Timeline for Why is radioactive half-life constant?
Current License: CC BY-SA 4.0
34 events
| when toggle format | what | by | license | comment | |
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| S Aug 9, 2022 at 6:54 | history | suggested | Melanie Shebel | CC BY-SA 4.0 |
minor language, mechanics
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| Aug 9, 2022 at 1:51 | review | Suggested edits | |||
| S Aug 9, 2022 at 6:54 | |||||
| Jul 25, 2022 at 22:40 | answer | added | Árpád Szendrei | timeline score: 1 | |
| Jul 23, 2022 at 21:07 | answer | added | John Darby | timeline score: 0 | |
| Jul 23, 2022 at 9:28 | answer | added | Prime Mover | timeline score: 1 | |
| Jul 21, 2022 at 21:24 | answer | added | d5c4b3 | timeline score: 1 | |
| Jul 21, 2022 at 19:47 | answer | added | AILSA | timeline score: 1 | |
| Jul 21, 2022 at 19:37 | comment | added | paul garrett | @scohe001, I suspected that eventually someone would! :) | |
| Jul 21, 2022 at 19:36 | comment | added | scohe001 | Very surprised to see no one here has mentioned the Law of Large Numbers. | |
| Jul 21, 2022 at 19:32 | comment | added | paul garrett | "Speaking of probability", the probability that flipping a fair coin 100 times will produce exactly 50 heads and 50 tails, is quite low: binomial coefficient $100$-choose-$50$ divided by $2^{100}$... Python tells me this is about $0.079$. Getting exactly $49$ heads has probability about $0.078$, and $48$ has probability about $0.073$. Getting exactly $30$ has probability about $0.000023$ :) | |
| Jul 21, 2022 at 15:33 | comment | added | AakashM | " There aren't only 2 atoms in a sample mass of anything" - ok, it was 35 rather than 2, but still: IBM would like to disagree with you ... | |
| Jul 21, 2022 at 14:49 | comment | added | Nuclear Hoagie | @21380 The true, underlying probability of getting heads on a coin flip is also a constant, despite the fact that the empirical observed probability varies across a run of trials. That doesn't mean I'd say the odds from a coin flip are non-constant. I find it odd to suggest that the half-life of an isotope can vary over time or between samples - the half-life doesn't suddenly start to vary when you observe tiny samples with few atoms. Half-life is the expected time for half a sample to decay, not the observed time - it is a constant because it's an average. | |
| Jul 21, 2022 at 14:08 | comment | added | user21380 | @NuclearHoagie To use the word "constant" to refer to an average value is .... weird. It is an average, meaning, there's variation. | |
| Jul 21, 2022 at 12:48 | answer | added | Trunk | timeline score: 1 | |
| Jul 21, 2022 at 11:01 | answer | added | Daron | timeline score: 2 | |
| Jul 21, 2022 at 2:48 | answer | added | Nikhil | timeline score: 4 | |
| Jul 21, 2022 at 1:53 | comment | added | Greg Martin | The meaning of the phrase "half-life of 1 hour" is that each atom has a 50/50 chance of decaying over any 1-hour span. That's true independent of the other atoms, and independent of how much time it's already spent not decaying. | |
| Jul 20, 2022 at 20:48 | comment | added | Nuclear Hoagie | @21380 Half-life is both an average and a constant. It is an average amount of time needed for half the atoms in a sample to decay. That value is invariant in time and place, making it a constant. The actual amount of time for half a sample to decay may indeed differ from the half-life due to probabilistic fluctuations (particularly for very small samples), but the half-life is not defined by observations from any one sample, it is defined as an average. Observing a fluctuating decay rate in a small sample doesn't imply that the half-life is changing at all - it is a constant. | |
| Jul 20, 2022 at 18:02 | comment | added | user21380 | It's an average, not a constant. You even say this in the question body. Averages aren't made from small samples. There aren't only 2 atoms in a sample mass of anything. There's trillions and trillions. This is a stats question, not physics. | |
| Jul 20, 2022 at 15:09 | comment | added | Roger V. | Related: What is the probability distribution for the detection times of radioactive emissions from a radioactive sample? | |
| Jul 20, 2022 at 14:45 | answer | added | Kamil Maciorowski | timeline score: 7 | |
| Jul 20, 2022 at 13:29 | answer | added | Nuclear Hoagie | timeline score: 12 | |
| Jul 20, 2022 at 12:00 | history | tweeted | twitter.com/StackPhysics/status/1549725829940273154 | ||
| Jul 20, 2022 at 11:43 | answer | added | Jack Aidley | timeline score: 7 | |
| Jul 20, 2022 at 9:06 | history | became hot network question | |||
| Jul 20, 2022 at 9:02 | answer | added | Farcher | timeline score: 14 | |
| Jul 20, 2022 at 8:14 | answer | added | badjohn | timeline score: 6 | |
| Jul 20, 2022 at 3:38 | history | edited | Qmechanic♦ |
edited tags; edited tags
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| Jul 20, 2022 at 3:18 | answer | added | Dale | timeline score: 25 | |
| Jul 20, 2022 at 2:53 | comment | added | PM 2Ring | Related: physics.stackexchange.com/q/633553/123208 | |
| Jul 20, 2022 at 1:20 | answer | added | M. Enns | timeline score: 117 | |
| Jul 20, 2022 at 1:15 | answer | added | DKNguyen | timeline score: 57 | |
| S Jul 20, 2022 at 1:05 | review | First questions | |||
| Jul 20, 2022 at 1:27 | |||||
| S Jul 20, 2022 at 1:05 | history | asked | Luke B | CC BY-SA 4.0 |