A few more things about the Gravity and Portals post...
One of the What-If.xkcd.com answers recently concerned airflow through portals. According to Randall's answer, the flow rate through portals in Mexico City and Boston would be about 440 mph.
The same thing would happen with our world-folding portals, assuming that you moved the air along with everything else. Maybe there are transparent walls on the "front" and "back" of our world in the fourth dimension?
[Stupid diagrams! Upload!]
This seems like it would pose a problem, if we had a very (very very) tall room.
But remember, we would still have to fold it. That takes quite a bit of energy, which is proportional to the square of the height (remember, Wnet = F Δx = mworld g Δx, and the mass of part of a uniformly-dense world would be proportional to the volume we lift).
We're already using a LOT of energy in our folding, so let's assume the mass-to-energy-converter in our portal gun can't quite lift enough of the world to make a significant difference in air pressure. Portals on the moon are right out.
I'm very impressed by the evolution of this blog, Daniel. The illustrations you offer are very useful. Thanks for this follow-up post.
ReplyDelete