Stone Henge

[TheDoctor]

You called?
<snip long complicated bit I didn't understand>
And I'm fairly sure it was marked on maps before then anyway,

Well, you can't go trusting maps. I once rode along something that was marked as a scenic road with a viewpoint. It was just a dirty great hill.

 

[Andy in Sig]

Report in the Indy today said they were hoping to find fragments of the stones to carbon date.


<and breathe>

So they get a bit of Keith Richards' hair. Wossat got to do with the missing roof of Stonehenge?

 

[papercorn2000]

Can you Carbon Date diamonds? They're stones. And made of carbon to boot.

 

[Andy in Sig]

Isn't it to do with the proportion of one isotope of carbon to another? And organic material i.e. remnants of plants and animals have differing proportions of the two over time.

Maybe diamonds are like that after all.

 

[red_tom]

Building a henge are you?

 

[TheDoctor]

Isn't it to do with the proportion of one isotope of carbon to another? And organic material i.e. remnants of plants and animals have differing proportions of the two over time.

Maybe diamonds are like that after all.

Pretty much it. There's a few isotopes (IIRC) and one is radioactive and therefore decays. Pretty sure carbon dating only works with remains of plants...

 

[Arch]

Pretty much it. There's a few isotopes (IIRC) and one is radioactive and therefore decays. Pretty sure carbon dating only works with remains of plants...

And animals. Things that contain carbon that were once living. And even then, sometimes it's hard to get a good sample, eg from something mineralised like bone, or anything very old, or very degraded.

But not stone, and I don't think, diamonds, because surely the carbon in them is locked into one form?

 

[Arch]

Building a henge are you?

Looking to see if the Flanders and Swann henge monologue was online, I came across this - a digression I know, but one of my favourites of their's and the lego just adds to the fun...


View: http://uk.youtube.com/watch?v=mOA_SUKEZRE

 

[Aperitif]

Report in the Indy today said they were hoping to find fragments of the stones to carbon date.

YOU CAN'T CARBON DATE STONE!

<and breathe>

Oh well, you can stone dates - will that do?

I don't give a fig - or a prune. Ooops, here I go again...

I'd like a date with Sharon Stone.

 

[Andy in Sig]

But not stone, and I don't think, diamonds, because surely the carbon in them is locked into one form?

In diamonds the carbon is most definitely locked into one structure but I can't think of a reason why the various isotopes couldn't form parts of that structure. At this point we need a chemist.

 

[Fnaar]

In diamonds the carbon is most definitely locked into one structure but I can't think of a reason why the various isotopes couldn't form parts of that structure. At this point we need a chemist.

The one near me is open till 8pm... I'll nip round and ask later...

 

[Bigtallfatbloke]

It's very simple. Even Giants sufferred from piles...it's just a big pile cushion...otherwise known as a pile of rocks

 

[papercorn2000]

In diamonds the carbon is most definitely locked into one structure but I can't think of a reason why the various isotopes couldn't form parts of that structure. At this point we need a chemist.

Ooh, got you thinking now!

Living things incorporate carbon into their bodies as they grow - virtually everything in your body is made on a carbon skeleton. Anyhow, living organisms incorporate C in its isotopes C12 and C13 (which are stable) and a teeny bit of unstable C14. These exist in a precise ratio in nature and so, in a living organism, C will be present in this ratio.
When an organism dies, it stops incorporating carbon. Scientists can measure the amount of C14 in a sample and determine its proportion. C14 has a half life of about 5500 years, and so, it is possible to determine when the specimen stopped assimilating carbon - ie died.

Diamonds are made of pure carbon. Again in the natural ratio of C12 to C13 to C14. However, the crystal diamonds were physically formed millions and millions of years ago. Over this geological period of time, the C14 will more or less all have decayed (it has a half life of about 5500 years) so there will be pretty much none left with which to date the sample.

Carbon dating is only really any use when used to date items up to a few tens of thousands of years old.

 

[Arch]

Carbon dating is only really any use when used to date items up to a few tens of thousands of years old.

Now, why didn't I think of that!

And of course, the dating is a tiny part of the 'mystery' of Stonehenge, and not something I think is so important to get precisely right - we know roughly, that's what matters. We'll never be able to say conclusively what it was, or why it was there, and that's part of the attraction of the place, the mystery.

 

[TheDoctor]

Now, why didn't I think of that!

And of course, the dating is a tiny part of the 'mystery' of Stonehenge, and not something I think is so important to get precisely right - we know roughly, that's what matters. We'll never be able to say conclusively what it was, or why it was there, and that's part of the attraction of the place, the mystery.

Well, I'm trying to build a time machine, so then I will know.
Can someone pass me a dilithium crystal, please?