Freethought & Rationalism Archive

Happy Wonderer · 11-04-2002, 10:08 PM

Quote:

Originally posted by Vanderzyden:
I'm sure that you realize that I am not referring to the total system volume. Rather, I am specifically referring to the local volume at a particular POINT in the system. The IVC and SVC both converge, and the combined volume flow-rate of both of these trunk veins drains into the right atrium. Therefore, it necessarily follows that there is no greater volume of blood flow in the entire CV system.
[QB][/QB]

Does anybody else see the comic genius in this statement? Bravo! Think about it -- the volume at a point -- just how many angels can dance in that volume, anyway?

HW

[ November 04, 2002: Message edited by: Happy Wonderer ]</p>

HRG · 11-05-2002, 01:46 AM

Quote:

Originally posted by Vanderzyden:
Jack,

I hesitate to even respond to you, because of your consistently abrasive and degrading tone. However, you should realize that you are so very much in error with your posts. Perhaps the worst statement you made is:

"And it's just as easy to pump up as it is to pump down."

Go back and read my posts about hydrostatic pressure. Then go pick up a first year physics text. Then go pick up a statics text to see hydrostatic principles reaffirmed. Then go pick up a fluid mechanics text and focus on fluid statics to see the principles yet again affirmed and extended (fluid dynamics also produce significant effects, but we may safely ignore them for our purposes here).

He can go as far back as Archimedes, since he has just applied that worthy's pr�nciple.

Within a water environment, it is as easy to pump up as to pump down - if you are pumping water. If you are pumping air, it is even more difficult to pump down than to pump up.

IOW, your talk about hydrostatics and fluid dynamics belongs to a different discipline: thermoaerodynamics (the science of blowing hot air).

HRG.

Nickle · 11-05-2002, 08:13 AM

I still didn't see any responses to the historical "leftovers" that lpetrich and sci-girl talked about near the beginning of the thread.

But, at any rate, I've been learning quite a bit, and the links were very informative. thx

"Oh what a goofy work is man!" - the Tick

Vanderzyden · 11-05-2002, 08:23 AM

"There is no point asserting and reasserting what the heart cannot believe."

-- Aleksander Solzhenitsyn, Nobel Prize Winner, author of "The Gulag Archipelago"

In this case, it is both the heart and mind.

Jack the Bodiless · 11-05-2002, 08:32 AM

I'm still hoping that you will one day tell us why your heart and mind became so firmly closed to the outside world, Vander.

pz · 11-05-2002, 09:43 AM

Quote:

Originally posted by Vanderzyden:
<strong>"There is no point asserting and reasserting what the heart cannot believe."

-- Aleksander Solzhenitsyn, Nobel Prize Winner, author of "The Gulag Archipelago"

In this case, it is both the heart and mind.</strong>

Your heart has some say in your beliefs about hydrodynamics?

Ted Hoffman · 11-05-2002, 10:13 AM

Great work Mr. Darwin, Rick, Scigirl, JTB, DD, Pz, Lpetrich and others. This is a very edifying discussion.
I have followed this discussion from the start. I think Vander has really put in quite some effort and I think its mildly impressive coming from a man I uncritically thought was a closed-minded retard. <from Vanders records, Intensity changes Vanders IQ to 120 - from 90>. I am very sure if he has a baby as he claims, he has ignored the baby (and wife?) of late. That is the price he has to pay to stay afloat when besieged by people who understand the subject - for someone out on a limb who has set himself up against a horde of no-nonsense experts, he is doing quite well. But he is letting his wounds show...

One of his greatest undoing in this gargantuan effort however is his huge phobia to admit error and I was impressed when he actually acted uncharacteristically and made a historic mea culpa.
Then Vandern has put his feet in his mouth over a very simple matter - this gravity thing which Jack the Bodiless has refuted without much effort.
Vander wastes time posturing and making irrelevant statements like he has taken advanced studies in fluid dynamics (WGAF!). That was a minus. Especially given the fact it has taken a combined effort to teach him that gravity is not a factor when pumping fluid within a fluid. He has to be dragged by the ear, kicking and screaming, to see such a simple fact.

His intransigent unwillingness to tackle Mr. Darwins responses is also childish and has served to make the discussion barren. This is inconsistent considering Vander claimed to rick that he was enjoying the discussion immensely and would like to see it progress. This childish stubbornness has justified Ricks comments that Vander is too ignorant, arrogant and dishonest to debate with.

