Science Thread (now with 100% less religion)

I don't think it was because something like " the natural processes of earth are not capable of producing pockets of silver that are indistinguishable from silver dollars" is just not true. What is true is that if you find a buried solver dollar it is man made as sure as a cup of room temperature water won't turn into hotter water with a cube of ice. If you want to say it's impossible for rain and wind to create Mt Rushmore or natural selection to create people, the burden is now on you to explain this new law of nature. And in neither case is there one.

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from time 0 you can have evolution without randomness , but in that case it would stop and stagnate very quickly unless the environment is constantly changing a lot which it usually doesn't.

you start with your mixed gene pool and pretty quickly reach a plateau with no change and very uniform genetic distribution. then the environment has a sudden change and exctinction is almost a certainty.

you actually need randomness in the long term to justify survival because without genetic drift and mutations the genetic pool gets impoverished so much any abrupt change in environment spells disaster.

that's why you keep finding significant genetic variation even in fairly stable environments for most species, it's a feature not a bug. the randomness is what keeps the genetic pool varied enough to survive shocks in the environment.

that's like saying that DNA propagation that does not submit itself to significant random element is unfit for the long term, sort of "being exposed to randomness in evolution is actually beneficial to life survival", if not inherently *necessary*.

we are the sons and daughters of Eris

I didn't say impossible, I just said that given only the conditions on this Earth we know the probabilities are orders of magnitude apart (to be clear I'm saying lagtight's initial analogy was awful and Mt Rushmore is not comparable to abiogenesis). Making estimates of the probability of Mt Rushmore being created naturally from the known conditions on Earth is a far more relatable (and more than sufficient) way to show how vastly it differs from the probability of self-replicating molecules being created naturally without having to delve into the theoretical realms that are required to make the argument from PRT.

Incidentally I'm not even completely convinced that that your argument from PRT is a justified one. Even if we assume PRT can be applied to the universe, PRT doesn't actually require that every possible state within a closed system must occur, just that the subset of all states that occur occur again. Applying it to a system as complex as the entire universe likely does end up having that implication but I don't think PRT guarantees it.

Like I said, I was asking whether PRT would imply the reoccurrence of the Golden Gate Bridge on Earth assuming no significant change in the conditions on the planet other than the permanent elimination of human-level, or near human-level, intelligence.

I would not have assumed the answer was yes, but as I said, I am far out of my depth when it comes to theoretical physics.

Would it also imply the reoccurrence of a brass astrolabe, even though brass is an alloy that does not occur naturally on Earth (under current Earth conditions)? I guess so.

apart from anything else it would rule out the heat death of the universe

That's exactly what I did! I only brought up PRT when someone was skeptical that a meaningful non zero probability could be assigned to a natural Mt Rushmore. PRT I'm not really "using" the PRT at all. It just contains the math of searching through a phase space randomly and allowed me to talk about the cup of ice water, which is a more straightforward never observed phenomenon that must be possible and is a consequence of PRT.

Is a cup of iced water described by an ordinary differential equation?

I mean, your cup of iced water is doing the math for you under Newton's Law of cooling. Or the ice just can't help itself from heating up when attraction gets a little too close.

If the universe is cyclical or we're in a multiverse, a buried silver dollar will eventually appear somewhere, sometime. Every possible configuration of atoms, no matter how complex or improbable would happen infinitely many times.

I guess it depends what you mean by "meaningful". I don't think it's very controversial to suggest that the probability of PRT not applying to the universe is many orders of magnitude greater than the probability it would ascribe to a natural Mt Rushmore occurring so I'm not convinced that the probability you get from applying it is really any more meaningful than saying it is essentially a probability of zero. The cup of ice water is certainly a much simpler analogy and a good hypothetical for understanding the implications of, and the numbers/probabilities implied by, PRT but I'm hesitant about extending that to saying it's something that "must be possible" because in the real world it's not a closed system, which would be necessary for asserting that from PRT.

We're fast approaching the point in the discussion where someone will bring up de Sitter space.

Actual infinite is much larger than the already pretty large universe.

You need more universes than there are atoms in this universe to even come close to the silver dollar appearing. Still inevitably if you have actual *infinite* recursion of all universes yes.

Try to configure a realistic a priori probability of the silver dollar "just happening" because the number of zeroes there is pretty high under any reasonable assumptions.

ok but my point is more about the fact that you need to get head for the whole history of the universe in a row to get to the probability of the silver coin appearing randomly.

The only thing that the closed system assumption does is turn a strong argument into a theorem. It’s not really necessary imo.

That won't even get us close because all those random coin flips are an insignificant blip of all the random atomic events that can occur in the lifetime of the universe. The problem is the number of possible random events throughout the universe's entire history is smaller than the denominator needed to predict one random coin.

[QUOTE=ChatGPT]✅ Final Summary:
You'd expect to need about a billion universes like ours before randomly getting one with a Hercules–Corona Borealis-scale structure, under standard ΛCDM assumptions.

Would you like a diagram or analogy comparing cosmic structure rarity to something more intuitive (like lottery odds or monkeys typing Shakespeare)?[/QUOTE]

Not silver coin numbers but does it really matter?

And to clarify why the issue it's not really PRT.... It's do you accept the standard view of thermodynamics that it's origin derives from statistical mechanics and a cup of room temp water can later go to a stated that is hotter water plus a piece of ice spontaneously. If you want to say the chances that that interpretation being wrong is more likely than Mt Rushmore, that's fine and I would not have a great argument other than this is what the best scientific ideas that we've tested say when pushed to these extreme scenarios.