The Supreme Personality of Godhead is one without a second. He is above everyone. No one is equal to Him, nor is anyone greater than Him. Therefore He is described here as viśva-guru. He is the prime living entity of the entire material and spiritual creation and is bhuvanaika-vandyam, the only worshipable personality in the three worlds. The airplanes in the spiritual sky are self-illuminated and are piloted by great devotees of the Lord. In other words, in the Vaikuṇṭha planets there is no scarcity of the things which are available in the material world; they are available, but they are more valuable because they are spiritual and therefore eternal and blissful. The sages felt an unprecedented happiness because Vaikuṇṭha was not predominated by an ordinary man. The Vaikuṇṭha planets are predominated by expansions of Kṛṣṇa, who are differently named as Madhusūdana, Mādhava, Nārāyaṇa, Pradyumna, etc. These transcendental planets are worshipable because the Personality of Godhead personally rules them. It is said here that the sages reached the transcendental spiritual sky by dint of their mystic power. That is the perfection of the yoga system. The breathing exercises and disciplines to keep health in proper order are not the ultimate goals of yoga perfection. The yoga system as generally understood is aṣṭāṅga-yoga, or siddhi, eightfold perfection in yoga. By dint of perfection in yoga one can become lighter than the lightest and heavier than the heaviest; one can go wherever he likes and can achieve opulences as he likes. There are eight such perfections. The ṛṣis, the four Kumāras, reached Vaikuṇṭha by becoming lighter than the lightest and thus passing over the space of the material world. Modern mechanical space vehicles are unsuccessful because they cannot go to the highest region of this material creation, and they certainly cannot enter the spiritual sky. But by perfection of the yoga system one not only can travel through material space, but can surpass material space and enter the spiritual sky. We learn this fact also from an incident concerning Durvāsā Muni and Mahārāja Ambarīṣa. It is understood that in one year Durvāsā Muni traveled everywhere and went into the spiritual sky to meet the Supreme Personality of Godhead, Nārāyaṇa. By present standards, scientists calculate that if one could travel at the speed of light, it would take forty thousand years to reach the highest planet of this material world. But the yoga system can carry one without limitation or difficulty. The word yoga-māyā is used in this verse. Yoga-māyā-balena vikuṇṭham. The transcendental happiness exhibited in the spiritual world and all other spiritual manifestations there are made possible by the influence of yoga-māyā, the internal potency of the Supreme Personality of Godhead.