Re: [Phys-l] Isotope chemistry and physics

[Bernard Cleyet <bernardcleyet@redshift.com>]

On a much grosser scale is the concentration of, for a notorious  
example, mercury up the food chain.  Another isotopic example:   
Because the difference is so great,  D2O is poisonous!!!  It is  
proposed because of its decreased reactivity to introduce D into  
drugs etc. for preservation.  I'm initially horrified!

http://www.isb.vt.edu/brarg/brasym96/kushner96.htm


bc remembers the New Yorker article on the Minamata disease, and  
refrains from making further comment about rampant capitalism and  
democracy.

http://en.wikipedia.org/wiki/Minamata_disease#Democratizing_effects

p.s. A very common corn product is contaminated by mercury.  I leave  
it to the reader to guess the reason.

> So, a few seconds with Google, proving that my personal first steps  
> in learning are not by inquiry methods :-), produced:

I think this is called not reinventing the wheel.  I doubt the PER  
people believe in that reinvention either!

Apropos John's initial question:

http://www.physlink.com/Education/askExperts/ae685.cfm

Perhaps it is indeed fortunate bioprocesses do not concentrate  
U-235!  However, I've  found many fossils that had concentrated  
yellow U ore.

On 2009, Mar 15, , at 09:20, John SOHL wrote:

> In a recent post on climate change and CO2 the link:
> http://www.realclimate.org/index.php?p=87
> was posted as evidence of the anthropomorphic source of carbon in  
> the fraction of greenhouse gasses that are the increase from  
> historic levels.
>
> In that link they state that we know the source "because plants  
> have a preference for the lighter isotopes (C-12 vs. C-13); thus  
> they have lower C-13/C-12 ratios."
>
> ** WHAT???!! **
>
> I was confused here. I was always under the impression that  
> chemical processes were pretty much totally independent of isotopic  
> content and mostly a matter of interactions with outer shell  
> electrons. End of story. After all, if we could chemically  
> manipulate isotopes then making nuclear fuel/explosives would be a  
> lot easier. (I'm not thinking here of things like using  
> isotopically prepared chemicals as things like tracers and the  
> like. That is all nuclear physics.)
>
> So, a few seconds with Google, proving that my personal first steps  
> in learning are not by inquiry methods :-), produced:
> http://www.bnl.gov/chemistry/History/IsotopeChemistry.asp
> It makes sense to me, now in retrospect, that the small isotopic  
> shifts in energy levels might have a tiny but uniformly detectable  
> effect on complex chemical processes such as photosynthesis. I had  
> never thought about it before, even though I can spectroscopically  
> detect these shifts in my own lab.
>
> So now I have to wonder how many other natural processes are  
> (slightly) isotopically dependent. What other cool secrets we can  
> coax out of the universe with such a fingerprint?
>
> Scientific sleuthing! I love it. It always amazes me that with the  
> wonderful complexities and curiosities of the universe that people  
> have to make up stuff like astrology and crystal power.
>
> All the best,
>
> John
>
> P.S. Despite the tongue-in-cheek comment above about not starting  
> with inquiry, my personal approach to many things, such as  
> electronics, computer programming, plumbing and auto repair, is to  
> read a tiny bit then just go fool around with it. The inquiry  
> approach in its full glory. :-)
>
>
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> John E. Sohl, Ph.D.
> Professor of Physics
> Weber State University
> 2508 University Circle
> Ogden, UT 84408-2508