Cosmologists got a freak on

[Smellyoldgit]

No it isn't

[Gnosital]

a different tim wrote

Strong anthropic parsing: "Humans somehow caused the universe to be like this, it must have been created for us or there's a quantum observer effecet etc".

Weak anthropic parsing: "We can deduce, from the existence of humans, that out of the many possible states for the universe, it happens to be in this one".

Thanks, ADT!!! I had not been seeking out much reading material on "anthropic principle" anything, mainly because I thought it was all polluted by the teleology bidness. I shall look into it more.

Your posts always make me get smarter.





Hmm... I just read page 3. I guess I first need to learn to do some maths... because Choobus also makes me get smarter.

[Kate]

Oh noes!!! Not the maths!!

Smellyoldgit wrote

No it isn't

You didn't pay here. This is the Ministry of Silly Walks.

[Gnosital]

OK, I'm going to display my utter ignorance of cosmology (at least!) here, and try to see if I've get this at all.

ADT, you can probably tell me if I'm completely off, but wouldn't that freaky observer thing be a bit like, well, teleology with explosive diarrhea? It seems to me that the Boltzman thingie is like saying, well, ANYTHING's possible, therefore EVERYTHING happened! Even bizarre things like floating brains.

What I don't understand is how a floating brain (and I do get that it's more of a metaphor for freakiness....or isn't it?) could possibly represent a simpler universe. In fact, biologically speaking, a floating brain would have to come from a far more complex universe, because a brain in a body would be far easier to maintain than a brain floating in space. And a floating brain wouldn't have any sensory inputs whatsoever, so how would it observe anything? I guess what I mean is how is it so "hard" for nature to make a universe? Where is there effort on the part of a non-entity? And parts are not necessarily easier to make than wholes (ew, gross, now I'm sounding like one of those idiot creationists!!)

I don't know, I think Boltzman's example of a brain as a simpler but freakier observer is a bad one for a lot of reasons, but I still don't see the problem with whole universes arising through the intersection of a few basic physical processes.

But I'm sure I'm being too pedantic and literal for the mathz. The whole cosmology thing bugs the crap out of me, because it's never going to be figured out before I die. Dammit. I think about it sometimes until I get a headache. But then I stop thinking about it.

[ghoulslime]

Sternwallow wrote

There must have been an all-powerful being with an exquisite artistic sense to have moved all of the more visible stars to exactly fill the outlines of ancient animals and people.

It is even more astonishing since many of the animals and people are considered to be fictitious so, knowing their outlines is a feat of super-human intelligence.

Science fails to explain this evidence for dragons and other so-called myths.

It is so very sad that God saw fit to leave out a Jesus constellation.

I'm telling you! God thought it all out really carefully! He gave us the sun to light our day, and all of those stars to make our night sky so pretty!

[a different tim]

Gnosital wrote

OK, I'm going to display my utter ignorance of cosmology (at least!) here, and try to see if I've get this at all.

ADT, you can probably tell me if I'm completely off, but wouldn't that freaky observer thing be a bit like, well, teleology with explosive diarrhea? It seems to me that the Boltzman thingie is like saying, well, ANYTHING's possible, therefore EVERYTHING happened! Even bizarre things like floating brains.

What I don't understand is how a floating brain (and I do get that it's more of a metaphor for freakiness....or isn't it?) could possibly represent a simpler universe. In fact, biologically speaking, a floating brain would have to come from a far more complex universe, because a brain in a body would be far easier to maintain than a brain floating in space. And a floating brain wouldn't have any sensory inputs whatsoever, so how would it observe anything? I guess what I mean is how is it so "hard" for nature to make a universe? Where is there effort on the part of a non-entity? And parts are not necessarily easier to make than wholes (ew, gross, now I'm sounding like one of those idiot creationists!!)

I don't know, I think Boltzman's example of a brain as a simpler but freakier observer is a bad one for a lot of reasons, but I still don't see the problem with whole universes arising through the intersection of a few basic physical processes.

But I'm sure I'm being too pedantic and literal for the mathz. The whole cosmology thing bugs the crap out of me, because it's never going to be figured out before I die. Dammit. I think about it sometimes until I get a headache. But then I stop thinking about it.

