Is subjectivity just a matter of context?

[Confused Ape]

Our definition of 'solid' describes a state of matter in which the arrangement of atoms/molecules are structurally rigid. It is not contingent upon density. So, there is no conflict here.

That definition suits everything which we experience as being solid in our everyday lives. Density is important, though.

Crazy-Dense Neutron Stars Reveal Their Secrets

Scientists have uncovered a new key to understanding the strange workings of neutron stars — objects so dense they pack the mass of multiple suns into a space smaller than a city.

Neutron stars are born when massive stars run out of fuel for nuclear fusion and collapse. They expel their outer layers, and their cores fall inward under the pull of gravity to become denser and denser. Eventually, the pressure is so great that even atoms cannot retain their structure, and they collapse. Protons and electrons essentially melt into each other, producing neutrons as well as lightweight particles called neutrinos. The end result is a star whose mass is 90percent neutrons. [Graphic: Inside a Neutron Star]

So back to my question. What is objectively real about the chair? Our experience of it as a solid object or the fact that it's mostly empty space? But is the chair being mostly empty space a fact? Does this fact depend on how one is defining empty space? I found an interesting discussion about it on Physics Forums - Atoms are 'nothing but' space versus 'mostly' space

Here's an informative article by Dr.Christopher S. Baird on the subject.

Why don’t atoms collapse if they are mostly empty space?

Atoms are not mostly empty space because there is no such thing as purely empty space. Rather, space is filled with a wide variety of particles and fields. Sucking all the particles and fields out of a certain volume won’t make the space completely empty because new particles will still flash into existence due to vacuum energy. Additionally, the Higgs field can’t be removed. Even if we ignore every kind of field and particle except electrons, protons and neutrons, we find that atoms are still not empty. Atoms are filled with electrons. It’s true that a large percentage of the atom’s mass is concentrated in its tiny nucleus, but that does not imply that the rest of the atom is empty. Rather, it implies that the rest of the atom has relatively low density.