On this gross planet earth, there are airplanes run by machine, but on other planets the airplanes are run not by machine but by mantric hymns.
We are simply engaged in temporary castle building which will be relics sooner or later. So are we not wasting our time?
The Kalki avatara is the fierce incarnation who vanquishes the class of the atheists born in this Age of Kali.
Srimad Bhagavatam 6.8.19