All these theories question the nature of space, time, and matter:

- Loop Quantum Gravity

https://en.wikipedia.org/wiki/Loop_quantum_gravity

- Causal Set Theory

https://en.wikipedia.org/wiki/Causal_sets

- AdS/CFT & Tensor Networks

https://qspace.fqxi.org/videos/121/a-tensor-network-approach...

- Relational Quantum Mechanics

The one discussed here

- “It from Qubit”

https://www.scientificamerican.com/article/tangled-up-in-spa...

- Thermodynamic Gravity

https://en.wikipedia.org/wiki/Entropic_gravity

- Noncommutative Geometry

https://en.wikipedia.org/wiki/Noncommutative_quantum_field_t...