APRIL 23 TO 28

The same shape as the transplant question and somehow heavier, because a ventilator decision happens in hours rather than months.

Oxygen in, carbon dioxide out, both moving by diffusion down their own gradients across a membrane about half a micrometer thick, two flattened cells and their shared basement membrane.

Measuring our own lung volumes. Tidal volume across three trials, then vital capacity.

A claim about respiratory capacity using my own numbers, compared to predicted values for height and age.

Sunday packet. The CER from Thursday needed a second pass. I had written the claim and called it done.