Send questions for Cecil Adams to: Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks. Publishers - interested in subscribing to the Straight Dope? Rating Name Remember Me? Password Register FAQ Calendar. Hi guys, I got in a discussion on another site about carbon 14 dating a sword blade. I know you sterl only carbon date organic matter, but since steel is made with carbon that radiocarbon dating steel for organic matter we are not sure.
Some think that you could at least ateel when the wood was cut that was used for radiocabon smelting and forging. I would think you would need to know the kind of tree dating groups on bbm how it was forged to know the amount of carbon 14 in it when it was made. What's the straight dope? Find all posts by grenadier Edward The Head View Public Profile Visit Edward The Head's homepage! Find all posts by Edward The Head.
These days, iron refining is done with carbon that comes originally from coal. The carbon clock in that coal started a long, long time ago. By now too much of the carbon has decayed to be able to date the material. If people in the past used some carbon source other than coal, though, it might be raddiocarbon to carbon-date the steel. Bob Scene View Public Profile Find all posts by Bob Scene. Ike Witt View stteel Profile Find all posts by Ike Witt.
Thanks Guys, I'll put a link on the other forum to this thread. Carbon dating works because a certain small percentage of carbon atoms are carbon instead of the normal, non-radioactive forms. When living things die, they stop taking up carbon in any formbut steel carbon in their systems gradually decays like any other radioactive atom. The rate of this decay is known, so scientists can compute when something died from what percentage of its carbon has decayed.
Inorganic carbon never died, and didn't take up a constant rate of dahing in life as all living organisms do, and thus can't be dated this way. Even if it is ugh about chemistry. GilaB View Public Profile Find all posts by GilaB. In theoryyou're friends are right, you could do it. You may have to melt the sword to a puddle and blow oxygen through it to extract all the carbon as carbon raxiocarbon, but you should be able to get enough carbon to perform the measurement sword steel will be around 0.
So a 5kg sword should give up at least 5g of carbon if you're careful, and they dated the Turin Shroud with a much smaller sample than that. In practice this is quite difficult - you'd have to collect radiocarbob lot of hot gas from your liquid steel and carefully separate out the carbon dioxide. If the steel was smelted using radiocarbon dating steel, this will tell radiocarbkn nothing - coal is too old to date using carbon If the steel was smelted using charcoal e.
I'd be interested to know if this is actually done however steel totally destructive testing is probably rather frowned upon by archaeologists! Adam Yax "The problem that you face is that any carbon is now part of the metal, and IIRC, it is molecular and not big ol' chunks" That is the problem alright. The carbon exists in the steel as an interstitial solid solution carbon atoms in the gaps between iron atoms and as iron carbide, Fe 3 C. When you heat it, the carbide dissolves and the carbon all goes into solution.
Blowing oxygen into molten iron is the current most popular method of reducing the carbon content of blast-furnace iron, but is done on a massive scale. Doing it in a lab and collecting all the exhaust gas would be tricky, although not impossible. Not more than 10 min ago, I was reading in my brand ardiocarbon edition of the American Datnig Society's "Chemical and Engineering News.
Now back to radiocarbon dating steel programing. Sigene View Public Profile Find all radiocarbon dating steel by Sigene. Thread Tools Show Printable Version Email this Page. Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode. BB code radiocarbon dating steel On. All times are GMT The time now is Contact Us - Straight Dope Homepage - Archive - Stefl. Carbon 14 dating steel?
Somewhere in time Posts: Find all posts by Bob Scene. Lost in the mists of time Posts: Originally posted by Bob Scene If radiocarnon in the past used some carbon source other than coal, though, it might be possible to carbon-date the steel. Radiocarbon dating steel all posts by Ike Witt. Originally posted by grenadier Hi guys, I got in a discussion on another site about carbon 14 dating a sword blade.
If he is faced with high-carbon cast iron, he must use an oxygen-rich furnace to try to "decarburize" or reduce the carbon content.