Upanishads and Vedanta philosophy?

I am far from being an expert at either of them but at the same time I have read things related to this question.
Waren Heisenberg had once famously said "After the conversations about Indian philosophy, some of the ideas of Quantum Physics that had seemed so crazy suddenly made much more sense".

Erwin Schrodinger once observed: This life of yours which you are living is not merely a piece of this entire existence,but in a certain sense the whole; only this whole is not so constituted that it can be surveyed in one single glance. This, as we know, is what the Brahmins express in that sacred, mystic formula which is yet really so simple and so clear: tat tvam asi, this is you. Or, again, in such words as “I am in the east and the west, I am above and below, I am this entire world.”
Bhawesh Kumar, Electrical Engineering Undergraduate at IIT Kanpur