Re: [Marxism] The Big Bang Theory

[Les Schaffer <schaffer@xxxxxxxxxxxxx>]

Mark Lause wrote:
> steve houston <stevehouston3000@xxxxxxxxx> wrote:
>   
>> C'mon..by definition there can't be two UNIverses. 
> I'm wondering what sort of scientific understanding is at work here,
> because this kind of rhetorically mocking dismissiveness smacks of how
> the Fundies talk about evolution.


kudos to Mark ... though i am not aware of anything in the colliding 
branes theory that deserves steve's derision. the ethereal parts of 
these theories require extra dimensions we have no sensory perception of 
at this time, true. but the "how can there be more than one universe" 
thing is not a real issue for colliding branes once you realize these 
collisions take place in higher dimensions. perhaps popular accounts 
call them colliding universes. who cares. serious marxists (thats a dig 
back) know how to sort thru popular accounts and separate the news 
headlines from the meat.

now, if steve wants to get into a serious (sorry, can't help it) 
discussion about the use of extra dimensions in theoretical physics, 
that would be an interesting conversation. i find myself bored lately 
with the "ultimate theory" fanfare.



chegitz guevara wrote re/ the colliding branes thing:
> That only makes sense *if* string theory is valid, and so far, string
> theory is nothing more than an unproven hypothesis. It may be what
> actually happened, but right now, the evidence isn't there.
>   

the evidence isnt there to distinguish between the two theories, i 
heartily agree. my point was there is more than one *theory* that can 
account for large scale observational features. things have changed 
since Big Bang was the only thing one could talk about.

but if you take your argument one step further, we need not accept the 
Big Bang as proven, because a key ingredient --  inflation -- is an 
unproven  hypothesis. i am ok with that too. yes, talking about vacuum 
energy is a lot more solid at this point than talking about branes. but 
i don't see your razor as that sharp.

and later you write:
> Disagree all you want, but no other testable theory accounts for the
> expansion of the universe and the background radiation.

Look thru Guth  and see if you can find such a "testable" claim. for 
others, here is how Guth (the first author on inflation)  concludes his 
summary of inflation to date (2007):

    We should keep in mind, however, that observations in the past few
    years have
    vastly improved our knowledge of the early universe, and that these
    new observations
    have been generally consistent with the simplest inflationary
    models. It is the success
    of these predictions that justifies spending time on the more
    speculative aspects of
    inflationary cosmology.

    http://arxiv.org/pdf/hep-th/0702178v1

i was going to ask if chegitz could prove the inflaton exists. but on 
checking this thought first, i came across a paper entitled "Inflation 
without Inflaton(s)". here is their opening paragraph

    Despite the simplicity and promising phenomenology of scalar driven,
    slow-roll inflation,
    much remains to make the idea theoretically viable. In particular,
    vexing issues such as the required
    flatness of the inflationary potential and the very existence of a
    fundamental scalar (which must
    be both extremely light and weakly interacting) remain elusive (see
    however [1, 2, 3]). In recent
    years, a substantial effort has been invested in understanding how
    to embed such models in a quantum
    theory of gravity [6, 7], and there has also been the suggestion of
    removing the need for slowroll
    completely [8] (see [9] for earlier work). However, in this paper we
    will take a different and yet
    complimentary approach to inflation model building based on
    fundamental scalars.

    http://arxiv.org/pdf/hep-th/0610054v3

the point is, things are a wee bit more open than chegitz lets on, So i 
find chegitz's take a little too bombastic. but i side with him over 
Yossi's view.


Les


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