It is surprising to most until they get into the engineering.
Another example that comes to mind and not to be off color. That is not my intent.
Standard latex condoms are only 32% effective against the HIV virus. What exactly is only 32%? Beats me. I need explanation of that term.
What I read was that the HIV virus is small enough to pass through the porosity of the latex. How small is that? I don't know. Ask the engineer but still very concerning scientific fact.
The first I came into contact with this subject was with magnesium wheels. American was making them in the '60s uncoated. Just as cast and machined.
Racers were having issues with the tires the next day as they were going flat. No leaks could be found.
At some point it was found that it was the porosity of the magnesium itself would vary according to temperature.
Maybe some of you Aerospace engineers are aware of this from the beginning but I have to learn by the empirical method. So far it hasn't been fatal and I suppose as long as you hear the bullet go past, you live...for now?