Why does the traveling twin come home younger?
The twins follow different paths through spacetime and can accumulate different proper times between their meetings. The apparent contradiction comes from treating each twin's entire trip as one interchangeable inertial frame; the turnaround and the comparison of distant events must be included. OPH's task is to reconstruct compatible physical clock readings along those paths from one observer history. Event counts or logical dependency depth alone do not supply the measured aging. Where the construction realizes relativistic proper time, it should reproduce the familiar result, rather than replace it with a preferred global stopwatch. The twin paradox is a demand for consistent clock comparisons, not evidence that one observer's real experience must be an illusion.
See also Why do moving clocks run slow?, Why do all clocks agree?, Is there a universal "now"?
Also in Chapter 22: Why Do All the Clocks Agree?, Chapter 25: Why Does Gravity Look Like Geometry?.
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 17: Why Is There a Speed Limit?watch a universe make its own particles