Starship Asterisk*

I could cos it's not right.... :twisted: Empeda, dear, I wouldn't keep trying if I were you. What little of what davecorsby says that is at all intelligible is also wildly incorrect. davecorsby, your inquisitive nature is refreshing, but you might really want to check some of your facts before list...

There is no Big Bang National Park.

Not sure as to why it is spherical, but a great many of these faint PN's exhibit a similar structure, they are faint because they are very large and spread out, hence it's fairly logical to assume they are at a very advanced stage (old!) maybe by this time in the PN's existence the expansion has ev...

To look in the direction of the galactic centre (or center, as we bastardized-English speaking Americans spell it) look at the constellation Sagittarius. The brightest stars of this constellation resemble a tea kettle, the spout of which is pointing to the galactic center.

You also might want to take a look here:

http://asterisk.apod.com/viewtopic.php?t=602

where the author of the image has posted.

Those two stars are foreground stars. So, yes, the brightening is a result of the different exposures and not a significant event.

I find it interesting that people assume an object is more "real" if it is photographed in the same tiny part of the EM spectrum that our eyes are sensitive to (at least what our brains tell us our eyes are actually seeing). But then...I suppose there is a "tactile element" that...

makc wrote:Can you suggest something online? We have real problem with printed media here.

A problem with printed media? That's a new one....

The only credible sources I could give you online are all references to papers. Are you at a university? Are you familiar with NASA's ADS service?

The Amateur Astronomers Association of New York holds several observing nights a year in and around NYC. http://www.aaa.org While some of their sights are still fairly light-polluted, they make regular trips out to Bear Mountain and several other places out on Long Island and Upstate NY. Check out t...

pamcse wrote:Cheers... I have to go hang my newest wall poster: Cassiopeia A.

I think what you both might be forgetting is that light echoes of this nature are one of those precious few three-dimensional phenomena that we can observe from Earth. The dust beginning to glow that gives the appearance of rapid expansion is distributed all around the remnant in every direction. So...

Therefore, I would like to see a metric in non-comoving coords, but I can't find it anywhere. I'd be surprised if you could find it. In classical mechanics, how many times do you find it is easier to describe a system in spherical coordinates instead of Cartesian? Fairly often, I'd suspect, unless ...

If the supernova occurred 325 years ago, why doesn't the size of Cassiopeia A as measured by the glow caused by the main shock span 650 light years instead of 125? Even supernova ejecta do not move at the speed of light, hence there would be no reason to think the remnant should span anything near ...

makc, both your math and your grammar make that post dificult to understand. What is it you're trying to say?

As for your R-W metric, it depends on the cosmology you want to use.