You bring a rat. Put that rat in a small cage in a so called Lab. Then, inject a hormone that cause cataract in that rat. Then, study the correlation between the hormone injected and cataract. Yogis avoided such cruel investigation and they adopted a different technique. Knowledge can be gain directly through intuitive power without hurting any animals. Today's modern science is destructive. They have build bombs but have no defense mechanism system to protect the mass from it's devastating effects. At least yogis knew how to divert the projectile of Brahma Shastra if someone misuse it.

Anybody interested in Yogic Kheti. I have many scientific papers for you to read !!