| Poutnik <poutnik4nntp@gmail.com>: Dec 22 10:10AM +0100 Dne 22/12/2015 v 01:04 M. Stradbury napsal(a): > Is it true (or an urban myth) that a swimmer would be sucked > under (presumably to drown) when a capital ship sinks? I suppose there are many eye witnesses. My not confirmed idea is, that for very most time is sinking too slow to be dangerous in this way. But in final stage, the one ship end is often submersed and the ship is sliding down fast, or the ships turns upside down, or horizontally positioned ship accelerates sinking toward the bottom. In such scenario the motion is fast, causing vertical streams and vertigos. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 10:18AM +0100 Dne 22/12/2015 v 02:56 Micky napsal(a): > I would think so. I was in a 6-man rubber raft that went over a > small falls and under water and though I wasn't tied to the raft, I > went under water too. How much more so with a big ship. But it could be because of your motion dynamics, as you inertially continue water under, until your buoyancy gradually reverted your velocity. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 10:36AM +0100 Dne 22/12/2015 v 04:51 Sylvia Else napsal(a): >> under (presumably to drown) when a capital ship sinks? > Mythbusters tried it, and concluded that there was no significant > sucking sown. I have often the impression their experiments are designed in the first place rather for the effect, than to really investigate the nature of phenomena. E.g. I watched their investigation of economic effect of frequent switching on/off the incandescent, fluorescent and LED lights. They were over focused to refute the obvious nonsense the light at switching consume more power than saved by being off, and were successful there. OTOH, experiment part about saving power versus shortening device life was very poorly designed and result had no statistical value. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Micky <NONONOmisc07@bigfoot.com>: Dec 22 05:04AM -0500 On Tue, 22 Dec 2015 10:18:34 +0100, Poutnik <poutnik4nntp@gmail.com> wrote: >But it could be because of your motion dynamics, >as you inertially continue water under, >until your buoyancy gradually reverted your velocity. True. I'm no longer convinced. (Even though I doubt mythbusters on general principles). If one were right by the ship when it went quickly down, one would fall into the hole it left, but the water it pushed aside would be crashing back right after the ship passed also. How deep the person would go is a question. I think if you were standing on the deck, whether the deck was horizontal or leaning, you could drop as fast as the ship did. Why not? Until there was enough water surrouding you for buoyancy to matter. But if you were 3 inches from the ship, already floating in the water, would you fall over like in a waterfall? I think so, but like I say, you'd be competing with the water to see who and what dropped first. One could experiement with little floating balls and big rocks dropped close to them, or better yet, held close to them at surface level and then released. A method for determining how deep they go would be needed. Anyhow my point originally was no swirling. I coudl have kept silent on other stuff. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 11:06AM +0100 Dne 22/12/2015 v 08:58 Sylvia Else napsal(a): > the vessel would suck me down if it sank? > Or do you think there's some sort of mechanism that allows enlightenment > by osmosis? Nautical society has advantage of collective experience of huge number of people, surviving the ship sinking. Even if I had been Nobel laureate for physics, sailors would know more about surviving on sea than me. If personalizing, Sea has already laughed to many theoretical thoughts. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 11:13AM +0100 Dne 22/12/2015 v 05:36 M. Stradbury napsal(a): > Theory 1: > Air mixes with water makes the water less dense, hence > sucking you down. I have seen a video where a boat was in a lab sinked by this way, in document about the Bermuda triangle, following the hypothesis about sudden huge gas release from the sea bad or underwater vulcanos. Sinking a swimmer with density close to water is much easier than sinking a boat. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 11:18AM +0100 Dne 22/12/2015 v 07:06 O napsal(a): > Back then, the reason to get away from the sinking ships was not the > suction but the boilers exploding. I agree it is the best to get far from a wreck independently on if whirl sucking is a danger or not. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Micky <NONONOmisc07@bigfoot.com>: Dec 22 06:07AM -0500 On Tue, 22 Dec 2015 11:13:47 +0100, Poutnik <poutnik4nntp@gmail.com> wrote: >> Air mixes with water makes the water less dense, hence >> sucking you down. >I have seen a video where a boat was in a lab sinked by this way, I knew a guy who drowned in club soda. I think there was a lot of scotch, too. |
