Go
New
Find
Notify
Tools
Reply
  
Doppler Effect Login/Join
 
Member
Picture of Kalleh
posted
I read a very funny article about women who wear heels and walk with a faster than normal gait. The author called the "click, clack, click, clack" of the noise of women in heels as they close in on you the "Doppler effect."

Shu says that the "Doppler effect" is about changes in the frequency of a sound wave and that this author's use was wrong.

Is Shu right, or is the author correct?
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
posted Hide Post
The Doppler Effect refers to the relative compression and decompression of energy waves. Sound waves create higher and lower pitches according to how far apart they are; close together makes higher tones, far apart makes lower tones. Consider a train horn sound when the train is at the station (that you are on). That is the unaffected sound of the horn. Imagine that same train coming towards the station, sounding its horn. The horn will be a higher pitch than in the first scenario because the sound waves are compressed by the train's (or more precisely, the horn's) motion towards you. As it goes past and away from you, the sound waves from the horn decompress because of the train's (horn's) travel away from you. This is also so for light. Blue light is a higher frequency energy than red light (the spectrum is red (lowest visible frequency), green (mids) and blue (highest visible frequency)). When you travel towards a light at speed, the light waves compress and appear more blue (blue-shift). Travel away from the light source, and it red-shifts (appears more red).

I doubt that a woman in heals could walk fast enough to create a genuinely discernable Doppler Effect, particularly as each footfall occurs at a distinct moment and so wouldn’t have the energy or velocity to compress (push together from the back) the sound waves of the previous footfall. At distance, there would be some time-sync difference in that the sound would reach you a discernable time after you see the footfall (but that has more to do with light being of a much higher velocity than sound and therefore reaching your position before the sound).

So yes, Doppler theory is applied incorrectly by the author in a literal sense, but the metaphor does convey a sense of high relative speed, albeit a somewhat obtuse observation designed to create a feeling of inhumanity towards the recipient.

So i vote that it works to describe the author’s emotional response to the situation described, but is not reasonably true of the situation. Everyone’s a winner. Smile

beans
 
Posts: 129 | Location: AustraliaReply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by Kalleh:
Is Shu right, or is the author correct?

You doubt Shu but you're going to believe us?

Beans explained it pretty well. Or check these sources . Or listen to Shu.

Tinman
 
Posts: 2878 | Location: Shoreline, WA, USAReply With QuoteReport This Post
<Asa Lovejoy>
posted
quote:

a somewhat obtuse observation designed to create a feeling of inhumanity towards the recipient.



Beans, if you should ever be stepped on by a woman's stiletto heel, you won't have a highly humane feeling about her either! Also, consider the damage such shoes do to flooring! Those *^#@)*!#@ things ought to be banned!!!
 
Reply With QuoteReport This Post
Member
posted Hide Post
quote:
consider the damage such shoes do to flooring!

Not to mention womens' feet and lower backs...
 
Posts: 669 | Location: EnglandReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
It was actually a funny article, I thought. Douglas MacKinnon, a former White House and Pentagon official and a feminist himself, talked about how women executives, aged 24-40, seem to "click-clack, click-clack" at above-normal speeds, as a way of competing with men. I laughed as I read, "Their subconscious thinking could well be: 'Men are sloths, men are basic, so let's beat them to the kill. Let's get our share before they waddle over and give us that 'men-are-superior' line and take what we earned."

I will try to link to it, but you may have to register to the Chicago Tribune site (free) to be able to read it.

You doubt Shu but you're going to believe us?

Good question, Tinman! Usually I believe Shu, but this time his example didn't make sense to me. He said that an oncoming train whistle will produce the Doppler effect. I didn't get why a woman's "click-clacking" wouldn't be the same. However, Beans used the same analagy, and now I get it. Thanks, Beans!
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
<Asa Lovejoy>
posted
quote:
Originally posted by Cat:
quote:
consider the damage such shoes do to flooring!

Not to mention womens' feet and lower backs...


I consider any woman who is so gullible as to wear them is getting what she deserves. I seriously doubt that a woman came up with the idea, after all. Wink

As for the Doppler effect/red shift, this discovery led to our being able to determine that the universe is expanding, and to get a pretty good idea of its age. And you thought the light at the end of the tunnel was just an oncoming galaxy! Ha!
 
