So far as I know, we still do not have a perfectly accurate, flawless, infallible way of knowing that a person is irretrievably dead. (Within a reasonable time frame, of course.) Many years ago, we thought we did: heartbeat. Now, of course, we know that’s not true. Then we had brain waves. But since brain waves can be stopped completely and a person can come back to life, we know that is not perfect, either. So lately I’ve seen death described as a process, rather than a moment.
But I believe it is a “moment” for somebody else. When we die, we begin rotting from the inside out: the creatures that live in our digestive tracts beneficially while we are alive begin eating us when we die. So it occurs to me, when does that process begin? Has there ever been a case that we know of where someone “died”, was then revived, and it was somehow learned that their gut organisms had mistakenly begun eating them? It seems the time frames would be too short for that to reveal itself naturally, but it’s a question that seems easily answered in a lab.
What signals do those organisms receive that tell them we are truly dead, what rings the dinner bell, so to speak? Is it temperature, some chemical signal? Perhaps if we pursue that line of inquiry and we could learn precisely what that is, it would lead to us being able to determine “true” death with perfect accuracy?
You’re looking at two boundary events that just won’t align - the microbes in your gut won’t start work on your body (at least, any more than they are working on it right now) until quite some time after you are very properly dead
Okay, but that is what I’d like to know: how do we know when they know that it’s okay to start eating? How do you know that they don’t start eating until sometime after we are very properly dead? I’m not arguing with anything I’m just wondering what information we actually have.
I think the gut bacteria are always trying to eat whatever they possibly can, including you, but your intestines have a number of active and passive defense to prevent that. The intestinal walls are a physical barrier that is constantly being replaced. It excretes mucous which has some anti-microbial properties, as well as assisting the physical barrier. Then there are sentinel immune cells to catch any microbes that manage to get through the barrier. And to put it delicately, your intestines regularly expel their contents before bacteria grow to an unmanageable level. Any defects in those processes can lead to systemic infection.
When you die, the intestines lose oxygen and nutrients so they can’t maintain the defenses. Once the defenses crack your intestines are no different from a bit of sausage casing from last night’s dinner.
Before defining what death is, you have to define what “alive” is. Sounds like a stupid question, but pinning it down to anything beyond “I know it when I see it” is actually kinda tricky.
Yes, by which time you (that is, your more vital organs such as nervous and circulatory systems) are really very dead way beyond any glimmer of hope of revival.
Also, there are no doubt medical conditions where the gut microbes do manage to get started eating a living person (peritonitis or diverticulitis maybe?). In other words, this is a lousy metric for determining whether someone is alive or dead.