Freethought & Rationalism Archive

CodeMason · 01-01-2002, 11:40 AM

Just some nitpicking.

Quote:

Yet another fallacy (YAC)

Wouldn't that be YAF?

Quote:

The rat poison does not cause the mutation.

Many of the poisons in use are, at least to some degree, mutagenic to rats.

wdog · 01-01-2002, 03:04 PM

oh... i know why david is confused and i really didn't answer the question.. when the sun 'burns' it's fuel, it is fusion of hydrogen into helium. the actual mass fraction lost to energy by the conversion of hydrogen to helium is very small (not fast enough to noticeably change the radius of the sun) and remember that the byproducts remain in the sun as helium and possibly other elements. david, a little advice, learn about a subject that you are going make thses type of comments about.

Coragyps · 01-01-2002, 03:21 PM

Whooee, it can get boring on a holiday afternoon! I was forced to figure this one out. The Sun converts 4.2 million metric tons of matter into energy each second. (It processes 140 times this mass of hydrogen into helium to do this.) That's a lot of mass going away - equivalent in weight to a billion gallons of water per second. Also, however, it is only a 0.0000000001% decrease in the mass of the Sun per century. Like Opticsguy said: you won't see it.

Bubba · 01-02-2002, 06:54 PM

From a non scientific newbie...
Regarding earlier post...

Wouldn't death be an evolutionary advantadge in that species that die allow younger and stronger examples of thier biological species to fill a certain niche and therefore pass on more DNA??? Just curious

Bubba

tronvillain · 01-02-2002, 07:47 PM

Not exactly. I assume that by "death" you mean "death due to aging", since death itself doesn't really require an evolutionary explanation. The problem with your explanation is that it doesn't explain why being younger should mean being stronger - why not simply be healthy and vigorous until death due to external causes? The explanation seems to be that eventually everything is going to die of an external cause, and that any genes that have deleterious effects or interactions which take place aftera certain age will be less selected against or not selected against at all. Look at salmon - they have essentially no chance of spawning again so they essentially fall apart (catastrophic senescence) after spawning.

graden1 · 01-02-2002, 09:52 PM

Quote:

Originally posted by Coragyps:
<strong>Whooee, it can get boring on a holiday afternoon! I was forced to figure this one out. The Sun converts 4.2 million metric tons of matter into energy each second. (It processes 140 times this mass of hydrogen into helium to do this.) That's a lot of mass going away - equivalent in weight to a billion gallons of water per second. Also, however, it is only a 0.0000000001% decrease in the mass of the Sun per century. Like Opticsguy said: you won't see it.</strong>

Very interesting! I was just wondering--would you mind posting the method you used to calulate that? I'd like to see how you approached the problem, for future reference.

Thanx heaps,

Grady

Coragyps · 01-03-2002, 10:32 AM

Grady - It's pretty simple, really, and I actually found results like mine here" target="_blank">http://www.seds.org/billa/tnp/sol.html]here[/URL]</a> a couple of minutes ago.
Start with the energy output of the sun, 3.83 x 10^33 ergs per second, from the link above or an astronomy text. Then remember what ol' Al Einstein said: E equals emcee squared, or E=mc^2. The appropriare value for c, the speed of light, is 3 x 10^10 centimeters per second. So now we have 3.83 x 10^33 = (3 x 10^10)^2 x m , so m, the mass converted to energy per second, is 4.26 x 10^12 grams/second. That converts to 4,250,000 metric tons. The "140 times this much hydrogen" is from the fact that four hydrogen atoms weigh 0.029 atomic mass units more than one helium atom - this lost mass is about 1/140th of the 4 amu the hydrogen weighed.
The loss per century is arrived at by multiplying the loss per second out to 100 years' worth and dividing by the mass of the sun.
Another fun way to express some of this is that the water equivalent of the mass-per-second is also 3450 acre-feet of water, or a 100-acre lake 34.5 feet deep.
And you can put this all in perspective, sort of, if you consider that the Hiroshima A-bomb converted about one gram of matter into energy.

