### Author:  [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)
#### Post date: [December 12, 2016, 3:37pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/1 "2016-12-12T15:37:16Z")
We’ve something of a major family dispute about this and I’ve been chosen to decide the matter. Unfortunately neither side is willing to pay the bribe I’m asking for, so that just leaves the StraightDope to answer.
Is the rate of nuclear decay effected by temperature?
One side insists that the decay will occur at exactly the same rate whether at 3 K or at 10,000 K … the other side says the 10,000 K sample will decay faster … this has already come close to a fist-fight … so please …
What’s the StraightDope?
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [December 12, 2016, 3:40pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/2 "2016-12-12T15:40:45Z")
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [December 12, 2016, 4:23pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/3 "2016-12-12T16:23:16Z")
In general, no, nuclear decay is not affected by temperature.
However, there is some evidence that some decay modes have a slight temperature dependence:
> **[Do Nuclear Decay Rates Depend on Temperature?](https://www.technologyreview.com/2009/10/27/208571/do-nuclear-decay-rates-depend-on-temperature/)**
>
> The debate over whether nuclear decay rates change with temperature is about to get hotter.
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### Author:  [@Pantastic](https://boards.straightdope.com/u/Pantastic)
#### Post date: [December 12, 2016, 4:24pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/4 "2016-12-12T16:24:45Z")
For most elements, no at normal temperatures. If you get really hot, up to around 10^7 K IIRC, then things are energetic enough that nuclei are forced to interact and you start having fusion events, but that’s not really the same thing as affecting decay rate. Also, if you get elements that decay by electron capture hot enough that they’re ionized then you’ll inhibit or block electron capture because there will be fewer or no electrons in the atom for them to capture, though that’s the opposite of what your people are betting, and isn’t directly a temperature effect.
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### Author:  [@MikeS](https://boards.straightdope.com/u/MikeS)
#### Post date: [December 12, 2016, 4:25pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/5 "2016-12-12T16:25:41Z")
Yes, it is affected. But only ever so slightly, unless you’re at stupidly high temperatures; 10,000 K doesn’t qualify; and it would actually decay _slower_ at higher temperatures. So everyone’s wrong!
Suppose you have a sample of uranium. Each uranium atom has a particular chance of decaying per second; it acts like it has an internal clock attached, and for every millisecond that goes by on that clock, it has a particular chance of decaying. If you then heat the sample up, the uranium atoms start moving; and we know from relativity that [a clock that’s in motion will run more slowly than one that’s at rest](https://en.wikipedia.org/wiki/Time_dilation) (more or less.) This means that for every second that ticks by on the clocks in your lab, a little less time will tick by on the “internal clocks” of the uranium atoms. Thus, the decay rate that you observe in the lab will be slightly less than the decay rate you would observe if all the uranium atoms were at rest. The higher the temperature of the sample, the greater this effect would be, and the further the decay rate would be reduced.
Now, this is a tiny, tiny effect. For a sample of uranium atoms at 10,000 K, the average speed of an atom is about 500 m/s. The factor by which the “internal clocks” of the uranium atoms will run slow, if they’re moving at this speed, is then about 1 - 10[sup]-12[/sup]; in other words, the decay rate would be reduced by about one part in 10[sup]-12[/sup]. The correction is roughly proportional to the temperature, so if you get up to about 10[sup]14[/sup] Kelvin you might start to notice the effect. But by that temperature your uranium atoms are basically going to be a plasma anyway.
This effect, however, is observed in particle accelerators routinely. Unstable particles such as muons can be “stored” for relatively long periods of time by accelerating them up to near the speed of light. They decay with a much longer half-life when they’re moving around at relativistic speeds than when they’re at rest.
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### Author:  [@OldOlds](https://boards.straightdope.com/u/OldOlds)
#### Post date: [December 12, 2016, 4:26pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/6 "2016-12-12T16:26:28Z")
My background is in Biology, but I have worked with radioactive pharmaceuticals for 20 years. I always understood that half-life was constant, and indeed when we calculate these things we do not correct for temperature. So my answer would be that no, temperature does not affect half life.
However, there is some evidence that there could be a small impact of temperature on decay rates:
> **[Do Nuclear Decay Rates Depend on Temperature?](https://www.technologyreview.com/2009/10/27/208571/do-nuclear-decay-rates-depend-on-temperature/)**
>
> The debate over whether nuclear decay rates change with temperature is about to get hotter.
So I would argue that conventionally, the NOs are correct… But if I were looking to weasel I might claim unsure…
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### Author:  [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)
#### Post date: [December 12, 2016, 6:07pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/7 "2016-12-12T18:07:03Z")
Good good good … the Millennials win … they’ll be pleased … thanx all
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### Author:  [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)
#### Post date: [December 12, 2016, 6:17pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/8 "2016-12-12T18:17:01Z")
Does the theory that radioactive decay is temperature sensitive come from creationists (to explain away or introduce uncertainty in radio-isotope dating)?
