N.Wells
Posts: 1836
Joined: Oct. 2005
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Gary's latest at http://sandwalk.blogspot.com/2015.......ny.html
| Quote | I never claimed that the time delay is necessary for the production of infrasound. It's simply an indicator of the lowest frequency that these large animals are able to produce, which is something that YOU need to consider to properly test YOUR hypothesis that the long route and the resulting time delay that slows down the shorter route (by not allowing full myelination hence transmission speed) to match the longer route is a bad design that serves no purpose. Demanding that I essentially do your science work for you is moving the goalposts in order to put the burden of proof on those who are not willing to jump to conclusions like you are.
A wise scientist waits until conclusive evidence has been provided before claiming to have a conclusive answer. It does not even matter to me which way the evidence goes. I'm just telling you that you do not have enough evidence yet. |
Let's set aside the minor details that I have been giving references for lots of evidence, and that Gary's modus operandi is to make grandiose claims with no evidence whatsoever, and that it does matter to him which way the evidence goes, and that it is Gary who keeps throwing chaff and running around with the goalposts, and that I'm doing my own science work as well as providing the facts relative to Gary's rubbish, and that I am not proposing an hypothesis without evidence but am merely questioning Gary's entirely unsupported hypothesis.
Let's concentrate instead on the lies that he starts with.
| Quote | | [From Gary] I never claimed that the time delay is necessary for the production of infrasound. |
| Quote | | [From Gary, 20 May 2014, this thread] 15 foot detour = 4.5 meters ........... Where the actual velocity equals ~4.5 m/s the time delay is ~1 second, which is the sound-chamber resonance shown in the video for a long distance adult giraffe call ......the math clearly indicates further investigation should have first been conducted, before concluding that a delay that increases with the length of the chamber to be resonated indicates a bad design. |
| Quote | | [Also from Gary] Ironically giraffes do not make the trumpeting type sounds like other large animals such as elephants are able to. This is expected of a vocal circuit that has a longer time delay than the others. |
| Quote | | [Also from Gary] I can see that you have never designed acoustic circuits to resonate a speaker or other resonant device. If the time delay between each wave is too short all you will hear (if anything) is a low volume high pitched squeal. For proper operation the system has to be timed to operate above and below the resonant frequency. It's very basic electronics, acoustics. |
| Quote | | [Also from Gary] See pages 1 through 9 (especially page 4) for an example of the information that is necessary to test your hypothesis that the extra length (hence time delay) of the recurrent laryngeal nerve serves no purpose |
His claim is thus shown to be a lie.
| Quote | | [Also from Gary] the time delay is ....... simply an indicator of the lowest frequency that these large animals are able to produce |
No, it’s not. Again, you have no evidence that there is a time delay, and we can produce infrasound from a dead larynx that has no nerve activity, and hence no transmission lag. Its nerves have passed on. They are no more. They have ceased to be. They’ve expired and gone to meet their maker. Bereft of life, their nervous processes are now history. They’ve kicked the bucket, shuffled off their mortal coil. It is an excised larynx, but it can still join the bleedin’ infrasonic choir inaudible.
Oh and you also asked for a circuit diagram: https://c1.staticflickr.com/1....1_....1_b.jpg
All the sound-producing muscles of the larynx except one are innervated by the recurrent laryngeal nerve rather than the superior nerve. The exception is the cricothyroid muscle, which tensions the vocal folds, thereby controlling pitch phonation: no signal lag or exceptional resonating chamber length are involved. The cricothyroid muscle works at the bottom of the larynx, but is innervated by the shorter, upper, nerve, while the lower (left recurrent) nerve innervates muscles at the top, middle, and bottom of the larynx. Not only have you not yet demonstrated that there is a signal lag, you have also not explained how giraffes would get around the resulting problems (pointed out to you over a year ago) that would be caused by a lag: synchronized nerve signal arrival is important in functions like coughing and swallowing as well as coordinating the cricothyroid muscle with the other phonation muscles. The available evidence indicate that this is taken care of by differential myelination (thicker myelin sheathing on the longer nerve, causing faster signal transmission).
Edited to add: note that nerves don't make circuits. Also note that alligators, rhinos, hippos, and cassowaries don't trumpet, despite not having large differences in RLN lengths.
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