Seeing I responed to Voodman on the topic of 'Forbidden Archaeology', I'll start this OT thread. For anyone who actually wants to know why archaeologists don't take pseudo-science people like Michael Cremo seriously, this is a good response; http://www.ramtops.co.uk/tarzia.html. The response pretty much goes through the list of ways that evidence and ideas can be selectively used or ignored and the logical shortcomings of these kinds of 'get rich quick' book writers or movie makers (some of you are old enough to remember von Deineken and his Gods from Space show that was extremely popular at the time. Or Thor Heyerdahl and the Kon Tiki expedition 10 years before that.

That is not an easy read!

Personally I take most archaelogy that extends beyond written history with a grain of salt. Radiometric dating is far from an exact science and lacks any sort of accurate means of calibration beyond written history. Since environmental conditions beyond that are assumed and not known, it's really a best guess based on a best guess. Obviously there are a variety of factors on which these assumptions are made and they presumably bolster the hypothesis but still; What always bothers me the most is that you hear items being dated as a fact and not a statistic, subject to magnitudes of error that are also unknown and the whole process is untestable since we can go back millions of years in time.

As for more recent history, the certainty is obviously much higher.

Actually, Nanmoo, radiocarbon dating is pretty well calibrated now because there is a continuous tree ring sequence that extends back over 9,000 years. Every fifth or 10th ring has been dated, with many samples by different labs, and we now have a very good calibration curve. The dates from a lab are statistical estimates still but you can be pretty sure you are within 50 to 100 years of the calendar date for most periods of prehistory and some of us are encouraging other archaeologists to always use the calibrated dates. Where the calibration curve is flat, the dates can have much larger calibrated + or - than the sample; a reported sample +- of 25 years at one sigma may actually be +- 200 years at 1 sigma. The amount of radiocarbon in the atmosphere isn't steady, but it trends up and down from an average in measurable amounts.

But conversely, we can sometimes actually use these deviations between the radiocarbon curve and tree-ring calendar dates to actually IMPROVE date accuracy - so you can get a +- 5 to 7 real calendar year accuracy by radiocarbon. This magic is done by something called 'wiggle matching' and you need to know the actual calendar years between each date and you need at least 3 dates per overall sample and each date needs to be at least 20-30 years apart (i.e., a big enough piece of wood or charcoal to have lots of tree rings visible, but varved sediment samples can work too). The changing value of the calibration correction means that the three dates will only match one place of the calibration curve - not sure who actually figured that one out, but it was brilliant!

A floating chronology of tree ring dates goes back quite a few thousand years more; but there is a missing gap of tree rings around 10,000 years ago and they approximate the gap somehow by ice layers from the Greenland cores and coral growth rings - I'm not so familiar with that since I don't ever need to use it.

Well that's exactly what I mean... Dating things back several thousand years is one thing, and I can buy into that... but Millions of years, accurately calibrating that is hokus pokus and is designed in support of pseudo scientific evolutionary hypothesis' not fact based science.

Of course you can argue this stuff to ends, because unfortunately none of us were around 4 million years ago to verify it.

Having it both ways is a favourite arguement of the junk 'scientists' like Michael Cremo. In his 'Forbidden' book (which I haven't read) and his videos (which I looked at) he argues in one place that the calibration is all off, that no one really knows how old anything is, the geological sequence is bumpff, etc. etc. Then throughout the book he goes on to give dates to everything he talks about; the Cretaceous shoe 510 million years old, or whatever. FAIL for logical consistency.

THe ice cores now give year-layer counts back a few hundred thousand years. Geologists have long figured out approximate time scales through comparison of layer thicknesses, etc, that have been calibrated and corroborated by different dating methods that are compared to each other; even things like amino acid racimization that works by looking at how long it takes for DNA strands to unravel, or something like that, and it compares well to potassium argon or U232 or whatever geological dating that accompanying rock dates to. But of course we don't know for sure. Science always tries to give the simplest, best explanation, while throwing out the preposterous.

I find it kind of amusing that geological time scales and human evolution in particular are now being attacked not only by the Christian fundamentalists who believe in 4,004 BC for creation because their religion tells them so, but now by the Hare Krishna's allegedly on behalf of Hindus, but from exactly the opposite view - that humans must have been around fully modern for hundreds of millions of years, because their religion tells them so.