"Race doesn't exist," and the myth is drowning blacks

[ApostateAbe]

[

My point, though, was that while more lung inflation is needed for the slightly more dense body, that difference is insignificant. We are talking a few square inches of volume. Remember, 1 gallon of air offsets about 70 lbs of weight. 5 lbs of extra density requires a fairly trivial amount more lung expansion... a sip of air.

It's actually 7 lbs of weight, but you are still on point. When all the factors which lead to a drowning death are considered, the density of bones is an insignificant factor.

Abe is so desperate to find someone who will concede some merit in his racist hypothesis, he wants to reduce it to a simple mathematical proof, and then demand everyone agree it is true. It doesn't matter that none of his hypothesis is supported by actual observation or common experience. He has the numbers on his side.

This discussion is silly on an elite level. No one ever stood over a waterlogged dead body and lamented, "If only his bones had been less dense."

What should matter more here: the numbers or the habits of people who lament over dead bodies? If the numbers matter more, then pay attention to them and analyze them appropriately, instead of just ignoring them in favor of arrogant dogmatic dismissals of perceived racism. Yes, 7 pounds per gallon really does make a big difference. Why wouldn't it? If you don't do the math, then all you have is belief.

 

[Bronzeage]

It's actually 7 lbs of weight, but you are still on point. When all the factors which lead to a drowning death are considered, the density of bones is an insignificant factor.

Abe is so desperate to find someone who will concede some merit in his racist hypothesis, he wants to reduce it to a simple mathematical proof, and then demand everyone agree it is true. It doesn't matter that none of his hypothesis is supported by actual observation or common experience. He has the numbers on his side.

This discussion is silly on an elite level. No one ever stood over a waterlogged dead body and lamented, "If only his bones had been less dense."

What should matter more here: the numbers or the habits of people who lament over dead bodies? If the numbers matter more, then pay attention to them and analyze them appropriately, instead of just ignoring them in favor of arrogant dogmatic dismissals of perceived racism. Yes, 7 pounds per gallon really does make a big difference. Why wouldn't it? If you don't do the math, then all you have is belief.

I did the math, and yet I do not believe you. Like the stopped clock that is correct twice a day, you find a trivial distinction in a statistical chart and extend it to explain a phenomena which exists only in folklore. Then, at noon and midnight, you demand that people acknowledge you have the correct time.

 

[ApostateAbe]

What should matter more here: the numbers or the habits of people who lament over dead bodies? If the numbers matter more, then pay attention to them and analyze them appropriately, instead of just ignoring them in favor of arrogant dogmatic dismissals of perceived racism. Yes, 7 pounds per gallon really does make a big difference. Why wouldn't it? If you don't do the math, then all you have is belief.

I did the math, and yet I do not believe you. Like the stopped clock that is correct twice a day, you find a trivial distinction in a statistical chart and extend it to explain a phenomena which exists only in folklore. Then, at noon and midnight, you demand that people acknowledge you have the correct time.

I think you are saying the math is correct, but it doesn't matter, because not everything has been absolutely proved, so until then they are trivial points and you will just rely on the consensus of people who lament over dead bodies.

 

[Bronzeage]

I did the math, and yet I do not believe you. Like the stopped clock that is correct twice a day, you find a trivial distinction in a statistical chart and extend it to explain a phenomena which exists only in folklore. Then, at noon and midnight, you demand that people acknowledge you have the correct time.

I think you are saying the math is correct, but it doesn't matter, because not everything has been absolutely proved, so until then they are trivial points and you will just rely on the consensus of people who lament over dead bodies.

You are free to think what you like, and even freer to imagine what I may be thinking. There are restrictions. I have considered all the evidence and come to the conclusion that you are incapable of the logical processes necessary to this sort of discussion.

When your threads are reviewed, especially this one, it would be easy for a casual observer to think you are the type who enjoys engaging others in frustrating exchanges in which you ignore all presented to you and insist all others concede the truth of your syllogism, even though it is irrelevant to the argument.

