The quantum world says that everything is just wave function.
Chemistry says there is a periodic table and there are so many different types of molecules.
Molecular biology says there are different molecules and different substances. But quantum says all these molecules are reduced into atoms; electrons, protons, neutrons. And then further down that molecule is all just wave function. So in the wave function there are no two things. It is all just one thing and that is what is quantum.
This is exactly what was said by Adi Shankara. He said the whole universe is Brahman.
‘Sarvam khalvidam brahma neha nanasti kinchana’, the whole universe is just made up of one thing.
It is nothing else, only Brahman.