But whether or not they exist in reality, studying these hypothetical objects could be the key to making concrete the tantalizing link between information and matter that has bedeviled physicists for decades. Surprisingly, a quantum computer is an ideal platform to investigate this connection. The trick is to use a correspondence called AdS/CFT, which establishes an equivalence between a theory that describes gravity and spacetime (and wormholes) in a fictional world with a special geometry (AdS) to a quantum theory that does not contain gravity at all (CFT). In "Traversable wormhole dynamics on a quantum processor", published in Nature today, we report on a collaboration with researchers at Caltech, Harvard, MIT, and Fermilab to simulate the CFT on the Google Sycamore processor. By studying this quantum theory on the processor, we are able to leverage the AdS/CFT correspondence to probe the dynamics of a quantum system equivalent to a wormhole in a model of gravity.

The effective capacity of neural networks is large enough for a brute-force memorization of the entire data set.

The point here that surprises most Machine Learning practitioners is the'brute-force memorization'. See, ML has always been about curve fitting. In curve fitting you find a sparse set of parameters that describe your curve and you use that to fit the data. The generalization that comes into play relates to the ability to interpolate between points. The major disconnect here is that DL have exhibited impressive generalization, yet it cannot possibly work if we consider them as just memory stores.

The Holographic Principle is a theory (see: Thin Sheet of Reality) that explains how quantum mechanics and gravity interact to construct the reality that we are in. The motivations for this theory comes from the paradox that Hawking created when he theorized that black holes would emanate energy. The fundamental concept that had been violated by Hawking's theory was that information was destroyed. As a consequence of this paradox, through several decades of research and experimentation, physicists have brought forth a unified theory of the universe that is based on information theoretic principles. The entire universe is a projection of a hologram.