Seth K · 01-03-2002, 03:39 PM

Quote:

Originally posted by Coragyps:
<strong>Whooee, it can get boring on a holiday afternoon! I was forced to figure this one out. The Sun converts 4.2 million metric tons of matter into energy each second. (It processes 140 times this mass of hydrogen into helium to do this.) That's a lot of mass going away - equivalent in weight to a billion gallons of water per second. Also, however, it is only a 0.0000000001% decrease in the mass of the Sun per century. Like Opticsguy said: you won't see it.</strong>

Or to put it into a bigger perspective, the Sun will only lose .07% of its mass over it's entire main-sequence lifetime (~10e9 years) due to fusion. There is also solar wind to take into account, however. I don't have a source at hand, but IIRC the mass loss is 10x that of the fusion mass loss, so the sun will likely lose ~0.8% of it's original mass over 10 billion years.

bluefugue · 01-03-2002, 03:46 PM

Quote:

The explanation seems to be that eventually everything is going to die of an external cause, and that any genes that have deleterious effects or interactions which take place aftera certain age will be less selected against or not selected against at all.

Right. Any debilitating genes that express themselves *after* an organism's reproductive heyday would have no reason to be selected out.

tronvillain · 01-03-2002, 06:20 PM

Well, they can be expressed all along, as long as the debilitating effects only become significant later.

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01-01-2002, 03:04 PM	#52
wdog Veteran Member Join Date: Dec 2001 Location: Ohio, USA Posts: 1,547	oh... i know why david is confused and i really didn't answer the question.. when the sun 'burns' it's fuel, it is fusion of hydrogen into helium. the actual mass fraction lost to energy by the conversion of hydrogen to helium is very small (not fast enough to noticeably change the radius of the sun) and remember that the byproducts remain in the sun as helium and possibly other elements. david, a little advice, learn about a subject that you are going make thses type of comments about.

01-01-2002, 03:21 PM	#53
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	Whooee, it can get boring on a holiday afternoon! I was forced to figure this one out. The Sun converts 4.2 million metric tons of matter into energy each second. (It processes 140 times this mass of hydrogen into helium to do this.) That's a lot of mass going away - equivalent in weight to a billion gallons of water per second. Also, however, it is only a 0.0000000001% decrease in the mass of the Sun per century. Like Opticsguy said: you won't see it.

01-02-2002, 06:54 PM	#54
Bubba Veteran Member Join Date: Mar 2001 Location: Orient, OH USA Posts: 1,501	From a non scientific newbie... Regarding earlier post... Wouldn't death be an evolutionary advantadge in that species that die allow younger and stronger examples of thier biological species to fill a certain niche and therefore pass on more DNA??? Just curious Bubba

01-02-2002, 07:47 PM	#55
tronvillain Veteran Member Join Date: Oct 2000 Location: Alberta, Canada Posts: 5,658	Not exactly. I assume that by "death" you mean "death due to aging", since death itself doesn't really require an evolutionary explanation. The problem with your explanation is that it doesn't explain why being younger should mean being stronger - why not simply be healthy and vigorous until death due to external causes? The explanation seems to be that eventually everything is going to die of an external cause, and that any genes that have deleterious effects or interactions which take place aftera certain age will be less selected against or not selected against at all. Look at salmon - they have essentially no chance of spawning again so they essentially fall apart (catastrophic senescence) after spawning.

01-03-2002, 10:32 AM	#57
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	Grady - It's pretty simple, really, and I actually found results like mine here" target="_blank">http://www.seds.org/billa/tnp/sol.html]here[/URL]</a> a couple of minutes ago. Start with the energy output of the sun, 3.83 x 10^33 ergs per second, from the link above or an astronomy text. Then remember what ol' Al Einstein said: E equals emcee squared, or E=mc^2. The appropriare value for c, the speed of light, is 3 x 10^10 centimeters per second. So now we have 3.83 x 10^33 = (3 x 10^10)^2 x m , so m, the mass converted to energy per second, is 4.26 x 10^12 grams/second. That converts to 4,250,000 metric tons. The "140 times this much hydrogen" is from the fact that four hydrogen atoms weigh 0.029 atomic mass units more than one helium atom - this lost mass is about 1/140th of the 4 amu the hydrogen weighed. The loss per century is arrived at by multiplying the loss per second out to 100 years' worth and dividing by the mass of the sun. Another fun way to express some of this is that the water equivalent of the mass-per-second is also 3450 acre-feet of water, or a 100-acre lake 34.5 feet deep. And you can put this all in perspective, sort of, if you consider that the Hiroshima A-bomb converted about one gram of matter into energy.

01-03-2002, 06:20 PM	#60
tronvillain Veteran Member Join Date: Oct 2000 Location: Alberta, Canada Posts: 5,658	Well, they can be expressed all along, as long as the debilitating effects only become significant later.

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