Search found 304 matches
- Fri May 11, 2007 9:04 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Astronomy and "controlled scientific tests"
- Replies: 86
- Views: 30765
- Thu May 10, 2007 6:33 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: SN 2006GY: Brightest Supernova (2007 May 10)
- Replies: 5
- Views: 3177
That all depends on what you mean by reasonably. :) I have colleagues that study objects several Billion light years away. Obviously though it becomes more difficult to really understand what is going on the furher away you look. However its surprising just how much you can learn from faint smudges ...
- Thu May 10, 2007 12:32 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Radiometric dating
- Replies: 23
- Views: 6774
bogus billions and billions of years Are you suggesting the world isn't about 4-5 Billion years old? :) The age dating of the Earth doesn't just depend of radioactive dating, the age of the Sun and material from meteorites is also a bit of a give away. Besides the type of radiocarbon dating describ...
- Tue May 08, 2007 2:26 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Dark Matter
- Replies: 113
- Views: 23883
Well some modifications of gravity allow extra terms in the gravitional law, only at large distances do these modification cause measureable effects, one of which would be for gravity on the very largest scales to be smaller than expected, making it less able to hold back the expansion of the Univer...
- Tue May 08, 2007 2:16 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Radiometric dating
- Replies: 23
- Views: 6774
It depends, as far as I know there are several types of radiometric dating, they each use different isotope ratios, these isotopes may or may not be products of nuclear tests. I think you mean the kind of radiocarbon dating done on biological matter. I'm not sure if any of the common products of a n...
- Sat May 05, 2007 5:14 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: why?
- Replies: 10
- Views: 3262
- Sat May 05, 2007 10:36 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: why?
- Replies: 10
- Views: 3262
The moon appearing fuzzy to both you and a camera would imply that the effect is real. I would guess it would be due to strong turbulent winds higher in the atmosphere, its the same kind of thing that makes stars twinkle, but would have to be very very turbulent to make something larger than a point...
- Fri May 04, 2007 10:54 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Astronomy and "controlled scientific tests"
- Replies: 86
- Views: 30765
- Thu May 03, 2007 2:08 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Astronomy and "controlled scientific tests"
- Replies: 86
- Views: 30765
I'll have a stab. Is 'dark energy' real? If its not something very odd is going on with gravity, or their is some strange systematic in the behaviour of distant SN. What about 'dark matter'? Again if it don't then our understanding of gravity must be off. Do 'black holes' really exist? If actual BHs...
- Sun Apr 29, 2007 5:06 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Dark Matter
- Replies: 113
- Views: 23883
Dark Matter and Dark Energy were invented as factors to fill in the 'missing mass' needed to account for our gravity calculations. Not entirely, the amount of DM required to explain the behavior of galaxies and galaxy clusters is oddly exactly the same amount as is required to explain the shape of ...
- Sun Apr 29, 2007 8:54 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Dark Matter
- Replies: 113
- Views: 23883
Its going to be interesting to see if any positive detections come out from the Dark Matter detectors in the next few years, or if anyone detects gamma rays from the annihilations that some possible forms of Dark Matter are thought to undergo. If we don't see any of these things then people are goin...
- Sun Apr 22, 2007 9:58 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: light pollution
- Replies: 12
- Views: 3890
The most extraordinary sight, however, would be the 'nearby' galaxy. It would be like that scene near the end of the movie, Star Wars, where a spiral galaxy takes up much of night sky. It really wouldn't be that impressive, your eyes aren't able to add up flux like a telescope CCD does, so the low ...
- Sat Apr 21, 2007 9:41 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Origins of the UNIVERSE
- Replies: 829
- Views: 148189
First off, to the frat party that seems to have taken over this board, get back on topic or go someplace else. If you can't answer Nereids questions, go away and do some research, your frankly borderline misogynist posting of late has no place here. Second kovil, you have succeeded in achieving your...
- Sat Apr 21, 2007 9:23 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: NGC 5139 Omega Centauri globular cluster (APOD 19 Apr 2007)
- Replies: 12
- Views: 3373
As I understand it, all galaxys appear to have super-massive black holes at their cores, whereas globular clusters do not. Yes this is true, there is a very well behaved relationship between the mass of a galaxies bulge and the mass of the supermassive black hole found there. (A version of the so c...
- Thu Apr 19, 2007 6:45 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: NGC 5139 Omega Centauri globular cluster (APOD 19 Apr 2007)
- Replies: 12
- Views: 3373
The reason why you don't see any discernable structure in GCs is essentially one of scale, they are simply not massive enough to be bound if they didn't form simple spheroids. This is partly because they lack any DM as far we can tell. There are GCs which are slightly non spherical because they are ...
- Thu Apr 19, 2007 12:44 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: NGC 5139 Omega Centauri globular cluster (APOD 19 Apr 2007)
- Replies: 12
- Views: 3373
Hi AZJames The orbits of the globular clusters are affected by the Dark Matter. We routinely use the orbital motion of GCs in other galaxies (mostly ellipticals) to infer the properties of DM. You can infer from the amount of light in the galaxies how much mass their is, and when you look how fast t...
- Sat Apr 14, 2007 11:20 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: Spiral Galaxy M83 (APOD 19 Apr 1997)
- Replies: 6
- Views: 2654
- Wed Apr 11, 2007 1:50 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Origins of the UNIVERSE
- Replies: 829
- Views: 148189
Would this by any chance be your good self harry? Harry Costas independent researcher Australia Just, how credible do you think any of those people on this list are?, barring Arp and about 3 other very old Astronomers. How many of them has actually studied real astrophysical data? Or published a pap...
- Wed Apr 11, 2007 12:31 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Origins of the UNIVERSE
- Replies: 829
- Views: 148189
Stars may form in regions in similar time frames. But! not all within a galaxy at the same time. No one ever said they did. I said that we routinely see star formation rates of hundreds to thousands of solar masses per year. At that rate you can build up a large galaxy in less than a Billion years....
- Tue Apr 10, 2007 9:52 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic:
- Replies: 26
- Views: 6769
Harry I repeat my statement where is your evidence? I can cite papers by real astronomers, working in real institutions, that say that everything makes sense. You have never provided any evidence to back up your claims. For one thing stars are not made at the same time. You lack info on star formati...
- Mon Apr 09, 2007 4:32 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic:
- Replies: 26
- Views: 6769
Harry we have had this conversation before, I see that you haven't paid any attention though. A galaxy cluster is made up of hundreds to thousands of galaxies. They all form stars at the same time , each galaxy can form stars at a rate of hundreds of solar masses per year, how long does it take to f...
- Sun Apr 08, 2007 4:19 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic:
- Replies: 26
- Views: 6769
- Fri Apr 06, 2007 9:30 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic:
- Replies: 26
- Views: 6769
- Fri Mar 30, 2007 8:55 am
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Just out of curiosity
- Replies: 14
- Views: 4757
- Thu Mar 29, 2007 8:20 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Just out of curiosity
- Replies: 14
- Views: 4757
I've always liked this for a sense of scale: http://xs511.xs.to/xs511/07042/universe5py.gif I'm afraid there are no pretty pictures, just a logarithmic graph that has the distances to essentially everything of interest in the Universe, from the centre of the Earth right to the CMB, then to the final...