... now I know that physics is about uncovering the reality behind appearances. It's about glimpsing this deep and hidden architecture of existence i… - Amanda Gefter

Putnam's insight was that quantum theory requires us to conceive of a world in which cognition is an active, participatory process — one that’s not mediated by internal representations. And so that’s what Putnam set out to do. He wanted to create a model of the brain and a philosophy of mind that replaced the old word “observer” with the new word “participator”.

… The whole expanding universe was described by the equations of general relativity, Einstein's theory of space and time and gravity, but the singularity was the one place where the equations couldn't go. If general relativity provides a map of the universe, the singularity is the uncharted spot that the cartographers aren't sure how to draw. .
Quantum dragons, most likely. The singularity suggested that general relativity would eventually give way to a more fundamental theory, but physicists already knew that Einstein's theory wasn't compatible with quantum mechanics, the theory that describes the behavior of matter at extremely small scales. In their day-to-day lives physicists could ignore the problem by keeping the two theories separate, using general relativity to describe how big things such as planets and galaxies distort spacetime and using quantum mechanics to describe the strange dice game subatomic particles play. But at the end of the day, the separation can't hold up.

Studies of the quantum properties of black holes by Stephen Hawking and Jacob Bekenstein in the 1970s led to the development of the , which makes the maximum amount of that can fit into any volume of space-time proportional to roughly one quarter the area of its . The largest number of informational s a universe of our size can hold is about 10¹²².