I Quantum wavelength in gravitation

[south]

TL;DR Summary

The habit is assuming a small wavelength when the phenomenon is quantum. Does this habit help or harm in the case of gravitation?

When a phenomenon is quantum, there's a wavelength involved. In trying to formulate gravity in quantum terms, is it important to know the order of the wavelength, macroscopic or microscopic?

 

[weirdoguy]

When a phenomenon is quantum, there's a wavelength involved

No, there does not have to be. Only if you learn quantum physics from pop-sci books or very basic high-school books that talk about de Broglie wavelength.

 

[south]

No, there does not have to be.

OK. Same question in terms of frequency. Should it be on the order of atomic frequencies or on the order of lower frequencies?

 

[weirdoguy]

Same question in terms of frequency.

Energy. Energy is the thing that is used, and it should be way more than the order of energies we see in atomic physics. If it was the same order, then we would already see quantum gravity effects. Check out the energies that particles in LHC have - and we still haven't seen any quantum gravity effects.

 

[south]

Quantum energy without frequency nor wavelength? Good bye
$$E=h.\nu$$
?

 

[div_grad]

The habit is assuming a small wavelength when the phenomenon is quantum.

@south It is the other way around, the shorter deBroglie wavelength is the more "classical" a system is. In very low temperatures, when the energy is low, the deBroglie wavelengths associated with the quantum systems are very large and therefore can easily overlap with each other. In this case the quantum effects are important.

Quantum energy without frequency nor wavelength? Good bye
$$E=h.\nu$$
?

The formula $\Delta E = h\nu$ is true for differences $\Delta E = E_1 - E_2$ between the energies of two quantum levels. Then $\nu$ is the frequency of a photon emitted or absorbed during the transition between the energy levels $E_1$ and $E_2$.

 

[PeterDonis]

Quantum energy without frequency nor wavelength?

Sure. Not all quantum energy is contained in radiation, and even for radiation, not all radiation is in a state which has a well-defined frequency or wavelength.