Reply With QuoteReport This Post
Member
Picture of shufitz
posted Hide Post
quote:
Originally posted by Kalleh: Shu says that the "Doppler effect" is about changes in the frequency of a sound wave and that this author's use was wrong. Is Shu right, or is the author correct?
1. The Doppler effect pertains to any waves, (e.g., light), not just 'sound waves'. As bean noted.

2. There's no way a human being, walking or running, can move fast enough to produce Doppler effect perceptible to the human ear. If you're a superbly fast runner, you can run a 100-yard dash in 10 seconds -- but that's less than 3% of the speed of sound. And a lady on heels can hardly move that fast!

3. So how does the author know, by sound, that the woman is running towards him? Simple: the fast pace of the heel-clicks tell that she's running, and since they're getting louder, she's running toward him. He knows -- but not by Doppler effect.
 
Posts: 2666 | Location: Chicago, IL USAReply With QuoteReport This Post
<Asa Lovejoy>
posted
Right Shu! And since women travel in pairs, it's the Doppelganger effect! Big Grin
 
Reply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
In health care we use a "doppler" for the evaluation of peripheral (occlusive) vascular disease. It is an augmented listening device for detecting the pulse in an extremity.
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by Kalleh:
It was actually a funny article, I thought.

It's possible he was using "Doppler Effect" as hyperbole for comic effect. It's also possible he was just wrong.
quote:
You doubt Shu but you're going to believe us?

Good question, Tinman!

That was a joke, Kalleh. I found it funny that you were questioning Shu after you had said earlier (June 3) that Shu was "the smartest person I know!" Of course, smart people can be wrong.

Tinman
 
Posts: 2878 | Location: Shoreline, WA, USAReply With QuoteReport This Post
Member
Picture of Caterwauller
posted Hide Post
quote:
quote:
Originally posted by Cat:

quote:
consider the damage such shoes do to flooring!

Not to mention womens' feet and lower backs...


I consider any woman who is so gullible as to wear them is getting what she deserves. I seriously doubt that a woman came up with the idea, after all.

Cat - that's exactly what I was going to say!

Asa - Women wear heels to attract the attention of men . . . and to give themselves some sort of ego boost because it feels sexy and strong or something. Personally, I've never been able to wear them, and don't feel they make me look good because the whole time I'm standing or walking in them I have a grimace on my face. Mad


*******
"Happiness is not something ready made. It comes from your own actions.
~Dalai Lama
 
Posts: 5149 | Location: Columbus, OhioReply With QuoteReport This Post
<Asa Lovejoy>
posted
I wonder if the Doppler Effect really hs to be at or above the speed of sound. Sonar - and Nancy's sonar-like application - use it, although it measures a denser fluid medium than air, in which waves travel much easier.
 
Reply With QuoteReport This Post
Member
posted Hide Post
i figured that high-heels as business dress are an executive symbol. besides the difference extra height can make to your social standing (think about that), they differentiate between a female executive and a flat-soled secretary, the still-perceived-as traditional office job for women. the white collar and black dress shoes/heels uniform of management.

i would suspect that women who wear heels are noticed for advancement over women who don't. so i'd say that talking to the people who hire about the nature of physical bias would be the quickest way of liberating women and men from the tyranny of stiletto heals. i have a dream...

no worries, kalleh. if a stiletto healed-woman falls in the foyer, does she make a click or a clack? the doppler aspect of your medical machine is the visual display; low frequency (slowed) sound is displayed as red, yes? green for mids, and blues for higher speed (uninterrupted) sound?

beans
 
Posts: 129 | Location: AustraliaReply With QuoteReport This Post
Member
posted Hide Post
actually, Asa, energy waves, such as sound, move more easily thru denser material than not. consider that sound travels much further under water than thru air. or have i mis-read your intent? anyway; the doppler aspect is the colour assignations, as doppler is the rule of measure rather than a description of physics. it's the gauge, not the weather. the effect that it measures is the compression of energy waves by the energy waves behind them. the energy has to be a continuous stream for this to happen. to create enough sound waves that are close enough together to push each other together before they reach your ears, the foot-falls would have to occur at least 101 times a second minimum. realistically, the figures would need to represent a difference of at least 500 footfalls per second (ff/s), between the range of 1000 and 15000 ff/s (audible sound). we can hear, at our best, between 100 hertz (cycles (events) per second) and 20000 hertz.

so she'd need to be one very angry woman to achieve it.

beans Smile
 
Posts: 129 | Location: AustraliaReply With QuoteReport This Post
<Asa Lovejoy>
posted
quote:
Originally posted by beans:
actually, Asa, energy waves, such as sound, move more easily thru denser material than not.


