Does it work the same way for reptiles, though?

>sucked the blood either directly into the bloodstream of the vampire

That seems evolutionarily suspect: blood-to-blood pathogens from ("near-"?)conspecifics sound like a huge threat compared to any foodborne pathogens that have to go through the digestive system.

> Nevermind anything below that.

Well, it actually is possible to get below 0 K. It's pretty different to how one might imagine it, though - it's hotter than the hottest temperature, rather than colder than the coldest temperature for starters.

I'm pretty sure "relativity of simultaneity" describes what you're talking about.

>neon lights

> different gases

Well... Can't be that different if they're all just neon, can they?..)

Sorry for taking so long to reply - I first wanted to get the numbers right and then kinda forgot about this comment.

> Does that need any special purification effort?

Yes. Specifically something called "superleak" or "superfluid helium filter" is used. It's basically a filter with material so tightly compressed that only a superfluid can go between the particles. As helium-3 reaches superfluidity at a much lower temperature level than helium-4, the isotopes can be thusly separated.

>Helium-3 is already a tiny fraction of the helium we extract.

Yep, but the less of it, the better. The natural content is about 10^(-6), whereas by using a superleak you can get something around 10^(-11), which is much better.

And if you want ultracold neutrons, superfluid isotopically-pure Helium-4 is by far the best, with deuterium ice in second place.

The unit for free-fall acceleration (as well as all other accelerations) is m/(s)^2, by the way, not m/s. m/s would be a velocity.