I must confess, putting science and mathematics for side for a moment, and by watching and judging with the heart, that I get puzzled with the drones transportation for passanger that are comming.
When kid I had a domestic fan that could be pointed 90 degree to top or to bottom. I put it to maximum speed and waited it could fly away, but it didn't, and I imagine that a electric motor wasn't powerfull enought even to fly itself.
Today small electric motors are flying a air taxi away.
Some machines looks like are defying the gravity law. Some with proppeler blades small, remembering a PC cooler fan.
I ask myself. How is that possible ???
-Low weight due carbon fiber?
-Extra high power electric motors ?
-Lithiun bateries of low weight ?
If science manage to create electric motor with power density even higher (more KWs per Kg) and could develop batteries with 10x more energy density than lithium batteries, these vehicles would change a lot of things.
Despite the science advances we will see in next years, they still could not drive close like car, and would still require a lot of space between each other to avoid crashs, since they alter the air flow near itselve generating a lot of turbulence.