Then there is his mealy-mouthed approach to issues he insults people then insists he has not. He has a poor grasp of terminology and Rick clearly pinned him down on the matters concerning volume, flow and pressure, space, potential space, heh, even thoracic surgeon and endoscipist etc.

Vander has obviously read a lot on the subject. Which is commendable. But he doesnt seem to have enough command on the subject to effectively deal with the dynamics of a discussion of this nature. Perhaps thats why he resorts to vacuous grandstanding (I am an expert in fluid dynamics) and demaning others which are basically diversions.

His sterile, post-mining response to sci-girls post, which Rufus has ably refuted and exposed for the closed-minded, tangential blather that it is has lost Vander more points.

Vander, I know its tough being where you are, but it would help your case a lot if you tried to stick to the issue at hand. Dont bother characterizing people (you arent qualified to do that and its irrelevant anyway). Dont respond to insults. Just pick the points and refute them one by one. Dont be distracted by the noise.

I am sure you can make at the very least a valid argument. But first, you must focus, be willing to learn (we all have knowledge gaps - its no biggie to admit error) and appreciate what other people feel and state.
Insults and grandstanding dont help your case. Unless you are here to insult people. Which I doubt very much - you just do it out of frustration and for lack of tact.

And Rick et al. I envy you for your stoic patience in dealing with Vander, but he is only human and is as frustrated as you are, so even as you beat him over the head, bear that in mind. A fallible, limited human trying his best to advance a belief he is willing to die for.

He reminds me of Layman. Layman is a well-read chap, very abrasive, stubborn and sometimes insulting. Toto handles him with implacable patience and totally ignores the insults. Its simply humbling to watch. Try it with Vander. You ignore every insult he throws and focus on the salient and pertinent facts in his post - if any. That is the only way to inspire the fear of God in him. If and when he spews crap, simply ignore the crap. Don't address it.

That is just my suggestion. When he leaves this board, he should know that we dont stoop down to his level whatsoever.

Intensity,
IIDB Moderetor, Third Class
<NB: That is Moderetor>

scigirl · 11-05-2002, 10:18 AM

Heh pz, maybe he means his real heart - you know the organ we are discussing!

Ok here's what my Animal Physiology text has to say:
(Eckhert 4th edition)

Quote:

Pooling of blood, with changes of position with respect to gravity, is not a problem for animals in water, because the density of water is only slighly less than that of blood, whereas air is much less dense than blood. In water, the hydrostatic pressure increases with depth, and effectively matches the increase in blood pressure due to gravity; thus transmural pressure does not change, so the blood does not pool.

Does that relate also to a fetus in the womb?

I also had these thoughts:

Quote:

Vanderzyden:
You continue to avoid the critical fact of gravity, both for its benefits and its implications. The height over which gravity acts is directly and significantly proportional to hydrostatic pressure. Until you address this central issue, you have done precious little to support your case.

Ok we can all agree (except John I guess) that this argument is irrelevant for fetal circulation. However, let's suppose we are talking about terrestrial vertebrate circulation. I was reading about the circulation in a giraffe. It seems to me that Vanderzyden's argument, when carried to its logical conclusion, would prove that giraffes can't exist:

Quote:

Gravity has little effect on capillary flow, which is determined by the arterial-venous pressure. That is, gravity raises arterial and venous pressure by the same amount and therefore does not greatly affect the pressure gradient across a capillary bed. Because the vascular system is elastic, however, an increase in absolute pressure expands blood vessels...Thus, pooling of blood tends to occur, particularly in veins, in different regions of the body as an animal changes position with respect to gravity. This effect is related solely to the elasticity of blood vessels and would not occur if the blood flowed in rigid tubes.

The problems of pooling and maintaining capillary flow are acute in species with long necks. For instance, when the giraffe is standing with its head raised, its brain is about 6 meters above the ground and over 2 meters above the heart. If the arterial pressure of blood perfusing the brain is to be maintained at around 98 mm Hg, aortic blood pressure must be 195-300 mm Hg near the heart. Aortic blood pressures greater than 195 mm Hg have been recorded in an anesthetized girrafe whose head was raised 1.5 meters.

The book goes on to say that giraffes compensate for this pooling problem by regulating vasoconstriction and vasodilation of the peripheral vasculature, NOT by alternative placement of vessels.

So I guess my point is - how important is the placement of vessels in our measly hearts, when a giraffe seems to survive just fine with its head meters above its heart vessels? If Vanderzyden's argument is correct, and the vessels have to be in those exact orientations in order for us to survive, then how in the bloody blazes is a giraffe (who has the same circulatory system we do) surviving?

Does this question make sense? I haven't taken physiology yet...

One more slightly off topic point I found while reading my Phys book:

Quote:

The presence of a similar physiological process supported by a similar anatomic structure in several distantly related animal species occupying a single enviornment would suggest that process-structure combination is adaptive. Such comparative studies are more powerful if they are coupled with the examination of closely related species in different environments. A classic example of the power of this approach involves the llama and its close relative the camel. Originally, researchers were convinced that the unusually high affinity of llama blood for oxygen was an adaptation to the rarefied air at the high altitudes at which llamas live. To their surprise, animal physiologists discovered that camels, who live at low altitudes, also have high-affinity blood. Thus, [i]the llama's high-oxygen affinity blood is not a specific adaptation to high altitude. That is, the blood characteristics of llamas and camels have little to do with the altitude at which they live, and much to do with their being in the camel family.

Once again, evolution explains the similarities better than intelligent design - why would an "intelligent" designer bother giving camels a blood system adapted for high altitude?

scigirl

scigirl · 11-05-2002, 10:29 AM

Quote:

Intensity,
IIDB Moderetor, Third Class
<NB: That is Moderetor>

Just wanted to clarify that Intensity is not indeed a moderator of the E/C discussion - in case this causes confusion!

Intensity - please check your PM. Thanks!

scigirl

Vanderzyden · 11-05-2002, 03:18 PM

Pressure:

Pressure is another parameter that we must be concerned with. There are two kinds of pressure, transmural pressure and perfusion pressure.

Transmural pressure is the pressure difference between the inside and the outside of a structure. For example, the pressure difference between the inside and the outside of the left ventricle, or the pressure difference between the inside and outside of a blood vessel.

Perfusion pressure on the other hand is the difference in pressure between two different sites in a system of tubes where fluid is flowing or has the potential to flow from one point to another. Perfusion pressure is also called the pressure head or the driving pressure. Perfusion pressure is equal to one transmural pressure minus a second transmural pressure; for example, one located at one point in a hydraulic system minus the transmural pressure at another point in a hydraulic system. Mean arterial (aortic) pressure minus mean venous pressure yields the perfusion pressure. It is largely responsible for the blood flowing through the systemic circulation from the aorta to the vena cavae.

<a href="http://www.coheadquarters.com/PennLibr/MyPhysiology/lect5/pen5.03.htm" target="_blank">http://www.coheadquarters.com/PennLibr/MyPhysiology/lect5/pen5.03.htm</a>

Think about it: If you are floating upright in a pool of water, will your blood not flow down your aorta, assisted by gravity? Of course it will.

The only way to avoid gravitational effects on internal closed systems is to move to a gravity-free environment (e.g. outer space). Buoyancy in a fluid does not diminsh the effects of sea-level gravity on internal hydraulics, whether natural or man-made.

John

[ November 05, 2002: Message edited by: Vanderzyden ]</p>

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11-05-2002, 08:13 AM	#233
Nickle Regular Member Join Date: Oct 2001 Location: Texas Posts: 385	I still didn't see any responses to the historical "leftovers" that lpetrich and sci-girl talked about near the beginning of the thread. But, at any rate, I've been learning quite a bit, and the links were very informative. thx "Oh what a goofy work is man!" - the Tick

11-05-2002, 08:23 AM	#234
Vanderzyden Senior Member Join Date: Jul 2002 Location: California Posts: 694	"There is no point asserting and reasserting what the heart cannot believe." -- Aleksander Solzhenitsyn, Nobel Prize Winner, author of "The Gulag Archipelago" In this case, it is both the heart and mind.

11-05-2002, 08:32 AM	#235
Jack the Bodiless Veteran Member Join Date: Feb 2001 Location: UK Posts: 5,815	I'm still hoping that you will one day tell us why your heart and mind became so firmly closed to the outside world, Vander.

