Science means simply theoretical knowledge is not sufficient. Observation and experiment. Experimental knowledge. That is called vijñānam.
So by practical knowledge you should be well-acquainted with God. That is brāhmaṇa's business. So sattva-sthāḥ, those who are strictly following the brahminical principles, they will be situated in upper planetary system. Ūrdhvaṁ gacchanti sattva-sthāḥ (BG 14.18). But a Vaiṣṇava is above these. Mad-yājino 'pi yānti mām (BG 9.25). Those who are following these principles with an aim for higher planetary system, they can go, elevated. Similarly, those who are trying to go back to home, back to Kṛṣṇa, they can also go. It is not very... This process, our Kṛṣṇa consciousness movement, is to help people to go back to home, back to Kṛṣṇa. It is not very difficult. Why it is difficult? Kṛṣṇa says, janma karma me divyaṁ yo jānāti tattvataḥ (BG 4.9).