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### Author:  [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)
#### Post date: [December 12, 2016, 6:28pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/9 "2016-12-12T18:28:23Z")
> [@Blue\_Blistering\_Barnacle](#):
>
> Does the theory that radioactive decay is temperature sensitive come from creationists (to explain away or introduce uncertainty in radio-isotope dating)?
No, chemists, cats and allied riff-raft … the creationists in the family rely on carbon-dating dinosaur fossils to make their point … which is a another good one but these folks won’t be picking the Rest Home I’ll live my final days …
Is there any written document from 8,000 years ago clearly stating that rocks existed … didn’t think so … [giggle]
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### Author:  [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)
#### Post date: [December 12, 2016, 6:29pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/10 "2016-12-12T18:29:29Z")
Here is an article discussing several experiments that did purport to show temperature sensitivity (both speeding and slowing) for polonium-210 and gold-198. Another groups showed small differences in decay rate for beryllium-7, which depended upon which metal it was in.
It concludes with an article undertaking very high precision measurements of decay of ruthenium-97 by electron capture and ruthenium-103 and rhodium-105, both by beta(-) emission,. This failed to show any temperature-related difference at all.
They raise a question about the possibility of publishing bias against null results.
> [@](#):
>
> The anomalous results are puzzling. One group found that the alpha emitter polonium-210, when placed in a copper container at 12 degrees Kelvin had a half-life that was six percent shorter than at room temperature. Another report claimed that the half-life of the beta(-) emitter, gold -198, was 3.6 percent longer at 12 degrees Kelvin than at room temperature. And yet another group showed that the half-life of beryllium-7, which decays by electron capture, depends on the material in which it is placed, increasing by 0.9 percent in palladium at 12 degrees Kelvin and at 0.7 percent in indium at 12 degrees Kelvin. There is even a theory to explain what is going on: that a temperature-dependent screening effect inside metallic containers influences electron capture. This, of course, ought to affect all nuclei that decay in this way.
> [@](#):
>
> Today, normal service returns with a report on the decay rates inside a metal host of ruthenium-97 by electron capture and ruthenium-103 and rhodium-105, both by beta(-) emission. John Hardy and pals at the Cyclotron Institute at Texas A&M University measured the decay rates of this stuff at room temperature and at 19 degrees Kelvin with a precision that was, in most cases, much higher than any previous experiments.
> **[Do Nuclear Decay Rates Depend on Temperature?](https://www.technologyreview.com/2009/10/27/208571/do-nuclear-decay-rates-depend-on-temperature/)**
>
> The debate over whether nuclear decay rates change with temperature is about to get hotter.
BTW- my quick perusal of Google did not seem to imply a creationism connection to me.
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### Author:  [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)
#### Post date: [December 12, 2016, 6:40pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/11 "2016-12-12T18:40:27Z")
> [@Blue\_Blistering\_Barnacle](#):
>
> Here is an article discussing several experiments that did purport to show temperature sensitivity (both speeding and slowing) for polonium-210 and gold-198. Another groups showed small differences in decay rate for beryllium-7, which depended upon which metal it was in.
>
> It concludes with an article undertaking very high precision measurements of decay of ruthenium-97 by electron capture and ruthenium-103 and rhodium-105, both by beta(-) emission,. This failed to show any temperature-related difference at all.
>
> They raise a question about the possibility of publishing bias against null results.
>
> [Do Nuclear Decay Rates Depend on Temperature? | MIT Technology Review](https://www.technologyreview.com/s/416009/do-nuclear-decay-rates-depend-on-temperature/)
> BTW- my quick perusal of Google did not seem to imply a creationism connection to me.
I forgot to include this passage from the same article:
> [@](#):
>
> While Hardy and his group point out that they cannot comment on the validity of other groups’ results, their null result has a significant bearing on the status of the screening effect. Their experiment shows that the screening effect does not apply to ruthenium-97 and therefore cannot be a general phenomenon.
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### Author:  [@si\_blakely](https://boards.straightdope.com/u/si_blakely)
#### Post date: [December 12, 2016, 7:10pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/12 "2016-12-12T19:10:43Z")
High temperature causing ionisation does impact neutral atom decay rates:
“The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions.”
[http://iopscience.iop.org/article/10.1088/0034-4885/74/1/016301/meta](http://iopscience.iop.org/article/10.1088/0034-4885/74/1/016301/meta)
However, we are talking about stripping all the electrons off a noble gas, so effectively a very, very high temperature. This _is_ a result that some creationist literature uses to attempt a challenge to the nuclear decay timeline.
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### Author:  [@Pantastic](https://boards.straightdope.com/u/Pantastic)
#### Post date: [December 12, 2016, 8:27pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/13 "2016-12-12T20:27:19Z")
> [@MikeS](#):
>
> The correction is roughly proportional to the temperature, so if you get up to about 10[sup]14[/sup] Kelvin you might start to notice the effect. But by that temperature your uranium atoms are basically going to be a plasma anyway.
