Ohm vs. Fick
Ohm's law states that, in an electrical circuit, the current passing through a conductor between two points is proportional to the potential difference (i.e. voltage drop or voltage) across the two points, and inversely proportional to the resistance between them. In mathematical terms, this is written as: V=IR
In the mid-1800's, Fick introduced two differential equations that quantified the above statement for the case of transport through thin membranes. Fick's First Law states that the flux, J, of a component of concentration, C, across a membrane of unit area, in a predefined plane, is proportional to the concentration differential across that plane.
Fick's Second Law states that the rate of change of concentration in a volume element of a membrane, within the diffusional field, is proportional to the rate of change of concentration gradient at that point in the field.
Monday, November 12, 2007
Round 2, Fight 2
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6 comments:
Fick takes this one, it is two on one after all; and the first law is analogous to Ohms law. Concentration gradients are gradients of potential energy, voltage is potential. Membranes resist the chemical flux, resistors resist electrical flux. Flux through the membrane can be favorably contrasted with current.
So there you have it, while Ohm and Fick-one get trapped in a stalemate, Fick-two shanks him in the back.
Ohm's Law is clearly the superior law, due mostly to the cleverness of Ohm. This nonsense about two on one is misleading; actually, there is only one Fick's Law.
It is true that Fick 1 is analogous to Ohm's law. However, Ohm manages it without resorting to differential equations. Simplicity wins out here.
As for Fick 2, "the rate of change of concentration in a volume element of a membrane, within the diffusional field, is proportional to the rate of change of concentration gradient at that point in the field." Who is he kidding? This is just technobabble from a Trekkie born 150 years too early. Everyone knows that diffusion fields and membrane gradients don't exist- they are abstractions invented by physicists because imaginary physics are so much easier than real ones.
Ok, this competition is not as easy as I originally suspected, so I'll have to break it down.
First, it might seem to the casual observer that Fick has 2 laws, and Ohm only has one. Actually, Ohm has 1 major law and two lesser laws (acoustic and phase laws).
Ohm and Fick's first laws are roughly equivalent, and 2 lesser laws are slightly more than Fick's 2nd law, putting Ohm in the lead.
However, since Fick is also credited with creating contact lenses, his coolness factor eclipses Ohm's number of laws. Contacts are exceedingly important to the history of the world, pushing Fick into the lead.
Finally, Ohm creeps into the lead with his name recognition. Most people have heard of him, since his name is a common electrical term, making his a (almost) household name. The only thing most people would think if you said "Fick" would be uncomplimentary, or overcomplimentary.
In either case, Fick loses on recognition and for having an almost dirty name. You can't let stuff like that win - it's immoral.
tommyp, need I remind you that this is a cage match between the laws given. Ohm's lesser laws are not so named for him, and did not get invited. Feel free to change your vote if you feel that it is necessary.
Just because you neglected to mention two of Ohm's laws doesn't mean they shouldn't matter, or somehow relate to the discussion. Fick can't go shanking anyone in the back if Ohm has a minor defense based on his other work.
Your comments smack of favoritism - corruption all the way at the top of our little organization!
Continuing my low-level results based selection process I'm going with Ohm on this one.
Ohm gives us electronics of all types, Fick gives us reverse-osmosis water purifiers.
And as important as clean water is, there are other ways to do it.
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