I guess I was thinking upside-down. I know that sound travels more readily through denser media, and I'm aware that whales can call others from many miles away, as can elephants by rumbling right on the ground. Also, government communications systems can reach halfway around the world through water. Then there's the tsunami warning system in some parts of the Pacific Ocean. Somehow, though, I had it in mind that the actual speed was lower than that in air. Thanks for setting me straight.
 
Reply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by Asa Lovejoy:
... sound travels more readily through denser media ...

So that explains why sounds sometimes travel so fast through my brain they don't have time to sink in.

Tinman
 
Posts: 2878 | Location: Shoreline, WA, USAReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
quote:
Of course, smart people can be wrong.

They just don't admit it as much as we mere mortals do. Wink

Asa - Women wear heels to attract the attention of men . . . and to give themselves some sort of ego boost because it feels sexy and strong or something. Personally, I've never been able to wear them,

I am not sure I agree that women only wear heels to attract the attention of men. My daughters both wear heels (not the really high ones) because they want to look nice, either for work or play. They surely don't wear them to attract the attention of men. I am going to see if I can find who invented heels for women, but I think it probably was women, not men.
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
posted Hide Post
Why do women wear high-heeled shoes? Because they're promoted by the fashion industry. It's all a marketing ploy, like most things that can be sold.

Just as ridiculous as high heels are pointy-toed shoes, another marketing ploy. I'd go barefoot before I would wear any such shoes! However, I haven't always been so smart and independent - I wore both high heels and pointy toes when I was young and foolish. Frown
 
Posts: 235 | Location: Portland, OregonReply With QuoteReport This Post
<Asa Lovejoy>
posted
quote:
I haven't always been so smart and independent - I wore both high heels and pointy toes when I was young and foolish. Frown


But, My Sweet Sunflowr, YOU LEARNED!!! Big Grin
 
Reply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
Well, apparently I am the only woman here to disagree. Unless I am totally unconscious to it, I don't think I like heels because they are promoted by the fashion industry. I think they look nice. Each to his/her own, I guess.

Women's feet do change over the years, and there is much less padding on the bottom. That does mean that women's choice of shoes change as they age. Still, I love my daughters' really cute heeled, strappy sandles and wish I could wear them.

Do you ladies hate open-toed shoes as well? I like them, too.

BTW, I found that Catherine de Medici wore the first high-heeled shoes in 1533, made by her male cobbler. So, you were right, Asa, a man came up with the idea. However, apparently Catherine had some say in it, as she was only 5 feet in height and wanted to make an impression on the French Court. I found this
article about it, and I found other sites that seemed to validate the information.
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
<Asa Lovejoy>
posted
quote:
I found that Catherine de Medici wore the first high-heeled shoes in 1533, made by her male cobbler. So, you were right, Asa, a man came up with the idea. However, apparently Catherine had some say in it, as she was only 5 feet in height and wanted to make an impression on the French Court. I found this


Finally, a valid reason for all the opporbrium against the French! Wink
 
Reply With QuoteReport This Post
<Asa Lovejoy>
posted
Here's another Catherine de Medici-related reason to hate the French: Jean Nicot brought tobacco plants to her from Portugal and got her hooked on the accursed weed! So now you know whence the word, "nicotine!"

BTW, have any of you noticed the paintings of Louis XIV wearing HIGH HEELS!?!?!? SILLY BOY!!!
 
Reply With QuoteReport This Post
Member
Picture of Caterwauller
posted Hide Post
quote:
My daughters both wear heels (not the really high ones) because they want to look nice, either for work or play. They surely don't wear them to attract the attention of men.

Umm - why bother to look nice, then, if not to attract the attention of men? What gives us the definition of "looking nice?" Isn't it the idea that others will find us attractive?

I love open-toed shoes. I prefer, in fact, to wear a little as possible on my feet. I, too, would go barefoot if that were feasible and safe . . . and I do go barefoot as often as possible. I was camping earlier this week, and was disappointed that the field we were in had so much poison ivy because it meant I had to wear my shoes all the time. Bummer! The sandals I wear to work are definitely open . . . and light-weight - and FLAT!!!


