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Just because two planets have been around for the same amount of time in similar conditions doesn't mean they should both exhibit life. The emergence of self-re
by mark-t 18y ago
Just because two planets have been around for the same amount of time in similar conditions doesn't mean they should both exhibit life. The emergence of self-replicating molecules at any given time may be extraordinarily unlikely, such that the expected amount of time for it to happen is on the order of trillions of years. However, when you've got several planets in the same circumstances, one of them will likely succeed much sooner than the others.
Here's a more concrete example. Consider the odds of rolling a 528 on a 1000 sided die, and you have 5 people rolling such a die. The expected number of rolls for any individual to get a 528 is 1/1000 + 2 * 999/1000^2 + 3 * 999^2/1000^3 + ... = 1000. However, the probability that at least one person has rolled a 528 passes 50% after n rolls, where (999/1000)^(5n) = .5, or n = log(.5)/(5log(.999)) = 139.
In other words, you expect to have rolled a 528 after 1000 rolls on average, but you expect somebody to have rolled one after 139.
- LPTS 18y agoI don't see why we should consider the evolution of DNA to be unlikely. We have increadible statistical evidence it isn't. Chance you evolved in a universe you observe: 100% Chance you evolved in a universe you dont: 0% Given: I exist. Therefore, from clear first principles, I should judge as 100% the chance of DNA evolving. I dont get how any conscious being could even concieve that percentage as less then 100.
- jauco 18y agothat's not how chance works. The chance that a given child becomes a boy is about 50% even though I am a boy. As the article explains: rerunning everything in a near-identical situation does not mean the same events happen. So based on the fact that something has happened once doesn't let you say anything about the chance of it happening.
- LPTS 18y agoI typed this comment on iPhone while I was waiting in line and lost it to a dead link. So I retype it. No you misunderstand the level I am speaking to. I know I exist before I know anything else. A prerequisite for existence is DNA, because DNA underlies the process that underlies consciousness. I'm not saying rerunning everything in a near identical situation would cause it to happen the same way. I'm not saying anything at all like that. I'm saying, for anyone with consciousness (which requires DNA), immediately, from I exist, and existence requires DNA, we should judge there is a hundred percent chance there is evolving DNA. The math that suggests otherwise is true enough, but the argument that the math gives the actual odds is flawed. It's just a sort of meta question about how being conscious and it's implications should impact the value we assign to the mathematical truths. The mathematician should say "To my necessarily incomplete formal system, the chance is low, but because I have direct evidence I am conscious, and this consciousness requires DNA, I have other, prior evidence that the chance is extremely high." I'm not denying the math, I'm pointing out that it's not the whole story in addressing questions like how DNA evolved.