I don't know which is harder to grasp, photographs larger than the earth or trillions of atoms made or rice and sand.
Seems to me that in either case there is a lot of air in between the objects.
If scientists ever figure out how to remove all that air it would make things easier to handle.

Air, Chas?

Frank: first I must offer this disclaimer: One of the few rules I impose on myself is rule 62. Don't ask what the other sixty-one are, I never thought of that.
Also, as this is a written medium I can type easily with my tongue in cheek. If I were speaking to you the result would be rather garbled and keeping a straight face would be difficult. My uncle Letsgo Lozko, who raised bantam chickens, he could keep a straight face better than I.
I graduated high school in 1964 so that would make my diploma the equivalent of a bachelor's degree these days, uh?
Anyway, I called it "air" in both the galactic and the atomic model. Consider a metaphor (even though they are most always insufficient to convey meaning, comparison breaking down at the fifty percent mark) of a pool table with the standard issue of fifteen numbered balls and the cue ball.
With all of them on the table I see what I call air between them. What else would it be called?
Out there in space there is an awful lot of emptiness. Miles and light years between planets just flying around there empty.
I think we have the means to measure the size of an atom of, say, carbon. We also can measure the size of protons, neutrons and electrons, can we not? So take the volume of the atom and subtract the volumes of the sub-atomic particles and we are left with empty space. It seems right to me to call that empty space "air".

Density is the word for how much air is between each atom or in the case of galaxies between all the planets and whatever other objects are flying around up there.
Can you imagine how small the world would be if much of the air was removed from between things?

To paraphrase old Lao-tzu, we build the house but we live in the space.

Bob: I was told one time "be lucid, but spare me the details". I'm gonna have to work on that. Yep.

Today, I went to the beach front with my kids. I found a sea shell and gave
it to my 4 year old daughter and said "You can hear the ocean if you put this to your ear." She placed
the shell to her ear and screamed. There was a hermit crab inside and
it pinched her ear. She never wants to go back! LoL I
know this is entirely off topic but I had to tell someone!