*******
"Happiness is not something ready made. It comes from your own actions.
~Dalai Lama
 
Posts: 5149 | Location: Columbus, OhioReply With QuoteReport This Post
Member
posted Hide Post
I own four pairs of shoes. All the same. New Balance. They fit, they were on sale. As one wears out I will don the next. I have no fashion sense. But I have foot sense. Smile
 
Posts: 915 | Location: IowaReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
I am beginning to think that we have a foot fetish on this board Wink...and I apologize for straying away from words. I just feel a little defensive since all the women here disagree with me; I can ignore Asa because he's a man and how does he know. However, my compatriots?!

quote:
Umm - why bother to look nice, then, if not to attract the attention of men? What gives us the definition of "looking nice?" Isn't it the idea that others will find us attractive?

Hoo...that question is near and dear to my heart! To me, you want to look nice (I agree that the definition of looking nice is all over the place) for yourself. When I look nice, I feel good about myself and probably do a better job (I haven't evaluated that aspect). I surely don't dress nicely to attract men! Heavens...what a waste; not only am I married to a wonderful man, but my profession is nursing where very few of my colleagues are men anyway! My daughters were raised that way, too, I sincerely hope, and I suspect they dress for themselves. Does fashion play into it? Yes, I will agree with that. Yet, it would be a cold day in Hell before my oldest daughter would ever wear a bare midriff; that's the fashion, but not her style.

Alright, I've probably bored everyone here to tears about my thoughts on shoes. Sorry. It is on to more important things...like words! Big Grin
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
Picture of jerry thomas
posted Hide Post
Living where the weather suits my clothes I now own and use my only pair of sandals. In a previous incarnation I was a Barefoot Boy
 
Posts: 6708 | Location: Kehena Beach, Hawaii, U.S.A.Reply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by Kalleh:

Do you ladies hate open-toed shoes as well? I like them, too.

.


I love sandals and open-toed shoes. When I wore heels as a young woman, I wore the open-toed variety, since my toes got smashed against
closed toes, thanks to the way high heels make the feet slide forward. What an awful invention! Frown
 
Posts: 235 | Location: Portland, OregonReply With QuoteReport This Post
Member
Picture of Richard English
posted Hide Post
quote:
2. There's no way a human being, walking or running, can move fast enough to produce Doppler effect perceptible to the human ear.
I accept Beans's comment about the frequency of the sound necessary and clearly there is no way that a woman's feet could hit the ground often enough to produce a note of that frequency. However, each click (or clack) has its own frequency and the shift of that single sound might be sufficient to produce a detectable change in pitch (although I accept that you would need to remember the pitch of the approaching clicks and compare that with the potch of the departing clicks).

The object does not actually need to be moving all that fast; I can detect the shift in sound of the freewheel ratchet of a bicycle as it passes at about 15 mph. I suppose it depends on how sensitive your ears are to pitch variation - but we can most of us tell the difference between two adjacent notes on a piano, even though the difference between them may be as little as 15 cycles. If we are very good at determing pitch, I am sure we could detect a difference of far less than that.

I can't do the physics necessary but I would be interested to know what the pitch change of, say a bicycle bell, is when the cyclist rings as he scorches past at 15 mph or so.


Richard English
 
Posts: 8038 | Location: Partridge Green, West Sussex, UKReply With QuoteReport This Post
Member
posted Hide Post
quote:
However, each click (or clack) has its own frequency and the shift of that single sound might be sufficient to produce a detectable change in pitch (although I accept that you would need to remember the pitch of the approaching clicks and compare that with the potch of the departing clicks).


The clicks could easily produce a detectable change in pitch. The click of a heel is an impulse that contains a broad range of frequency components. Sounds of different frequencies are not conducted equally well through the air -- think of the last time you heard only the booming bass of someone's distant stereo. Similarly, the timbre of the clicks would change as the distance from the observer changed.

quote:
the effect that it measures is the compression of energy waves by the energy waves behind them.


This is not a good explanation for several reasons. The effect is heard as the train is moving away from the observer as well as towards it, so it can't be because the waves behind it are compressing the waves in front. The doppler effect is seen in electromagnetic radiation as well as sound. Em waves are not compression waves and they can't be compressed by photons following behind them, because they are all going the same speed.

