In which I falsify the Level IV Multiverse

[Robin]

They most definetely are noticeable.

Perhaps you could be just a little less cryptic and tell me what you are talking about or give an example?

 

[Robin]

So have it your way. Unlikely. Unlikelier than Ken Ham being right.

Especially since MUH predicts that there is a universe which is just the way Ken Ham suggests.

 

[Hercules Rockefeller]

Perhaps you could be just a little less cryptic and tell me what you are talking about or give an example?

Sorry, I'm not trying to be cryptic. Everything that happens is an incredible coincidence.

http://en.wikiquote.org/wiki/Lawrence_M._Krauss

Richard Feynman used to go up to people all the time and he'd say "You won't believe what happened to me today... you won't believe what happened to me" and people would say "What?" and he'd say "Absolutely nothing". Because we humans believe that everything that happens to us is special and significant. And that — and Carl Sagan wrote beautifully about that in The Demon-Haunted World — that is much of the source of religion. Everything that happens is unusual and I expect that the likelihood that Richard and I ever would've met. If you think about all the variables: the probability that we were in the same place at the same time, ate breakfast the same. Whatever. It's zero. Every event that happens has small probability... but it happens and then when it happens; if it's weird, if you dream one million nights and it's nonsense but one night you dream that your friend is gonna break his leg and the next day he breaks his arm... *sound of revelation* So the real thing that physics tell us about the universe is that it's big, rare event happens all the time — including life — and that doesn't mean it's special.

 

[Robin]

Sorry, I'm not trying to be cryptic. Everything that happens is an incredible coincidence.

OK, but I am thinking that maybe if the laws of physics could be varied at random then the range might be a little more than is being suggested here.

For example if a 200 foot pink Godzilla suddenly appeared and smashed several buildings and then danced the macarena and pooed on him then there is a chance that he might regard that as a little out of the ordinary, might consider it just a little special.

This is the kind of thing I mean by noticeable.

 

[Robin]

Or to give another example, if he was giving a lecture and all the students turned into giant cockroaches and scuttled out of the room then he wouldn't say "Oh, that's nothing special because everything is a giant coincidence". Or possibly he would. I don't know.

 

[Gord_in_Toronto]

Yes I could, but I am just a little surprised at being asked, so I think you have maybe misunderstood.

I am saying that there are many more ways my day could pan out if there were random miraculous events then if the laws of physics held all day.

Do you still want me to prove that?

Of course I want you to prove it.

I do understand what you are saying. "It's obvious".

But, come on, let's see a mathematical proof.

 

[Hercules Rockefeller]

I think Tegmark is just taking anthropic reasoning to the extreme. I don't see how it's possible to either prove or falsify. It's only speculation.

 

[ctamblyn]

(...snip...)

If this is not convincing then consider that it is mathematically possible that there is a digital demigod who wants to create arbitrarily many universes and arbitrarily many other digital demi-gods who want the same thing.

Under MUH this digital demigod exists and, since the next universe or next digital demigod carries zero improbability given the first such one, then it is clear that these universes will outnumber natural ones.

(...snip...)

I don't see how this can work.

For every one of the (uncountably many) universes which is a simulation created by a digital demigod, itself running on one of uncountably many implementations of a universal Turing machine, there will be uncountably many universal-computer-based universes which (effectively) run that program directly, without it having being written by a demigod, and also uncountably many (non-universal) Turing machine universes implementing the same algorithm. There will, presumably, also be uncountably many mathematically possible universes not based on Turing machines which nevertheless execute the same series of events as any given Turing machine universe, except for some unobservable non-computable stuff going on at their peripheries (ETA: or even without such non-computable stuff).

Given that, it seems to me that it is overwhelmingly unlikely that we would be in a digital demigod universe, as defined in the OP.

 

[phunk]

Robin, in your scenario, there are an infinite number of universes that stick to the laws of physics and have an exact copy of you posting in a thread like this. Sure, there might be a bigger infinity of universes with bored digital gods that randomly mess with people, but that doesn't mean the first infinity is impossible and allow you to use this universe as proof the others don't exist.

