3.2 Summary

summary

In a classical computer chip, the state of each bit can be on or off; in a quantum “qubit,” there are an infinite number of superposition states, each of which are a different mix of the two classical states.
The differences between classical computing and quantum computing become more dramatic when there are more and more qubits.
Quantum entanglement is when the states of different qubits are correlated.
According to Maldacena’s theory, the geometry of 3-D space is encoded in a 2-D “quantum memory chip.”
In order to decipher what’s happening in the 3-D reality that we live in, we need to understand the patterns of entanglement in the 2-D “quantum memory chip.”
Based on the work of Ryu and Takayanagi, a smooth and connected “fabric of spacetime” emerges from the “threads” of quantum entanglement. It’s possible to derive Einstein’s equations from entanglement physics.
Empty space corresponds to the lowest-energy state of the “quantum memory chip.”
A “classical memory chip” with no superpositions and entanglement will not give rise to any spacetime at all.
Quantum gravity isn’t about fitting together quantum mechanics and gravity but about figuring out how gravity was present in quantum mechanics all along.