The effect occurs because the emitter is at a different distance at different times. Imagine a metronome standing still, clicking once per second. You will hear it click once per second if you are standing right next to it. Now imagine it moving away at, say, 500 ft/sec, roughly half the speed of sound at sea level. Each click takes half a second longer to reach you than the last click, because the emitter is 500 ft farther away, and you will hear the clicks 1.5 seconds apart rather than 1 second apart. Replace the clicking emitter with sinusoidal vibration and the effect is to lower the frequency of the sound.
 
Posts: 1242 | Location: San FranciscoReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
Interesting, neveu.

The clicks could easily produce a detectable change in pitch.

Could the click-clack of a woman's high heels then produce the Doppler effect?
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
posted Hide Post
yeah, neveu, mine was only half an answer. the effect is in reference to relative effect, so if a foot-fall was amplified sufficiently, and i were to move away from it at 180m/sec, then i may indeed observe a doppler shift. how fast would a person have to walk away from a fixed position for a doppler shift to occur, considering that the footfalls are not sinusoidal vibration but rather distinct peaks? i would suspect that the answer would be a practical impossibility, meself. so, did the author experience a doppler effect? nay, 'tis folly.

photonic doppler shift are, as you say, caused by the relative speed of the observer to the light. although within the influence of a black hole, all bets are off.

the interpretation of footfalls approaching the observer is one of increasing quality, as you suggest with the sound-system example. and so it is as the footfalls recede that the quality of information decreases. this is not a doppler effect.

so the footfalls increase in quality of information, peak and then decrease. the variation is due to the relative distance distortion of various frequencies, rather than signal compression/decompression.

as a means of expressing an experience to the reader, i think it fails. if you don't know what a doppler shift is, the comparison is meaningless, and if you do know then it is flawed. so i take it back; the author loses. Wink

beans
 
Posts: 129 | Location: AustraliaReply With QuoteReport This Post
Member
posted Hide Post
When a motocycle is approaching you at a constant speed it produces a high-pitched sound. As it get closer, the sound becomes louder, but the pitch remains the same. At the moment it passes you, the pitch noticeably drops very abruptly. As it goes away from you, the noise subsides, but the pitch remains the same.

In the case of the woman with high heels (sounds like a Perry Mason mystery), the clack of her heels would produce a high pitch (relatively) as she approaches you and the sound would also increase in loudness. The moment she passed you the pitch would drop and the loudness of the sound would begin to decrease. The change in loudness is not the Doppler Effect. The change in pitch is. Whether it would be detectable I don't know, but I doubt it. It would depend on how fast she was going and the hearing acuity of the listener and probably other things.

So, yes, I think there would be a change in apparent frequency (Doppler Effect, Doppler Shift) whenever a noise source passes a person at a constant speed. But it may not be noticeable to the ear.

Maybe this can explain it.

Tinman
 
Posts: 2878 | Location: Shoreline, WA, USAReply With QuoteReport This Post
Member
posted Hide Post
This is actually an interesting physics problem. It has layers.

quote:
Originally posted by Richard English:
I suppose it depends on how sensitive your ears are to pitch variation


This is precisely what it depends on. The equation for the change in wavelength is just y' = y(1 + u/v) where y' is the observed wavelength, y is the wavelength produced by a stationary source, u is the signed velocity of the source (positive for moving away from, negative for moving toward the observer), and v is the velocity of the wave. So, if the woman is walking at a very brisk 8 mph, and the speed of sound at sea-level is roughly 800 mph, the wavelength of her voice would be 0.99y as she's approaching and 1.01y as she's departing, and the frequency likewise 1% higher or lower, respectively (frequency is inversely proportional to wavelength). I'm speculating, but I think under the best conditions, with a single tone, and maybe a reference tone, you could actually hear the difference. Remember, a whole octave is only double the frequency, and 1/12 of that, on a log scale, is a note. But you'd have to ask a psychologist.

The explanation above refers to her voice. As to the clicks of her heels, Kalleh, I think those wouldn't show a doppler effect, because the source isn't moving. They are like hammer blows, no different than a line of people with hammers hitting in a floor sequentially; the source isn't moving. If she were hitting two shoes together as she was walking, that would create a doppler effect. And if she was walking on a treadmill, those clicks would also create a doppler effect. On the other hand, as she was walking on the sidewalk, you would perceive the number of clicks per second as slightly faster then slower than she would as she was walking towards then away from you. Like I said, it has layers.

