Monday, October 23, 2006

String Theorists on the Anthropic Principle

String theorist:
The weak anthropic principle is a selection effect.

No, that's not necessarily true. For example; The weak anthropic principle as defined by Tipler and Barrow describes the general form of the special case if there is only one possible configuration that the universe can take.

String theorist:
One possible universe?!?!... What ever gave you that crazy idea?

The least action principle.

String theorist:
phhhht... we gave up on that years ago, the multiverse is the only way, you can even ask Richard Dawkins and Lenny Susskind!

Oh, sorry, I forgot that you guys gave up doing real physics, for religion.

String theorist:
Look, you're a crackpot, because you don't believe in unproven assumptions.

Indeed, you mean, because I trust what the physics indicates, that carbon based life is weaved into the path of least action in a relevant way.

String theorist:
You're a crackpot because you think that carbon based life might be weaved into the path of least action in some relevant way, and I can deny without justification all evidence that you provide to support it.


String theorist:
Selection effects Selection effects Selection effects!!!


L. Riofrio said...

HI Island. Your last posts are great. Someone needs to question the mantra that WMAP "proves" inflation. In fact the scale-invariant spectrum that is inflation's key prediction is ruled out by both WMAP and COBE. Can the WMAP team not read graphs? The mis-anthropic principle is so unscientific that it is beneath comment.

island said...

Hi, Louise, thank you. I have noticed that the different camps have their own way of interpreting things to their advantage, and I have observed others protesting this method.

I honestly don't know why they don't ever openly recognize hard physics, (like you do), when they see it written down right in front of their faces. There is no excuse for that.

B-Nimble said...

Criminy, I wish there was a way to check whether modern theories actually still make predictions that match what we see in the universe. I've seen some remarkably circular reasoning, of the type that says "a previous theory predicted this, but even though the previous theory was superseded due to incorrect assumptions, the new theory now has had predicted this". All the while, nobody notices that the prediction isn't really a prediction any more - the new theory has been tuned to match. (Talking CMB and Inflationary Theory here, in particular)

I was surprised to see Roger Penrose tearing Inflationary Theory apart. Perhaps Inflationary Theory's extra constraints make it easier to do so.

We seem to be in the midst of deciding that the universe's expansion is increasing, and determining whether or not it had slowed down previously (at least, that was the big story in 2004). I'm not sure that's compatible with Inflationary Theory.

Regardless, having the universe inflate that much faster than the speed of light for 100 million Planck-seconds seems like an amazingly cheap hack on a theory to solve horizon and causality problems.

I wouldn't rule out multiverses or the like, but to stop questioning there seems the height of laziness, something akin to Dirac's famous dictum, "Shut up and calculate". There probably is a reason for the physical constants to be as amenable to life as they are. I am certainly not impressed with theories that need the physical constants to be "amazingly fine-tuned" to produce stars, elements, life.

Interesting blog you have, Island. That's a more laser-like focus on an interesting problem than I could attain :)

island said...

All the while, nobody notices that the prediction isn't really a prediction any more - the new theory has been tuned to match. (Talking CMB and Inflationary Theory here, in particular)

Exactly! That is so right on the money it isn't even funny.

I don't think that any potential science should be ruled-out without a more naturally preferred theory, BUT my point is that this also includes the MOST APPARENT implications of the evidence... duh.

Thank you for your kind words, dear Sir. They are few and far between when it comes to strong interpretations.

M.C. said...

Excellent blog, island.

a quantum diaries survivor said...

Don't worry Island, cracked pots may not hold much water, but string theory has been on diapers for the last twenty years...


island said...

Anybody that is reading this junk should drop everything and immediately proceed to Tommaso's blog to witness empirical history in the making:

"A Quantum Diaries Survivor"

You didn' just call me a crackpot... ;)