Ceeboo, on ages assigned to specimens wrote:I don't have a clue (I simply don't "know" and I would propose that nobody else "knows" either, no matter how many times it is suggested that they do "know")
Ren's storytelling has inspired me -- may I have go?
Captain Nemo, in the course of planning a new underwater city, summoned his First Mate, Sebu. "Ah, Sebu, there you are. If you would be so kind as to look off the larboard beam, you will observe some empty beef casks that have been anchored in a roughly circular pattern. These casks mark the proposed boundaries of my new undersea project. However, I need a rough idea of the ocean depth within the area defined by the markers. Be so good as to have a report ready for me this evening."
Now, Sebu's many responsibilities left him no time to personally conduct the requested survey, so he enlisted the aid of three clever Midshipmen. However, each Midshipman had his own idea about making the required measurement, so each went about the task individually. After completing their measurements, the budding oceanographers reported to Sebu in turn.
The first to report was Midshipman Aitken: "Sir, I took the small cutter into the area defined by the casks, and used a weighted line which had knots tied at regular intervals. By counting the number of submerged knots I could determine the depth at any given spot. I took several measurements at various spots within the defined area. The measurements fall in the 20 to 23 fathom range."
"Ah," thought Sebu to himself, "well and good. But what if there exists a strong but undetectable undercurrent -- could it not cause the line to drift somewhat horizontally, thereby inflating the measurement?"
Next, Midshipman Milankovitch reported: "Hullo, Sir. I used rocks tied with a slipknot to an inflated sheep bladder, which I sank at diverse points within the proscribed area. Using a very long bit of string I could undo the slipknot, dontyousee, Sir? After undoing the slipknot, Sir, I used my watch to count out how long it took the bladder to break surface. Using the elapsed time as a variable, I used a buoyancy equation to calculate the depth. Sir, I took several measurements, and got between 21 to 24 fathoms. Sir."
"Aha," Sebu mused, "his results are similar to those of Aitken, but perhaps he has not accounted for possible changes in buoyancy caused by, say, undetected thermal layers? Hmm."
The last Midshipman to report, a jaunty young gentleman with every bit of the swagger expected of a son of the Earl of Isochron, sauntered up to Sebu. "Sir: I took it on myself to devise a mechanical device whereby sound waves may be transmitted through the water and bounced off distant objects. By measuring the returning waves I can plot not only the
depth of an area, but can also make some rather clever inferences about the
shape of the seabed. The floor here is relatively smooth with some small ridges of no consequence. My soundings measured between 21.3 to 24.5 fathoms, with an average depth of 22.7 fathoms."
"Crikey," thought Sebu, "this cove is too confident by half. His results are consistent with those of the other fellows, but I wonder whether he has considered whether something like variable salinity levels may alter his results?"
That evening Sebu reported to Captian Nemo. "So, there you are, Sebu. What news? Have your measurements been successful?"
"Sir! As to the depth -- well, Sir, it's like this: I don't know. And neither does anyone else."
