You apparently overlooked the '...' around 'empty', and the note[1], where I said that 'empty' is a deceptive description of space to astrophysisists.
What I was alluding to was the average Joe picturing vast volumes of space as being empty of stuff that can be detected with the human eye in context to TFA talking about using the human eye and brain in searching out these particles collected in the aerogell.
As far as space being actually mostly empty, that is not true. it is chock full of stuff, mostly requiring dectors that far exceed human eyesight.
Quarks, gluons, nuetrinos, leptons, dark matter, black holes, most wavelenghts of EM radiation, gravity, the 'fabric' of space time, many more are crammed int the volume of what would look to a human using the good old 'Eyeball, Mark 1' as a mostly empty void.
Most layman/people only beleive in what they can see, but that is only the barest 'tip of the iceberg' to what's actually out there.
'Tenous gas', various EM radiation, sub atomic particles, 'dark matter, etc. and ad nausem and quantam foam, and more are all presented as theories.
Taken altogether, 'empty' space is actually more crowded than a Tokyo subway during rush hour, and busier than a one-armed paper hanger.
I do actually agree with you, but I was trying to play to a more 'layman/mainstream' crowd, and tried to give the more knowledgable here acknowledgement that it was far from 'empty'
Sorry I failed to make that clear. :-)
But then again, because I like to stir the mudpuddles....;-)
Look at how 'empty' aerogel is: 99.8% 'empty space', and how much 'empty space' there is in an atom.