 

[ctamblyn]

Of course I am happy to accept "No, you haven't, the Mathematical Universe Hypothesis never made sense in the first place" as an answer

Well, there is that.

 

[aggle-rithm]

Random "miraculous" events happen to you all day long. You just don't recognize them as such.

If we lived in a universe which had physical laws that allowed miraculous events (such as flying carpets or teleportation), we wouldn't see them as miraculous.

 

[theprestige]

As for the "extremely unlikely=false" thing.

I suppose that it is possible that the Universe was created in 6 days three thousand years ago by God and that he created everything in just the order that they say in Genesis and that he created man and woman out of dust and that the whole human race was bred off of them and that the evidence has been carefully doctored to make it seem like there was a 14 billion year old universe and that evolution had taken place.

I suppose that this is possible but I think it so unlikely as to be, in effect, false.

So have it your way. Unlikely. Unlikelier than Ken Ham being right.

Fair enough.

But in that case, we can easily answer the question at the end of your OP:

Have I falsified the “Level IV” multiverse?

You have not: An argument from incredulity does not falsify a hypothesis.

HTH. HAND!

 

[Roger Ramjets]

If we lived in a universe which had physical laws that allowed miraculous events (such as flying carpets or teleportation), we wouldn't see them as miraculous.

Unless we do. Like when simply following the laws of physics is touted as 'The Miracle of Life', or someone survives by pure chance and it's described as a 'miraculous' escape!

An argument from incredulity does not falsify a hypothesis.

My hypothesis is that all the logical and mathematical relationships we think exist are really just an amazing string of coincidences. Sooner or later, someone will be adding up 2+2 and the answer will come out as 5.

Since logic is actually random and doesn't work the way you think it does, you cannot use it to falsify my hypothesis. Therefore it must be true!

 

[theprestige]

Since logic is actually random and doesn't work the way you think it does, you cannot use it to falsify my hypothesis. Therefore it must be true!

Luckily, there's no need to falsify hypotheses that aren't even wrong.

 

[Soapy Sam]

I'm starting to think there is a continuous spectrum grading from complete nonsense at one end , through philosophy, mathematics and physics to a higher frequency form of complete nonsense at the other end. Somewhere in the middle is the narrow range of frequencies comprising reality, common sense , tripe & onions and chartered accountancy.

Exactly where this thread lies is a matter of speculation.

 

[drelda]

Clearly the number of ways your day could go with a noticeably miraculous event vastly outnumber the ways your day could go if the perceived laws of physics hold.

So it is a definite prediction and consequence of the MUH that it is vanishingly improbable that I can see even one day out without a noticeably miraculous event occurring to me.

But I spend my entire life and never see anything that does not conform to the laws of physics. The Randi Million Dollar challenge appears to suggest that others might have this same experience.

You don't have to resort to the MUH to see the problem with this reasoning. Mainstream quantum physics also means that 'miraculous events' are possible - you could apply your argument the same way and conclude that there are vastly more outcomes where weird stuff happens through macro-quantum effects - therefore quantum theory is falsified.

However with quantum mechanics we also have a good grasp of how the probabilities work - and it turns out that although there are vast numbers of possible outcomes where weird stuff happens - there are even more outcomes where everything seems normal (at least on a macro scale).

We don't have an equivalent grasp of the probabilities that would be involved in infinite number of universes (whether they be just areas of space that are far far away from us, or more exotic ideas like the MUH). This is (I think) what physicists all the 'measure problem'.

But just because we don't have an answer to the measure problem - I don't think we can conclude that 'weird stuff' universes would be more likely than normal seeming ones (at least when conditioned on the fact that the universes have to include conscious observers like us).

Just to give an example of how this could be the case - maybe there is a penalty on the complexity required to define the universe - with universes that are simpler to define being much more frequent than complex ones. A universe that is completely driven by a simple set of underlying physical laws would seem to be much simpler to define that one where arbitrary miracles take place.

