[MosesKnows]

I have a question.

I take the position that for all practical purposes of discussion space is empty.

Without involving Solar Mass and Astronomical Units in the question what is ratio of the volume of these 88 objects to the volume of the solar system?

Solar Mass and Astronomical Units are acceptable in explaining the answer but the answer should just be the ratio.

[LibWhacker]

Let's just use the Sun, since it is larger in volume than all the planets combined, with room to spare for all of the asteroid belt objects, Pluto (which is no longer classified as a planet), and probably much, if not all Oort Cloud objects. In other words, we'll be conservative (of course, hehe, what else on FR?) in our attempt to estimate the sparseness of matter in interplanetary space, never mind interstellar space or intergalactic space.

We should perhaps be looking at mass, not volume, since the amount of matter in a cubic foot of space at the center of Jupiter is much greater than the amount of matter in a cubic foot of Mars' dusty surface. In other words, by looking at volume alone, we're losing information about how much matter exists in these volumes, which was the original question.

Okay, so we want to look at this ratio:

r³ / R³ ,

since the (4/3)pi cancel, where r is the radius of the Sun and R the radius of the Oort Cloud from the Sun out to the Oort Cloud's outer edge.

Now, (r/R)³ = (430000 mi/ 20 x 10¹² mi)³

= 9.9 x 10^-24.

In other words, matter in the Solar System occupies only ten trillion-trillionths as much volume as empty space. Roughly speaking.