Reading Bruno Marchal's last email, I realized that it may contain the
answer that Norman seeks.
The answer I think is simply that the set of states for the lamp is
incomplete under the operation of turning the lamp on and off an
infinite number of times as described by Norman.
Just like the paradox of the square root of minus one was resolved by
adding a new type of quantity, i, we may resolve the Thompson problem
by adding a new state, ONF, which is neither ON or OFF but the result
of the infinite process. We now have a lamp capable of being in three
states: ON, OFF and ONF. No more paradox. We have also upgraded our
lamp. With this new lamp capable of being ONF we can do all kinds of
things. For example if reading a newspaper requires the lamp to be ON,
what could you do to with the newspaper with the lamp ONF? And if
having sex requires the lamp to be OFF what would you do with the lamp
ONF? This is something we should really worry about instead of
worrying about the lamp!
Norman Samich wrote
I've been looking for an idiot savant
to answer this question: Perhaps you've heard of Thompson's Lamp.
This is an ideal lamp, capable of infinite switching speed and using
electricity that travels at infinite speed. At time zero it is
on. After one minute it is turned off. After 1/2 minute it is turned
back on. After 1/4 minute it is turned off. And so on, with each
interval one-half the preceding interval. Question: What is the
status of the lamp at two minutes, on or off? (I know the answer can't
be calculated by conventional arithmetic. Yet the clock runs, so there
must be an answer. Is there any way of calculating the answer?)
Bruno Marchal wrote:
14/07/03 -0400, PaintedDevil wrote:
However - what mainly interests me is what
reason one could have for not
taking the Pythagorean view, which does, after all, explain why the
exists (or appears to exist).
Perhaps because most people believe that the Pythagorean view
has been refuted.
Just consider the "little Pythagorean view" according to which
-Every length can be measured by integers or ratio of integers
This has been refuted by the Pythagorean themselves when they
discovered that the square root of 2 *is* not given by any ratio of
It is the discovery of the irrational numbers, a long time ago.
Now Pythagore could have "corrected" his doctrine with:
-Every length can be measured by integers, ratio of integers or
radical of integers.
But this would have been refuted by Abel's discovery in 1824 that
with degree greater than 4 can have solutions which cannot be described
term of ratio and radicals.
Now Pythagore could have corrected his doctrine again with
-Every length can be measured by polynomial's zeros.
But then Pythagore would have been refuted by the discovery of the non
algebraic numbers: the transcendant numbers like euler e, and PI.
Perhaps at this stage Pythagore would begin to think his Pythagorean
could may be not work.
And then he would have been destroyed by Cantor's discovery, who showed
with his famous diagonalization, that the set of reals (the lengths) is
But then Pythagore would perhaps have postulated the comp hypothesis,
thinking that *algorithmic* real , which should be obviously
enumerable, exist and are easily defined.
Alas, the more subtle Post-Turing-Markov-Church-Kleene-Godel
diagonalisation makes the algorithmic real not *algorithmically*
Surely at this stage Pythagore should abandon the Pythagorean view.
NOT AT ALL. With *Church thesis* you can still say:
-Every length can be measured by a FORTRAN program.
Only you have a price to pay:
FORTRAN programs will measure *much more* than "length", and an
enumeration of the algorithmic reals, will enumerate the reals +
other objects, and no theories at all will give you an algorithmic way
distinguish the reals from the other objects. That is, the price is
incompleteness, randomness, unpredictability, etc.
(Click on the diagonalisation posts in my URL where I explain this,
with the notion of function (from N to N) in place of the reals).
But that is nice (for a realist platonic), and this shows that
Church thesis not only rehabilitates the little Pythagorean view (in
of length), but makes consistent the large Pythagorean view
according to which:
-everything emerges from the integers and their
And my PhD result shows that, with the comp hyp, the appearance of
physics *should* emerge in the average memory of the consistent
anticipating universal machine/program/number. And then I derived a
theorem prover for the logic of the physical propositions from that,
for reason of inefficacy of that theorem prover I can still not decide
it gives really a quantum logic, or which one ...
Other weakness, I have neither a semantics nor an axiomatic for that
quantum logic, only a theorem prover, and a naive semantics in term
of maximal consistent computational histories.
I have written 2/3 of a paper which summarize the proof and I intend
to submit it to some international journal (once finished ...).
Sure, there exists other reasons to believe the Pythagorean view
is coming back, like more direct astonishing relations between
number theory and theoretical physics. Look at