A list I made a few years ago:
This morning I harnessed the power of lightning to make breakfast, made some synthetic milk for my baby daughter, watched some moving pictures that were sent over the ether, and then piloted my metal horseless carriage to work. I had some productive discussions about how to improve the ways in which we send people to space and back. (Although making predictions by using machines to solve trillions of nonlinear equations is very cheap, the results need to be more reliable.) Once I finish sending my musings to you folks via this world-girdling network of glass and copper wires, I plan to drive home at a hundred kilometers per hour over a few concrete ribbons (often suspended dozens of feet off the ground), instantly reheat some food with microwave radiation, and maybe enjoy a glass of grape juice that's been partially consumed and replaced by yeast excretions.
Some of these ideas are better or worse than others, they're all relatively normal today, and some of them have been pretty normal for decades or even millennia. But could you imagine what a crackpot you would sound like explaining each concept for the first time to someone unfamiliar with it?
When attempting to introduce non-rationalists to the ideas of cryonics or Strong AI, it appears that their primary objections tend to be rooted in the absurdity heuristic. They don't believe they inhabit a universe where such weird technologies could actually work. To deal with this, I thought it would be useful to have a cache of examples of technologies that have actually been implemented that did, or ideally, still do, challenge our intuitions about the way the universe works.
The first example that comes to my mind is computers in general; imagine what Ernest Rutherford, let alone Benjamin Franklin, would have thought of a machine that uses electricity to calculate, and do those calculations so fast that they can express nearly anything as calculations. Nothing we know about how the universe works says it shouldn't be possible, indeed it obviously is knowing what we do now, but imagine how weird this would have seemed back when we were just coming to grips with how electricity actually worked.
I suspect there may be better examples to challenge the intuitions of people who've grown up in an age where computers are commonplace though. So does anyone have any to volunteer?