Am 19.11.2011 22:56, schrieb Harry Veeder:
If the same water is _theoretically_ supposed to boil at the same
precise temperature at a given pressure, I just don't understand how
water can _theoreticallly_ survive as a liquid drop while surrounded
by steam which is above the boiling point. In other words, the theory
that the same water always boils at the same _precise_ temperature for
a given pressure is an idealisation and an approximation.
If a water droplet vaporizes, the local pressure increases and this
stops vaporization. Vaporization at air pressure means an 1700 times
increase of volume.
My conclusion is consistent with Prof. Hasok Chang (Cambridge
university) experimental finding that the same water does not always
boil at the same precise temperature for a given pressure. In
particular he has shown the surface characteristics of a boiler can
lower the boiling point by two or three degrees. He also says such
anomalous behaviour is well known among people who work with with
steam but it has been ignored or dismissed by the academy.
In this case there should be steam at lower temperature than the boiling
point.
If this is possible, then it is an exotic effect, because this is rarely
observe.
Its an interesting claim, but it should be proven by experiment, before
it can been considered true.
Peter
