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Is quantum chromodynamics well understood? Is the problem with unification just gravity?
- Nadien (age 21)
The big problem with unification is definitely gravity. Quantum chromodynamics is at least well-formulated, but the consequences of the basic theory are fairly hard to calculate because the interaction is too strong to calculate effects by first ignoring it, then considering direct effects, then a sequence of effects acting on effects, etc.
There is a stage of unification (electroweak + chromodynamics) which is far from settled yet, but isn't expected to raise the really big problems that come up with gravity.
(published on 03/08/10)
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