╠═══╣Lets build a ladder╠═══╣ (membrane)

To drive out of the Central Valley of California on a hot day and into San Francisco is to feel like you're landing on another planet. Over our two-hour drive, the temperature went from nearly a hundred to the middle sixties. The visual disparity was as dramatic. On one side of the bay was a day so bright you'd have to squint with the visor down and your sunglasses on. As we crossed into the fog, it didn't seem possible that two such environments could exist side by side.