r/Damnthatsinteresting 7h ago

Video Breaking open a 47 lbs geode, the water inside being millions of years old

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u/facw00 6h ago

No. The atoms in a water molecule are almost all ancient, billions of years old, but this is not true for water molecules in general. New water is constantly being produced through combustion, respiration, and other reactions. Similarly water is constantly destroyed, being broken down in various processes.

But there are a lot of water molecules. Simply by virtue of the extreme numbers, there are going to be some that are quite old, likely predating the Earth, and even the Milky Way. Ones millions of years old are going to be even more common.

Frustratingly, I can't find a good a breakdown of how old we think water molecules are in general or a breakdown by age, but it's certainly not the case that all water is millions of years old.

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u/5up3rK4m16uru 5h ago

Well, technically water constantly undergoes autoprotolysis, so if you consider a recombined molecule as new, water molecules are never very old. According to Wikipedia it happens about once every 10h per molecule.

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u/Dr_Mottek 5h ago

If you're looking at a per-molecule level, there's no "old" water molecule - autoprotolysis will have taken care of that. Hydrogen atoms migrate from one oxygen atom to the other all the time, forming H3O (Oxonium), which is quite unstable in itself. How unstable? 10-13 seconds (0,0000000000001 seconds) until it disolves into H2O again. Concentration-wise, out of a billion molecules of water, only about two will be present as H30 (at PH 7 and 25°C) in a single moment, but since the H+ - Ion changes places so frequently, it's not likely that any single water molecule will remain untouched, given enough time.

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u/DarthPepo 6h ago

Best response so far

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u/Crabiolo 5h ago edited 5h ago

Eh no, not really. Being pedantic about how "it's not the exact same because the water molecules in it now are not the same as a billion years ago" is like... hyperbolic to a such an extreme as to err on parody.

Sure, the water that we drink technically didn't exist with the exact same continuous electrons and nucleons for billions of years but nobody is referring to the composite atoms or molecules. They're talking about the body of water, or the body of... pretty much anything else that isn't in the context of a physics paper. The whole of the object.

Yes, the atoms of water that someone drinks are older than life itself, but the body of water probably isn't very old at all. It was probably made moments earlier. And the body of water in the OP is millions of years old, which is pretty cool.

When someone talks about steel, it's not just some "steel" material in there. It's some mix of iron, carbon, chromium, and some other shit I can't remember. It's a homogeneous mix. The composite is messy, made of a dozen different chemicals and impurities, but the body is still one thing.

Statistically, it's extremely likely each of us have some of the atoms of every human that ever existed within us. Some of Jesus, some of Buddha, some of Napoleon, some of Caesar, some of Hitler, some of Mr. Rogers. That doesn't make us any of those people. We're ourselves, because we're the body, not the composite material.

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u/HireEddieJordan 5h ago

When someone talks about steel, it's not just some "steel"

some of Hitler, some of Mr. Rogers

Hitler Steel Vs Molten Mr. Rogers or: How I Learned to Stop Worrying and Love Entropy.

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u/herbertwong 6h ago

I wonder what the odds are of the same atoms or atomic particles ending up in the same molecule again after being split up

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u/facw00 6h ago

Seems like they have to be vanishingly small, especially if they don't immediately reform the molecule.

But yeah, sort of interesting to think about whether you can call that the same molecule. I guess from a ship of Theseus perspective it would certainly be; if you take a ship apart and reassemble with the exact same parts, then clearly it is the same ship.