Yes of course, I meant to say 1 kW·h = 1 kg; but I'm not certain if I remember correctly now; I could be off by a factor of 10 I guess. It was either 1 kg battery weight = 1 kW·h, or perhaps he said 10 kW·h had to be contained in a 1 kg battery to allow all types of air travel.
I think the 100 kW·h Tesla batteries found in the Model S/X weigh around 750 kg; so I guess electric air travel is still difficult unless a battery breakthrough happens; at least in terms of weight.
That's generally what you should do with a scientific model: state your assumptions and methodology clearly.
And most if not all scientific and engineering models spread properties across a group of objects and use averages. R_0 is an average. And it's the average behavior that matters here
In a well tested population, you might be able to focus interventions on infected people and their contacts. In the US population, the people most likely to spread the disease are those who interact most with other people. That means getting those people to reduce their interaction rate.
It's a semi-empirical model, as are many if not most models used to make decisions.
Yes to pressure part and no to the venturi part. Well, it's not enough. You still have to generate a downdraft to conserve momentum and the venturi idea doesn't explain that.
Seconded. Masters in ASE, written my own vortex lattice code from scratch.
"Wings generate lift by changing the velocity of the flow around them" seems general and correct but the why part is pretty tricky without notions of continuity and conservation laws. And vorticity helps a lot, too.
