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I tell my students that zero is not nothing.
the
Quantities have dimensionality and "carry" units with them. Their
value is a product of a number and those units. The unit for mass is
kilogram. Thus it is appropriate to say "this object has mass m = 0 kg"(where
the "m" is in sloping type). One might say that, for example, of aphoton.
said
As the lead reviewer of new and revised IEEE standards for adherence
to proper use of the SI and so forth, I would "ding" a standard that
something silly like "the potential at this point is 0";
it should be "the potential at this point is 0 V".
The same would occur with a statement about the resistance of a
superconductor, so this is not a matter of scale or reference
point.
Though the magnitude (numerical value) of a quantity may go to zero,
it retains its dimensionality and thus its units.
Jim
On Thursday 2004 September 16 14:33, leinoffs@SUNYACC.EDU wrote:
Hello,version of
Sorry to join this discussion so late, but I get the digest
Phys-L (and don't read them until days later, even so). Iappologize if my
point has already been madeuse them?"
Did someone say:
"Since the number 0 doesn't need units for anything, why try to
stating the
I think that it is pretty important to include the units in
value of a temperature, even if the value is zero (e.g. 0 degreesCelsius)
I don't think any of us would have it any other way.quantities?)
Obviously this is a problem with temperature (and any other
since the value of zero on the Celsius and Fahrenheit scales arebased on
an arbitrary temperature. Those zero values of temperature do notcoincide
and do not represent an "absolute" temperature value.
Stu Leinoff
Adirondack Community College