Re: virus: KMO quotes Plato

Jason McVean (
Wed, 30 Oct 96 19:45:09 MST

David Leeper wrote:
> > Every time I measure the brightness of a star, I get a different
> > answer and I can never say that one of those measurements was the
> > "correct" one. However, I can calculate the standard deviation of
> > the measurements from the mean and use this as an uncertainty. In
> > other words, I can calculate the likelyhood that my mean
> > measurement is within a certain range of the true value. So
> > (1/TV) for a statement can be compared to the uncertainty of a
> > measurement.
> Or each measurement could be true in relation to things such as
> time of day or atmosphere conditions. Then the mean becomes a
> convient falsehood.
> Comments?

Those factors definitely affect my measurements, but they can be
acconted for and/or rolled into the uncertainty estimate. The
star also doesn't have a constant brightness but I can still talk
about the average brightness or the brightness at a particular
time. All of these things must be considered but in the end they
affect the truth value of the measurement, not whether there is
a true (objectively real) brightness.


Dept. of Physics and Astronomy University of Calgary

"And it would have worked if it weren't for those meddling kids."