George S
Veteran Member
Asimov built his robots with positronic brains. The word positron was first used in 1933 (before that it was the antielectron theorized in 1928 and discovered in 1932); he was writing in 1939. Was he, perhaps, the first to use the word positronic? If only he'd thought of imaging instead of robots he'd have arrived at PET scans. Positron Emission Tomography.
I first encountered tomography back the tomographs were done on the x-ray table. It was a way to take three to ten sheets of x-ray film and expose them simultaneously with each sheet imaging a different vertical depth. Lots of radiation and only a few slices. Next was computer-assisted tomography (CAT). Then PET ... tomography of metabolic activity.
The 3D images are built in the computer and 2D projections onto a screen are made that can be rotated about.
Could it be made more real by printing on a 3D printer? The closer the slices the finer the 3D printer prints.
It builds from a beginning when there is simply no image ... and then a single point somewhere is the first to be printed (perhaps simultaneous with [or nearly so]) ... and as that first slice hardens the print-head moves up to the next slice ... now at the printhead liquid plastic is beginning to change state and solidify ... any given drop will solidify in time.
Perhaps the device that produces the PET image might be said to have a positronic brain in part.
I first encountered tomography back the tomographs were done on the x-ray table. It was a way to take three to ten sheets of x-ray film and expose them simultaneously with each sheet imaging a different vertical depth. Lots of radiation and only a few slices. Next was computer-assisted tomography (CAT). Then PET ... tomography of metabolic activity.
The 3D images are built in the computer and 2D projections onto a screen are made that can be rotated about.
Could it be made more real by printing on a 3D printer? The closer the slices the finer the 3D printer prints.
It builds from a beginning when there is simply no image ... and then a single point somewhere is the first to be printed (perhaps simultaneous with [or nearly so]) ... and as that first slice hardens the print-head moves up to the next slice ... now at the printhead liquid plastic is beginning to change state and solidify ... any given drop will solidify in time.
Perhaps the device that produces the PET image might be said to have a positronic brain in part.