None of this analysis has anything to do with relativity, either. This is all pure Newtonian physics.
 
Posts: 1242 | Location: San FranciscoReply With QuoteReport This Post
Member
posted Hide Post
quote:
As to the clicks of her heels, Kalleh, I think those wouldn't show a doppler effect, because the source isn't moving. They are like hammer blows, no different than a line of people with hammers hitting in a floor sequentially; the source isn't moving.


this is, indeed, the crux of the question. the footfalls are distinct from each other. if you, the observer, were to move away from, or towards, an individual footfall, you would get a doppler shift. but for successive footfalls to effect each other such that a stationary observer would perceive a doppler effect said footfalls would have to happen close enough together such that the frequency of footfalls would create a tone that was a product of the footfalls, and not the footfalls. that is, they would have to happen so fast that we would be unable to tell one footfall from another and so we would hear a 'continuous' tone being shifted rather than the effect of individual footfalls being shifted. not even if they tap-dance...

beans
 
Posts: 129 | Location: AustraliaReply With QuoteReport This Post
Member
posted Hide Post
Excellent work, neveu. Let's take your example a little further. You have the formula precisely right, and as you say, the question is whether one could notice a pitch-change of 1% (1.01).

And as you say, an octave is a doubling of frequency, and it contains 12 notes (actually, 12 half-notes, as from C to C-sharp), so a single half note would be a pitch variation equal to the twelfth root of 2. That is, a half-note change is the percentage that, multiplied by itself a dozen times, produces 2.

Is 1% enough? Do some multiplying; take a 1% rise twelve times, and the result is nowhere near a doubling. It's barely more than a 12% rise, for at these small percentages the effect compounding is minor. So a 1% rise in frequency is far less than a half-note change.

(Or alternatively, what's a half-note; what's the 12th root of 2? Do some fiddling to estimate, and you'll find that it's a shade under a 5.95% rise (that is, 1.0595 raised to the 12th is a bit over 2).¹ A 1% rise won't do it. The lady would have to be moving almost 6 times as fast to produce a pitch-change of a half-tone, from the Doppler-effect.)

A minor point: 8 mph isn't a walk, but rather a slow run. It's a 7½-minute mile (60 min. ÷ 8 mi. = 7½ min.), probably faster than I could now run even a quarter mile. I recall, from my days of treadmill walking, that at a very brisk walk I'd do a mile in 10 minutes; that is, the pace was 6 mph.


¹Simplest way to estimate, if your calculator can do square roots: the cube of 5/4 is 125/64, or a bit under 2 so 5/4 or 1.25 is a bit under the 2's cube root. 1.26 is a bit over, but it's closer. Take the square root of that 1.26, and then take the square root of the result, to get the 12th root of 2.
 
Posts: 1184Reply With QuoteReport This Post
Member
posted Hide Post
quote:
what's a half-note; what's the 12th root of 2? Do some fiddling to estimate, and you'll find that it's a shade under a 5.95% rise


Thanks for working out the size of a half-note rise.

A half-note rise is a big jump, it's huge and easily recognizable. The question is whether a 1% rise is noticable, and under what conditions. I think 1% is close enough to 6% that I'll guess that a 1% change is noticeable. When you tune an instrument you've got to be making adjustments of less than 1% of the frequency. I'm sure someone has done the experiment.

quote:
8 mph isn't a walk, but rather a slow run.


Yeah, but it goes nicely into 800 (which is within Greiner's approximation of the speed of sound).
 
Posts: 1242 | Location: San FranciscoReply With QuoteReport This Post
Member
posted Hide Post
Someone has done the experiment. The just-noticeable-difference for modulated pure tones depends on frequency, but it is less than 1% for tones higher than about 400 Hz, and approaches 0.5% for tones between about 1000 and 4000 Hz. We're even more sensitive to sudden changes in tone, according to the author, but no data is given.
 
Posts: 1242 | Location: San FranciscoReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
Wow! This has been a wonderful discussion...that part of it that I could follow! I imagine the author of this article would be rather amused by the sophisticated discussion of his obviously offhand comment. In fact, if I can find his e-mail address, I will send him a link.