I do not think you do this for fun. If there is some aid for your condition, I hope you avail yourself to it.

 

[NobleSavage]

Which makes me wonder about the success rate of blacks trying for special forces. ARE there any black SEALS? Do the entry/graduation figures for SEALS show a marked difference along racial lines?

Blacks are reportedly less than 2% of the Navy Seals, while 17% of the Navy (not that swimming ability is the deciding variant).

Maybe the black guys looked up SEAL training on YouTube and said, "Fuck that!" This could be a sign of superior intelligence.

 

[ApostateAbe]

I am done arguing with the forum staff. If they have any extra word in this thread, then that word will be the last, if I can restrain myself. They habitually target my ego and my patience, and it gets dangerous when I return fire. Instead, I will lay out the full case that has developed over the course of this thread, with links to all the math. If you disagree, then it is best done in terms of the math, as the argument from the math seems especially strong. Tell me how the physical arguments as presented are either wrong or irrelevant.

There are confirmed racial differences in drowning rates in America, per the OP.

There are confirmed significant differences in body densities between whites and blacks, per post #38.

These racial body density differences imply, for example, that one in 11 black men is like the average white man but wearing an extra five pounds of gold chains, which is 15 times as many blacks as whites, per the statistical calculations in post #63.

To compensate for five pounds, 2.1 liters of extra air must be inhaled, per post #199. The average extra air volume from forced inhalation is only 3.0 liters, proving that extra body density makes a big difference.

In conclusion, the racial body density differences are a strong explanation for the racial differences in drowning rates for having predictive power. Differences in drowning rates are directly expected from the data and the physics concerning body density. If the drowning rates between the races were somehow the same, then it would be unexpected and anomalous, in need of an explanation.

None of this is to claim that differences in average body density is the dominant explanation for any and all group differences. Differences in psychological swimming ability also have a significant effect, and they MAY have an effect on the racial drowning differences. But, if there exists differences in psychological swimming ability between the races, then differences in average body density would likewise predict that, too. And, regardless, any significance of such an explanation does not minimize the significance of the data concerning body densities and the physical predictions that follow.

 

[Malintent]

My point, though, was that while more lung inflation is needed for the slightly more dense body, that difference is insignificant. We are talking a few square inches of volume. Remember, 1 gallon of air offsets about 70 lbs of weight. 5 lbs of extra density requires a fairly trivial amount more lung expansion... a sip of air.

5 lb = 2.26 kg

The average body density of a young white man is 1.065 kg/L, so, to compensate for five pounds of extra weight downward, such a person would need to inhale this much air:

2.26 kg/(1.065 kg/L) = 2.1 L

According to Wikipedia (citing Ganong, William. "Fig. 35-7". Review of Medical Physiology 21st ed.), the average inspiratory reserve volume (IRV) for men is 3.0 L. The IRV is the volume of air that is the difference between the top peak of the curve of lung volume after FORCED inhalation and the top of the peak of the curve of lung volume after normal inhalation. So, 2.1 liters versus 3.0 liters. Maybe a normal person carrying five pounds of gold chains can stay afloat after taking in a big breath of air, but we know sure as hell the chains make a big difference! And it follows that racial body density variations likewise make a big difference.

2.1 L of air would lift over 30 lbs of dead weight in salt water. I have no idea what you are calculating.

A standard birthday party balloon (made of sufficiently strong rubber) would lift a cinder block off the ocean floor and carry it to the surface in quite a hurry. This I have personally observed and is an exercise I have performed myself.

