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Posted: Sat May 23, 2009 11:17 pm
by Minimalist
I would guess that a WWII firestorm would exceed 1300 F though.
I'd think that, for example, the destruction layer at Hazor which was clearly burned, would have been hot enough too. But that's okay because Hazor was not rebuilt so it would enable us to date the destruction.
Posted: Tue May 26, 2009 2:54 pm
by Samra
Hi Min,
I took a look at the BBC article and it states the reset temperature is 500 deg C (932 deg F). That's well below your firing temp of 1300 deg F but still pretty hot.
http://news.bbc.co.uk/2/hi/uk_news/scot ... 058185.stm
Sheppard Baird
www.minoanatlantis.com
Posted: Tue May 26, 2009 3:38 pm
by Minimalist
A good brush fire might get that hot, wouldn't it? But, would the heat be directed downward to a buried pottery shard or upward?
I suppose if we get a piece of Philistine pottery from Ashkelon coming up with a date of 5 AD we could assume that it was reset. If it comes up with a date of 750 BCE one cannot make any assumptions about it. It could have been produced anytime between 1150 and 750.
Posted: Wed May 27, 2009 9:09 am
by Rokcet Scientist
Aha!
That explains a lot!
Posted: Wed May 27, 2009 9:13 am
by Rokcet Scientist
Minimalist wrote:would the heat be directed downward to a buried pottery shard or upward?
In
my science/physics class I was taught that (on the Earth's surface) heat (in a medium; like air, water, brick, or concrete) always rises, while cold sinks, as they are subject to gravity.
Heat
radiation, however, is
not subject to gravity, afaik. It's direction and extent would be governed by its (direct) environment (heat 'conductors' or 'resistors'/'isolators'/'reflectors').
Posted: Wed May 27, 2009 9:28 am
by Minimalist
To be sure. Still, they are going to have to answer the questions about heat and "resetting the clock." If you were laying in a box below a forest fire I suspect you would feel some heat from it. The question is, would it be hot enough to fry you?
Fortunately, it would seem that this question can be answered by experimentation.
In a situation such as Megiddo, where there are 26 separate levels, and most have some sort of destruction layer separating them because of war or earthquake, we'd have to know what the impact of a later fire would be on the lower levels. A fire storm caused by an attack or an earthquake would seem, on initial consideration, to be much hotter than a natural brush fire because of the various fuel sources that could be found in a town.
Posted: Wed May 27, 2009 9:40 am
by Rokcet Scientist
Minimalist wrote:A fire storm caused by an attack or an earthquake would seem, on initial consideration, to be much hotter than a natural brush fire because of the various fuel sources that could be found in a town.
Afaik a "fire storm" is a special condition, and much more than a few dozen, or even a few hundred, dwellings ablaze. I've heard the expression "fire storm" used only in descriptions of really
HUGE city fires. Like Rome, London, Rotterdam, Hamburg, Dresden, and Tokyo. And wasn't Megiddo inhabited by no more than maybe 2,000 or 3,000 people in X years BC in 'optimistic' estimates (but probably no more than a few hundred in reality)?
Posted: Wed May 27, 2009 9:44 am
by Minimalist
I'm not going to quibble. A fire which breaks out, inside defensive walls and thus contained, will get hot enough to do the job of resetting the pottery clock. If it destroys the whole city it is bad enough.
The issue remains that we can assume that pottery IN the destruction level is impacted by the fire (and that's not all bad if it helps us date the destruction) but what about pottery buried below?
Posted: Wed May 27, 2009 10:15 am
by Rokcet Scientist
Minimalist wrote:I'm not going to quibble. A fire which breaks out, inside defensive walls and thus contained, will get hot enough to do the job of resetting the pottery clock. If it destroys the whole city it is bad enough.
The issue remains that we can assume that pottery IN the destruction level is impacted by the fire (and that's not all bad if it helps us date the destruction) but what about pottery buried below?
'Quibbling' is important here, imo, because
any 'normal' fire would not have any heat impact on anything buried more than, say, 10 centimeters (4 inches) distanced from (deeper than) where the fire burned.
But a fire storm is a whole different beast! For instance: it has many similarities to the consequences of an A-bomb or H-bomb detonation. Which for a split second actually strain the laws of physics themselves. Strange things happen to stuff
exposed to it. And that is of course the key concept here, because the first question to ask is:
was there exposure? So, how thick and of what materials, and how much compacted/heat conductive, are the isolating strata? If yes, there
was, considerable, exposure, then how intense was it? And what was its duration.
In short: many important variables to consider here, imo. Any of which can completely turn around all finds and assumptions. But of which currently 99% is lacking. Making any assumptions or hypotheses not much more than projection.
Kinda like my 'Solutrean Walkabout' hypothesis... ;-P
Posted: Wed May 27, 2009 12:52 pm
by Minimalist
many important variables to consider here, imo
Yes, but testable variables which puts them into a whole other realm than Arch's magic.
Here's a discussion of fires.
http://en.wikipedia.org/wiki/Conflagration
The main characteristic of the ravages of fire temperature is developed during combustion. For residential houses and public buildings indoor temperature reaches 800–900 °C. Typically, the highest temperatures occur during outdoor fires and the average for combustible gases 1200–1350 °C, for liquids 1100–1300 °C, for solids 1000–1250 °C.
Hot enough, to be sure. But there is that damnable direction issue again because you're right. Heat rises.
Posted: Wed May 27, 2009 5:25 pm
by dannan14
Well, warm fluids rise not heat itself, but if the ground is heated to 1000-1250 C then some, probably alot, of heat will flow down through conduction since down would be the direction of the greatest delta T.
Posted: Thu May 28, 2009 9:08 am
by Minimalist
It's still up to the proponents of the new theory to address these issues with credible experimentation. The idea looks fascinating.
Posted: Thu May 28, 2009 7:17 pm
by kbs2244
Well said Min.
My point in bringing up the heat “resetting” argument was that this is going to be far from another “unassailable” technique, like RC14 was supposed to be.
Re: Intersting Technique
Posted: Tue Jun 09, 2009 2:35 pm
by Minimalist
A new link on the News page today contains this url for the scientific paper.
http://rspa.royalsocietypublishing.org/ ... 090117.pdf
For anyone who wishes to wade through it.
Re: Intersting Technique
Posted: Fri Jun 12, 2009 8:24 am
by Samra
Thanks Min for the PDF.
Here's a link to a critique of the ceramic dating technique I received from the archaeologist Judith Weingarten. It's from George Mason University's History News Network titled "Hugely important new archæological technique not quite so important once actually published" by Jonathan Jarrett.
http://hnn.us/blogs/entries/88608.html
The interesting thing about it is that it doesn't even consider the reheating issue.
Sheppard Baird
http://www.minoanatlantis.com