Nerds on Christmas Eve

Only a true nerd would post Nerd Self-Help on Christmas Eve. And look how many comments there were that evening!

One of those comments is such a beauty that I have to re-post its core argument:

It’s not very helpful to assign a predicate E(x) to mean “x exists”, since you are forced to conclude ∀x E(x).

After all ~∀x E(x) is equivalent to ∃x ~E(x), a contradiction.



Hours of philosophical dispute resolved with a two-liner!



Also, Scott mentions Kant’s refutation of Anselm’s ontological proof of the existence of God, which gives me an opportunity to link to Goedel's ontological proof, which fascinated me for quite a while when I first learned about it many years ago. (Nowadays it is on Wikipedia and you can easily read all the pros and cons arguments.)

a first post which is not the first post

As I understand it, quantum theory consists of two parts.

... the 2nd part is Born's rule and using it
one can follow the 'shut up and calculate' approach which is so
successful. On the other hand, trying to really understand or
even derive it can be quite confusing and I admit that I am confused [*].

But in my case, this is just one of several issues in physics which I
do not understand. To be honest, I already have a problem to explain
what exactly 'probability' is supposed to mean. And why do we use
it most often when considering the future but not the past?
I feel like Augustinus and if I wish to explain, I recognize that I do not know.



Whenever I considered myself to be a physicist, I suffered from the suspicion of being a fraud. Like most physicists I used (and abused) various mathematical
concepts, but quite often I really had no clue
what I was doing.
But it seems that I am perhaps not the only one [x] with this problem...



Later, I found a solution to my doubts - I simply do not consider
myself to be a real physicist any longer.
At least I can feel free now to ask stupid questions and make silly proposals...

This is why this blog exists. Again.

As some readers know there is that chance that I may delete it as soon
as the feeling of being a fraud creeps up again. What is the probability of
that? A good question, which I may be able to answer as soon as you help me
figure out what probability means .-)



If you found this first blog post by chance and want to get a better idea in advance what this blog will be about, I suggest you
take a look at this page.

Welcome to the statistical mechanic and let's hope it will be an interesting journey.



PS: Perhaps you noticed that this text was somehow written in reverse order.
It is not that I try to be confusing on purpose - but often it just comes out that way...



[*] A good starting point is this paper by Zurek and I also recommend these comments.
Notice that the comments appeared earlier than the original paper on the arxiv 8-)

And there is a video of a lecture by Sidney Coleman on quantum theory, which I recommend. (If you want to jump to his treatment of the 'measurement problem' move to min. 38 and probability is discussed at min. 55)



[x] I should clarify that in my opinion the interesting part of the Bogdanov Affair is not played by the two brothers, but the community of professional physicists. E.g. consider this statement of Roman Jackiw: "It showed some originality and some familiarity with the jargon. That's all I ask."