I'm not going to give you a hard time because I can debunk any claim you've thrown out so far. But I would like to awnser this little thingy with a fairly extensive debunk.
reconciliation said:
lack of old supernova remnants;
http://www.rochesterastronomy.org/snimages/
Let's see what NASA has to say about 3rd stage events:
http://imagine.gsfc.nasa.gov/docs/science/know_l2/supernova_remnants.html said:
The third phase, the Snow-plow or Radiative phase, begins after the shell has cooled down to about 106 K. At this stage, electrons begin recombining with the heavier atoms (like Oxygen) so the shell can more efficiently radiate energy. This, in turn, cools the shell faster, making it shrink and become more dense. The more the shell cools, the more atoms can recombine, creating a snowball effect. Because of this snowball effect, the SNR quickly develops a thin shell and radiates most of its energy away as optical light. The velocity now decreases as 1/r3. Outward expansion stops and the SNR starts to collapse under its own gravity. This lasts a few hundreds of thousands of years. After millions of years, the SNR will be absorbed into the interstellar medium due to Rayleigh-Taylor instabilities breaking material away from the SNR's outer shell.
So over a great lenght of time this 3th stage will dissapear. This works well in theory, but it doesn't work in practice. Some of the reasons for this are:
- The ISM in which supernovae occur is rarely isotropic or of a uniform consistency and density, which leads to asymmetry and differences within the remnant (Dohm-Palmer & Jones 1996; Maciejewski & Cox 1999; Slavin et al. 2000).
- If a supernova occurs in a pre-existing bubble of interstellar material surrounded by a massive shell of gas then the Sedov phase will not necessarily occur (Wheeler et al. 1980; Franco et al. 1991; Franco 1994; Gvaramadze 2000), indeed, the SNR may not be detectable at all in this scenario unless it hits the walls of the shell (Fich 1986; Koo & Heiles 1995; Chu 1997).
- If the density of the medium in which the SNR is located is low enough, it is possible for the SNR to finish its life by merging with the ISM before cooling becomes important (Asvarov 2000).
- Different stages can occur simultaneously in different locations within a single remnant (Cioffi et al. 1988; Tenorio-Tagle et al. 1990; Franco et al. 1994; Jones et al. 1998; Asvarov 2000; Bykov et al. 2000; Reynoso & Mangum 2001).
- If the ISM is strongly magnetized, then the evolution of the SNR will differ in terms of the length of the various phases and the overall shape of the remnant (Insertis & Rees 1991).
What I'm trying to say here is that the argument that Supernovae are relativly easy to put in a box, is not as easy as it seems.
Unfortunatly the gist of the your argument is right (that there are not many snr3), observations of ongoing radioactive decay in supernova remnants can only date the very young ones. The expansion method of dating a supernova remnant similarly only works for young supernova remnants (up to about 15,000 years old).
Why? Because after that time if has disperged so much it's not possible to trace it back with the equipment we have now. Supernova remnants are relatively hard to see they would not be visible for billions of years. Fewer than 1% of SNRs last more than 100,000 years. It may be that as few as 15 to 20% of supernova events are visible at all through the interstellar matter.
There are ways to date older supernova remnants (ages > 15,000 years), however they are not very accurate. These methods involve X-ray observations which measure the temperature of these supernova remnants. From the temperature, one can estimate the speed of the shock wave, from the speed of the shock wave one can estimate the age. Using these methods, we observe supernova remnants up to abound 100,000 years old, when they fade into the interstellar medium.
However by creationist's logic it would mean that 3th stage supernovae (because they are over 6000 years old) never ever could exist. Right? Therefor, if I could find even one (1) I would have disproven them.
And what do you know? I can! The Galactic HI shell GSH 138-01-94 studied by the Canadian Galactic Plane Survey (CGPS), has detirmined the expansionage of GSH 138-01-94. It's 1.3 Million years (an extreme find, others have tested it to be around 4 million years, but let's not get into that).
See the point is that many more SNRs have been found, including many stage three remnants older than 20,000 years. Look at the
cygnus loop, veil nebula or
Velax for instance! And the census is not over yet. If the universe is old, many supernova remnants should have reached the third, oldest stage, and eventhough there may not be many easily detectable ones, that is exactly what we see.
All supernovas and SNRs are more than 7000 light years from us. SN 1987A was 167,000 +/- 1,000 light years away. Now if the goal of this is to find the age of the universe, supernova remnants are not the objects to look at. This is simply because they become mixed up with the interstellar medium after only about 100,000 years.
The evidence contradicts a young universe though, not an old one.
Check here to see that the number of supernovae (not even counter the extargalactic ones) has been far outnumbered in
2003. Long story short: There are 3rd stage supernovae remains, which are over a couple of hunderds of thousands years old. That means that God is showing us stars that were never there.