When I Woke Up, I Got the Strongest Equipment and a Spaceship, so I Went and Became a Mercenary in Order to Live as I Please while Aiming for a Detached House - Chapter 19.2

I mean. If this is truly a sci-fi world that wouldn’t even happen. For literally every species on Earth, regeneration takes a long time not because of genetic differences, but rather by practical constraints.

Remember Einstein’s E = mc^2? Yeah, every kilogram of flesh you spontanously create is actually equivalent to 9 * 10^16 Joules. For comparison, the US uses about 3 * 10^12 Joules each year. That means each kilogram of flesh regenerated is equivalent to the entire power usage of the United States for 30 thousand years. You cannot be pulling that energy out of nowhere within the span of 5 seconds.

And if you’re thinking, “that doesn’t make sense, I’m sure I’ve regenerated more than a kilogram throughout my lifetime, there’s no way I ever had that much energy” – you would be right. But that’s because you don’t regenerate that mass by creating mass out of energy, but rather by converting the food you eat, which is already in mass form. You are not pulling tens of thousands of years of energy expenditure to generate mass from energy, you are changing a burger’s mass into, say, a scab’s mass.

This doesn’t really destroy the reading experience or anything – it’s just a minor physics nitpick I felt like I had to point out.