[sigmaprimus]

Things are pretty tight in Singapore, I wonder if you take into account places not safe to stand like roads and places occupied by walls, trees, bank vaults etc., if it would be impossible. Almost 6 million people in 7.8 billion square feet if it was just flat land = approx 1300 square feet per person if my math is right.

[eesmith]

The density needs to exceed 223,563/sq. mile (says the essay).

Singapore's density at 20,445/sq. mile is less than 1/2 that of Monaco, says its reference 5, which is https://en.wikipedia.org/wiki/List_of_countries_and_dependen... .

Thus, only 10% of the land is needed, giving plenty of space for roads, etc.

Of course, if you include walls then you can place people on either side of the wall without an infection problem, so that changes the calculation considerably.

FWIW, I wondered if Vatican City could reach the limit during a papal audience. It looks like perhaps 15,000 people could be there for one? That alone gives a density of 88K/sq. mile (bearing in mind that Vatican City has nearly 6 popes per square mile - or nearly 12 if we include Popes Emeritus.)

Then there's the staff, and the people visiting the museum, and others beyond the estimated population of 1,000.

Even with those, it doesn't seem like it comes close to 223,563/sq. mile.

[sigmaprimus]

I stand corrected, also the model does not take into account the Z axis, magnitudes of area added by highrises.

[robertlagrant]

Yes - it really should be spheres, but ones that cannot use other spheres for support :-)

[eesmith]

I think "should be" pushes things beyond the limited humor there was.

The 6 feet suggestion is based on the travel distance of possible virus-carrying particles, given people on a flat surface.

Since gravity pulls particles downward, I suspect that being 5 feet above someone sick is better than being 6 feet below. Possibly even better than being 6 feet to the side.