 

[ApostateAbe]

5 lb = 2.26 kg

The average body density of a young white man is 1.065 kg/L, so, to compensate for five pounds of extra weight downward, such a person would need to inhale this much air:

2.26 kg/(1.065 kg/L) = 2.1 L

According to Wikipedia (citing Ganong, William. "Fig. 35-7". Review of Medical Physiology 21st ed.), the average inspiratory reserve volume (IRV) for men is 3.0 L. The IRV is the volume of air that is the difference between the top peak of the curve of lung volume after FORCED inhalation and the top of the peak of the curve of lung volume after normal inhalation. So, 2.1 liters versus 3.0 liters. Maybe a normal person carrying five pounds of gold chains can stay afloat after taking in a big breath of air, but we know sure as hell the chains make a big difference! And it follows that racial body density variations likewise make a big difference.

2.1 L of air would lift over 30 lbs of dead weight in salt water. I have no idea what you are calculating.

A standard birthday party balloon (made of sufficiently strong rubber) would lift a cinder block off the ocean floor and carry it to the surface in quite a hurry. This I have personally observed and is an exercise I have performed myself.

I am presuming dead weight in my calculation, but a cinder block is NOT dead weight. Hard concrete was about 2.5 times the density of water, whereas steel has about 8 times the density of water and gold has about 19 times the density of water (which is in part why I like the analogy of gold chains). A cinder block for its relatively low density already has considerable buoyant force without the balloon.

 

[Angra Mainyu]

ApostateAbe,

Some questions/suggestions:

1. I think you should address Canard Dujour arguments more carefully, in light of Bomb#20's point.
2. You're apparently equating increased density to having some high-dense extra weight (chains or whatever), regardless of what the extra density actually is.
For example, you say:

These racial body density differences imply, for example, that one in 11 black men is like the average white man but wearing an extra five pounds of gold chains, which is 15 times as many blacks as whites, per the statistical calculations in post #63.

What is your argument for that?
I mean, in this case, a non-negligible portion of the extra density seems to be from denser muscles. How do you know the denser muscles aren't like chains, but actually contribute to swimming ability, compensating to some degree to be determined for the extra density?
3. You're comparing two races, Caucasian and Black (well, actually, "Black" is not a race, but I take it you're referring to a race that has no politically correct name, not to a color). But what about comparing other races, or sexes?
One can make two parallel arguments, comparing:
a. Caucasians and Asians (not literally "Asians").
b. Males and females.

Given that males clearly have a greater body density than females (usually, of course; not in all cases), and given also that Asians also seem to have (usually) greater lung capacity than Caucasians of the same height, then arguments similar to yours (at least to parts of yours) could be made as well.
My question is: would you make similar recommendations against encouraging Caucasians and/or males to learn how to swim? Or do you think there are relevant differences? If so, what is your evidence?
More precisely, you said:

Over four thousand blacks have drowned from 1999 to 2010 in all aquatic settings per the CDC. The racial drowning gap is a well-known problem, and the common way for authorities to solve this problem is to encourage blacks to learn how to swim. I take this to be akin to encouraging the public to learn how to juggle chainsaws, to make it a safe hobby. No. If you are buoyant, then it is plausibly safe to learn how to swim. Maybe you can be both black and buoyant. But, if you sink like a rock, then don't learn how to swim. Just trust your instincts and stay the hell away from the water.

Granting that Blacks are usually denser than Caucasians, that does not imply that the former are not buoyant but the latter are, just as the fact that males are usually denser than females does not imply that males aren't buoyant but females are.
But you don't make a statement like:

The sex drowning gap is a well-known problem. Encouraging males to learn how to swim would be akin to encouraging the public to learn how to juggle chainsaws, to make it a safe hobby. No. If you are buoyant, then it is plausibly safe to learn how to swim. Maybe you can be both male and buoyant. But, if you sink like a rock, then don't learn how to swim. Just trust your instincts and stay the hell away from the water.​

Perhaps, you don't make that argument simply because that's not what you wanted to focus on. So, I will ask: Would you endorse that parallel statement for males and females? If not, what is the relevant difference?

 

[Malintent]

2.1 L of air would lift over 30 lbs of dead weight in salt water. I have no idea what you are calculating.

A standard birthday party balloon (made of sufficiently strong rubber) would lift a cinder block off the ocean floor and carry it to the surface in quite a hurry. This I have personally observed and is an exercise I have performed myself.

I am presuming dead weight in my calculation, but a cinder block is NOT dead weight. Hard concrete was about 2.5 times the density of water, whereas steel has about 8 times the density of water and gold has about 19 times the density of water (which is in part why I like the analogy of gold chains). A cinder block for its relatively low density already has considerable buoyant force without the balloon.

Your last post is so factually ridiculous that I can't even respond. I guess you seem to think 'cement boots' are a floatation device that the mafia used to ensure dead bodies are found after dumping them.... because of its 'considerable buoyant force'.

 

[Bomb#20]

2.1 L of air would lift over 30 lbs of dead weight in salt water. I have no idea what you are calculating.

What are you calculating? "2.1 L of air would lift over 30 lbs of dead weight in salt water" doesn't mean anything unless you specify the density or the volume of the 30 lb object being lifted. All by itself, 2.1 L of air will lift 4.7 lbs of dead weight in salt water, which means the only way a 30-lb object is lifted by a 2.1 L balloon is if 25.3 lbs are being lifted by the water displaced by the object, which will only happen if the object is no more than 21% denser than water.

A standard birthday party balloon (made of sufficiently strong rubber) would lift a cinder block off the ocean floor and carry it to the surface in quite a hurry. This I have personally observed and is an exercise I have performed myself.

A standard birthday party balloon is a lot bigger than 2.1 L.

 

[exodiasrightleg]

A cinder block for its relatively low density already has considerable buoyant force without the balloon.

As opposed to black people, who are just too dense to float.

Tell me, how's the weather in Bizarro Earth?

 

[Bomb#20]

Your last post is so factually ridiculous that I can't even respond. I guess you seem to think 'cement boots' are a floatation device that the mafia used to ensure dead bodies are found after dumping them.... because of its 'considerable buoyant force'.

Um, cinder blocks aren't made of cement. Concrete blocks come in a wide range of densities; "cinder block" refers to the lighter sort. (They used to keep the weight down by including actual cinders in the mix.) Cement has a specific gravity of about 1.5; a cinder block is about 1.3.

Oh, and incidentally, you're misunderstanding what AA meant by "buoyant force". He meant the upward force on an object exerted by the difference in water pressure between the top and bottom of the object -- i.e., the weight of the displaced water. The phrase is commonly used both for that and also for an object's lifting power in water -- i.e. the difference between the weight of the displaced water and the weight of the object. You evidently took him to mean the latter. A cinder block has positive buoyant force in the first sense and negative buoyant force in the second sense.

 

[Bomb#20]

Drowning is either caused by mechanical action (being held underwater by something or someone), or by fear. It is never due to negative buoyancy.

Source?

The prima facie way a person would drown from negative buoyancy rather than from fear or being held underwater is by not being able to artificially maintain positive buoyancy by overfilling his lungs, due to loss of consciousness, due to exhaustion.

 

[ApostateAbe]

A cinder block for its relatively low density already has considerable buoyant force without the balloon.

As opposed to black people, who are just too dense to float.

Tell me, how's the weather in Bizarro Earth?

I should not presume that everyone has taken full college physics courses and retained the knowledge. Both objects that float and objects that sink have upward buoyant force as a function of the inverse of the object's density (in part). If an immersed object has less density than another immersed object, then they may both sink, but the less dense object will have greater buoyant force.

 

[ApostateAbe]

ApostateAbe,

Some questions/suggestions:

1. I think you should address Canard Dujour arguments more carefully, in light of Bomb#20's point.
2. You're apparently equating increased density to having some high-dense extra weight (chains or whatever), regardless of what the extra density actually is.
For example, you say:

What is your argument for that?
I mean, in this case, a non-negligible portion of the extra density seems to be from denser muscles. How do you know the denser muscles aren't like chains, but actually contribute to swimming ability, compensating to some degree to be determined for the extra density?
3. You're comparing two races, Caucasian and Black (well, actually, "Black" is not a race, but I take it you're referring to a race that has no politically correct name, not to a color). But what about comparing other races, or sexes?
One can make two parallel arguments, comparing:
a. Caucasians and Asians (not literally "Asians").
b. Males and females.

Given that males clearly have a greater body density than females (usually, of course; not in all cases), and given also that Asians also seem to have (usually) greater lung capacity than Caucasians of the same height, then arguments similar to yours (at least to parts of yours) could be made as well.
My question is: would you make similar recommendations against encouraging Caucasians and/or males to learn how to swim? Or do you think there are relevant differences? If so, what is your evidence?
More precisely, you said:

Over four thousand blacks have drowned from 1999 to 2010 in all aquatic settings per the CDC. The racial drowning gap is a well-known problem, and the common way for authorities to solve this problem is to encourage blacks to learn how to swim. I take this to be akin to encouraging the public to learn how to juggle chainsaws, to make it a safe hobby. No. If you are buoyant, then it is plausibly safe to learn how to swim. Maybe you can be both black and buoyant. But, if you sink like a rock, then don't learn how to swim. Just trust your instincts and stay the hell away from the water.

Granting that Blacks are usually denser than Caucasians, that does not imply that the former are not buoyant but the latter are, just as the fact that males are usually denser than females does not imply that males aren't buoyant but females are.
But you don't make a statement like:

The sex drowning gap is a well-known problem. Encouraging males to learn how to swim would be akin to encouraging the public to learn how to juggle chainsaws, to make it a safe hobby. No. If you are buoyant, then it is plausibly safe to learn how to swim. Maybe you can be both male and buoyant. But, if you sink like a rock, then don't learn how to swim. Just trust your instincts and stay the hell away from the water.​

Perhaps, you don't make that argument simply because that's not what you wanted to focus on. So, I will ask: Would you endorse that parallel statement for males and females? If not, what is the relevant difference?

Thanks for your attention. All good points! It is plausible that the greater muscle mass of blacks would actually help them swim better, not worse. If that were the only difference or the primary difference, then I may not have an argument. The greater body densities of elite swimmers are probably due to greater muscle mass. So, maybe a case can be made for that. But, since there are three known potential sources of the differences in body density and not just muscle mass, the other differences must be considered. Elite swimmers have greater lung sizes, but, blacks have smaller lungs, which is certain to be a disadvantage, not just for the greater body density at normal rest, but also for the less lung volume after forced inhalation, often necessary to stay afloat.

I do not have body density data for other races. Maybe the data is out there and I have not looked long enough. If you can find the average body density of Asian Americans, I absolutely will analyze it in relation to drowning rates.

The sex differences are a very good point--boys are three times as likely to drown than girls--and I absolutely agree that the greater drowning risk for males should be a strong consideration. It means, at the very least, lifeguards should be informed of the average body density difference pay closer attention to boys than to girls. Parents should pay more attention to their sons than to their daughters in the swimming pool. I don't think most of us would have a problem with that proposal, right? Well, maybe the anti-sexists and those who don't want to give credit to the "racist" argument.

 

[ApostateAbe]

Your last post is so factually ridiculous that I can't even respond. I guess you seem to think 'cement boots' are a floatation device that the mafia used to ensure dead bodies are found after dumping them.... because of its 'considerable buoyant force'.

Um, cinder blocks aren't made of cement. Concrete blocks come in a wide range of densities; "cinder block" refers to the lighter sort. (They used to keep the weight down by including actual cinders in the mix.) Cement has a specific gravity of about 1.5; a cinder block is about 1.3.

