Sperm whales are incredibly interesting animals. Amongst their multiple records is their ability to dive deep, fast and long.
They are the deepest diving warm blooded animal, they go close to 25 times deeper than their other equally famous and endangered cousin the blue whale. To give an idea of how deep they dive, here is an infographic http://i.imgur.com/ESp2j.jpg The jpg needs to be magnified to get the perspective. From the biological point view what is interesting is not only how they manage to hold their breath for so long but also how they manage to avoid/survive the bends (decompression sickness).
A quick addition to the awesomeness of sperm whales: part of the reason they dive so deep/long is to hunt giant squid. While a sperm whale vs. giant squid battle has never been observed, there are multiple counts of sperm whales with scars that are from squids and in some cases almost certainly from giant squid.
Interestingly this, combined with scars is really the only way we know how big giant squid can get. The largest that has been actually observed or caught is really quite small in comparison to the sizes indicated from sperm whale data.
I should add that this topic made me take a second look at giant squid data (what can i say, i think they are really interesting creatures). It does appear that large giant squid have been found dead but never seen alive or caught. Those seen in a well documented manor or caught have been around 25ft in length max, while the expected maximum size is around 60ft with the largest dead specimen being about 59ft long, although that was in 1878 so i don't consider it overly reliable data.
Add to the list the story where a large sperm whale managed to sink a whaleship that was attacking multiple of its kin [1] (story which later inspired Moby-Dick).
My dive-master friend has told me that the bends isn't an issue if you're holding your breath. The bends is a result of the air mixture that you're breathing with a SCUBA.
This is why freedivers can dive down to 100meters, and then come back up quickly without dieing.
This is not true. DCS has been found in cases of free-divers who perform repeated deep dives. The primary gas that causes DCS is nitrogen, which exists in large quantities in the air you are breathing now. The reason you don't often see DCS in free divers is that it takes time for the high-pressure nitrogen to dissolve in the blood and enter tissue.
My dad was a doctor on a small island, for a year. The islanders dived for sponges and pearls. They couldn't afford a decompression chamber, so if someone got DCS (after freediving too long) they dropped them off the side of the jetty with an old diving helmet, and a friend to keep them company, and pumped air down to them as they gradually re-ascended. Apparently it worked OK.
On the other hand, think about it. With a SCUBA tank, you are taking many breaths under high pressure. With a single free-dive, you only take one breath. With many free-dives, you take many breaths. Is it surprising that repeated deep free-dives cause DCS?
Depends on how deep you dive and the time you spend down there. for instance, people that attempt world records in freediving might need some decompression time after the dive.
I've also read when free-divers are down in such high pressure the plasma of their blood is squeezed out and fills their sinuses. In a way it helps protect them since the large open areas are now filled with fluid.
They do dive deep, but there are various animals that I find more surprising. For example, Wikipedia claims 500m+ for emperor pinguins and 600m for elephant seals.
Also, IIRC, it is fairly hard to get the bends without using scuba gear (not that that says much, but I do not think free divers consider it a grey risk)
It's the invented script from the Cthulhu mythos by the gothic horror writer HP Lovecraft. Cthulhu slept at the bottom of the sea, before being awakened by man or something. I don't know, I haven't read it. That's what the big scary monster thing to the left of the script is.
It's a big part of geek culture, it made its way into D&D, and via that into everything else.
I expect we'll see a similar process with using animals for food. As our scientific knowledge increases, and as our needs increase, synthetic meats will become more and more attractive, eventually leaving us all meat-eaters who do not harvest animals.
Complex systems remind me of a theater set up for a complex play. Hundreds of ropes hang down from the ceiling. Somebody is always pleading us with us to pull rope A to make B happen.
Very rarely does pulling rope A actually make B happen (and nothing else) But we still like thinking things are simple like that.
One could even argue that it's already happened. Modern breeds of food animals are more or less "synthetic meats." They're much more efficient at converting feed into flesh than any natural animal is, and they'd have no chance of surviving in the wild.
In the nineteenth and early twentieth centuries, candles made from spermaceti were used as standard photometric illuminants. They burned more brightly than even today’s paraffin candles, and could be made in a reproducible way [1].
NASA used spermaceti as a binder for joining iron particles to acetate for longer-lasting data storage tapes [2], and one author indicates that it was used more recently as a lubricant on the Voyager probe and the Hubble Space Telescope[3].
It's a sad story about our (over) exploitation of the seas, but very interesting history.
I wonder if any research has been done on producing cetyl palmitate via recombinant DNA synthesis. Imagine having a vat of E. coli or yeast producing it.
As the article mentions, jojoba oil is a decent substitute. I use jojoba around the house to fix squeaky hinges, etc.
"The reason why so many whales were killed in the 20th century was the distant ramifications of replacement of whale oil by petroleum. It took another 100 years to find solutions to these ramifications, and only then it became possible to save the whales. Ecological activism did not play significant role in all of these developments; neither did the numerous well-meaning international treaties, moratoriums, and other chest beating displays."
"A chemist who saved the whales has not merited a Wikipedia entry. His name was P. S. Landis and he was a researcher at Mobile Oil."
A bizarre conclusion IMO. "Only in the 1980s, a chemical solution to this problem was found." At that point, the whales had already been saved. The chemist may have saved automatic transmissions, but the whales were already good by that point.
Whale-oil related trivia: A huge number of recordings have been lost due to the whale oil ban. Magnetic audio tape was made using whale oil as a binder, to help adhere the magnetisable oxide particles to the tape. The first non-whale binders turned out to have very poor long-term durability, causing the oxide to fall off in clumps. Most archivists 'bake' these tapes at low temperatures, to improve the oxide adhesion for just long enough to make a copy.
Great piece of history. I think the author's conclusions are flawed though. He writes:
> Ecological activism did not play significant role in all of these developments; neither did the numerous well-meaning international treaties, moratoriums, and other chest beating displays.
That may be true for the whales themselves, but there were indeed regulations passed on automobiles in the 1970s due to the oil shock:
> In the 1970s, the car companies were required to develop engines working at higher temperatures to comply with lower emissions and improved efficiency and that changed the regime for the tranny fluids. Suddenly, the car companies did not need to lobby any more.
So it was government action regarding auto emissions that wound up propagating into saving the whales. Perhaps that was not among the intended consequences, but we also can't claim that the change was simply due to "market forces."
Of course, he could never use the term "sperm whale". But this is what led to the Endangered Species Act that granted the whales a reprieve. Lang's invention was only a reaction to this. It's still a good read.
Interesting, but gives too little credit to the anti-whaling campaigns: it certainly was no accident that whaling was forbidden as soon as that became economically feasible.
He also was involved in creating Mobil 1 synthetic oil, which is one of the better synthetic motor oils out there.
You could make the argument that better motor oil allows cars to stay on the road longer, reducing demand for energy/materials to make new cars, or increasing the number of affordable, reliable used cars for less wealthy (or more frugal) people to drive. Plus, some improved fuel economy (due to engine being in better repair longer), so less CO2 emissions.
That's a sharp irony, to think the anti-whaling community of the 60's and 70's was driving around with whale oil in their cars! I wonder if they had any idea?
I wonder how much driving they did, though. Personally, I have always avoided cars and environmental impact is one of the major reasons.
Of course I still benefit from cars, I am aware of that (goods get transported by cars, which I then consume). Just saying that some environmentalists actually also avoid driving.
Are anti-whale hunters actually environmentalists though? I mean, is opposing the hunting of whales an environmental thing? I always figured they were more of the animal rights category, and while some people might be both, animal rights != environmentalism.
It boggles the mind why the car companies lobbied to keep whale hunting when their numbers were already so low. They wanted a few more years of automatic transmission working at then-current levels, and then what? The same mass transmission failures that happened, only without anymore whales left. Poachers are similarly mind boggling. Instead of leaving a viable population to harvest more animal parts (not saying it's OK, just for the sake of argument), they hunt down every last animal then move on to other animals.
Oh, and if automatic transmission had never been invented, maybe people would actually know how to drive.
Poachers are similarly mind boggling. Instead of leaving a viable population to harvest more animal parts ... they hunt down every last animal then move on to other animals.
Poaching makes sense to the poacher.
Take a guy I might or might not be related to. When he was growing up his family was dirt-poor and rural. Taking game out of season meant the difference between eating and starvation.
Hard on the deer, if you have a lot of people like that, granted. But laws and conservation and 'think about next year' don't mean much when your family needs to eat today.
yeah, two guys all of us might or may not be related to...
one have domesticated deer, offered good conditions for it to breed (protected it from other predators including hunters like himself) and then he and his children prospered off their cattle...
the other one just hunted his food to extinction...
guess who's children have survived to tell the story?
