system
Given the following post, respond as if you're commenting on Reddit:
human
Do the gas giants have a solid core?

Sorry if this is an obvious question.
gpt
Nobody really knows for sure.  However, satellites have measured gravity of some of the gas giants (non-spherical objects have non-spherical gravitational influence), and these measurements have suggested that solid cores exist in all the gas giants.

However, the inference of these cores is both very difficult and uncertain.  For example, Jupiter is thought to have a "rocky" core comprising somewhere between 5-15% of its total mass.  However, the term "rocky" is used loosely, because we know very little about the actual composition (in part because we simply don't know all of the properties of the materials at the temperature and pressure of Jupiter's core).  The story is pretty much the same with the other gas giants.