The man who reaches R0 does not yet see it.
A virus caused its citizens to abandom the ground a long· time ago. Thin Babels rise today from the earth at a great distance from one another, blurred in the cloucls, supporting the city.
Spiralling· towards the sky, each Babel has a hollow centre, deep as a well; from there, looking down, the citizens contemplate, fascinated, the lost ground and the monuments of a past era.
A formula determines life and rhythms in R0: when its value is minor than one, life flows horizontally between the connected Babels. When it excesses one, each Babel closes in itself like a shell, providing· life and sustainment to its inhabitants.
A description of R0 should include all its past: the city reveals it, contains it, and teils it as lines of a hand.

It is worth noting that if a virus were to attain a state of wholly benign equilibrium with its host cell it is unlikely that its presence would be readily detected or that it would necessarily be recognized as a virus[...].

The word has not been recognized as a virus because it has achieved a state of stable symbiosis with the host.

In contrast to these survivalist fictions, is that borders are porous by definition; no matter how fortified, they are more like living membranes than inorganic walls. An individual or a state that effectively manages to cut itself off from the outside will be as good as dead.

Meme are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation.