- #1
Tibetan Blackbird
- 2
- 1
I am thinking about lambda, the nuclear decay constant and what it actually means.
I have built spreadsheet models looking at decay using lambda to determine the decay for each time period and then comparing the number left to that determined by using e ˆ- lamda x time.
These are my conclusions.
If lambda is very small, less than 0.00001 then it is true to say that it represents the probability of decay per time period. And that iterative calculations using lambda give results within negligible percentage difference from calculations using e.
Here is a summary of these findings. Here I used initial nuclei at 1e18
Value of lamda Percentage difference between nuclei left after 50 time periods
As lambda gets above 0.1 the maths of decay works but is no longer in agreement with A = N x lambda.
We can use any type of value for lambda including values such as 760 and the exp formula works correctly but if lambda is bigger than 0.2 and in particular bigger than one what does it mean? A = N x lambda cannot be true for values bigger than 1.
So here is my question: What precisely is lambda when it gets big?
I have built spreadsheet models looking at decay using lambda to determine the decay for each time period and then comparing the number left to that determined by using e ˆ- lamda x time.
These are my conclusions.
If lambda is very small, less than 0.00001 then it is true to say that it represents the probability of decay per time period. And that iterative calculations using lambda give results within negligible percentage difference from calculations using e.
Here is a summary of these findings. Here I used initial nuclei at 1e18
Value of lamda Percentage difference between nuclei left after 50 time periods
0.00000001 | zero |
0.0000001 | zero |
0.000001 | -0.0000000025% |
0.00001 | -0.0000002500% |
0.0001 | -0.0000250017% |
0.001 | -0.0025016992% |
0.01 | -0.2519962456% |
0.1 | -30.7380847639% |
0.2 | -218.0942592831% |
As lambda gets above 0.1 the maths of decay works but is no longer in agreement with A = N x lambda.
We can use any type of value for lambda including values such as 760 and the exp formula works correctly but if lambda is bigger than 0.2 and in particular bigger than one what does it mean? A = N x lambda cannot be true for values bigger than 1.
So here is my question: What precisely is lambda when it gets big?