How did you calculate that? The question didn’t even mention a specific speed, just “near the speed of light”.

The kinetic energy for a grain of sand near the speed of light is somewhere between “quite a lot” and “literally infinity” (which is, in a sense, the reason you can’t actually reach light speed without a way to supply infinite energy).

That’s going to be a problem whatever solution you come up with, because of the federated nature of the lemmy system.

There’s no central authority to hand out usernames, so if two people sign up to different instances with the same username, any design which didn’t attach instance name to each username would fail. The only way around it would be for each instance to contact every other instance which exists, including the ones which haven’t federated yet, and negotiate ownership of the new username, and that’s just not possible

It depends on what exactly gets cut or punctured, of course, but my understanding is that without proper surgical intervention it can be an exceptionally slow and painful way to die.

The organs in the gut are mostly intestines. You’re not going to die just because they’ve spilled out, but you’re going to be bleeding pretty badly and if whatever caused them to spill out is still around then you’re pretty screwed.

The bigger problem is that it’s unlikely they’ve just spilled out, they’re probably also sliced open. Now you’re in serious trouble, because there’s lots of blood in there so now you’re bleeding really badly. You’ve also got blood and the content of your digestives system mixing together, and that means some very nasty bacteria which are normally safely contained now have access to your blood.

I suspect the most likely dangerous situation is a stab wound. In that case you’ll probably experience internal bleeding. There are no shortage of places for blood to go inside your body around there, including into your digestive system. I don’t think there’s anything much to stop blood from flowing endlessly into there, and you could bleed to death even if the external wound doesn’t look like it’s bleeding all that badly.

In summary, getting stabbed in the gut will contaminate your blood and lead to potentially endless bleeding which can’t be treated with bandages because it’s inside. Even if you avoid bleeding to death, you’re probably going to die from a massive infection

Not exactly. There are some species which haven’t changed all that much for millions of years, and those have certainly managed excellent adaptability.

Others, though, might find themselves evolving to cope with the climate right now at the expense of being vulnerable to some future problem. Say the climate is very hot, but in a few tens of thousands of years there’ll be an ice age. An animal which is well adapted to the ice age will probably go extinct before it arrives, having all been eaten by an animal well adjusted to the heat which is here right now.

“In the end” isn’t useful if you get outcompeted in the meantime