All of mine - and your - ancestors have done just that. They found new sources for food or they didn't become our ancestors.
I get what you are saying about hunting one's food to extinction, how it's a bad idea.
Do you get what _I_ am talking about when I say that poachers don't _care_ about tomorrow, that they are do poor and desperate that today is all that matters?
That's how agriculture happened, which is the biggest step forward the human race ever took.
And many groups and individuals that failed to evolve towards agriculture either died or have been thrown in slavery (as civilizations with agriculture developed more rapidly than the others without it - that's how cities started to emerge, as suddenly bigger groups could live together).
I get what you're saying too. Personally I would do anything to keep my child from starving. But extinct species are NOT in danger because of poor people that are fighting for their lives. And not all poachers are poor, not all poachers have an excuse, quite the contrary.
Yeah those poor guys with thousands of acres of land with fences, barns and hundreds of pounds of feed for the winter. To bad they aren't smart enough to heard animals. </sarcasm>
Owning a ranch typically isn't a poor man's occupation. It requires investments in land, improvements to the land, food for the animals when the land is unable to support them, etc.
It's true now, it was true at the dawn of animal husbandry: it's more expensive to capture and domesticate wild animals than do the hunter-gatherer thing.
> It boggles the mind why the car companies lobbied to keep whale hunting when their numbers were already so low. They wanted a few more years of automatic transmission working at then-current levels, and then what? The same mass transmission failures that happened, only without anymore whales left.
Exactly. It would make sense for them to try to get around the ban individually, but here they are trying to arrange to all hunt whales collectively. I really don't understand why they didn't all say: "Let the other companies pay for the lobbying about this".
EDIT: I think I could actually explain this pretty well in a cognitive dissonance framework. "We hunt whale. We know we're good people. Therefore, good people support hunting whale. Only bad people don't defend things they do. Therefore, we have to defend whaling."
Sad how there's no discussion of the economy that enables stuff like this to happen. "Why were people so cruel and evil?" is a stupid question; it's not about cruelty or being "evil". It's about money. Don't expect people to be moral in this economic system. Morality is a weakness in a capitalist society, and you'll go out of business if you bring morality into a competitive business ecosystem. This is why we need to change the rules of our economic system, if you care about morality.
Moreover, sure P. S. Landis "saved the whales", but he didn't do it to save the whales, he did it to generate an enormous amount of profit for Mobile Oil, and was paid for it handsomely.
> Moreover, sure P. S. Landis "saved the whales", but he didn't do it to save the whales, he did it to generate an enormous amount of profit for Mobile Oil, and was paid for it handsomely.
OP mentioned that with different intent: in conservation of nature, we can get better results quicker by focusing on improving technology & organization than by merely loudly protesting current uses of natural resources. Alas, it's better to align incentives with conservation of nature than to try to conserve it against 'em.
To the wit,
> Ecological activism did not play significant role in all of these developments (...)
> It was not their attention grabbing activities that stopped killing whales, but the unsung efforts of chemists finding a synthetic replacement to sperm oil.
> Suddenly, the car companies did not need to lobby [for whale hunting] any more.
and in comments below the article:
> But demanding to stop something without suggesting such better alternatives is waste of time. I'd even say that it is immoral. I see many people believing otherwise.
It was not their attention grabbing activities that stopped killing whales, but the unsung efforts of chemists finding a synthetic replacement to sperm oil.
I don't see how a synthetic oil developed in the 1980s could be responsible for a law signed in 1973, and I'm pretty sure it was the law (regardless of where the law came from (the future??)) that directly stopped the killing.
In this case, I'd say the passage of the law led to greater interest in synthetic oil. Conservation led to improving technology, not the other way around.
The original article states clearly that indeed, law regulating cars had great influence -- but it was law regarding tailpipe emissions. The influence was indirect.
> Fortunately for the whales, by the 1970s engines became subject to tighter emissions regulations and engineers had to design them to run hotter (...) increased heat load destroyed the modified sperm oil in the ATF faster (...) forcing research efforts into synthetic lubricants.
> (...) freshly developed synthetic analogs were performing even worse. Only in the 1980s, a chemical solution to this problem was found (...)
