Math Forum / Mathematics / Mathematical Logic / September 2006

Any suggestion about
"Relational Model for Classical Modal Logic"?

The author of the Tractatus intended it to be a mystical document that,
by annexing logical discourse, allowed mysticism to triumph over the
best that a logico-materialist view of the world had to offer against
the mystical vision. This is why it makes uncanny reading. For

At the end of his career (in 1954) Einstein predicts a possible death
of physics:
"I consider it quite possible that physics cannot be based on the field
concept,i.e., on continuous structures. In that case, nothing remains

http://www.pbs.org/wgbh/nova/einstein/genius/
"Genius Among Geniuses" by Thomas Levenson
"And then, in June, Einstein completes special relativity, which adds a
twist to the story: Einstein's March paper treated light as particles,

By the end of Chapter 23 in his "Relativity" Einstein claims that
measuring rods laid out along the rim of a rotating disc are Lorentz
contracted whereas those laid out along the radius are not and
therefore the ratio of the circumference and the diameter, as judged by

Not mathematician, could someone explains to me in plain words what
this pseudo code means.  If you provide an example it would be very
appreciated. I understand the first part.
Many thanks

I have recently read "Useful Counterfactuals" by Costello and McCarthy,
1999, and have a question about an example there -- the Skiing Problem. (
http://www-formal.stanford.edu/jmc/counterfactuals.pdf ) Its "real world"
scenario is as follows:

Clever Einsteinians should reconsider the problem in
http://www.courses.fas.harvard.edu/~phys16/Textbook/ch13.pdf pp.2-4
by applying Einstein's 1911 formula:
http://www.physlink.com/Education/AskExperts/ae13.cfm

Mathematical SOAP Operas
                                      ~v~~
The difficulty with definitions drafted in the form of "set of all
points . . ." (SOAP) is that we're still left with a bunch of points

A mathematical string is a pictogram, a synthesis of geometry,
mathematics and human intentions. The human intention is to create
start and end, so that elements in a string can be counted. To create
'start' and 'finish', start and finish are conflated with the

This is the first of several posts based on some
handwritten notes I wrote about ordinals numbers
in 1991. Corrections and/or additions, if any,
will be posted in this thread, and later posts

The main concern of Einstein's hypnotists is to camouflage the fact
that the speed of light does depend on the speed of the light source
and therefore Einstein's theory (and modern physics in general) is just
a farce. The camouflage involves even simulated fights among

Are there any enthusiasts for playing around with Turing machines out
there? :-)
I'm finishing writing something at the moment, and one (short) chapter
introduces the idea of a Turing machine and describes, as examples,

By Frege's Theorem, I mean the result that second-logic plus Hume's
Principle is sufficient to prove second-order arithmetic.  Hume's
Principle is the intuitively true statement that the number of a
predicate or concept F is equal to the number of the concept G iff

The set of all reals, R, is said to be uncountable and therefore
unlistable: but it is not necessary to list the set to construct a
Cantorian diagonal-type number from its members; it is only necessary
that its members be distinguishable and that one is free to choose from