One philosophical objection derives impossibility from an older cosmology of celestial spheres: putting Paradise beyond a particular sphere, or Hell in a specified lower region, is alleged to conflict with celestial motion or combustion.
The objection depends on the assumed structure and necessary properties of the spheres. If those premises are not themselves established decisively, they cannot conclusively disprove the existence of the abodes. This is a historical cosmological dispute, not a modern scientific finding.