Oh, and incidentally, you're misunderstanding what AA meant by "buoyant force". He meant the upward force on an object exerted by the difference in water pressure between the top and bottom of the object -- i.e., the weight of the displaced water. The phrase is commonly used both for that and also for an object's lifting power in water -- i.e. the difference between the weight of the displaced water and the weight of the object. You evidently took him to mean the latter. A cinder block has positive buoyant force in the first sense and negative buoyant force in the second sense.

Good points! I was unaware of the lower density of cinder blocks. They look heavy but it would be no surprise that they are lifted by a balloon in water.

 

[Angra Mainyu]

Thanks for your attention. All good points! It is plausible that the greater muscle mass of blacks would actually help them swim better, not worse. If that were the only difference or the primary difference, then I may not have an argument. The greater body densities of elite swimmers are probably due to greater muscle mass. So, maybe a case can be made for that. But, since there are three known potential sources of the differences in body density and not just muscle mass, the other differences must be considered. Elite swimmers have greater lung sizes, but, blacks have smaller lungs, which is certain to be a disadvantage, not just for the greater body density at normal rest, but also for the less lung volume after forced inhalation, often necessary to stay afloat.

You're welcome, but my point is that you have two sources of greater density each of which may plausibly count as a factor making it more difficult (all other things equal) for a person to stay afloat - namely, denser bones and smaller lungs -, but a source of greater density (namely, denser muscles) whose impact (all other things equal) on a person's ability to stay afloat is more difficult to assess. How those sources interact with each other (i.e., all other things are not equal) is also difficult to assess.

On the other hand, the parallels you make count entirely against a person's ability to stay afloat. The difference can be very significant.

For example, consider the following scenario:

Let's say Bob and Tom both know how to swim equally well, but Bob has extra density resulting from his denser bones, muscles, and smaller lungs, whereas Tom is carrying the gold chains you mentioned, and that equals their weight (they have the same height). Which one would you expect to survive for longer, before drowning?
It seems to me that Bob very probably would survive for longer, all other things equal (assuming Tom can't get rid of the chains, of course).

This does not imply you don't have a point regarding the contribution of race to drowning rates, but you seem to be going beyond what your evidence warrants with regard to the extent of the differences.

I do not have body density data for other races. Maybe the data is out there and I have not looked long enough. If you can find the average body density of Asian Americans, I absolutely will analyze it in relation to drowning rates.

I'm afraid I don't know the numbers, either, but the difference in length of legs and trunk would seem to predict bigger lungs in at least American aborigins.
Also, there are some studies showing difference in lung capacity based on ethnicity (e.g., http://www.ncbi.nlm.nih.gov/pubmed/9493668 )
Then again, I found a study that shows greater lung capacity in Caucasians than Chinese (http://www.ncbi.nlm.nih.gov/pubmed/1955006 ), so that's not so clear to me.
I will withdraw that example, since it's unclear and the point I was trying to make is about your recommended policy with regard to Black people, and your claim about buoyancy (e.g., "Maybe you can be both black and buoyant.", etc.), can be made without it.

The sex differences are a very good point--boys are three times as likely to drown than girls--and I absolutely agree that the greater drowning risk for males should be a strong consideration. It means, at the very least, lifeguards should be informed of the average body density difference pay closer attention to boys than to girls. Parents should pay more attention to their sons than to their daughters in the swimming pool. I don't think most of us would have a problem with that proposal, right? Well, maybe the anti-sexists and those who don't want to give credit to the "racist" argument.

A similar proposal in the case of race would be that lifeguards should be informed and told to pay closer attention to Blacks than Caucasians. That's not the sort of proposal I was asking about, though. I was asking about the claim I quoted, and your recommended policy.

For example, you say:

Maybe you can be both male and buoyant. But, if you sink like a rock, then don't learn how to swim. Just trust your instincts and stay the hell away from the water.

