The only person who has analyzed Brahman from the Upanishads directly in this thread so far is me
Why materialism is probably false: A Hindu argument
And as usual you are selectively citing. What about the Upanishads that say "Then Brahman will that he shall be many, then Brahman thought, Brahman is the Lord, Worship Brahman the creator etc
Verily in the beginning, All this was Atman, one only, there was nothing else blinking whatsorever. He thought "Shal I send forth worlds" He send forth these worlds
Aitareya Upanishad
He the knower of Self, knows the highest home of Brahman, in which all is contained and shines brightly. The wise one without desiring happiness, worship that person, transcend this seed and are not born again.
Mundaka Upanishad
He who knows the Brahman attains the highest Brahman. On this the following verse is recorded: He who knows Brahman, which is the cause and not the effect, which is conscious which is without end, as hidden in the depths of the heart, in highest ether, enjoys all blessings, at one with omniscient Brahman
He wished, may I be many, may I grow forth. He brooded over himself, like a man performing penance. After he had thus brooded, he created all, whatever there is
Taitttriya Upanishad
But what is praised in the Upanishads is the highest Brahman, and in it there is the triad. The highest Brahman is the safe support, it is imperishable. The Brahma-students, when they have known what is within this world, are devoted and merges into Brahman, free from birth. The Lord supports all this together, the perishable and the imperishable, the developed and the undeveloped. The living Self, not being a lord, is bound, because he has to enjoy the fruits of his works, but when he has known God, he is freed from all fetters.
This whole universe is filled by this person, to whom there is nothing superior, from whom there is nothing different, than whom there is nothing smaller or larger, who stands alone, fixed like a tree in the sky. That which is beyond this world is without form and without suffering. They, who know it, become immortal, but others suffer in pain. That Bhagvat exists in the faces, the heads and necks of all, he swells in the cave of the heart of all beings, he is all pervading, therefore he is the omnipresent Shiva. That person is the great lord; he is the mover of existence; he possesses the purest power of reaching everything, he is light, he is undecaying
He is the creator and supporter of the gods, Rudra, the great seer, the lord of all, who saw Hiryangarbh(primordial womb of the universe), may he endow us with good thoughts. He who is the sovereign of gods, he in whom all the worlds rest, he who rules over all two footed and four-footed beings, to that god let us sacrifice our oblation
He being one, rules over all and everything, so that the universal germ ripens its nature, diversifies all nature that can be ripened and determines all qualities.
Some wise men deluded, speak of nature, and others of time as the cause for everything; but it is the greatness of the God by which this Brahma-wheel is made to turn. It is at the command of him who always covers this world, the knower, the time of time, who assumes qualities and all knowledge, it as his command, that this work, creation unfolds itself, which is called earth, water, fire, air and ether. He who, after he has done that work, rested again.
He is the One God, hidden in all beings, all pervading, the Self within all beings, watching over all works, dwelling in all beings, the witness, the perceiver, the only one, free from all qualities
Shvetasvatara Upanishad
Summary of the words used to describe Brahman
"He thought"
"Worship that person"
"He created all"
"Conscious"
"Omnscient Lord"
"He is the One God"
"Rules over all beings"
"Omnipresent"
It will therefore become clear to the readers that "Brahman" which Sayak is passing off here as "ur-field" as the basis of all laws of physics, chemistry biology and consciousness etc, is none other than the Hindu concept of God. Not only is what Sayak presenting pseudoscience(dressing up Hindu god in fancy scientific words) it is pseudo-Hinduism too(misrepresenting the Hindu god as some abstract field)