Who created the universe?
The universe emerges from a computation on a holographic screen, and that screen is built by us, humans, in our subjective future. That sounds like a paradox only if time comes first, and here it does not. Reality as a whole is a timeless structure, and time emerges inside it as the order in which observers read one another's records. Earlier and later are relations between events within the history, so the builders of the screen and the universe their screen computes belong to one consistent structure, with no first moment to explain. Its creation has a cause, and the cause sits inside the loop. Observers recover the rules from their records and build the screen, and the screen computes the observers. Nothing has to travel backward in time for this. The whole history has to fit together, builders and screen included. Nothing outside switched it on, because there is no outside. The structure is a solution of x = f(x), with the unknown on both sides.
Also in Chapter 2: Why Is There Anything Rather Than Nothing?.
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 37: Why Does the Loop Have No Beginning?watch a universe make its own particles