I'm not claiming this is definitely the case - just giving it as a counter-example to show that your assumption that the answer to the measure problem definitely leads to an overwhelming number of 'weird' universes is not clear.

- Drelda

 

[Perpetual Student]

A “Level IV Multiverse” is what Max Tegmark calls his Mathematical Universe Hypothesis (MUH).

He claims that it is a logical consequence of the External Reality Hypothesis (ERH).

One of the consequences of MUH is that any mathematically possible object actually exists.

A universal computer is, of course, mathematically possible and so, under MUH, there will exist arbitrarilily many universal computers with arbitrarily many different programs.

Many of these programs will be produce minds able to comprehend and form intentions and run algorithms themselves and so will be able to compute universes like our own universe. I call these digital demigods.

If the simplest computer is of a similar complexity to the simplest entity that can produce complexity then it is likely that digital-demigod created universes will vastly outnumber natural universes such as our own.

If this is not convincing then consider that it is mathematically possible that there is a digital demigod who wants to create arbitrarily many universes and arbitrarily many other digital demi-gods who want the same thing.

Under MUH this digital demigod exists and, since the next universe or next digital demigod carries zero improbability given the first such one, then it is clear that these universes will outnumber natural ones.

So under MUH it is vanishingly improbable that we are living in anything else than a digital-demigod created universe.

Since our universe is being calculated by a digital demigod then the DD can alter the perceived laws of physics at will and can create miracles.

So, under MUH, there is a universe where, starting next Thursday all of our heads grow to twice their normal size and shrink back again at 7.20 pm. Or a universe where each 2nd March Mothra completely destroys Seattle and then the Mysterons come and reconstruct it again.

Under MUH these universes definitely exist.

Now consider all the ways in which a noticeable miracle might happen to you today. You might turn into a large bug. Godzilla might suddenly appear and poo on you. You could go on all your life naming these.

Clearly the number of ways your day could go with a noticeably miraculous event vastly outnumber the ways your day could go if the perceived laws of physics hold.

So it is a definite prediction and consequence of the MUH that it is vanishingly improbable that I can see even one day out without a noticeably miraculous event occurring to me.

But I spend my entire life and never see anything that does not conform to the laws of physics. The Randi Million Dollar challenge appears to suggest that others might have this same experience.

And so the MUH is false. And if Tegmark is right about it being a consequence of ERH then external reality is false too. But I think he is simply wrong about that.

So whaddya think? Have I falsified the “Level IV” multiverse?

Referring to the bolded sentence above, this is a consequence of MUH much in the way many worlds is a consequence of QM (level III in Tegmark's jargon) or "pocket universes" (level II) are a consequence of fine tuning. My take is that one can consider MUH without this added conjecture. I believe that the word "consequence" as used by Tegmark in this context should be replaced by possible consequence.

 

[Gord_in_Toronto]

Referring to the bolded sentence above, this is a consequence of MUH much in the way many worlds is a consequence of QM (level III in Tegmark's jargon) or "pocket universes" (level II) are a consequence of fine tuning. My take is that one can consider MUH without this added conjecture. I believe that the word "consequence" as used by Tegmark in this context should be replaced by possible consequence.

Why do you believe this?

 

[Perpetual Student]

Why do you believe this?

I suppose we all use words with differing shades of meaning. When I say B is a consequence of A, I mean if A is true then B must be true. Tegmark does not present a scientific argument making that case. He does say that B is possible given A. So, I would use the expression "possible consequence" to characterize that. Suit yourself.

 

[Gord_in_Toronto]

I suppose we all use words with differing shades of meaning. When I say B is a consequence of A, I mean if A is true then B must be true. Tegmark does not present a scientific argument making that case. He does say that B is possible given A. So, I would use the expression "possible consequence" to characterize that. Suit yourself.

And yet.

If pigs had wings, they still could not fly. Square-Cube Law you know.