slippery slope controversy
By Pim van Meurs
Posted February 24, 2006
A little known secret is quickly growing into a worldwide scandal of
unimaginable size and intensity: scientists do not know why ice is slippery. I
am sure that many among you remember the textbook e planation that the pressure
of the ice skate melts the ice and the skate slides on the water which then
freezes. But now, the dedicated reporters of the New York Times have uncovered
the scandal which is growing into what some claim to be the Waterloo for the
Melting Ice Theory (MIT).
A public outrage is spreading across continents over how science books have
misrepresented why ice is slippery while scientists knew that the explanation
was erroneous. What motives are guiding the 'MIT' lobby to surpress the truth
about why ice is slippery?
In a hard hitting article in the New York Times Kenneth Chang is showing how the
scandal is slowly unraveling and how the ivory tower of science has been dealing
Some scientists, despite facing the inevitable backlash from their colleagues
are no longer staying quiet. Although persistent rumors of scientists having
lost their funding for spring break ski trips are spreading, the veracity of
these rumors has yet to be determined.
Ice, said Robert M. Rosenberg, an emeritus professor of chemistry at
Lawrence University in Appleton, Wis., and a visiting scholar at Northwestern
University, "is a very mysterious solid."
Dr. Rosenberg wrote an article looking at the slipperiness of ice in the
December issue of Physics Today, because he kept coming across the wrong
explanation for it, one that dates back more than a century.
For more than a century, scientist and science textbooks have been promoting
the slippery slope explanation while dogmatically surpressing those who tried to
assail the leading theory of 'slippery ice'. Who is trying to hide this mystery
from science and worse from public scrutiny?
According to the frequently cited -- if incorrect -- explanation of why ice
is slippery under an ice skate, the pressure exerted along the blade lowers
the melting temperature of the top layer of ice, the ice melts and the blade
glides on a thin layer of water that refreezes to ice as soon as the blade
"People will still say that when you ask them," Dr. Rosenberg said.
"Textbooks are full of it."
But the explanation fails, he said, because the pressure-melting effect is
small. A 150-pound person standing on ice wearing a pair of ice skates exerts
a pressure of only 50 pounds per square inch on the ice. (A typical blade
edge, which is not razor sharp, is about one-eighth of an inch wide and about
12 inches long, yielding a surface area of 1.5 square inches each or 3 square
inches for two blades.) That amount of pressure lowers the melting temperature
only a small amount, from 32 degrees to 31.97 degrees. Yet ice skaters can
easily slip and fall at temperatures much colder.
While alternative explanation have been proposed, they have so far failed to
present the details necessary for such theories to be accepted. Some critics of
the MIT theory have assailed these explanations as 'just so stories' and
'pathetically lacking in detail'. They argue the existence of a specified and
complex process shows that it is time for science to accept that the slippery of
ice may be best explained by Intelligent Design.