First some links to interesting things:<\/p>\n
In the category of things that have gotten tedious, first there’s the ongoing hullabaloo about “firewalls” and Hawking (with the bottom line as far as I can tell just that, yes, there is an information paradox, might have something to do with the fact that we don’t understand quantum gravity…). If this interests you, you can take a look at<\/p>\n
In the multiverse-mania category, I’m forcing myself to read the Rubenstein book I’ve mentioned, will report on this when done, in the meantime there’s\t<\/p>\n
It is therefore fair to say, that much of the standard model, and certainly the peculiar values of many of the parameters in the standard model, cannot have an anthropic explanation. In string theory, extra generations of matter correspond to more tuning of moduli, small parameters do not appear to arise without a symmetry explanation, and symmetries are rare on moduli space.<\/p>\n
One cannot escape the implication that, on the basis of current theoretical knowledge, the String Landscape is ruled out by experiment. <\/p><\/blockquote>\n
Besides being experimentally ruled out, the whole Landscape thing doesn’t work anyway<\/p>\n
My personal conclusion from all of this analysis, is that the theory of CDL tunneling provides no positive support for, and lots of negative evidence against, the proposal of a String Landscape…<\/p>\n
When combined with the phenomenological challenges I presented in Section 2, I conclude that the String Landscape is an hypothesis of dubious validity.<\/p><\/blockquote>\n
This is a subject in which solid predictions are hard to come by, but I’ll make one here: string theory partisans will just ignore this, with the “String Landscape” now an hypothesis which has achieved some sort of new extra-scientific status. It’s an ideology you sign up for to justify not giving up on string theory (or as a foundation for your multiverse-mania), and as such, arguments like those from Banks are irrelevant.<\/li>\n
- Also in the category of serious scientific arguments against the anthropic landscape that will just be ignored, see Sesh Nadathur<\/a> who explains why Weinberg’s original argument for the CC implies one that is 103<\/sup> times too big. This is part of some arguments with Shaun Hotchkiss you might want to have a look at, see other blog postings here<\/a> and here<\/a>.<\/li>\n
- Finally, Max Tegmark is on tour promoting multiverse-mania and his Level IV version of it. The latest from him is here at Scientific American<\/a>, where he’s claiming that his Level IV multiverse is science because it could be falsified by finding “some physical phenomenon that has no mathematical description.\u201d I’ve tried arguing the absurdity of this with him in the comment section, so far no luck getting anything other than a dismissal of me as “emotional”.\n
I was interested to see that his perception of what has been going on for the past decade as endless popular books promoting the multiverse have appeared is that <\/p>\n
whenever a physicist writes a book about them [multiverse ideas], the Web erupts with claims that they are unscientific nonsense.<\/p><\/blockquote>\n
Curious to know what part of “the Web” he is referring to other than my blog…<\/li>\n","protected":false},"excerpt":{"rendered":"
First some links to interesting things: There’s a fascinating interview with Deligne in the latest AMS Notices. Alexandre Grothendieck: A Mathematical Portrait includes some great expository pieces about the mathematics developed by Grothendieck. There’s also available Grothendieck’s own Esquisse Thématique, … Continue reading