To us, the physical universe appears “solid” — that is, most physical objects appear impermeable. If you strike a nail with a hammer, the nail head does not pass through the head of the hammer. If it did, the hammer would be useless as a tool for driving nails. Fluids or gases, of course, behave differently. We can pour one liquid into another, such as two-cycle oil into gasoline for our line trimmer or snow thrower. The fluids mix in such a way that we can’t immediately grasp the oil and pull it bodily out of the gasoline. But the two fluids remain what they were, and if left undisturbed the oil may eventually separate from the gasoline. Unless a chemical reaction results in the recombination of the molecules into some new compound, the molecules of each fluid or gas in the mixture remain “impermeable” — that is, they retain the properties of the original substances.
What makes the impermeability of “solid” substances, such as steel, wood or even human flesh, a puzzling phenomenon is that no object we encounter in the normal course of events is really solid. All substances and objects are made up of atoms which, in turn, consist of subatomic particles — protons, neutrons, electrons, with the first two being further subdivided into “quarks.” (This is an oversimplification of a more complicated picture, which I am equipped neither to fully understand nor to describe.) The distances between the components of an atomic nucleus, and between the nucleus and its orbiting electrons, are comparable in terms of scale to the astronomical distances between the bodies of our solar system. This means that “solid” substances are not solid at all; in fact, the space they occupy is mostly just that — space. It has been suggested that if the space between all subatomic particles of the universe could be removed, the entire universe would shrink to the size of something like a grapefruit, or even a golf ball. Physical objects are not “solid” at all, but consist mostly of space between the subatomic particles that make up their molecules.
Within four-dimensional Newtonian space, material objects and substances — despite their not being “solid” at all — are held together by some kind of organizing force. Their molecular structure is sustained by what is called “nuclear binding energy,” or some similar term. Several nuclear, electro-magnetic and gravitational forces operate to both bind and keep apart the subatomic particles of matter. Reading discussions of this topic, one gets the feeling that physicists do not really understand how these forces and energy particles operate but are simply giving technical names to phenomena thought to occur, as though naming them would explain why they behave as they do. This is like saying that people gather together because they are gregarious, when being gregarious is just another way of saying that people like to be sociable. Exactly how and why an object or substance is able to hold its “shape,” given the fact that it consists mostly of space, is probably as puzzling a question now as it ever was.
What would happen if, from within four-dimensional Newtonian space, we could observe the effect of introducing additional dimensions into consideration — dimensions of which we cannot conceive given the limitations of a four-dimensional world of distance, volume and time? Would some kind of “nuclear binding energy” allow an object to retain its shape while ceasing to be impermeable? There is plenty of space between the subatomic particles of physical objects to allow them to “pass through” each other, if particular forms of binding energy allowed each object to retain its integrity while doing so.
Is this what happened at the resurrection of Jesus Christ? “Eight days later, his disciples were again in the house, and Thomas was with them. The doors were shut, but Jesus came and stood among them, and said, ‘Peace be with you’” (John 20:26). A four-dimensional universe could not have come into existence unless its Creator was operative in dimensions beyond the four that we normally experience. Could Jesus’s resurrection, and what He is able to do as the risen Lord, be the result of God’s continued multi-dimensional activity? Perhaps the universe is kept from collapsing into a tiny “golf ball” of spaceless matter through Jesus Christ, who “reflects the glory of God and bears the very stamp of his nature, upholding the universe by his word of power” (Hebrews 1:3).