system
Given the following post, respond as if you're commenting on Reddit:
human
Why are Gravity, Electromagnetism, and the Strong force transmitted by massless particles but the weak force is transmitted through massive particles?
gpt
The force carriers of the weak force acquire their mass from the Higgs mechanism.

Let's leave gravity out for the moment; we don't have a reliable particle theory of gravity yet.

The other forces all have a common mathematical structure, implying that they are mediated by spin 1 particles with no intrinsic mass.  However, the force particles of the weak force interact with the Higgs field. Consequently, since there is a non-zero Higgs field filling space, the force particles for the weak force acquire mass.

If gravity has a particle explanation, it requires a massless spin 2 particle, and like the photons and gluons of the electromagnetic and strong forces, would have no interactions that could undo its masslessness.