Occam’s razor is not a “law” in the common sense. For instance, for a simple mathematical problem such as 1+1, Occam’s razor would tell us to first examine the initial quanties of a+b in a base-10 system (since that would be the simplest method). However, what if you add 1+1 visually in a linear pattern? 1+1 now becomes 11 and is equal to 10+1 (in base-10). Furthermore, if you view 11 in a binary system, it becomes 3. In hexadecimal it becomes 16.

I am not necessarily saying that we do not exist in a multiverse, but rather that, just because it makes logical sense, does not mean that it is fact. Likewise with subatomic particles — just because they behave one way, does not mean that the macro-universe is also bound by such a pattern. I am simply saying that I would not be so bold as to say ‘there is no magical cut-off’ since both views for and against universal wavefunction remain unproven.

Occam’s razor is merely a suggestion of logic, not a law of physics.

As I noted in the earlier comment, there is indeed such a “law” or rather a really solid correlation (with outliers).

Why that is one can speculate over.

Degrees of freedom translates to algorithmic complexity. Anthropically universes that prefers parsimony are simpler, less messy, so more likely to have life.

Also, such physics need less resource to produce a reaction on an action. Everything else alike that translates to time. That should also be a win in the anthropic sense, more productivity of universes and life both. In an eternal inflationary cosmology these are exponentially competitive advantages, so even small differences from “simplest possible” would get prohibitively punished.

Finally, consider cooling in an expanding universe and the spontaneous symmetry breakings that follows.

A maximum symmetric, chaotic initial state is simple enough. Many symmetries (charges; laws) but then also likely divided into simple similar ones.

Similar to the suggestion above the later processes of symmetry breaking would only add smaller amounts of additional parameters as each universe cools.

Indeed, what are you discussing?

- We can’t “prove” theories. But we can test them to see which we can discard. If we can’t know what is wrong, we can’t know what is correct.

And beyond testing, competition on the market of ideas means there will be only one; we know the process converges.

That is a valid, tested theory of science. You can easily run a meta test on actual numbers of successfully tested theories up to a many sigma certainty test of testing itself!

- As for quantum mechanics, the arguable existence of the decoherence process and its as of yet validity under special relativity means that theories of quantum mechanics can tentatively be rejected: classical “instant collapse” copenhagen, consciousness collapse.

So this is a putative test that many world theory can pass. It is further _based_ on decoherence instead of being compatible with it like remaining copenhagen theories. And it is the most parsimonious. It has two axioms less than others in an axiomatic formulation, so a minimum of parameters.* Therefore it is favored by many theoretical physicists (Tegmark poll.)

In the same way that it looks like multiverse cosmology can be observed and tested (read Cosmic Variance’s posts here), it is likely that many worlds theory can be probed.

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* In theoretical physics it is not the number of variables that is minimized but the sum of degrees of freedom. In a model each variable is preceded by parameters that tells of freedom of the model.

The value of those parameters is what the theory predicts, so that is the number of tests that needs to be performed to fully test it.

The degree of freedom can be minimized if the model can be put on unit free basis, so that is the true sum of freedoms. *That is the real independent number of ways the model changes when parameters changes.* (In loose words, it is the topology of the model.)

So it tells of complexity of the model, and how easy it is to get it wrong. It also tells you how many times you risk reversal between models under testing, and that parsimony minimizes that. That is two reasons to use “parsimony first” in a research strategy.

The last reason is that one can observe that nature “prefers” simpler theories in practice. Not always, but most often.

So that is not what is meant when one loosely says quantum mechanics has “no hidden variables”. That is true but inconsequential here.

But one can also show that quantum mechanics minimizes the number of needed parameters compared to classical mechanics. So quantum mechanics is truly more parsimonious than classical mechanics.

But, a nitpick:

Physicists call the phenomenon behind the quantum-classical boundary “decoherence.” Simply put, as soon as atoms start to interact irreversibly with objects close to them, be they other atoms or some aspect of their environment, their zany superpowers seem to disappear.

Decoherence is likely not irreversible.

At least as far as experiments shows. There is one first that probes decoherence more directly than these by studying coupling to photons in a cavity. It showed that you can go into and back out of partial decoherence reversibly. (I’m sure you can all google it.)

That accords with Hardy’s toy model of quantum mechanics, where he recovers it by way of a probability formulation. There it is classical mechanics which is discrete (pre and post states) and quantum mechanics which is continuous (continuous transformation between states).

Of course you can observe irreversibility, which is what observation builds on. But it is no more mysterious than having reversible and irreversible interactions of thermodynamical systems.

Philosophy and science cannot coexist. Science is the process of making sense of the world around us using specific rules, and philosophy is merely the pondering of all possibilities. Why respond to a this post suggesting that the perspective covered is wrong or misinformed? Philosophy itself rejects the idea that anything can be proven at all, thus negating the argument that science is wrong.

There is no way to prove that multiple universes even exist for 100% certainty, nor that we are not an elaborate program for another consciousness. To truly appreciate this post, rather than suggest it is not true, read it for what it is. The fact that there is no way to disprove it makes it just as viable as any other theory. Occam’s razor is merely a suggestion of logic, not a law of physics. “Plurality should not be posited without necessity” simply means that one should examine solutions with the least amount of variables before moving to the complex ones, not that the complex ones are incorrect.

I don’t believe you are correct, and furthermore I don’t believe you understand what Potu is even talking about. Don’t attack it as “mysticism” because it mystifies you.

I believe you are correct. But I think consciousness is nothing more than the illusion of experiencing 1 instance at a time. The same thing, expressed in two different ways, essentially. The illusion of choice is another expression of this.

@MorePlease and anyone else that’s interested, start reading here:

http://lesswrong.com/lw/r5/the_quantum_physics_sequence/

http://en.wikipedia.org/wiki/Dimension#Time

also could this be used as a way of communication?

Please don’t use physics as a crutch for mysticism. Both of these questions are extremely well understood, and have been understood for hundreds of years. Many worlds, assuming its true, which we don’t know, offers no refuge for superstion here.

The reason you only experience 1 moment of time is not a mystery. Its because your only in one period of time, the present. The future hasn’t happened yet so it can’t be experienced because it doesn’t exist, however you DO experience the past via stored memory in your brain.

The reason you can’t experience multiple universes is because your only present in the one your in. You MIGHT experience some of the outcomes of the resultant physics of it, but you cant experience another universe, because backwards in time only one universe, the one your in is visible (Its a directed tree graph and backwards in time points at the root thus memory can only consist of a single universe) and of course because you can not experience the future (it hasnt happened yet and thus doesnt exist) so therefore you can never experience more than one universe.

Please don’t import silly mysticism into science.

What do you think a good thing to read would be for me to get a grasp on the ideas you’re saying? I’ve heard all of these ideas before but I’ve never found a good, thorough source that seemed to make sense of them and step through them piece by piece. Do you (or anyone else) have any suggestions?

The unknown part is why our consciousness only experiences 1 universe out of many parallel universes. It’s a similar question as to why we only experience 1 moment in time (now) out of the whole of eternity.