| Sylvia Else <sylvia@not.at.this.address>: Dec 22 10:13PM +1100 On 22/12/2015 9:06 PM, Poutnik wrote: > of huge number of people, surviving the ship sinking. > Even if I had been Nobel laureate for physics, > sailors would know more about surviving on sea than me. For most things, perhaps. But how many sailors have experience of a sinking, much less such experience from the the immediate vicinity of the ship. Those who got sucked down, if any, won't be around to tell the tale. Those who didn't get sucked down, and survived, would be counter-examples. Sylvia. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 12:45PM +0100 Dne 22/12/2015 v 12:13 Sylvia Else napsal(a): > the ship. Those who got sucked down, if any, won't be around to tell the > tale. Those who didn't get sucked down, and survived, would be > counter-examples. I do not say current sailors, but history of survival records and withnesses. There are 2 other options. Those surviving seeing others being sucked down, Those being sucked down not enough to die. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 02:04PM +0100 Dne 22/12/2015 v 04:51 Sylvia Else napsal(a): > Mythbusters tried it, and concluded that there was no significant > sucking sown. > https://www.youtube.com/watch?v=rvU_dkKdZ0U But the did not make any attempt to maintain geometrical similarity. IF a sailor size was 1/4 of a ship size, he would not be sucked either. I am not sure, if the viscosity has to be scaled as well for that matter, but I guess it has. As I mentioned in my other post the Mythbusters do not care much about reliability of their experiments and interpretations. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| "taxed and spent" <pleasedonot@spamme.com>: Dec 22 05:08AM -0800 "Sylvia Else" <sylvia@not.at.this.address> wrote in message news:ddrvmlF4vpjU1@mid.individual.net... > sown. > https://www.youtube.com/watch?v=rvU_dkKdZ0U > Sylvia. mythbusters is a crock. |
| "(PeteCresswell)" <x@y.Invalid>: Dec 22 08:53AM -0500 Per M. Stradbury: >Is it true (or an urban myth) that a swimmer would be sucked >under (presumably to drown) when a capital ship sinks? Dunno what a capital ship is but am guessing it's big. I saw an interview clip in which Lord Louis Mountbatten told of surviving his destroyer's sinking - along with a senior NCO who said at the time something like "Well sir, the scum always rises to the surface" so I am guessing that both were in the water when the ship went down under them. -- Pete Cresswell |
| "M. Stradbury" <mstradbury@example.com>: Dec 22 02:28PM On Tue, 22 Dec 2015 08:53:14 -0500, (PeteCresswell) wrote: > Dunno what a capital ship is but am guessing it's big. My bad for not defining it, but you, sir, are correct, although in looking it up, I realized I was not correct: https://en.wikipedia.org/wiki/Capital_ship |
| Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Dec 22 10:52AM -0500 On 12/21/2015 07:04 PM, M. Stradbury wrote: > Is it true (or an urban myth) that a swimmer would be sucked > under (presumably to drown) when a capital ship sinks? Yes. The main mechanism iirc is that air escaping from the sinking ship causes enough bubbles that the swimmer can't stay afloat, and sinks too deep to get back to the surface. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net |
| "Bob F" <bobnospam@gmail.com>: Dec 22 08:16AM -0800 M. Stradbury wrote: > Is it true (or an urban myth) that a swimmer would be sucked > under (presumably to drown) when a capital ship sinks? I would think that huge bubbles of air coming out of a sinking ship could easily drop people deeply under water. If a bubble surrounds you, you will not be floating anymore. You will be falling. |
| "Bob F" <bobnospam@gmail.com>: Dec 22 08:19AM -0800 M. Stradbury wrote: > (and even hurricanes or cycloness) preferentially spins > counter-clockwise in the north and clockwise in the south, you just > might not be able to see it with your toilet water." I just flushed both my toilets. One went clockwise. The other went counterclockwise. QED. |
