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> Isn't that just our understanding of gravity not being complete. No. It's that, but it's not just that: if a QFT in 4-d spacetime has a coupling constant wit
by nyssos 3y ago
> Isn't that just our understanding of gravity not being complete.
No. It's that, but it's not just that: if a QFT in 4-d spacetime has a coupling constant with a negative mass dimension, it has infinitely many free parameters, which means you can only use it below a given energy scale. We live in a 4-d spacetime, and the mass dimension of Newton's constant is -2, so either the true theory is not a QFT, or it's an infinitely complicated QFT we can never actually find.
> That seems to be a big leap, is not the existence of flaws in our understanding of gravity also certain?
Yes, both GR and the standard model are known to be incomplete.
- ben_w 3y ago> It's that, but it's not just that: if a QFT in 4-d spacetime has a coupling constant with a negative mass dimension, it has infinitely many free parameters, which means you can only use it below a given energy scale. Huh. Do you know of any videos that go into more depth? (My level is the "PBS Space Time" and Sabine Hossenfelder videos as I don't do this professionally).