I’d say you’re well outside of ‘plasma’ range, the neutron star core after a supernova ‘only’ has a temperature of about 10^11 K, and you’re talking about a thousand times larger than that. That’s not a plasma that you can contain in any kind of apparatus we could build today, that’s a super-high energy chunk of matter that you’d need a compact solar mass of gravity to hold in one place without it scattering all around the neighborhood, and it’s energetic enough that nuclear collisions would be happening regularly. It’s definitely not a temperature that you could meaningfully get a lump of matter to and observe (particle accelerators move single particles, not a a quantity that you could discern on a human-noticeable scale).
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### Author:  [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)
#### Post date: [December 13, 2016, 3:36am UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/14 "2016-12-13T03:36:22Z")
Has anyone attempted to bring a radioactive material down (close) to Absolute Zero to achieve Bose-Einstein Condensate?
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### Author:  [@Isilder](https://boards.straightdope.com/u/Isilder)
#### Post date: [December 13, 2016, 12:20pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/15 "2016-12-13T12:20:05Z")
> [@Enola\_Straight](#):
>
> Has anyone attempted to bring a radioactive material down (close) to Absolute Zero to achieve Bose-Einstein Condensate?
No because bosons are basically the ones where there are an even number of protons and an even neutrons, and therefore are the stable isotopes (the primordial ones…) of the elements, or remarkable odd odd nuclei , remarkable in that they are stable at all… and then more so because they are very very stable where other odd nuclei are very unstable.
Basically the bosons are either very very stable or very very unstable.
Your useful half-life radioactive isotopes or those artificial elements (americurium and the like) are not bosons to be in a bose einstein condensate.
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### Author:  [@Pasta](https://boards.straightdope.com/u/Pasta)
#### Post date: [December 13, 2016, 4:44pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/16 "2016-12-13T16:44:05Z")
> [@Isilder](#):
>
> No because bosons are basically the ones where there are an even number of protons and an even neutrons
You importantly forgot electrons. Isotopes that lend themselves to BECs have an even number for the sum of all three particles, which for neutral atoms means an even number of neutrons but any number of protons (odd or even).
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [December 13, 2016, 5:42pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/17 "2016-12-13T17:42:19Z")
And even neutral atoms which are fermions can still sometimes form Bose-Einstein condensates, by pairing up the atoms.
Back to the OP, another way you could change decay rates via bulk properties like temperature would be if it’s a decay mode which can be induced, such as fission. The products (especially neutrons) of one fission event can trigger other nuclei to fiss, and so how closely the nuclei are packed and how they’re arranged could change the total event rate (quite notably so, in the case of a supercritical arrangement).
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### Author:  [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)
#### Post date: [December 13, 2016, 6:38pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/18 "2016-12-13T18:38:37Z")
> [@Chronos](#):
>
> And even neutral atoms which are fermions can still sometimes form Bose-Einstein condensates, by pairing up the atoms.
>
> Back to the OP, another way you could change decay rates via bulk properties like temperature would be if it’s a decay mode which can be induced, such as fission. The products (especially neutrons) of one fission event can trigger other nuclei to fiss, and so how closely the nuclei are packed and how they’re arranged could change the total event rate (quite notably so, in the case of a supercritical arrangement).
Interestingly, this has occurred in nature, in Gabon.
> **[Natural nuclear fission reactor](https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor)**
>
> A natural nuclear fission reactor is a uranium deposit where self-sustaining nuclear chain reactions occur. The conditions under which a natural nuclear reactor could exist were predicted in 1956 by Paul Kuroda. The remnants of an extinct or fossil nuclear fission reactor, where self-sustaining nuclear reactions have occurred in the past, are verified by analysis of isotope ratios of uranium and of the fission products (and the stable daughter nuclides of those fission products). This was firs Ok...
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### Author:  [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)
#### Post date: [December 13, 2016, 11:51pm UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/19 "2016-12-13T23:51:33Z")
> [@Chronos](#):
>
> … The products (especially neutrons) of one fission event can trigger other nuclei to fiss,…
Pronounced with an “ess” or “esh?” The latter is logical but sounds silly, to my ears, but who knows how physicists talk when they let their hair down…
Is it a thing, or does no-one except you being lazy in this one post use/say “fiss” as a verb?
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### Author:  [@Kiwi\_Fruit](https://boards.straightdope.com/u/Kiwi_Fruit)
#### Post date: [December 14, 2016, 1:14am UTC](https://boards.straightdope.com/t/rate-of-nuclear-decay/774522/20 "2016-12-14T01:14:34Z")
> [@Leo\_Bloom](#):
>
> Pronounced with an “ess” or “esh?” The latter is logical but sounds silly, to my ears, but who knows how physicists talk when they let their hair down…
>
> Is it a thing, or does no-one except you being lazy in this one post use/say “fiss” as a verb?
As “fiss” would normally be written as “split”, perhaps no one but **Chronos**.
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