tag:blogger.com,1999:blog-622245026181649435.post4493410259014727740..comments2023-09-04T08:54:47.705-07:00Comments on Penguinology: Drag Reduction by Air Release Promotes Fast Ascent in Jumping Emperor Penguins paper download linkUnknownnoreply@blogger.comBlogger1125tag:blogger.com,1999:blog-622245026181649435.post-78440599874693298652015-01-13T03:22:19.132-08:002015-01-13T03:22:19.132-08:00I do not understand how the air that is trapped wi...I do not understand how the air that is trapped within the "plumage" of the Emperor penguin is retained while the penguin dives to depths far in excess of three standard atmospheres? I am assuming that a penguin cannot achieve some form of internal equilibrium (isostatic balance) of pressure within its rapidly changing surrounding environment? I would reason that a penguin descending in water depth would simultaneously undergo a rapid external compression with a subsequent loss of external surface area (S.A.). The loss of S.A. being due to the necessary volume changes occurring within the birds formerly "aerated" plumage layer. This gaseous layer or envelope of air that is trapped within the plumage of these birds would reduce in volume at a rate proportional to the density of the surrounding liquid medium and with increasing depth of dive. <br />For the life of me I cannot fathom how a penguin can trap air within its plumage layer in such a way that it is not rapidly expelled or expressed from within the interstices of their plumage during a rapid descent where much higher static water pressure levels exist?<br />It is suggested that these birds can voluntarily control and hold onto this ballast gas until such time as it is needed. How on earth can they do this? Is there some form of voluntary, and rapidly reversible form of chemisorption occurring within the boundary layer of the plumage and the trapped air? <br />Sincerely,<br /><br />mrc109Mrc109https://www.blogger.com/profile/11397856022645397410noreply@blogger.com