Energy storage. We could already produce all the power we need and more using solar power, the problem is that we can’t store it in an efficient energy dense form. The word efficient there is doing some heavy lifting. It needs be comparable or better than our methods today in terms of cost, safety, energy density, climate impact. If we could solve energy storage, it’d change society and technology dramatically.
I think an additional effect is that, the drop in pressure causes any liquids exposed to it to vaporise, which is an exothermic process, and it’s a race to see whether it boils off entirely or the inner part freezes to solid from the drop in temperature through conduction. So the immediate surface of your body would either dry out or flash freeze but the inner part take a while to solidify.
Why there is any ice in space and it doesn’t just sublimate away over time I’m not sure.
I can pop my ears whenever I want, like someone else mentioned. Handy on flights, but I haven’t been able to teach my kids how. If I forget to blink for a bit and then blink involuntarily when my eyes itch, my jaw snaps shut also involuntarily, causing my teeth to snap together. I can roll my tongue, which is apparently a genetic thing. I can hear high frequency sounds, like bats, and rodent repellents. It can be painfully loud when noone else around me can hear them, so they have a degree of disbelief if I mention it.
This was 30 years ago. I was from Australia. The night is still a clear memory to me. I had a choice and thought, well if I’m going to get drunk for the first time in my life, why not do it in a country where alcohol is illegal? At least I’ll have a story to tell.
My father worked in Saudi Arabia, and I was visiting on school holidays. They had brewed wine and gin on site and I had enough to get drunk for the first time in my life at 17. I had to talk to my father and pretend I wasn’t drunk. Apparently it worked as he has never mentioned it. I climbed up a water tower, and we got spotted doing that, and not realising my brother was snogging the girl I fancied while we did it. Then a girl I’d barely spoken to cornered me and wanted to know who I fancied, I asked what that meant and she said who would I kiss. I said I’d never kissed anyone, and she kissed me, then left without another word. I left the country the next day.
Facebook started out as invite only for a few years so they might have been looking to emulate its early trajectory. Gmail also started that way.