Falsifying a young Universe. (re: Supernova 1987A)

As far as absolute distances in space go, there's at least one that's purely trigonometrically determined at 25,000,000 light years, plus or minus a million. It's to a galaxy called Messier ( pronounced mess-ee-AY, after a French astronomer) 106. The galaxy's nucleus has a ring of gas orbiting it, and we can tell how fast it's turning from the Doppler effect - its light is redshifted on one side and blueshifted on the other. Also, "knots" of radio emission in the ring are moving across our line of sight, and their angular motion was measured over a few years with terrifically accurate radiotelescopes. The combination of angular distance and speed immediately gives distanc traveled by the knots, and thus distance to them by triangulation.I have the paper at home - link tonight when I get there.

Reference for the galaxy distance above is Herrnstein, et al., Nature, v 400, pp 539-541, (1999). And, like most professional astronomers talking of distance, they never say "light year." The parsec is the real unit of distance in astronomy - 7.2 megaparsecs in this case.

Off topic, I know, but I spewed coffee all over the screen at this one. Wow!

In case you're not clear on this - the gas in the ring was ejected long before the supernova blew, and at velocities of maybe a couple of hundred km/sec - negligible compared to the speed of light. My guess would be that the actual motion of the gas making up the rings would be so slight as to be undetectable at that distance - unless we might be able to see Doppler effects at the near and far edges. The progressive illumination of different parts of the rings is what we saw.

The supernova was in the Large Magellanic Cloud, which is in orbit around the Milky Way. The cosmological red shift that you're thinking of doesn't apply here - only to much further-off galaxies that aren't gravitationally bound to us. I've read, long ago, of distances to the LMC based on Cepheid variables, a type of star whose period of variation correlates with brightness. Distance using these was similar to that from 1987A, but as I remember it, there's uncertainty in the Cepheid yardstick arising from the slightly different chemical composition of the LMC relative to our neighborhood.Added in edit:
http://arxiv.org/PS_cache/astro-ph/pdf/9805/9805215.pdf
gives a comparison of a couple of methods with SN1987A, but the results are stated in terms of "distance modulus", something expressed as a brightness. We'll need a real astronomer to help here.....
But the distance moduli are all within each others' error bars, anyway.
Added in another edit:
http://arxiv.org/PS_cache/astro-ph/pdf/0010/0010590.pdf
gives several methods, and has all distances coming out within 7% of each other.
This message has been edited by Coragyps, 01-23-2005 09:33 AMThis message has been edited by Coragyps, 01-23-2005 09:38 AM

Alas, it's not that easy....
I'm sure there are plenty of red shifts measured for objects in the LMC, but they have nothing to offer as far as distance to the LMC. It's in orbit around us and not receding due to cosmological expansion.Conversely, though, there is a lot of data on Cepheid and RR Lyrae variables in the LMC that can be compared with data on those same two types of stars in galaxies that are far enough away to exhibit cosmological redshifts - say, in the Virgo Cluster. The links I gave above allude to this, but they are preaching to the choir of astronomers who already know all the basics of such measurement - we need a more popularised treatment here. Whatever the case, my 2nd link claims 7% spread in distances derived from SN1987A and the variable-star methods. That sounds pretty good to me....

Hello, Minnesotan Bear! That's not strictly on topic for this thread, but there are other threads near at hand here that deal with these questions. Briefly: yes, there's heaps of evidence (not "proof"). The Big Bang was not an explosion but more of a seriously large "unfolding."Poke around this one forum a while, and you'll find some very detailed discussions.....

"Big Bang - Big Dud" is open and closer to your topic. The admins and mods around here try hard to keep threads focussed - it really does make for more productive discussions.The Bang preceded any matter at all - only energy was there. We don't have a word, or even a good non-mathematical concept - of what it was like, because nothing analogous to it is anywhere in our experience. Calvin (of Calvin and Hobbes) liked "The Humungous Space Kerblooey!!!!" - and why not?

A slight veer to the edge of this topic:
A. Brunthaler, et al., Science, v307, pp1440-1443 (2005 Mar 4)
"The Geometric Distance and Proper Motion of the Triangulum Galaxy (M33)" - the abstract: 730 kiloparsecs = 2.4 million light years. That's by direct measurement and trigonometry.PH, if SN1987A is 4144 light years away, why are the stars in the LMC so very, very dim?

The only time that enters into parallax measurement is the time it takes for the earth to travel halfway around the sun. Will you agree that six months on Earth is about, oh, six months in duration? And that the time doesn’t matter anyway, only the distance?

Yeah, you might want to stay away from Tyre, at least.

You are mistaken again/still. Time has crap-all to do with measuring parallax, except that it takes six months for our earth to go half an orbit. And you, creation, have said that orbit is inside our bubble . Parallax is just 11th grade trigonometry.

Was post 931 intended to have any meaning, or to respond to anything I wrote?