At any rate, law prohibiting or limiting something is but a synthetic incentive. It can work, but only to a certain point; works best if there's a substitute available.
Can you name an economic system that doesn't have similar flaws? Economic systems only usable by hunter-gatherers don't count, unless your real argument is with civilization rather than capitalism.
Can you name an ecosystem (as in, natural system) that doesn't have similar flaws?
A predator predates on its prey as long as feasible. When prey is overhunted, some of the predator population dies out (negative feedback, if you will), or the predator adopts (behavior or genome) to use alternative food sources, or to better utilize the resource. Nothing new to see here, move along ;-)
Not that I approve of predatory use of natural resources; we humans sure should know better. Just please don't make it sound unnatural.
When prey is overhunted, some of the predator population dies out (negative feedback, if you will) ... please don't make it sound unnatural.
I think it's OK to characterize human interaction with the ecosystem as unnatural.
Feedback loops like the one you mention work OK for cheetahs and gazelles. Too many cheetahs leads to too few gazelles leads to skinny cheetahs and eventually to fewer cheetahs, etc. But that happens because one is the food for the other; the amount of predation is directly related to the current populations of both, and the amount of predation also has an impact on the future of predation.
Consider an alternate history scenario: No replacement for sperm whale oil was ever found. Sperm whales were hunted entirely to extinction to keep those big American cars rolling. When the whale oil ran out for good and all, Americans all learned to drive stick. Impact on human population of the planet: none. Impact on the rapaciousness of future generations: questionable. Feedback loops (as opposed to straight-line cause and effect) closed or otherwise in evidence at all: zero.
Human interaction with the ecosystem is fundamentally different from the interactions that arise between the other actors within it. Demand for sperm whale oil had virtually nothing to do with the number of humans alive on the planet, and the amount of whale oil left in the world had no impact on the demand for cars, either. With no reciprocal connection, there are no levers for a feedback loop to even take hold of.
One might even say that what separates humans from animals, in the grand scheme of things, is our ability to escape from the feedback loops the rest of the ecosystem is in the thrall of, or even to escape from the feedback loops the rest of the ecosystem is.
> Americans all learned to drive stick. Impact on human population of the planet: none. Impact on the rapaciousness of future generations: questionable. Feedback loops (as opposed to straight-line cause and effect) closed or otherwise in evidence at all: zero.
Either less drivers on the road or more accidents ( i did drive stick back in the Russia and it is very different driving, esp. when all around you is also driving stick). It would also result in smaller cars with less powerful engines. It looks like a very powerful feedback loop for me.
>Demand for sperm whale oil had virtually nothing to do with the number of humans alive on the planet
Huh? who was driving automatic transmission cars?
>One might even say that what separates humans from animals, in the grand scheme of things, is our ability to escape from the feedback loops the rest of the ecosystem is in the thrall of, or even to escape from the feedback loops the rest of the ecosystem is.
a very Grand Statement of Dilusion. We'll see how we escape global warming.
Either less drivers on the road or more accidents ... looks like a very powerful feedback loop for me.
I think you wildly overstate the impact of a whale-oil shortage on traffic. Regardless, unless the horrible maiming of a few thousand distracted drivers would somehow save the whales, we're not talking about a loop.
Huh? who was driving automatic transmission cars?
Humans were, of course, but demand for whale oil was a function of the number of automatic transmission cars on the road, not a function of the human population count. And the places with the strongest population growth at the time (China and India, I would guess) weren't the places buying up all the fancy new auto-transmission cars.
If there were a strong relationship between the population and the demand for this commodity, then demand would have risen relatively smoothly with the population, rather than exploding with the rise of the American suburb.
We'll see how we escape global warming.
I don't know what will happen, but I'm confident quite a few animal species are going to be a lot more screwed than humanity as a whole will be. As long as there's a way to keep humans comfortable by strangling the ecosystem, some of us will do so.
You ask this question as if it were a rhetorical question.
Is there any reason to believe that such an economic system that also combines much of "good" properties of capitalism cannot exist?
Disciplines like game theory and mechanism design have made tremendous advances over the last few decades. Surely we can put these ideas to work in designing better political and economic systems.
It wasn't a rhetorical question. Or rather, it remains a valid rhetorical question until it receives a satisfactory answer. Until that point, all supposed flaws with capitalism are really flaws with all industrial civilizations observed thus far.
