What is quantum entanglement?
Entanglement is definiteness that lives in the relation between two systems and in neither one alone. A playing card shows the idea. “The seven of hearts” splits into a fact about the suit and a fact about the rank. “The red seven or the black eight” fixes how color and rank go together while leaving both unsettled, and learning one hands you the other. Most joint descriptions are of that second kind. Cut an entangled pair in two and each half on its own comes back vague, and that vagueness measures how much the cut severed. Quantum pairs go one step further. There is no hidden face underneath the relation for it to describe, which is why entangled pairs agree more often than any pre-arranged answer sheet allows. The relation is the object.
Also in Chapter 24: Why Does a Region's Memory Scale With Its Surface?.
This answer comes from OPH, Observer Patch Holography. OPH is a rigorous, consistent and complete description of the unified, self-creating computational Universe we inhabit. Its consistency is machine-checked: the fixed point at its core is constructed explicitly, and a theory with a model contains no contradiction.
To understand OPH and check every step yourself, start with the free book Reverse Engineering Reality. It builds the theory from the ground up, and the OPH Notebook answers your questions while you read.
read the free bookask the notebookor ask sage:read chapter 20: Why Does Nature Cheat, But Only By Exactly 2√2?watch a universe make its own particles