Sri Aurobindo translates Katha Upanishad First Cycle: Second Chapter, Verses 20-22: “Finer than the fine, huger than the huge the Self hides in the secret heart of the creature: when a man strips himself of will and is weaned from sorrow, then he beholds Him; purified from the mental elements he sees the greatness of the Self-being. Seated He journeys far off, lying down He goes everywhere. Who other than I is fit to know God, even Him who is rapture and the transcendence of rapture? Realising the Bodiless in bodies, the Established in things unsettled, the Great and Omnipresent Self, the wise and steadfast soul grieves no longer.”
Modern-day scientists have struggled with the application of Quantum theory, which govens sub-atomic particles, to real life events in the outer world. Some years ago, however, a breakthrough was reported. It seems that scientists could not determine how things could happen unless there was a “mechanism” for it to happen. That mechanism would have to involve the transmission, not just of energy but also of information. The development of the concept of the Quantum Hologram, and the experiments that supported these concepts, showed that information was delivered along with the packets of energy.
This opened the door to the next step beyond the conversion of matter and energy, as set forth by Einstein. This opened up the idea that the energy is conscious. Consciousness is One and universal, consciousness pervades all that exists in the universe, each physical form partakes of consciousness. There is a dual-track of information. The forms and forces we see with our senses of perception are the gross manifestation. There is a subtle communication of consciousness that pervades and is perceived, not by the outer senses, but by the inner being, “in the secret heart of the creature” as the Upanishad aptly explains it.
The scientists also determined that consciousness is not restricted to one particular being or form, but pervades everything. This implies that information moves without regard to limits of time or space, and that if an individual is “receptive” and has “tuned” to the wave of information, he can know things that are not obvious to the outer senses. The explanation provided by the Katha Upanishad in these verses fits what these scientists have now discovered through their attempt to understand quantum theory on a universal basis.
The practices of the Rishis and Sages were intended to hone in on the pervasive consciousness of existence, that also transcends all the forms and forces that manifest. Science is now catching up and recognizing there is a real truth to the Upanishadic descriptions.
Sri Aurobindo, The Upanishads, Katha Upanishad, pp. 213-241, and Kapali Sastry, Lights on the Upanishads, pp. 104-129