11-05-2002, 10:13 AM	#237
Ted Hoffman Veteran Member Join Date: Feb 2001 Location: "" Posts: 3,863	Great work Mr. Darwin, Rick, Scigirl, JTB, DD, Pz, Lpetrich and others. This is a very edifying discussion. I have followed this discussion from the start. I think Vander has really put in quite some effort and I think its mildly impressive coming from a man I uncritically thought was a closed-minded retard. <from Vanders records, Intensity changes Vanders IQ to 120 - from 90>. I am very sure if he has a baby as he claims, he has ignored the baby (and wife?) of late. That is the price he has to pay to stay afloat when besieged by people who understand the subject - for someone out on a limb who has set himself up against a horde of no-nonsense experts, he is doing quite well. But he is letting his wounds show... One of his greatest undoing in this gargantuan effort however is his huge phobia to admit error and I was impressed when he actually acted uncharacteristically and made a historic mea culpa. Then Vandern has put his feet in his mouth over a very simple matter - this gravity thing which Jack the Bodiless has refuted without much effort. Vander wastes time posturing and making irrelevant statements like he has taken advanced studies in fluid dynamics (WGAF!). That was a minus. Especially given the fact it has taken a combined effort to teach him that gravity is not a factor when pumping fluid within a fluid. He has to be dragged by the ear, kicking and screaming, to see such a simple fact. His intransigent unwillingness to tackle Mr. Darwins responses is also childish and has served to make the discussion barren. This is inconsistent considering Vander claimed to rick that he was enjoying the discussion immensely and would like to see it progress. This childish stubbornness has justified Ricks comments that Vander is too ignorant, arrogant and dishonest to debate with. Then there is his mealy-mouthed approach to issues he insults people then insists he has not. He has a poor grasp of terminology and Rick clearly pinned him down on the matters concerning volume, flow and pressure, space, potential space, heh, even thoracic surgeon and endoscipist etc. Vander has obviously read a lot on the subject. Which is commendable. But he doesnt seem to have enough command on the subject to effectively deal with the dynamics of a discussion of this nature. Perhaps thats why he resorts to vacuous grandstanding (I am an expert in fluid dynamics) and demaning others which are basically diversions. His sterile, post-mining response to sci-girls post, which Rufus has ably refuted and exposed for the closed-minded, tangential blather that it is has lost Vander more points. Vander, I know its tough being where you are, but it would help your case a lot if you tried to stick to the issue at hand. Dont bother characterizing people (you arent qualified to do that and its irrelevant anyway). Dont respond to insults. Just pick the points and refute them one by one. Dont be distracted by the noise. I am sure you can make at the very least a valid argument. But first, you must focus, be willing to learn (we all have knowledge gaps - its no biggie to admit error) and appreciate what other people feel and state. Insults and grandstanding dont help your case. Unless you are here to insult people. Which I doubt very much - you just do it out of frustration and for lack of tact. And Rick et al. I envy you for your stoic patience in dealing with Vander, but he is only human and is as frustrated as you are, so even as you beat him over the head, bear that in mind. A fallible, limited human trying his best to advance a belief he is willing to die for. He reminds me of Layman. Layman is a well-read chap, very abrasive, stubborn and sometimes insulting. Toto handles him with implacable patience and totally ignores the insults. Its simply humbling to watch. Try it with Vander. You ignore every insult he throws and focus on the salient and pertinent facts in his post - if any. That is the only way to inspire the fear of God in him. If and when he spews crap, simply ignore the crap. Don't address it. That is just my suggestion. When he leaves this board, he should know that we dont stoop down to his level whatsoever. Intensity, IIDB Moderetor, Third Class <NB: That is Moderetor>

11-05-2002, 03:18 PM	#240
Vanderzyden Senior Member Join Date: Jul 2002 Location: California Posts: 694	Pressure: Pressure is another parameter that we must be concerned with. There are two kinds of pressure, transmural pressure and perfusion pressure. Transmural pressure is the pressure difference between the inside and the outside of a structure. For example, the pressure difference between the inside and the outside of the left ventricle, or the pressure difference between the inside and outside of a blood vessel. Perfusion pressure on the other hand is the difference in pressure between two different sites in a system of tubes where fluid is flowing or has the potential to flow from one point to another. Perfusion pressure is also called the pressure head or the driving pressure. Perfusion pressure is equal to one transmural pressure minus a second transmural pressure; for example, one located at one point in a hydraulic system minus the transmural pressure at another point in a hydraulic system. Mean arterial (aortic) pressure minus mean venous pressure yields the perfusion pressure. It is largely responsible for the blood flowing through the systemic circulation from the aorta to the vena cavae. <a href="http://www.coheadquarters.com/PennLibr/MyPhysiology/lect5/pen5.03.htm" target="_blank">http://www.coheadquarters.com/PennLibr/MyPhysiology/lect5/pen5.03.htm</a> Think about it: If you are floating upright in a pool of water, will your blood not flow down your aorta, assisted by gravity? Of course it will. The only way to avoid gravitational effects on internal closed systems is to move to a gravity-free environment (e.g. outer space). Buoyancy in a fluid does not diminsh the effects of sea-level gravity on internal hydraulics, whether natural or man-made. John [ November 05, 2002: Message edited by: Vanderzyden ]</p>

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