
Scientific Realism in the Age of String Theory (2007) [pdf] - lainon
http://philsci-archive.pitt.edu/3584/1/latex-scientific_realism_in_the_age_of_string_theory%28new%29.pdf
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Lukman
Worth reading for this sentence (p.5): "The core obstacle to an integration of
gravity in the context of quantum field theory is the occurrence of
untreatable infinities in calculations of particle interactions due to the
possibility of point particles coming arbitrarily close to each other." First
time I've heard the problem of integrating gravity with QFT explained that
way.

~~~
westoncb
I remember hearing about this issue—or perhaps a related one in another
formulation/area of quantum theory—where the 'infinities' had to be treated by
something called renormalization[0].

Every time I hear about these problematic 'infinities,' I can't help but think
of a novice programmer looking at the console output of their failing program,
"it gave me all these weird symbols and says something about an 'exception'".

Maybe what's confusing to me is that 'getting infinities' in this way is
somehow normal and not indicative of a bug, maybe? Otherwise, how can they be
brought up in this way without the conclusion being, "seems like we got it
wrong, time to try something else."

[0]
[https://en.wikipedia.org/wiki/Renormalization](https://en.wikipedia.org/wiki/Renormalization)

~~~
chunky1994
The problem is that the gravitational infinities one gets in QFT are non-
reonormalizable. Renormalizable theories must follow a very strict criteria
(and even then they are rather difficult to grasp if you don't really put a
lot of thought into it).

~~~
westoncb
I assumed that was the case, but it doesn't alter the impression I get about
the situation. That still sounds to me like, "we can only apply this fix when
instances of the problem follow certain strict criteria".

