h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Carbon, the creation of. - A743519
Author: Eggy (1+8)x(8-3)-(3+0)=42 Good eh? - U188330

ok, its been through writting workshop and has ben extensivly re-written. What now?

Hi there!

You may want to stick this Entry through a spellchecker first... there are several typos and spelling mistakes here.

I notice that this entry is only on the creation of carbon-12... if I remember rightly there is also a carbon-14, still carbon but somewhat radioactive and unstable (please correct me if I'm wrong... I'm not a physicist). Unless there a part on the creation on that isotope of carbon as well, I would suggest a change of title, like 'How Carbon-12 is Created', or something along those lines.

Can you create carbon anywhere else other than the heart of a red giant? Is it possible to do it in laboratory conditions? I was a bit confused by the first sentence:

'The way below is not the only way to make cabon.'

Perhaps changing it to something along these lines:

'The method shown below uses helium nucleii in a red giant star to create carbon. There are several other methods of creating carbon, such as the radioactive decay of other larger atomsBut in the case of Beta decay, this uses smaller atoms.. For the purposes of this Entry, it is only relevant to the helium nucleii collision method.'

Are you only creating a carbon-12 nucleus and not an atom? I don't see any mention of electrons or electron shells in this Entry. Could you clarify this?

I think there is a lot of good material here to merit an excellent Guide Entry; obviously I'm not a physicist, but a little more explanation here and there would make it clearer!

Don't give up! (sorry for sounding really pedantic)

Caper Plip

at fusion type temperatures, you are talking about stripped atomic nuclei, and thus electron shells wouldn't really be relevant.

Also the same general paths used to make carbon 12 also make carbon 14, and I vaguely remember something about carbon 16, but don't quote me on that last one as it was a long time ago.

Whoah, most of that is pretty dm right as well *slaps own forehead* just so you know, carbon-14 generally decays into carbon-12 which is the sort of standard isotope.
Theres no electron clouds as the Carbon is made in a plasmtic state, the electrons and nucleii are seperate.
I'll go and add this just now.

Is that it then?

There are some minor niggles as to the GuideML (.. looks better than <BR&gt, and there's the occasional first person in the footnotes, but basically...


I think so

you say "As it happens, the energy from the heat in the heart of the star changes the energy of the nuclei by the missing 4 per cent." which seems to imply that it changes the energy requirements.

don't you mean "the missing 4 percent is what produces the heat"?

Just to let you know that this entry has been scouted, but before I can process it, the entry needs a little clarification as mentioned above.

Can you let me know when we are green for go?

Cheers

Ashley

Just to let you know that I am freeing up this entry so the Scout who picked it can recommend another one.

It's a great entry, but it just needs the points above clarifying a little before it can go into the Edited Guide.

I'm really looking forward to seeing this in the Scouts inbox in the near future.

sorry bout the big silence (good my brain hurts) but ive been on holiday, gona fix it now.
E

I'm not sure if it's worth mentioning carbon-14, at least in the context of stellar nucleosynthesis.
On the timescales of stars, the half-life of C14 is very short, and a reader could get confused about where the C14 on Earth (as used in carbon dating) actually comes from, and end up thinking it had a stellar origin, rather then an atmospheric one.

Right, done that.
E

"the energy from the heat in the heart of the star changes the energy of the nuclei by the missing 4 per cent" still implies that the extra 4 percent of excess energy is used to change the parameters of the reaction.

this isn't the case.

the reaction occurs, and leaves 4 percent missing mass, which is then experssed as a lot of heat as per e=mc^2.

this needs to be fixed.

ok. emm..... i'll just fix it

E
(nice site BTW)

still not quite right.

The reaction occures whenever conditions are right. however the fusion of the berylium and helium results in carbon which is 4 percent lighter than the combined weight of the other two.

this four percent often emited as neutrons which then collide with the surounding matter, resulting in a higher temperature. this is the way a fusion rector works (in that case by having the neutrons collide with water which is then converted by the heat into steam, thereby driving a turbine).

your current statement in the article still implies that the 4 percent is required to maintain the reaction somehow.

Got most of that......... emm....... aye.
E

That anybetter?
E

much better, but perhaps "to create the heat energy which gives us E=mc2." could be "to create the heat that you would expect from e=mc2."

The paragraph

"The reaction takes place and Carbon is created, strangly the mass of the carbon create if 4% less than the combined mass the Helium and Berylium. the 4% is generally emited as neutron radiation (like Beta, but not true Beta) which then colides with surounding matter to create the heat energy which gives us E=mc2."

Is still a bit confusing. Correcting the typos gives

"The reaction takes place and Carbon is created, strangely the mass of the carbon created is 4% less than the combined mass the Helium and Berylium. the 4% is generally emitted as neutron radiation (like Beta, but not true Beta) which then collides with surounding matter to create the heat energy which gives us E=mc2."

but even so, I'm unsure where the neutron could come from. If a Helium-4 and Beryllium-8 nucleus merge to give a Carbon-12 nucleus, there aren't any spare neutrons.
Creating an extra neutron from the 4% lost mass does seem a bit strange, since the mass of one neutron is about 8% of the mass of a Carbon-12 nucleus.

Looking around the web, it seems to be the case that when the helium/beryllium fusion has taken place, an *excited* carbon-12 nucleus is formed. This unstable nucleus can then either break apart, or emit a gamma ray and become a stable carbon-12 nucleus.

OK, im now really lost, gives a min.
E