| Author | Message | ||
     Bomber |
whoa, Pammy . . .beauty AND brains . . . . no wonder your husband wears such a beatific smile | ||
| Blake |
Rick, "Blake, it's just a well known fact." Apparently not. You are confusing the speed of propagation (equivalent to that of sound in the local medium) with the mechanism causing the alternating vacuum/pressure pulses, which is the violent expansion and ensuing flow of hot gases. Pammy nailed it. Thank you Pammy. Well said, and from someone who is responsible for some of the best performing exaust systems I've ever seen, thanks for sharing. Dan, I've never understood the "if it was not heard was there a sound" postulate. Sound is a rapid vibration of any medium within the frequency range corresponding to that which our ears can detect. Just because no one is there to hear it, doesn't mean that such a vibration did not exist. | ||
| Hootowl |
The vibrations exist, but unless there is an eardrum to convert it to electrical impulses interpreted by the brain as sound, there is no sound. Technically. I like that answer. Mainly because it gives me a smart ass answer to the commonly asked question. | ||
| Hootowl |
Do dog whistles make sound? Not to us, but to dogs, sure. So is sound the waves, or the interpretation of the waves? | ||
| Court |
Blake: What is the meaning of life? Court (P.S. - if a man speaks in the woods and there's no women there to hear him. . . is he still wrong? - Pammy, you are no allowed to answer) | ||
| Rick_A |
Well, I know it's the pressure pulse that creates the sound...that was just the best I could explain it  | ||
| Josh |
42 (of course!) | ||
| Henrik |
There is a great shot of the reversion blowing gas out the intake here. you'll also notice the 2 Thunderjet injectors (?). Henrik (aside from that, I have nothing useful to add  ) | ||
| Cjmblast |
(P.S. - if a man speaks in the woods and there's no women there to hear him. . . is he still wrong? - Pammy, you are no allowed to answer) Well you didn't say I couldn't answer, Absolutely he's still wrong !!! LOL CJM  | ||
| Buelliedan |
You should clarify that to "no American woman there to hear him"  | ||
| Pammy |
Sometimes they're not wrong...sometimes they're just confused. As far as the tree falling in the woods. The way the question is posed,the answer "no" would be correct, IMO. Now if one should query as to whether the sound/vibration occurs, the answer would be yes.A deaf person can 'sense' sound waves without the benefit of properly functioning 'hearing' organs. So I would say that eardrums are optional. | ||
| Cjmblast |
VERY Confused !!! CJM | ||
| Court |
>>>The way the question is posed,the answer "no" would be correct, IMO. Now if one should query as to whether the sound/vibration occurs, the answer would be yes.A deaf person can 'sense' sound waves without the benefit of properly functioning 'hearing' organs You've made your point, the blondes real. | ||
| Hootowl |
If a man posts something on a BBS, and a woman never reads it, is he still wrong? | ||
| Blake |
Rick, "The waves that cause reversion and are traveling the speed of sound...(they are) created by sound, after all." "Exhaust sound waves are used to aid in efficiency as well Blake." "I know for a fact that negative waves are derived from sound... it's just a well known fact." "There's (sic) two basic factors considered in exhaust tuning and design... the gas speed and negative pressure wave (created by sound)." "Well, I know it's the pressure pulse that creates the sound...that was just the best I could explain it." I'm glad you learned something here. I did too. Hoot, If you define "sound" as the perception of audible vibrations you would be correct and that is an accepted definition. The more prevalently accepted definition however is that sound is... Vibrations transmitted through an elastic material or a solid, liquid, or gas, with frequencies in the approximate range of 20 to 20,000 hertz, capable of being detected by human organs of hearing. So I guess either answer applies depending on how you define sound. For me though the former is like saying if a tree is struck by lightning and burns, but there is no on to see it then there is no light. I'm a science oriented kinda guy and the gist of that kind of philosophical silliness elludes me. The falling tree produced vibrations of audible frequencies that were transmitted through ground and air, therefore it made a sound. ![:]](http://www.badweatherbikers.com/buell/clipart/proud.gif) Court,
Why are we here? To live and learn. I look at human physical existence as the larval stage of spiritual existence. | ||
| Hootowl |
