: APOD: Comet Lovejoy with M44 (2013 Nov 09)
It looks like it could be a single exposure tracking on the comet, which would mean a one shot color camera.
- Thu Nov 07, 2013 11:37 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Kepler 78b: Earth Sized Planet... (2013 Nov 05)
- Replies: 190
- Views: 132188
Re: APOD: Kepler 78b: Earth Sized Planet... (2013 Nov 05)
So... Does the periodic table (which is the same table used by all aliens, everywhere), give up any clues about whether there are potentially other ways to create life besides "carbon based"? The answer will help us to know more about what to look for in potential habitable planet candida...
- Tue Nov 05, 2013 5:28 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Humans used to find galaxies
- Replies: 1
- Views: 577
- Sun Nov 03, 2013 4:13 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: What did you see in the sky tonight?
- Replies: 1303
- Views: 1135007
Re: What did you see in the sky tonight?
I got up to see the eclipse but the clouds didn't cooperate. There was a small break in the clouds, so I got off a couple of shots. Not much to look at but you can see it.
- Sat Nov 02, 2013 3:59 am
- Forum: The Communications Center: Breaking Science News
- Topic: Most Earth-like exoplanet ever is hellishly hot
- Replies: 12
- Views: 1836
Re: Most Earth-like exoplanet ever is hellishly hot
And thanks for your understanding, geckzilla. Ok, to put this back onto real astronomy, I do have a real astronomy question here. What causes some planets to “spiral in” or have their orbits decay over time. I know the inner moon of Mars is destined to do this, but why might this have occured in Ke...
- Wed Oct 23, 2013 5:28 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: optimising the dull job of image stacking
- Replies: 31
- Views: 2966
Re: optimising the dull job of image stacking
OK, Chris
I guess read noise IS the limiting factor. So, after the images are stacked, as long as the SNR is at least 3 then it can be separated from the noise.
I guess read noise IS the limiting factor. So, after the images are stacked, as long as the SNR is at least 3 then it can be separated from the noise.
- Wed Oct 23, 2013 3:56 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: optimising the dull job of image stacking
- Replies: 31
- Views: 2966
Re: optimising the dull job of image stacking
In terms of S/N, there is no difference between summing and averaging. It doesn't matter which you use. The average is just the sum multiplied by a constant, which affects the signal and noise equally. Median averaging results in poorer S/N compared with the sum or mean, but has the advantage that ...
- Wed Oct 23, 2013 3:06 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: optimising the dull job of image stacking
- Replies: 31
- Views: 2966
Re: optimising the dull job of image stacking
In terms of S/N, it is always better to take a single exposure than to break that exposure into shorter subexposures and sum them. There are, of course, good reasons to build an image up from shorter exposures- advantages that often outweigh the reduced S/N that you inevitably get. I think you have...
- Wed Oct 23, 2013 2:30 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: optimising the dull job of image stacking
- Replies: 31
- Views: 2966
Re: optimising the dull job of image stacking
http://www.astropix.com/HTML/J_DIGIT/COMPEXP1.HTM The formula for calculating the signal to noise increase when images are composited by averaging (adding the pixels in each image and then dividing by 2) is: n/SQR n... (n divided by the square root of n), where n is the number of negatives to be ad...
- Wed Oct 23, 2013 2:07 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: optimising the dull job of image stacking
- Replies: 31
- Views: 2966
Re: optimising the dull job of image stacking
In response to your original question, adding(stacking) your exposures does not equal the sum of the exposures. It just makes for a cleaner short exposure. What taking a lot of shorter exposures DOES do is increase your SNR. Here is a link explaining just that. http://www.astropix.com/HTML/J_DIGIT/C...
- Tue Oct 15, 2013 4:24 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 891 Edge On (2013 Oct 11)
- Replies: 51
- Views: 4845
Re: APOD: NGC 891 Edge On (2013 Oct 11)
Or, if your eye could store thirty seconds worth of photons, then relay them to the optic nerve, we could begin to compete with a camera. Of course, viewing our surroundings in thirty second intervals wouldn't be all that pleasant!
- Sun Oct 13, 2013 3:19 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Cometary Globules (2013 Oct 12)
- Replies: 24
- Views: 3456
Re: APOD: Cometary Globules (2013 Oct 12)
I think it is kind of amazing to think that WE - or the specific life forms on Earth - are so unique. At least I'm convinced that all the multicellular life forms that have ever existed on the Earth are unique to this planet. So take a look around, and consider the fact that it took the entire univ...
- Wed Oct 09, 2013 7:51 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Arp 94 (2013 Oct 09)
- Replies: 32
- Views: 4461
Re: APOD: Arp 94 (2013 Oct 09)
To a non professional astronomer, observations, for the most part, are qualitative!Nitpicker wrote: But one can still ponder the interaction between two distant galaxies, as in this APOD, with only a 19th century understanding. It still makes sense qualitatively.
- Sat Oct 05, 2013 6:56 pm
- Forum: Open Space: Discuss Anything
- Topic: Stream of Stuff
- Replies: 780
- Views: 397654
Re: Stream of Stuff
That IS a stream of stuff, alrightmakc wrote:I misread your "critters" as "crickets".
- Mon Sep 30, 2013 6:31 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Mysterious Green Patches on the Sky (2013 Sep 30)
- Replies: 275
- Views: 518362
Re: APOD: Mysterious Green Patches on the Sky (2013 Sep 30)
My guess is the light source that is hidden behind the foreground rock, illuminating the other rocks with a greenish hue, is then reflecting off the incoming tide water, and illuminating the bottoms of the low clouds (fog) hovering just above the waters. I think you're exactly right. The low layer ...
- Sat Sep 28, 2013 3:47 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: MyCn18
- Replies: 10
- Views: 21787
Re: MyCn18
2MASS 13393507-6722518
This is the star in question. I couldn't find anything on it.
This is the star in question. I couldn't find anything on it.
- Fri Sep 27, 2013 1:13 pm
- Forum: Open Space: Discuss Anything
- Topic: Tomorrow's APOD
- Replies: 74
- Views: 6410
Re: Tomorrow's APOD
Either way, you're probably right.geckzilla wrote:No, I meant buildings. Like skyscrapers. Ancient megalithic structures are also an option, however.stephen63 wrote:Don't you mean "ancient megalithic structures"?geckzilla wrote:Maybe the sun between buildings again.