From what I recall a Boltzmann brain isn't one that evolved. The idea is that if you have a universe that lasts for more than a certian amount of time such a brain will spontaneously arise at some point because of quantum because sooner or later a bunch of atoms will fall into that configuration. Complete with sensory inputs and possibly a jar full of nutrients to keep it from instantly exploding in a vacuum.

Sure, the odds are pretty low, but then again given enough time anything can happen, and the assumption is that there is enough time.

Now, the simpler universe thing, I think, arises because our kind of consciousness can only arise in a relatively low entropy universe because our kind of life depends on reasonably constant and predictable energy flows to evolve (in our case, sunlight), which means that there must be some fairly major thermodynamic imbalances to create them. But a Boltzmann brain could arise in a high entropy universe (one in which everything has evened out thermodynamically and that is basically just a low temperature gas) if you wait long enough. This kind of universe is simpler, and a universe that has reached a high entropy state has nowhere else to go. So we get a model of the universe in which we have a relatively short period (a few tens of billions of years) of stars, life etc, and a much longer period of low temperature gas and boltzmann brains.

The complication comes because we don't know if this high entropy state is stable. Lots of models of the universe don't end there - you can get proton decay getting rid of all the atoms, or a big rip caused by the expansion of space, or indeed a gravitational collapse and big crunch. So the question is, is this low entropy period finite, and if so, is it long enough for the Boltzmann brains to outnumber us?

If so, it is claimed we are not typical observers, and we are observing the universe in an atypical state, and we therefore can't draw any general conclusions from our observations, therefore science is fucked (although since our observations are systematic, well documented, and we take care that any general conclusions are testable or we don't let them into science I don't think this claim holds water). Some people also think that it would mean that we in some way "ought" to be Boltzmann brains, because that is more likely, and the observed fact that we aren't means...er...something profound. And some people claim that the fact we aren't Boltzmann brains means that there must be an upper limit to the potential age of the universe, otherwise we would be.

A brief look at the above will reveal the tenuous chain of assumption, teleology with explosive diarrhea, half baked philosophy, dubious logic, and untestable hypothesis that it's all based on, so my advice is shrug and say wtf. This is what happens when physicists think that philosophy is trivial and try to embark on it without proper training.

[Choobus]

a different tim wrote

This is what happens when physicists think that philosophy is trivial and try to embark on it without proper training.

A similar thing happens when philosophers start talking about physics.

[Rhinoqulous]

I have to agree with Choobus. Philosophers playing as physicists come up with much more asinine theories than when a physicist plays at philosophy.

[nkb]

Dole Office Clerk: Occupation?
Comicus: Stand-up philosopher.
Dole Office Clerk: What?
Comicus: Stand-up philosopher. I coalesce the vapors of human existence into a viable and meaningful comprehension.
Dole Office Clerk: Oh, a *bullshit* artist!

My last boss has a Ph.D. in Mech eng. When he finished uni he was on the dole for a couple of months while he looked for a decent job/smoked pot.

The guy at the dole office listed him as "Auto Mechanic."

[a different tim]

Choobus wrote

A similar thing happens when philosophers start talking about physics.

I knew that would wind you up.

Rhino wrote

I have to agree with Choobus. Philosophers playing as physicists come up with much more asinine theories than when a physicist plays at philosophy.

It wasn't philosophers that came up with anthropic principle though. Or the fine tuning argument for the existence of God. Or indeed the Boltzmann brain argument, or the doomsday argument, or the simulation argument. I will admit that philosophers have come up with some pretty weird crap, but for true out there bullshit physics you need to go to a physicist.

[Kate]

[a different tim]

Why thank you Kate! I think that's my first pic from you.

[Choobus]

Some fringe physicists stray into the realm of philosophy, at which point they are just as qualified as any philosopher to waste oxygen by talking shite. Most physicists don't do this. Instead they do something useful. Alas, the same cannot be said of philosophers who stay within their area of expertise, since their area of expertise is entirely useless (with the exception of mental masturbation, which is fun, but not very useful).