Namaste all.
It is interesting to note that the author of such Upanishad tells the following verses with great convinction.
By http://www.advaita.it/library/tejobindu.htm
76-98. When the blueness of the sky really exists in it, then the universe really is. When the silver in mother-of pearl can be used in making an ornament, when a man is bitten by (the conception of) a snake in a rope, when the flaming fire is quenched by means of a golden arrow, when milky food is obtained in the (barren) forest of Vindhya (mountains), when cooking can take place by means of the fuel of (wet) plantain trees, when a female (baby) just born begins to cook, when curds resume the state of milk, or when the milk (milked) goes back through the teats of a cow, then will the universe really be. When the dust of the earth shall be produced in the ocean, when the maddened elephant is tied by means of the hair of a tortoise, when (mountain) Meru is shaken by the thread in the stalk of a lotus, when the ocean is bound by its rows of tides, when the fire flames downwards, when flame shall become (really) cold, when the lotus shall grow out of flaming fire, when Indranila (sapphire) arises in the great mountains, when Meru comes and sits in the lotus-eye, when a mountain can become the offspring of a black bee, when Meru shall shake, when a lion is killed by goat, when the three worlds can be found in the space of the hollow of an atom, when the fire which burns a straw shall last for a long time, when the objects seen in a dream shall come in the waking state, when the current of a river shall stand still (of itself), when the delivery of a barren woman shall be fruitful, when the crow shall walk like a swan, when the mule shall fight with a lion, when a great ass shall walk like an elephant, when the full moon shall become a sun, when Rahu (one of the nodes) shall abandon the sun and the moon, when a good crop shall arise out of the waste (burnt) seeds, when the poor shall enjoy the happiness of the rich, when the lions shall be conquered by the bravery of dogs, when the heart of Jnanis is known by fools, when the ocean is drunk by the dogs without any remainder, when the pure Akasa shall fall upon men, when heaven shall fall on the earth, when the flower in the sky shall emit fragrance, when a forest appearing in pure Akasa shall move and when reflection shall arise in a glass simply (without mercury or anything else in its back), then the world really is.
Regards,
Orlando.