Put that chunk of uranium on a scale and you have a 700 milion year calendar
this post was submitted on 14 Sep 2025
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Thanks but i find an annual calendar already pretty overwhelming
GOD DAMNIT! Who touched my Uranium-235?? I left it RIGHT HERE where this lead is.
Hey where did my thorium 231 go?
hey where did my francium go
burps
Just eat the lead to make all the worries disappear
Somebody touch-a my U235
Whose responsible this?!?!
Who measures uranium in pounds? I feel like if you're not using metric you probably shouldn't be handling uranium.
Woahhh. That's heavy maaannn.
So I ran the numbers. U-235 decays into Pb-207, which means about 12% of its mass is radiated away in alpha decay. Which sounds like a fuckton.
Also, it'll mean that that chunk of lead will be a touch heavier, at 13.2 lbs
The Maths:
U-235 decays into Pb-207. To three significant digits, 207/235 = 0.881, equivalent to 88.1%, meaning 11.9% is radiated away.
88.1% of 15 lbs = 13.2 lbs.
And that's ignoring spontaneous fission which is probably happening to some extent to some of the isotopes
also, uranium's half life is 700 million years, so we expect (207/235)*7.5 (of lead) + 7.5 (uranium) ~ 14.106382978723405 lump.
also, a lot of the helium produced will remain trapped inside (most heavy metal lumps act as sponges for little gasses). but 700 mil years is also a large amount of time, so much of it would diffuse out. I could checkup diffusion statistics for he d pb-u but i would have to probably do a double integral (as pb-u combination is not fixed, and we can not simply do the error function calculation), so skipping that. but it is safe to say that we will have a lump of ~50% U, 44% pb, and 6% He (by mass), and a significant amount of he will remain in
So it would be more accurate to say that 13.2 lbs would be a minimum for the lump's mass.
u-235 has a half life of 704 million years. only half of it would have decayed.
1 hour here is 7 years on earth .jpg
No snoot, there'd be crabs!!
This meme is false.
So a chunk of lead today could have been pre-cambrian uranium?
A little older, with a ~700 million year half life and about ten half lives to be practically completely converted you're looking for 7 billion years ago
Reminds me of my ingot of invar. Every few years I try to think of something to do with it, but still haven't come up with anything.
What's invar?
https://en.m.wikipedia.org/wiki/Invar
In short, it is an alloy that experiences almost zero thermal expansion or contraction.
And I thought it was some deez nuts joke that I wasn't aware of
Awww greyhound snoot 😍