A parallel would be:

Maybe you can be both male and buoyant. But, if you sink like a rock, then don't learn how to swim. Just trust your instincts and stay the hell away from the water.​

Even if Caucasians/females are less dense than Blacks/males, it doesn't follow that Caucasians/females are buoyant, but Blacks/males are not.
Moreover, even if Caucasians/females are less dense than Blacks/males, it doesn't follow that it's somehow detrimental for Blacks/males to learn how to swim. In fact, one can learn how to swim in a swimming pool in which one can walk, with the water at the level of the neck or the chest. There is problem with density in such cases, and learning how to swim can save a person's life in other situations (e.g., if they fall from a boat, or there is a flood, etc.), so learning how to swim remains advisable as far as I can tell.

Granted, avoiding swimming altogether, avoiding boats, etc., will reduce the risk of drowning (you can still get caught by a Tsunami or a flood or something, but it's much less likely), but that works for both males and females, and for all races, even if to different degrees. Moreover, the increased risk from Caucasians to Blacks is lesser than the increased risk from males to females, but you're not advocating that males refrain from learning how to swim - just that lifeguards should be informed, etc.

In any event, the risks involved do not seem to support the view that it's generally ill-advised for Blacks or males to, say, swim for fun, even in water deeper than their height. All healthy humans can learn to do that, and we often take some risks in activities that we like. Do you think this particular risk is too much for Blacks and/or males?

ETA: Actually, females have less lung capacity than males. But the main point is not about the differences in risk. The comparison of the Black/Caucasian differences with male/female difference and with other racial differences was meant to draw attention to the fact that an advantage when it comes to staying afloat is not sufficient to warrant the courses of action in question.

 

[RavenSky]

Both psychological swimming ability and body density affect drowning probability.

Fixed it for you

 

[Canard DuJour]

I am done arguing with the forum staff. If they have any extra word in this thread, then that word will be the last, if I can restrain myself. They habitually target my ego and my patience, and it gets dangerous when I return fire. Instead, I will lay out the full case that has developed over the course of this thread, with links to all the math. If you disagree, then it is best done in terms of the math, as the argument from the math seems especially strong. Tell me how the physical arguments as presented are either wrong or irrelevant.

There are confirmed racial differences in drowning rates in America, per the OP.

There are confirmed significant differences in body densities between whites and blacks, per post #38.

These racial body density differences imply, for example, that one in 11 black men is like the average white man but wearing an extra five pounds of gold chains, which is 15 times as many blacks as whites, per the statistical calculations in post #63.

To compensate for five pounds, 2.1 liters of extra air must be inhaled, per post #199. The average extra air volume from forced inhalation is only 3.0 liters, proving that extra body density makes a big difference.

In conclusion, the racial body density differences are a strong explanation for the racial differences in drowning rates for having predictive power. Differences in drowning rates are directly expected from the data and the physics concerning body density. If the drowning rates between the races were somehow the same, then it would be unexpected and anomalous, in need of an explanation.

None of this is to claim that differences in average body density is the dominant explanation for any and all group differences. Differences in psychological swimming ability also have a significant effect, and they MAY have an effect on the racial drowning differences. But, if there exists differences in psychological swimming ability between the races, then differences in average body density would likewise predict that, too. And, regardless, any significance of such an explanation does not minimize the significance of the data concerning body densities and the physical predictions that follow.

Nah, you're arriving at the 5 lb extra downthrust by comparing unusually dense black men to averagely dense white men. What you actually find in post #63 is a 1.65 lb differential between average black and white men. Small enough to be rendered nugatory by positive buoyancy from inhalation. A good fart could make all the difference. For a 5 lb racial differential to explain differences in drowning rates, it'd have to be that drowning occurred mostly among unusually dense black men and averagely dense white men. Now it might be that drowning is concentrated among the unusually dense, but it would be for whites too, which would even out the buoyancy differential again. And there is - unsurprisingly - more density variation within than between groups.

It's not nothing, just near-nothing compared to acquired swimming ability in drowning terms. I needn't rattle on about what contrived bollocks this whole thing is as pretty much everyone seems to have noticed.