## RANE 2 years ago "why is not possible to predict when any particular radioactive nucleus will decay?"

1. RANE

@UnkleRhaukus @amistre64 @ParthKohli

2. RANE

@thomaster

3. RANE

@ganeshie8 @dan815

4. RANE

i didnt form this question,its in my phys report, and i dont know the answer to it

5. UnkleRhaukus

Perhaps there is some missing context

6. RANE

the question asked is "why is not possible to predict when any particular radioactive nucleus will decay?"

7. UnkleRhaukus

Ah, that is a bit different.

8. RANE

u there?

9. UnkleRhaukus

Radioactive decay is probabilistic in nature. If you have a large number of radionuclides you can make probabilistic predictions about the group- in one half-life about half of the nuclides will have decayed. But you cannot tell when any individual will decay,

10. RANE

y cant u tell when any individual will decay?

11. UnkleRhaukus

because they dont all decay at the same time

12. dan815

so you want to know why a nuclues never decays?

13. RANE

"why is not possible to predict when any particular radioactive nucleus will decay?"

14. thomaster

because it's random when they will decay?

15. UnkleRhaukus

Consider; i have ten coins, i flip them all over, if a tail that coin is removed, if a head the coin can be re flipped, every minute i re-flip all the coins that were heads last time, . You could do some statical analysis and predict that the game will last less then 10 minutes - most of the time. however sometimes, all coins will be tails on the first flip, and sometimes, all the coins continue to flip heads and the game never ends

16. UnkleRhaukus

Making predictions about the coins game is similar to making predictions about the radionuclides, The data used to make the predictions is probabilistic data. [this analysis is very different to trying to determine the behaviour of a single coin, (that would require knowing trajectories, velocities and dynamics.)(we dont have this data)]

17. RANE

thank u so much

18. UnkleRhaukus

did you try the game, do you have ten coins,? i took me exactly ten flips, but that was just lucky

19. RANE

um.. no, i didnt try it becoz i'm busy with other q's of the report bt i will do it at sometime

20. amistre64

as far as i can recall, the particles in question are soo small that any attempt to measure them affects their situation.

21. RANE

wht????

22. RANE

this time can u pls explain using the example of dice

23. UnkleRhaukus

do you have some dice to roll?

24. RANE

yes

25. RANE

can u ist explain the q then give example

26. RANE

"why is not possible to predict when any particular radioactive nucleus will decay?"

27. UnkleRhaukus

ok , well im gonna roll eight dice, and if one of them lands on a 1, it take it aside, every thing else, i re-roll , this repeats. how long does the game last?

28. RANE

can u pls explain ist so we have a clue abt whts happening

29. RANE

explain the q' then examp

30. RANE

r u there?

31. UnkleRhaukus

i am hear, but i am not sure what you are asking me

32. GGfreak

Thnkx for the help don't worry bout it

33. gleem

A radioactive nucleus is often modeled as a hollow sphere in which there is a small marble. The hollow sphere has a small hole but large enough for the marble to pass through. The marble is considered to be bouncing around in the sphere until after a time it passes through the hole and escapes. consider a piggy bank with a coin that you are trying to shake out. Is it possible to predict when the coin will come out ie. how many shakes will it take to get the coin out? I think not. You can estimate the average number shakes to get the coin out of say 10000 bank by shaking them until a coin comes out and averaging the number of shakes that released a coin. that way if you came across another set of similar bank you could estimate how long it will take to release all the coins. So goes the coin in the bank so goes the radioactive nucleus.