It is a strangely worded sentence for sure, but it's probably referring to previous sensitivity analysis done on the original Alcubierre negative mass-energy re

It is a strangely worded sentence for sure, but it's probably referring to previous sensitivity analysis done on the original Alcubierre negative mass-energy requirements: https://en.wikipedia.org/wiki/Alcubierre_drive#Difficulties https://en.wikipedia.org/wiki/Alcubierre_drive#Difficulties 60 orders of magnitude is about the difference of the mass of the observable universe to 'a few milligrams'.