I have learned a lot!
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
Hey, I wrote the author of the article and told him to look at this thread. Here was his very prompt response:

"Just wonderful stuff. Thank you for sending it to me.

Before my grades betrayed me, I was a physics major, so I had a basic understanding of the doppler effect. That said, I was just trying to be cute.

Mostly, I just write boring, serious columns, so this one was great fun.

Here are a few of the boring ones.

Be well and you guys have a great language site."
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
posted Hide Post
so the footfalls would have to occur at better than 400 times a second. that's what makes the description the 'cute' comparison of the author's intent; the increase in information received by the ear (especially of higher frequency noises) from each click and each clack is not due to doppler but rather to proximity; the closer, the clearer, the higher. not shifted, just clearer. and so receding clicks and clacks would loose information to distance distortion, starting with the more-easily disrupted high frequencies.

it's interesting that the (likely) most used explanation of doppler theory is the train analogy. because of that 'doppler' may evoke to the reader a feeling of being passed by a large, unstoppably imposing body as much as relating a sense of relative speed. works for me, anyway.

beansSmile
 
Posts: 129 | Location: AustraliaReply With QuoteReport This Post
Member
posted Hide Post
quote:
Umm - why bother to look nice, then, if not to attract the attention of men? What gives us the definition of "looking nice?" Isn't it the idea that others will find us attractive

Hoo...that question is near and dear to my heart! To me, you want to look nice (I agree that the definition of looking nice is all over the place) for yourself. I surely don't dress nicely to attract men!



As a man, I've never really been able to grasp the female obsession with shoes, though I like to see a woman in heels because they tend to show off her legs better. As to CW's comment on the grimace that comes with them, depending on what the woman looks like, a man may never get as far as looking at her face anyway but I take your point.

I know I will be torn apart for this but I always hear women say that they don't dress to attract men but I just don't believe it. I've seen women out in the middle of winter wearing skirts that are like belts, tops that are little more than bras and shoes that are so high they can barely walk. Who is going to be looking and who is going to care? Men. In our society women are routinely judged on the way they look and historically, men have run that society. Women may have more rights now but I think they are conditioned from a very young age to believe that they have to look good and what looks good on a woman has traditionally been defined by what men like.

To a degree it also works that way for men. We may not want to admit it but we want to look good for the approval of women even if we are happily married. We are simply more fortunate because women aren't as influenced by or attracted by visual means and so it is generally seen as less important. CW sent me a CD with a wonderful comedy routine on it that sums it up well. Women's magazines are full of articles on how to get a good man, how to avoid a bad man, how to make a bad man into a good man etc., while in mens magazines we really just need the pictures. This comedian said that he wished he could tell women that there was more to it than that but most men's lives would be happy if they could have a beer and see a woman naked. It's hyperbolic I know but I found it funny and like most good comedy it's based on a strong element of truth.
 
Posts: 291 | Location: EnglandReply With QuoteReport This Post
Member
posted Hide Post
quote:
Women may have more rights now but I think they are conditioned from a very young age to believe that they have to look good and what looks good on a woman has traditionally been defined by what men like.


Again, you've come back and said exactly what I wanted to say - welcome back, Doad!

Women's bodies are used as commodities to sell everything - and not just whole bodies: bits of them are often used instead (and you can guess which bits), which, when cut off from the face, only aids in the objectification of my sex. Look at the amount of films where the romantic male lead is at least a decade older than his female counterpart - sometimes far more; nobody bats an eyelid - unless it's reversed. Actresses are criticised (or praised) more often on their looks than actors: I've witnessed female comedians get heckled for their looks and/or age but rarely males. And after all this negative judgment that men generally don't have to endure (and there's loads more I could have mentioned), women are accused of vanity when they desperately try to reset the balance with make-up, prosthetics, plastic surgery etc! And believe me, having heard some of my male acquaintances my own age and older talk about the relative unattractiveness of women in my age group (as opposed to 18-year-olds), if I had the money I'd get the lines around my eyes done.

I find it very demoralising that my worth as a person is based by society more on how I look than who I am. Fortunately I'm surrounded by wonderful people who value me as me, which makes it easier to cope with this cruel mirror that society puts up to my face.
 
