Science help please, I'm not a scientist

Sternwallow wrote

Mister Space, Ihave a pretty comfortable handle on half-life as applied to millions of atoms, but I am not real clear what that would say about the expected life of a single radioactive atom after 80 or so half-lives.

Did I learn incorrectly that fusion of lighter elements could create elements up to Iron and that fission of very heavy elements could break down only as far as Iron so that a star could not fuse heavy elements into, say, Uranium nor fission Helium into two Hydrogen atoms?

A diferent form of the same question, what is the stellar fusion and/or fission chain that leads to Uranium?

Your general solar evolution allows production of elements up to iron by fusion. After that, things go haywire, and a reasonable rate is impossible. That's generically where the death starts to occur. As Choobus says, then all the heavier stuff gets formed, eventually, when the star goes "ker-flooey" and snots all over the place.

As far as fission goes, the products are generally centered about the middle of the periodic chart, but any daughter nuclide is possible. Those daughters that have a ratio of protons to neutrons that are off the "normal" number, which are stable, are really unstable, with half-lives in as little as nanoseconds and worse. Those are the bad boys that get you sick in a hurry, and make you glow in the dark like Homer Simpson. For instance, Uranium 238 has a half life in the 4.5X10^9 year range. That is basically stable. We have to play games with it to make a nuclear fission reaction, and that is the whole point. If it takes work to make it go, then it is easier to shut off.

[Tenspace]

Stern, I'll pass those off for Choobus or someone who is better than I at this...

I will say that I wasn't aware a half-life could be calculated on a single particle - I thought the statistical nature of half-life required a larger data set. It's been awhile since I've been into the physics... my time of late has been spent reading Dawkins and other biologists.

[Choobus]

Tenspace wrote

Stern, I'll pass those off for Choobus or someone who is better than I at this...

I will say that I wasn't aware a half-life could be calculated on a single particle - I thought the statistical nature of half-life required a larger data set. It's been awhile since I've been into the physics... my time of late has been spent reading Dawkins and other biologists.

that is exactly right tenspace. Half life means nothing for a single event, or even many events if the central limit theorem is not satisfied. anyone who says different is a cunt.

[Sternwallow]

Tenspace wrote

Stern, I'll pass those off for Choobus or someone who is better than I at this...

I will say that I wasn't aware a half-life could be calculated on a single particle - I thought the statistical nature of half-life required a larger data set. It's been awhile since I've been into the physics... my time of late has been spent reading Dawkins and other biologists.

Yes, that is just my question, converting the statistical understanding of large groups to individual cases.

Doesn't it make sense to say that, if the half-life of an element (many atoms) of, say, 1 year, means that, if I have a single atom of that element, I may expect it to decay sometime within a half-year (I don't know when it was created)? If I sample many individual atoms of this Annualanium, won't the average decay time approach 1/2 year?

Maybe I got the signs swapped and my expected time is two years, not 1/2. The question remains.

[Sternwallow]

logarithm wrote

Your general solar evolution allows production of elements up to iron by fusion. After that, things go haywire, and a reasonable rate is impossible. That's generically where the death starts to occur. As Choobus says, then all the heavier stuff gets formed, eventually, when the star goes "ker-flooey" and snots all over the place.

Do you have available the contribution to intergalactic recession velocity caused by cosmic snot?

[Tenspace]

Sternwallow wrote

Yes, that is just my question, converting the statistical understanding of large groups to individual cases.

Doesn't it make sense to say that, if the half-life of an element (many atoms) of, say, 1 year, means that, if I have a single atom of that element, I may expect it to decay sometime within a half-year (I don't know when it was created)? If I sample many individual atoms of this Annualanium, won't the average decay time approach 1/2 year?

Maybe I got the signs swapped and my expected time is two years, not 1/2. The question remains.

Try stating it like this: If I have a collection of elements, then 1/2 of them will decay in a single year.

If I have a single element, then there is a 50% chance it will decay within a year.

[Tenspace]

Sternwallow wrote

Do you have available the contribution to intergalactic recession velocity caused by cosmic snot?

Easily calculable using the strong nuclear theory, where quarks are held together by gluons, also known as snotons. I think it was Dr. Carlin that said, "Snot: The original rubber cement". Thefefore, the gluon/snoton association is relevant.

[Choobus]

Tenspace wrote

Try stating it like this:


If I have a collection of elements, then 1/2 of them will decay in a single year. true (if half life is 1 year)

If I have a single element, then there is a 50% chance it will decay within a year. false

Shame on you. Read my link to the central limit theorem, then pray to chuck norris for forgiveness.

[Tenspace]

Choobus wrote

Shame on you. Read my link to the central limit theorem, then pray to chuck norris for forgiveness.

I feel shamed, dirty. I should be spanked. Kate?

[Choobus]

may chuck have mercy on your hole.

Sternwallow wrote

Do you have available the contribution to intergalactic recession velocity caused by cosmic snot?

:lol::lol::lol::lol:
Yes, but you are going to have to give me a snootful of unobtanium for the answer.

Tenspace wrote

I feel shamed, dirty. I should be spanked. Kate?

NOPE. You would enjoy that WAY too much.:lol:

[Kate]

YUP! Drop 'em, Tenny. What would the proper number be here? One for each element in the table? Can you handle that?

[Sternwallow]

logarithm wrote

:lol::lol::lol::lol:
Yes, but you are going to have to give me a snootful of unobtanium for the answer.

Oh dear, what is the current rate of exchange between unobtanium and gold-presslatinum?

[Tenspace]

Kate wrote

YUP! Drop 'em, Tenny. What would the proper number be here? One for each element in the table? Can you handle that?

Only if the force of the stroke is equivalent to the atomic weight.

And you start with the heaviest element.