5 ms·
How can one have a few grams of deuterium in their body from the time of Big Bang? And how does it make its way in one's body?
by dragosmocrii 6y ago
How can one have a few grams of deuterium in their body from the time of Big Bang? And how does it make its way in one's body?
- ISL 6y agoThe protons that make up more than half of your mass are also mostly from the big bang. Some of the hydrogen in the world around us is deuterium, again mostly from the big bang. When your body was assembled, and when you drink water/breathe, some of the generally-hydrogen sites in our bodies happen, instead, to be deuterated.
- warent 6y agoAren't 100% of the protons that make up your body from the big bang?
- miemo23 6y agowell neutrons decay in about 10min (avg) into fresh new protons (plus an electron) so perhaps not
- saagarjha 6y ago*free neutrons
- DrAwdeOccarim 6y agoWow, I didn't know that. Do you have a reference?
- magicalhippo 6y agohttps://en.wikipedia.org/wiki/Free_neutron_decay https://en.wikipedia.org/wiki/Free_neutron_decay https://phys.org/news/2020-09-mystery-neutron-lifetime.html https://phys.org/news/2020-09-mystery-neutron-lifetime.html
- DrAwdeOccarim 6y agoTIL. Thanks so much for sharing, this is wild...Reminds me of pair-production. Nuclear physics is so fascinating.
- sandfly 6y agoIs the free electron immediately captured by the H+ particle, or is the energy high enough that this can produce an acidic gas of H+?
- corty 6y agoConservation of momentum dictates that proton and electron will move away from each other. The decay energy might be absorbed by a nearby nucleus in an medium to a large part, leaving only a small momentum for both particles so they can form an atom, but usually it won't. In the average low-density case, the proton and electron will find other partners only after quite some cooldown. In very rare cases most of the energy might also be carried away by the neutrino that is produced as well, so decay to hydrogen is not impossible in a vacuum.
- ISL 6y agoThe energy release in neutron beta-decay is ~780 keV. This should be compared with the hydrogen binding energy of ~13 eV. Hence, there is far too much energy released for the electron to stay bound in essentially any case. If the neutrino carries away all the energy (with momentum conservation soaked up mostly by the recoiling proton), it could re-bind, but that process should be exceedingly rare. In that case, the result would see an (excited, probably) hydrogen atom recoiling away from the invisible neutrino.
- robocat 6y agoHalf-life ~10 minutes, which has a mean of ~15 minutes. Per https://en.wikipedia.org/wiki/Free_neutron_decay https://en.wikipedia.org/wiki/Free_neutron_decay
- p1mrx 6y agoThey're from the big bang indirectly, but they haven't all been protons the whole time. For example: https://en.wikipedia.org/wiki/Beta_decay https://en.wikipedia.org/wiki/Beta_decay
- delibes 6y agoJust being a bit pedantic ... more than half? Atoms typically have more neutrons than protons, and neutrons also weigh slightly more. Surely I'm >50% neutrons by mass?
- marcosdumay 6y agoHydrogen mostly does not have neutrons. You have a lot of those.
- CapriciousCptl 6y agoIt’s probably close to 50%. 80% of your mass is water and carbon. Hydrogen makes up 10% taken by itself but generally didn’t have a neutron which balances out the comparatives rare bigger elements with more neutrons.
- ISL 6y agoAgreed -- I should have gone with "roughly half" or "almost half". As I wrote last night, I incorrectly recalled that n/p is often below 1 -- if I had thought for a moment about high-Z nuclei, the error would have been obvious. A great place for a reader to begin to reach their own conclusions is here: https://en.wikipedia.org/wiki/Neutron%E2%80%93proton_ratio https://en.wikipedia.org/wiki/Neutron%E2%80%93proton_ratio Thank you for the correction.
- deleted 6y ago[deleted]
- manmal 6y agoThere‘s even a recent health fad that claims deuterium is bad for health, and those people also happen to sell deuterium-depleted water.
- simonh 6y agoI suppose that’s one way to lose a little weight.
- shawnz 6y agoIt does have health effects (in huge quantities). https://www.thoughtco.com/can-you-drink-heavy-water-607731 https://www.thoughtco.com/can-you-drink-heavy-water-607731
- vl 6y agoThink about it, it’s a great business: they process water, sell deuterium, and then also sell by-products! :)
- jen729w 6y ago> How can one have a few grams of deuterium in their body. > ... > And how does it make its way in one's body? Just like any other element – it’s around, in parts-per-million, and it finds its way in to your cells as a result. It’s just a non-harmful form of hydrogen. > from the time of Big Bang? Because that’s where the majority of the deuterium in existence was made. Crazy, but true. Unlike most of the heavier elements, it isn’t a by-product of stellar evolution. Extraordinary to think that the Universe is almost fourteen thousand million years old, and most of our deuterium was made in the first twenty seconds. After that, it cooled down and just wasn’t hot enough for fusion to do its work. Physics is mental.
- sethammons 6y agoReminds me of the idea that all the water you drink has already been drank and cycled through dinosaurs n times. https://www.techtimes.com/articles/56727/20150530/you-are-drinking-dinosaur-pee-everyday-heres-why.htm https://www.techtimes.com/articles/56727/20150530/you-are-dr...
- ars 6y agoThis isn't really totally accurate. A lot of the water in the world is process water, it's created when things combust. And much of the water consumed by plants is turned into carbohydrates which then gets processed back into water after combusting or being oxidized in a animal. I actually highly doubt that any water remains that has never been broken back into its constituent atoms and then combined with other atoms. I suspect the true answer is actually 0% of the water remaining today has ever been in a dinosaur. (I.e the atoms might have been, but not the molecule as a molecule.)
- vl 6y agoAll elements come from somewhere. With the minor exception of heavy element decay, there is no nuclei synthesis on Earth. So elements planet and we consist of were made before, some of them in stars and then spread out though supernovae explosions, and some of them in the Big Bang. Since we have so much heavy elements, our elements are not even from the first generation of stars. AFAIR it’s a third generation of supernovae explosions.