Yeah, I know, I was just being goofy. But... "Light" is also interpreted by our brains from electrical impulses from our eyes stimulated by the detection of electromagnetic radiation in the visible spectrum. Cats can see into the IR spectrum. So they can see "light" that we can't, just like dogs can hear "sound" that by your definition of sound (20-20Khz) is not sound at all. | ||
| Rick_A |
Call it a sonic pressure pulse, or high intensity sound wave...I'd say your talking about the same thing. Pammy, don't the collector length and shape also have an influence? Thanks for the clarification, BTW... | ||
| Bluzm2 |
Henrik, Thanks for that link. I was trying to remember where I had seen that picture. I spent way too much time looking for it here on BWB. As soon as the "pressure reversal" topic came up I thought of that picture. It speaks volumes. Kind of like the picture of the jet fighter breaking the sound barrier during a low level fly by. You can see the shock waves causing the humid air to condense into "clouds" around various parts of the plane. I have the pic at home for anyone who hasen't seen it. BTW, there is another pic floating around somewhere that is even more dramatic. It's a side shot of the carb,the air/fuel charge is about 2-3 inches out of the carb mouth! Brad | ||
| Jim_Witt |
Court asked Blake: What is the meaning of life? Chaitin© TMAX(n)=S (n+0(1)) Cheers, -JW:> | ||
| Hans |
Queen of the universe: : Your explanations will be carved in stone. Happy Valentine Pammy, and Whatever and Whoever. Hans | ||
| Davegess |
Blake, have you seen the news on the BIG BANG? A new high resolution map of the universe shows solid evidence for the big bang. Interesting is way over my head. Seems that most of the universe is made up of stuff we have yet to discover? Will this effect how my cylinder head flows? | ||
| Aesquire |
ok, before we get a topic police thing, the race header (99+ M2 etc) is longer right? where does that move the powerband / peak?? | ||
| Aesquire |
meaning of life? "to see your enemies driven before you........" "the eternal blue sky and a fiery steed between your legs" Both mongol, I like the latter. | ||
| Blake |
Rick, "Call it a sonic pressure pulse, or high intensity sound wave...I'd say your talking about the same thing." You'd be mistaken. Hoot, Detection of sound, light, energy, or anything else for that matter is not required for its existence. As humans we choose to define certain familiar portions of the aural and electromagnetic spectra as sound and light. Ever imagine the scene if our eyes were able to detect radio frequencies? Dave, Hadn't heard that. Last I heard I was still a very weak theory due to the discovery that the universe is expanding at an ever increasing rate. | ||
| Davegess |
Blake it was over my head, (this site will have a very good explanation up soon i suspect http://www.sciencenews.org) But the idea is that the only way the universe could be expanding at the rate it is is if there is way more matter than we know about. This latest experiment or observation supports the existence of this so called dark matter. If I fine a god link I will post it. Pretty scary stuff this astro physics. Makes me appreciate the relative certainty of internal combustion. | ||
| Davegess |
Blake talk about totally off topic http://skyandtelescope.com/news/current/article_877_1.asp | ||
| Blake |
Interesting... Everything confirms our beliefs that we don't have a clue about what comprises 96% of the universe.  | ||
| Hans |
Bluzm2, Those cloud formations are seen even at the vortices from the wingtips at F1 cars in humid atmosphere. I suppose it is the adiabatic cooling effect when air expands at low pressure areas, bringing the air below the dew point. I witnessed once a test for pilots within a big drum where the air pressure was suddenly lowered. A magnetic valve was suddenly opened to a second drum which was vacumised. When the red FIRE button was pushed the inside of the test chamber was at once full of heaviest mist (and the bad smells from intestinal gases, as appeared later, when they came out). Hans | ||
| Pammy |
The collector length and shape most definitely have an infuence. Court...Blonde to the core, baby... Happy Valentines day to everyone...Big cyber-hug to you all!!! | ||
| Bomber |
vapor trails similar to those left by jet aricraft (above) can also be observed at the tips of Huey blades, illustrating two things . . . .. thing the first -- the body doesn't have to be moving real fast (depending on temp and humidity and baro pressure, I assume) thing the second -- in an earlier incarnation, I was WAY too easy to distract! |
