There's a TV game show on now where they hook contestants to a lie detector machine and ask them personal questions.
Do lie detector machines actually work? Or do they work only on people who are innocent most of the time, but are no use on the kind of sociopaths who commit most crimes? Or are they basically just an intimidating prop that can assist somebody who is good at asking questions to break down somebody who is good at lying? (I suppose I could watch the show and see if that helps answer my question, but that would require me to break my rule of not watching more than three minutes of TV at a time.)
Similarly, have there been any advancements in polygraph technology in decades? I haven't heard of any. Kind of makes you wonder ...
In contrast, in the mid-1890s, my Swiss grandfather was a delivery boy for an optical glass company. One of his customers was physicist W.C. Roentgen, who was using the tubes my grandfather trundled in to invent the X-ray machine, for which he won the first Nobel prize. (Later, my grandfather, knowing a good thing when he saw it, became an international X-ray machine salesman.) The point of this digression is that scanning the inside of the body really works, so they keep inventing new scanners: x-rays, then CT scans, MRIs, and PET scans. What about polygraphs?