all those constraints

[Michal Frackowiak]

szajtan wrote:

>Boud, I got your point about those constraints ;)
>
>(Maeybe there arose a little confiusion because I treat everything from the
>CMB point of view (CMB & rest of the world) as everything  else (other
>methods) were just a kind of supplementary thing, some aid of narrowing our
>choices in space of parameters.)
>
>When we have a theory describing sth. with some free parameters, it doesnt
>give any constraints on  unknown values until we know the values of those
>parameters. In that moment measurments enter the scene as some kind of
>calibration. Then we have a model and can derive whatever we want
>quantitatively.
>(e.g. LSS constraint - from assumption on model + "calibration"
> measurments )
>
>But what if we had such a good theory that it doesnt need any additional
>measurmenst (except some well known physical constants) (nb measurments that
>introduce additional uncertanities) to predict  the thing we're looking for.
>That would be a constraint of purely theoretical nature.
>(e.g. BBN constraint - only from physics of high energy particles - which
>happens to be more less consistent with constraints from observations of
>Ly_\alpha forest)
>
>Do you agree with this approach to the word "constraint" in astronomy ?
>  
>
holy grail of physics? gut? theory of everything? that's how they should 
work. they predict values of all constansts instead on depending on 
measurements. good way...
but at the moment we have only parametrizable theories. :-(

pozdr - michal