Pops feels the need to prove himself to some internet kid ;-) Been thirty or so years since you left high school I bet.
Congratulations!
And yes, like I said, it would be compressed and liquified. It "must be kept at -423.166 F".... yeah, ok Pops, or it will just evaporate like liquid nitrogen or dry ice at room temperature. So you're telling me that right now there is NO WAY of containing liquified Hydrogen? You're telling me that if I have a proper license, that I could not obtain a tank of liquified Hydrogen?
"1% a day" - that's pennies. I'm sure I lose more gasoline to evaporation and an old gas cap on my 77 Chevy.
No my point was that even at -423.166F you still loose 1% a day. if you want to keep LH2 a liquid you have to maintain it at that temp. So if you want a LH2 powered car it will need a cryogenic system to maintain that temp. For me accidents worry me the most
"Some parts will just crack due embrittlement" - Yes, that's what happens when things get reallllllllllllly cold. That's why you need to use the proper materials. Sorry Pops, the plastic gas tank that you were imagining would not work on a liquified Hydrogen powered car.
No actually the process starts as soon as a susceptible metal comes in contact with concentrated H2
"Lets talk about H2 fires...." - Ok, #1 - you might be able to hear (maybe not you, gramps) the escaping gas. #2 - you would see a big chunk of 'ice' forming around the leak. #3 - if it caught a flame, you'd hear it, you'd be able to feel it, you'd see something else burning around it, and you'd smell whatever was burning, and there would be smoke coming off whatever else is burning.
No you wouldn't see Ice, because it would combust as soon as it mixed with air, expecially at such a concentrated level.
"So now you risk severely injuring yourself trying to put out the fire. The only way to see it is with a flame detector, or thermal imager." - Only a tardo would try something like that. But you're old-school like that ;-) Just take a shovel and throw some dirt on it gramps! I don't need to see the "invisible flame" to know that something is burning. I'd just be a hero and plug the leak with the tip of my finger
To stop that type of fire you have to secure the H2 source (cut the car off in this case) and let it burn its self out.