Big
In a discussion of the (still totally theoretical) Alcubierre Warp Drive, the author notes that modern estimates of the energy needed to create a space-time bubble are down from the clearly infeasible “energy mass equivalent to the entire Universe.”
However, it goes on to note, the current estimate of the energy equivalent of “a Jupiter-mass amount of exotic matter is still prohibitively large.”
Don’t plan to book your ticket for Alpha Centauri any time soon.
