Hṛdayānanda: ...the movement who previously had been expert in mathematics, how could he use that for Kṛṣṇa's service if he's expert in mathematics?
Prabhupāda: Mathematics? So you can calculate, "After so many years the whole universe will be destroyed." (laughter) Not of the universe but everyone's life. This body will be destroyed. Bhūtvā bhūtvā pralīyate (BG 8.19). And again you get another body. It will stay for so many years. Again you annihilate. Again you get. In this way eternal time is being wasted.
Hṛdayānanda: In the modern world the engineers are designing everything. So how can an engineer use his talent for Kṛṣṇa?
Prabhupāda: Design a temple, nice temple. There are wonderful temples, very expert engineering. And they were ordinary men but the engineer was so nice that nobody can manufacture such temple in the whole world, still.
Hṛdayānanda: Prabhupāda, that was really wonderful, what you explained, that previously the people would build a very wonderful temple, and the ordinary people would just live in a very common, simple house.
Prabhupāda: Not for themselves. They knew the art how to manufacture nice building, but they did not care for personal use. It was used for Kṛṣṇa. Sometimes only the kings, in order to keep their position, they used to have gorgeous building. Otherwise ordinary men, cottage. (break) To live in cottage means to save time.