| "(PeteCresswell)" <x@y.Invalid>: Dec 22 11:41AM -0500 Per M. Stradbury: >https://en.wikipedia.org/wiki/Capital_ship Then I guess my little anecdote is moot because a destroyer looks much smaller than an aircraft carrier or battle ship... -- Pete Cresswell |
| Poutnik <poutnik4nntp@gmail.com>: Dec 22 05:45PM +0100 Dne 22/12/2015 v 17:19 Bob F napsal(a): >> might not be able to see it with your toilet water." > I just flushed both my toilets. One went clockwise. The other went > counterclockwise. QED. There are too strong forces, fast current speeds and random turbulent processes for Coriolis force to have any effect. -- Poutnik ( the Czech word for a wanderer ) Knowledge makes great men humble, but small men arrogant. |
| Tim R <timothy42b@aol.com>: Dec 22 05:59AM -0800 There is an old paper where a musician claims to have used an oscilloscope to measure a particular trumpet tone and proved it was a pure sine wave. There is no date available but probably late 50s, the company was started in 1956. So we're talking whatever scope technology would have been available then. I've always been a bit skeptical about the claims because there are some other aspects that don't make sense to me. However, my question is about how you would use a 1950s era scope to determine a sine wave or the degree of harmonics present. Most musical tones have a series of harmonics above the fundamental that add the characteristic tone. |
| ggherold@gmail.com: Dec 22 07:26AM -0800 On Tuesday, December 22, 2015 at 8:59:55 AM UTC-5, Tim R wrote: > There is an old paper where a musician claims to have used an oscilloscope to measure a particular trumpet tone and proved it was a pure sine wave. There is no date available but probably late 50s, the company was started in 1956. So we're talking whatever scope technology would have been available then. > I've always been a bit skeptical about the claims because there are some other aspects that don't make sense to me. > However, my question is about how you would use a 1950s era scope to determine a sine wave or the degree of harmonics present. Most musical tones have a series of harmonics above the fundamental that add the characteristic tone. Seems doubtful, I mean I can play a pure sinewave into a speaker and I know what that sounds like. A trumpet sounds different. George H. |
| "Ralph Mowery" <rmowery28146@earthlink.net>: Dec 22 10:29AM -0500 "Tim R" <timothy42b@aol.com> wrote in message news:08de2443-cf3c-4789-9b30-ab353a31ae82@googlegroups.com... >determine a sine wave or the degree of harmonics present. Most musical >tones have a series of harmonics above the fundamental that add the >characteristic >tone. An easy way would be to use a high pass filter or a notch filter to filter out the frequency of the note and then look to see if anything is left. Look for a SINAD or distortion meter. When you filter out the origioinal wave (first harmonic) anything that is left is from a frequency that is not the sine wave. It could be distortion or a harmonic. The scope could be used to determin what frequency or which harmonic is left over. |
| Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Dec 22 10:57AM -0500 > Seems doubtful, I mean I can play a pure sinewave into a speaker and > I know what that sounds like. A trumpet sounds different. > George H. Well, given that the trumpet is driven by a relaxation oscillation of the player's lips, it would be quite strange if there weren't a lot of harmonics. Odd harmonics would be nearly resonant, I think, though the shape of the bell means that the resonance isn't really an organ-pipe mode. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net |
| c4urs11 <c4urs11@domain.hidden>: Dec 22 04:02PM On Tue, 22 Dec 2015 05:59:52 -0800, Tim R wrote: > However, my question is about how you would use a 1950s era scope > to determine a sine wave or the degree of harmonics present. Scopes from that era easily reached several MHz of bandwidth. That should be considered adequate to inspect audio signals. Cheers! |
| Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Dec 22 11:39AM -0500 On 12/22/2015 11:02 AM, c4urs11 wrote: > Scopes from that era easily reached several MHz of bandwidth. > That should be considered adequate to inspect audio signals. > Cheers! The eyeball is a really lousy detector of harmonics, though, especially odd harmonics. Plus he had to use a 1950s-era microphone, so the scope bandwidth is irrelevant. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net |
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