When I was a kid, my friend's dad was an engineer at Grumman, and he took us to see a test in their supersonic wind tunnel. The most prominent memory, is how unbelievably loud it was, and the next most prominent memory was that all the engineers were jealous of Lockheed, who had a much better wind tunnel that could run for much longer tests.
I happened to read Trollope's The Way We Live Now, which is a fantastic take on the railway mania, at the height of the dot com bubble. Really increased the enjoyment to read about it and see it unfold in real time.
Pretty sure even under DPA, taking without fair compensation would be a violation of the takings clause of 5th Amendment and wouldn't withstand legal scrutiny. If they wanted to get them clandestinely, yeah, they'd likely get away with it, but it is stealing.
It was required at my first job in 1989, for entry level actuaries.
In fairness, part of job performance was passing the actuarial exams, the first two of which were calculus and statistics. I imagine testing well on the SATs for a math or EE degree (what they hired) was a good indicator of passing tests.
My understanding was that your body was absorbing some amount of whatever electromagnetic stuff passes through you for the image. And the techs have told me it’s nothing to worry about.
My building is 15 stories, built in 1916. I’m on the 2nd floor. Every apartment can sign up for the monthly exterminator when he comes to do common areas. Are there roaches? You bet. Not a ton but you’ll see one or two a few times a month.
I’m a weirdo who vaguely enjoys my MRIs. I’m moderately claustrophobic, but they still don’t really bother me. And I love the warming feeling that makes me feel like I’m getting microwaved.