Is information physical?
Yes, information is physical, with a measurable price in heat and a measurable size in area. Erasing one bit pushes a minimum amount of heat out of the device, 2.87×10⁻²¹ joules at room temperature, and a 2012 experiment with a trapped silica bead measured that floor. Storage has a size too. The most a region can hold is set by the area of its boundary, at one natural unit of memory per four Planck squares, squares 1.6×10⁻³⁵ meters on a side, so the area of a black hole's horizon is its memory quoted in square meters. Underneath both, the objective world is whatever the shared records jointly pin down, with no further fact hiding behind them.
Also in Chapter 24: Why Does a Region's Memory Scale With Its Surface?, Chapter 11: What Does Everybody Actually End Up Holding?.
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 23: Why Does Writing Something Down Cost Heat?watch a universe make its own particles