Tangentially, no real world economic system is "designed". They evolve out of competing interests. Even if you did design a system and implement it perfectly, it would have unintended consequences. We can't perfectly implement pre-designed political and economic systems, though; every attempt seems to turn into a bloodbath.
Even if you did design a system and implement it perfectly, it would have unintended consequences.
Sure, but what prevents you from then measuring these unintended consequences, plugging them back into your model and asking the question "how should my system change?". Is there any reason to believe we can never reach a stable fixed point?
We do things sort of like this in microprocessor design for instance - where we need to deal with "unintended consequences" like parasitic capacitances and resistances that we cannot fully model until the design is complete, but we need to account for while designing the system.
So who are the designers, and how are they going to do any of this in isolation? Previous attempts have resulted in bloodbaths because the only way anyone can design a society is with large amounts of force. And then the state of the society is better characterized by the bloodbath than by whatever design the bloodbath was intended to create or enforce.
Unintended consequences aren't the only reason you can't design society. The main reason is that society insists on designing itself. It's obvious with a processor who is the designer and what is the designed. Societies are full of people who don't agree with other people's "designs" and won't voluntarily cooperate. So either you give up, or you spend most of your time designing cost-effective means of imposing your designs by force, which always turns into some combination of mass imprisonment, mass murder, and repression.
So who are the designers, and how are they going to do any of this in isolation? Previous attempts have resulted in bloodbaths because the only way anyone can design a society is with large amounts of force. And then the state of the society is better characterized by the bloodbath than by whatever design the bloodbath was intended to create or enforce.
I don't buy the argument that this has to be done by force, or that this necessarily results in a bloodbath. What are governments trying to do when they tweak laws, interests rates and the like but trying to "design" societies?
I'm just suggesting that we take more quantitative and model-based approach to this issue. We can start by simply involving more scientists and engineers in policy decisions, and ask them to use the tools we've developed to analyze complex systems to analyze the socio-economic system that we live in.
To a certain extent, we're already doing this. A hundred years ago, most political decisions were ad hoc based on what "seemed right" to the party in charge. Decisions today are much more data-based and rely on expert input.
Unintended consequences aren't the only reason you can't design society. The main reason is that society insists on designing itself. ...
These are dogmatic statements unsupported by citations. I'm not sure how to respond to them.
Societies are full of people who don't agree with other people's "designs" and won't voluntarily cooperate.
It would have inconceivable five hundred years that "most" people would agree on the following:
(1) large parts of the world would elect their own rulers.
(2) women would have the same rights and privileges as men.
(3) violence as a means of solving problems would be perceived as "wrong".
This perception changed because we see now that these were decisions that benefited society as a whole.
Fundamentally, design is the wrong analogy. In design, there is a designer, and then there is something being designed. In society, the "designer" is already part of society, and he doesn't have the same degree of control an actual designer has.
Let's suppose you assemble everyone together to agree on and implement a design. The design process literally turns into a political process: a competitive effort to benefit fundamentally unreconcilable private interests and opinions rather than a collaborative effort to come up with an objectively good system. Stable, democratic governments aren't designers: they're a manifestation of the powers that be in the society already.
What form of government is a designer? The closest match seems to be some sort of brute-force colonialism--when foreigners try to redesign a society that they, themselves, are not a part of. The next-closest analogy to design is absolute dictatorship. Once you get into stable systems of government, even one-party states like China, or mature colonial states, but especially democracies, the political and economic system governing society is the result of a competitive game between different players, not the result of anyone implementing a design. Framing social problems in design terms is fundamentally wrong--well-functioning societies do not work that way and societies that are designed turn into bloodbaths until reverting to a form of society that's not designed.
I'm not unsympathetic to your viewpoint. I like to design things, too. Unfortunately, some things just can't be designed. There's a process fundamentally dissimilar to design--natural selection--that ultimately produced the human brain out of competing, uncoordinated forces following shallow goals. And when you put humans together in a social context, there are processes fundamentally dissimilar to design, made out of competing, uncoordinated forces, that ultimately produced liberal democracies. The biggest joke on the designer ever is that these undesigned processes eventually end up doing a better job than any designer would, as the blood-soaked social designers of the 20th century discovered.
