SB 4.18.19
prakalpya vatsam kapilam
siddhah sankalpanamayim
siddhim nabhasi vidyam ca
ye ca vidyadharadayah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
After this, the inhabitants of Siddhaloka, as well as the inhabitants of Vidyadhara-loka, transformed the great sage Kapila into a calf, and making the whole sky into a pot, they milked out specific yogic mystic powers, beginning with anima. Indeed, the inhabitants of Vidyadhara-loka acquired the art of flying in the sky.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The inhabitants of both Siddhaloka and Vidyadhara-loka are naturally endowed with mystic yogic powers by which they not only can fly in outer space without a vehicle but can also fly from one planet to another simply by exerting their will. Just as fish can swim within water, the residents of Vidyadhara-loka can swim in the ocean of air. As far as the inhabitants of Siddhaloka are concerned, they are endowed with all mystic powers. The yogis in this planet practice the eightfold yogic mysticism — namely yama, niyama, asana, pranayama, pratyahara, dharana, dhyana and samadhi. By regularly practicing the yogic processes one after another, the yogis attain various perfections; they can become smaller than the smallest, heavier than the heaviest, etc. They can even manufacture a planet, get whatever they like and control whatever man they want. All the residents of Siddhaloka are naturally endowed with these mystic yogic powers. It is certainly a very wonderful thing if we see a person on this planet flying in the sky without a vehicle, but in Vidyadhara-loka such flying is as commonplace as a bird’s flying in the sky. Similarly, in Siddhaloka all the inhabitants are great yogis, perfect in mystic powers.
The name of Kapila Muni is significant in this verse because He was the expounder of the Sankhya philosophical system, and His father, Kardama Muni, was a great yogi and mystic. Indeed, Kardama Muni prepared a great airplane, which was as large as a small town and had various gardens, palatial buildings, servants and maidservants. With all this paraphernalia, Kapiladeva’s mother, Devahuti, and His father, Kardama Muni, traveled all over the universes and visited different planets.