A couple of links that expand on the errors in booboo's claim:
Missing Supernova Remnants as Evidence of a Young Universe? A Case of Fabrication
Supernovae, Supernova Remnants and Young Earth Creationism FAQ
Quoting from the first link:
"As for the supernova remnants, Keith Davies (self taught astronomer; his degree is in education) assumes that supernova remnants (SNR) should be visible for millions of years (wrong), that we see all or most of the ones it is possible to see (wrong again), and so derives from these very bad assumptions a very large number of SNRs in various states that we "should see" but don't."
"Obviously, Davies never went SNR hunting in a galactic environment, but I have. For one thing, an SNR becomes essentially invisible, even in a non-crowded environment, within 1,000,000 year tops, maybe less, depending on the specifics of the supernova and environment. But in practice they become essentially invisible long before."
"The galaxy is full of distracting clutter, and full of stuff that looks just like a SNR but isn't. We don't know exactly what a SNR looks like, and we never know were the SNR are a-priori. So when you go looking for SNR you will in practice see only a fraction (maybe a small fraction) of those that can possibly be seen, because you are in essence doing a blind search in a cluttered and confused environment. So Davies' ideas of how many SNR there should be, and how many of them we should see are both vast overestimates of reality."
"Feel free to repost, spread around, whatever."
"Tim Thompson
NASA/JPL Terrestrial Science Research element
Advanced Spaceborne Thermal Emission and Reflection Radiometer.
Atmospheric Corrections Team - Scientific Programmer."