Posts: 669 | Location: EnglandReply With QuoteReport This Post
Member
posted Hide Post
You have my unqualified sympathy and support Cat. There are still times when I can behave a little like the male stereotype you describe but it is difficult to break a pattern of behaviour that is instilled in you from birth. Women clearly have the same problem in breaking their stereotypes but I'm not sure how we can break the cycle. Twelve year old girls at the school where I teach are already along way down that road. They try to wear huge amounts of make-up, spend fortunes on clothes and hitch their skirts up as far as is possible without showing their knickers. Why? To attract boys and so they are already set in a pattern of behaviour that will define their lives.
 
Posts: 291 | Location: EnglandReply With QuoteReport This Post
Member
Picture of Kalleh
posted Hide Post
quote:
I know I will be torn apart for this but I always hear women say that they don't dress to attract men but I just don't believe it.

I see that I am, once again, the lone wolf in this argument. Yet, how could we ever discuss issues if we all agree?!

I do agree with a lot of what both of you say. Yet, I just don't think all women are so worried about what men think...some are, I agree. I, too, have seen the examples that Doad posts about. I know a lot of 20-something young women, on the other hand, who really don't care about dressing for men. They are comfortable enough with themselves that this isn't an issue for them. Few and far between? I'd like to think not, but then maybe I am being too optimistic.

quote:
And believe me, having heard some of my male acquaintances my own age and older talk about the relative unattractiveness of women in my age group (as opposed to 18-year-olds), if I had the money I'd get the lines around my eyes done.

Cat, for heaven's sake I don't know what you are talking about. Have you looked in the mirror? You are beautiful! Any man would say that.
 
Posts: 24735 | Location: Chicago, USAReply With QuoteReport This Post
Member
posted Hide Post
quote:
Cat, for heaven's sake I don't know what you are talking about. Have you looked in the mirror? You are beautiful! Any man would say that.


At first I wasn't going to comment on this because I thought I'd just be castigated for being a typically shallow man but curiosity got the better of me. I went and had a look at your picture Cat and have to agree with Kalleh on this one. You are an extremely beautiful young woman who certainly doesn't need any kind of help. Just so that I won't be attacked for focusing excluisively on the physical side, I'd also like to point out that I realise that you are alot more than that.
 
Posts: 291 | Location: EnglandReply With QuoteReport This Post
Member
posted Hide Post
Thank you both Smile. I feel a bit embarrassed now, as I wasn't actually fishing for compliments - although they're always nice to get!

I know that currently I'm not hideous (well, most of the time - I still get wobbly moments), but time is getting on: there are lines where there never used to be lines, and they'll only get deeper, along with the other signs of aging - and I won't look like much of a catch any more. That's what I meant when I talked of hearing contemporaries go on about women in their 30s and beyond - that is, being a bit past it physically compared to those up to their mid 20s.

Of course I wouldn't want someone who is that shallow (and Bill certainly isn't Smile), but it is a sadly proven fact of life that men tend to have looks high on their list of priorities (and as Doad pointed out, generally more so than women). So the feeling among women (and I speak from experience) can be that they need to find someone before their looks run out and the difficult task of finding the right person is made even more difficult - hence the massive profits made by anything that claims to keep you looking younger. It's painful to have your worth judged by society on something you have so little control over - and then to be accused of vanity when you succumb to the pressure and try to gain some control.
 
Posts: 669 | Location: EnglandReply With QuoteReport This Post
Member
posted Hide Post
I can't deny that men are primarily motivated by looks, certainly in the initial stages of a relationship, though I think this diminishes a bit as we get older. I'm not convinced that this is entirely a situation created by society though. While I admit that society encourages men to be this way, I also believe that it is something that is built into our genes and we just can't help it. Knowing how women are pressured in this way I feel rather guilty about the way men are.

I'm pleased you were able to accept the compliment in the spirit in which it was intended. I was seriously worried that I would be accused of pandering to stereotypical attitudes by commenting on your looks.
 
Posts: 291 | Location: EnglandReply With QuoteReport This Post
Member
posted Hide Post
I have to add my two cents worth here. I believe men are initially attracted by a woman's appearance. If she passes the attractiveness test, they move on to her personality, character, intelligence, etc.

I feel that most women select men based on personality, character, etc. rather than getting bogged down so much by looks.

(Asa, this does not mean I don't think you're cute! Wink

This message has been edited. Last edited by: Sunflower,
 
Posts: 235 | Location: Portland, OregonReply With QuoteReport This Post
  Powered by Social Strata  
 


Copyright © 2002-12