4 ms·

> There's no way cooling will interfere with the half-life of the elements. Wow, so even at absolute zero, decay happens at the same rate? It kind of makes sen

> There's no way cooling will interfere with the half-life of the elements. Wow, so even at absolute zero, decay happens at the same rate? It kind of makes sense, but it's surprising if you've never thought about it. Wikipedia seems to confirm it: "A number of experiments have found that decay rates of other modes of artificial and naturally occurring radioisotopes are, to a high degree of precision, unaffected by external conditions such as temperature, pressure, the chemical environment, and electric, magnetic, or gravitational fields." ( https://en.wikipedia.org/wiki/Radioactive_decay https://en.wikipedia.org/wiki/Radioactive_decay )

Alupis 11y ago
> so even at absolute zero, decay happens at the same rate You'll never get to absolute zero (reality and practicalness aside), because the element radiates it's own heat.
- danbruc 11y ago
  I don't see any reasons why you could not cool radioactive isotopes to essentially zero Kelvin and observe the decay rate. It would probably be hard(er) to do with larger chunks because the decaying nuclei would dump parts of their energy into the sample but if you only use a single atom or maybe tens or hundreds of them and measure the time until the first decay event or between the fist two events you could certainly determine the decay rate close to absolute zero.
  - Alupis 11y ago
    > I don't see any reasons why you could not cool radioactive isotopes to essentially zero Kelvin and observe the decay rate See the GP, this has been tested and proved to have no effect.
arrrg 11y ago
Ha, I remember first reading about this when I was discussing with Young Earth creationists. (What a pointless exercise that was …) Their big point about dating methods was that radioactive decay could be influenced by external factors. No matter how slight that influence, a tiny little bit was enough to disprove all our dating methods.
sevenless 11y ago
I have to tell you this is only mostly correct, and there are a few really impressive exceptions. Certain nuclear decay modes, such as electron capture, do depend on the chemical environment of the nucleus. Beryllium-7 decays purely by electron capture with a half-life of somewhat over 50 days. Differences in chemical environment can alter the half-life by around 0.2%, and high pressures produce somewhat similar changes. A much more spectacular alteration is if you strip away all the electrons from the very weak beta-emitter rhenium-187 in a particle accelerator, to form a bare nucleus. Neutral rhenium-187 has a half-life of 42 × 10^9 years, the fully ionised rhenium-187 has a half life of just 33 years - a billion fold speed up in decay rate! http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/decay_rates.html http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/dec...

Alupis 11y ago

> so even at absolute zero, decay happens at the same rate You'll never get to absolute zero (reality and practicalness aside), because the element radiates it's own heat.

danbruc 11y ago
I don't see any reasons why you could not cool radioactive isotopes to essentially zero Kelvin and observe the decay rate. It would probably be hard(er) to do with larger chunks because the decaying nuclei would dump parts of their energy into the sample but if you only use a single atom or maybe tens or hundreds of them and measure the time until the first decay event or between the fist two events you could certainly determine the decay rate close to absolute zero.
- Alupis 11y ago
  > I don't see any reasons why you could not cool radioactive isotopes to essentially zero Kelvin and observe the decay rate See the GP, this has been tested and proved to have no effect.

arrrg 11y ago

Ha, I remember first reading about this when I was discussing with Young Earth creationists. (What a pointless exercise that was …) Their big point about dating methods was that radioactive decay could be influenced by external factors. No matter how slight that influence, a tiny little bit was enough to disprove all our dating methods.

sevenless 11y ago

I have to tell you this is only mostly correct, and there are a few really impressive exceptions. Certain nuclear decay modes, such as electron capture, do depend on the chemical environment of the nucleus. Beryllium-7 decays purely by electron capture with a half-life of somewhat over 50 days. Differences in chemical environment can alter the half-life by around 0.2%, and high pressures produce somewhat similar changes. A much more spectacular alteration is if you strip away all the electrons from the very weak beta-emitter rhenium-187 in a particle accelerator, to form a bare nucleus. Neutral rhenium-187 has a half-life of 42 × 10^9 years, the fully ionised rhenium-187 has a half life of just 33 years - a billion fold speed up in decay rate! http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/decay_rates.html http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/dec...