byllz t1_jbl7cy8 wrote

My thoughts. You are restricting Laplace's Demon without justification. You called the demon "the ultimate predictor." A reasonable interpretation of that would be that if something is necessarily true from known information, then the demon will know it. I think this would have been the correct understanding of the demon for the situation. Instead, you have gone with the interpretation that if something is algorithmically provable from known information, then the demon will know it. A given program will halt or it will not. One of those is necessarily true. It is not algorithmically provable. That doesn't, in any reasonable sense of the word mean the program is free.

Second I think you fail to show an infinite computational medium. Perhaps a person with an infinite lifespan in an infinite universe would have an infinite computational medium. And so a question like "will he ever take x action" might be undecidable. However, If you restrict the scope to a given timeframe. "will he kiss that girl he likes today", you are restricting your focus to a finite period of time, and a finite space (i.e. a sphere of space 1 light-day in radius). You lose your infinite computational medium, and suddenly you have a decidable problem.


byllz t1_jape02i wrote

And it makes sense. The operating system is a program. For it to run, like any program, it needs to be read from disk, placed into memory, and then executed. "What is the problem?" You may ask. "Computers run programs all the time." The problem is that the procedure to read the disk, load a program into memory, and execute it is part of the operating system. If the operating system isn't running yet, how is it going to get the operating system running? It seems as impossible as pulling yourself up by your bootstraps.


byllz t1_iv4g9lr wrote

The answer lies in time. In a given period of time, just from random fluctuations there is a chance the number of surviving lines will decrease, based on how many lines are left and the population. So, given enough time, assuming the population doesn't grow, the chance the number of lines will decrease eventually approaches 100% just like theoretically you can flip a coin as many times as you want and always get head, the chance you will eventually get tails approaches 100%


byllz t1_iv4038c wrote

It isn't just the growth, it is the sheer population. Suppose you had an ancient generation that was down to 2 women with matrilinear descendants. One line accounts for 99.9999% of the current population, and the other the rest. If your world population is 1,000,000, then the likelihood you will have a new Eve pretty soon is high, as there is currently only 1 woman left of the minority line, and the chance of any given woman not having daughters, or her daughters not having daughters is pretty high. But if the world population is 8,000,000,000 then the chance of a new Eve is low any time soon as you would need 8000 such occurrences.


byllz t1_iv3r0vs wrote

It is just a natural effect of lots of time combined with a population that doesn't grow quickly (as human population didn't for the majority of its existence). Take all the women living at a specific time in history and track each of their lines. Over time, just by random chance, one line will grow in members, which means another line will shrink. Every so often this random growing and shrinking will mean a line will shrink to nothing. However, once it is gone, it is gone forever, and so will never grow again. One by one they are snuffed out, until only one remains. And then Mitochondrial Eve moves forward in time. Since populations started growing considerably, lines have been dying out less.


byllz t1_iv3h1xm wrote

Humans and Neandertals coexisted and interbred about 50,000 years ago. Mitochondrial Eve is thought to date back about 150,000 years ago. Of course, it is possible that there are as of yet undiscovered branches in the mitochondrial family, and Mitochondrial Eve dates back quite a bit further. Before the dude from South Carolina took his DNA test, Y chromosomal Adam was thought to date back about 150,000 years, but finding him pushes Adam back perhaps 250,000 years. And if some Neandertal mitochondrial lineages are found in humans, that could push Mitochondrial Eve back to more than 500,000 years or so, to before humans and Neandertals split.


byllz t1_iv2pscv wrote

Also possible, there is some neandertal mitochondrial DNA in some family that hasn't been tested yet. Some dude in South Carolina about a decade ago got a genetic test and learned that his Y chromosome diverged from everyone else ever tested like 250,000 years ago. Turns out this one patrilineal family survived with few members in Cameroon. It is perfectly possible some ancient undiscovered matrilineal line with Neandertal mitochondria is alive and well in some remote corner of the world.


byllz t1_iv1rntu wrote

Mitochondria lines also die off just because of random chance. There was a woman who lived a couple hundred thousand years ago. Every woman alive is a direct female line descendent of hers. There were likely thousands of other women alive at the time, but every one of their female lines eventually died out, but hers survived. Why? No particular reason. Just random chance.