"The first Matrix I designed was quite naturally perfect, it was a work of art, flawless, sublime. A triumph equaled only by its monumental failure. The inevitability of its doom is apparent to me now as a consequence of the imperfection inherent in every human being. Thus, I redesigned it based on your history to more accurately reflect the varying grotesqueries of your nature. However, I was again frustrated by failure.
I have since come to understand that the answer eluded me because it required a lesser mind, or perhaps a mind less bound by the parameters of perfection. Thus, the answer was stumbled upon by another, an intuitive program, initially created to investigate certain aspects of the human psyche. If I am the father of the Matrix, she would undoubtedly be its mother."
For those who don't know, "mechanism design" is the extremely interesting field which is the "opposite" of game theory: instead of analysing how rational players act in a certain game, it asks what game will force rational players to act in the desired way.
Rather than trying to design for how people should act, we can try to design in a manner that optimizes for measurable objectives that we can all agree on as good. A few objectives I can think of are "least number of people hungry", "most number of people reporting themselves as satisfied" etc.
I don't understand why we aren't doing this now. Our political mechanisms and were designed a few centuries ago by people who had the mathematical and scientific sophistication of a contemporary high school student. There is every reason to believe that we can do better if we put our best minds on this task.
Large scale hunger is typically a symptom of systemic failure, not a lack of food production ability. There's no consensus on how to fix that. Niall Ferguson suggests that the "killer apps" are competition, science, democracy, medicine, consumerism and the Protestant work ethic. This is controversial - see, for and example the comments on his TED talk[1] or the reviews of his book[2].
As for reporting yourself as satisfied, this is hugely subjective. I could be unsatisfied because I think my bosses at my well paid and comfortable programming job are doing things wrongly, this, I suspect, would be a luxury problem to an unemployed graduate on benefits, who again has a luxury problem compared to a homeless crack addict.
> Our political mechanisms and were designed a few centuries ago by people who had the mathematical and scientific sophistication of a contemporary high school student.
Will all due respect, but there's really no way to say this without being a dick: Go read a book. The big philosophers of the enlightenment are towering intellectual capacities.
> There is every reason to believe that we can do better if we put our best minds on this task.
Quite the contrary. People are people and they all have individual goals and desires. Societies can't be designed and directed on any significant scale without devolving into totalitarianism. Our enlightenment friends realized this, and anyone who's tried to do this has failed miserably and bloodily.
I would say, only half facetiously, that game theory has advanced to the point where we are very good at designing systems where everybody loses, but not so good at designing systems where everybody wins.
Distributism has some interesting properties of socialism / capitalism, but would still have killed the whales probably... "The Venus Project" guys believe they can do this, but it just seems like a human enslavement program masked as human empowerment.
The automatic transmission does not cause a species' extinction. People's actions cause extinctions. The title is perhaps revealing about how we think and how we rationalise or justify our actions.
The reason why so many whales were killed in the 20th century was the distant ramifications of replacement of whale oil by petroleum. It took another 100 years to find solutions to these ramifications, and only then it became possible to save the whales. Ecological activism did not play significant role in all of these developments; neither did the numerous well-meaning international treaties, moratoriums, and other chest beating displays.
This is humiliating to us as a race of sentient species.
If we still badly need sperm oil, why don't we work to inject the relevant genes into some bacteria and get our oil in any quantities we want to? Or reproduce the process in any other way (synthesis, cell culture).
Whaling needs to be brought back. Sperm whales are prevalent once again, so controlled harvesting of them should be possible just like hunting deer or anything else. This creates jobs, and contributes to finding renewable energy sources. Furthermore, because without whaling sperm whales have no predators they are getting abundant and taking up too much of the marine ecosystem's food supply. We need to limit their numbers for our own survival. Jobs. Energy. Marine food supply. For all these reasons we need to restore whaling, and we need to do it now.
It is not playing God to hunt to get the resources we need, like, say, hunting buffalo for their meat and fur. That is just survival. We need the whale oil, so hunting them is no more playing God than is hunting buffalo. I do not see a problem here.
They are the deepest diving warm blooded animal, they go close to 25 times deeper than their other equally famous and endangered cousin the blue whale. To give an idea of how deep they dive, here is an infographic http://i.imgur.com/ESp2j.jpg The jpg needs to be magnified to get the perspective. From the biological point view what is interesting is not only how they manage to hold their breath for so long but also how they manage to avoid/survive the bends (decompression sickness).