Re: Do MDs need to know physics?

[David Bowman <dbowman@tiger.gtc.georgetown.ky.us>]

> I had an interesting argument from an MD, a number of years ago, as he
> tried to explain to me that a "cubic centimeter" and a "milliliter"
> were different.

How many years ago was this episode?  At one time a cubic centimeter *was* 
different than a milliliter.  For some time in the past the liter was not
defined in terms of the (cubic) meter.  It was defined as the volume
occupied by 1 kg of pure water (with average terrestrial isotopic
compositions) under 1 atm of pressure and at the temperature at which the
density of water was experimentally greatest (i.e. 3.98 deg C).  Using this
definition there is a discrepancy (as I recall) in the 5th significant
figure between the size of this liter and a cubic decimeter.   If you have
access to an old 60's vintage copy of the CRC handbook you can look up
just how many of these old ml were equal to a cm^3.  I do not recall just
when the liter was redefined as a cubic decimeter (but my guess is that it
was sometime in the early 70's).

So my guess about the context of the above encounter with the physician is
that either it may have happened back when the MD would have been correct,
or he/she had been educated back when there was this discrepancy and was
unaware of the subsequent redefinition of the liter as of when the
encounter with the physician took place.  It is even possible that the MD
was educated after the liter was redefined, but had had a physics professor
who was unaware of the changed definition and had inadvertantly passed on
some misinformation to his/her students, which for some (near) miraculous
reason was actually remembered by the MD years later.

David Bowman
dbowman@gtc.georgetown.ky.us