Water, water, everywhere

[skizzerflake]

I'm not an accoustic expert but I have spent lots of time at the beach and my impression is just the opposite of amplification. It's so open and huge over the ocean that sounds just disappear. Rock bands are quiet and fireworks are just little poofs. With nothing to echo off, sound just disappears.

 

[Geno]

Sorry folks, I was a bit greenjellied here.



(It would seem that one must be careful of hot air. )

It seems that a certain thankfully departed has spawned a new adjective. God, I hate to see what you guys will do to me after I'm gone

 

[astrodon]

You don't need those other guys!! I think I found the answer for you. Enjoy.

http://www.kettering.edu/~drussell/Demos/refract/refract.html

Thanks for this link, even so-called experts can learn a thing or two.

 

[edonsmith]

I cant imagine how anything without a power source could actually amplify sound. Would that not be against the laws of physics?

 

[Tomorrow]

I cant imagine how anything without a power source could actually amplify sound. Would that not be against the laws of physics?

Not at all, but it's really sort of an illusional amplification. (Sound is also 'de-amplified' in other parts of its wave range.)

Perhaps a more clear analogy, is the megaphone used by cheerleaders. There is no power being applied, but the device uses a directional focus of the sound to "amplify" it to a certain area. As with the original question of water amplification, the laws of thermodynamics are maintained. (Here, what sound you gain in one area, you lose in another.)

You might also consider an analogous situation of the Voyager satellites being sent outside our solar system. They didn't just blast off with the rocket motor engine providing all the power for the trip directly into the interstellar space. Instead they were aimed to arc around the sun, which through gravity, slingshot the probes to accelerate it in a less direct, but faster, appointment with the outer space. No additional 'power' is being applied, but the laws of physics allow for accelerated motion. (The issue of gravity pulling back on the probe after the slingshot must be considered, of course, with the Second Law of Thermodynamics...all actions have opposite and equal reactions. But total velocity is important and "escape velocity" is imparted. That's why the probes are now outside the gravitational pull of our sun.) With sound, it is the accelerated motion of the sound wave over temperature layers that causes this amplification.

 

[astrodon]

Not at all, but it's really sort of an illusional amplification. (Sound is also 'de-amplified' in other parts of its wave range.)

Perhaps a more clear analogy, is the megaphone used by cheerleaders. There is no power being applied, but the device uses a directional focus of the sound to "amplify" it to a certain area. As with the original question of water amplification, the laws of thermodynamics are maintained. (Here, what sound you gain in one area, you lose in another.)

You might also consider an analogous situation of the Voyager satellites being sent outside our solar system. They didn't just blast off with the rocket motor engine providing all the power for the trip directly into the interstellar space. Instead they were aimed to arc around the sun, which through gravity, slingshot the probes to accelerate it in a less direct, but faster, appointment with the outer space. No additional 'power' is being applied, but the laws of physics allow for accelerated motion. (The issue of gravity pulling back on the probe after the slingshot must be considered, of course, with the Second Law of Thermodynamics...all actions have opposite and equal reactions. But total velocity is important and "escape velocity" is imparted. That's why the probes are now outside the gravitational pull of our sun.) With sound, it is the accelerated motion of the sound wave over temperature layers that causes this amplification.

You're on the right track, but a few of your statements are not quite correct. Both Voyager I and II were placed in solar orbit with their small "course-correction" rockets firing at the appropriate time in their orbit to get them out to Jupiter's orbit, coincidentally when Jupiter was at the same approximate position. The trajectory past Jupiter was calculated to increase the spacecraft's angular momentum about the Sun at the expense of some of Jupiter's orbital angular momentum through the conservation of angular momentum. Jupiter's orbital angular momentum is so large that Jupiter "didn't even notice the change." This is what the phrase "sling-shot effect" means in celestial mechanics (buy the way, this phrase has been misused in "Star Trek" as well). Both spacecraft were then sent to Saturn through this "sling-shot" from Jupiter. Voyager I then was directed out of the solar system's plane at Saturn in order to make a close pass to Saturn's moon Titan. Voyager II used some of Saturn's orbital angular momentum to send it to Uranus, then some of Uranus's orbital angular momentum to get to Neptune, and finally at Neptune to gain even more speed. Right now, Voyager II is the fastest man-made probe in the Galaxy due to its encounters with 4 gas giants (the 3 other interstellar-bound spacecraft interacted with only 2, Jupiter and Saturn).

Your statement "with the Second Law of Thermodynamics...all actions have opposite and equal reactions" is not correct. The statement "all actions have equal and opposite reactions" is a simplified statement of Newton's 3rd law of motion. This 3rd law is nothing more than the conservation of linear momentum and is the basis behind the operation of rockets. The 2nd law of thermodynamics has to do the change of entropy (energy that is no longer available to carry out work) in an isolated (so-called "closed") system. In classical thermodynamics, the 2nd law can be described as follows: in a closed system, entropy always increases (on average). In statistical mechanics (the modern physics version of thermo), the 2nd law deals with probabilities and is a bit too technical to describe here (besides I have bored all of you enough).

Finally, through their various encounters with the Jovian planets (the large gas giants), the two Voyagers, and Pioneers 10 and 11, have exceeded escape velocity with respect to the Sun. However, they still "feel" the gravity of the Sun which is currently (and for tens of thousands of years) the strongest gravity source they "see." Because their velocities are so high, this gravitational force is not strong enough to return them to the inner solar system. Another way of saying this is that their kinetic energy (energy of motion) is greater than the Sun's gravitational potential energy (energy of position). Gravity is an inverse square-law, the Sun's gravitational force will never go to zero as these spacecrafts depart the solar system. However, sometime in the far distant future, the Sun's gravity will be negligible with respect to the backgound gravitational field of the Milky Way galaxy as a whole (or by another star if they venture too close to one). I'm sorry to go into lecture mode here and I mean no slam against you rjbudz -- I appreciate where you are coming from. This is something I know a little about, I just wanted to offer some helpful corrections.

 

[Tomorrow]

You're on the right track, but a few of your statements are not quite correct. Both Voyager I and II were placed in solar orbit with their small "course-correction" rockets firing at the appropriate time in their orbit to get them out to Jupiter's orbit, coincidentally when Jupiter was at the same approximate position. The trajectory past Jupiter was calculated to increase the spacecraft's angular momentum about the Sun at the expense of some of Jupiter's orbital angular momentum through the conservation of angular momentum. Jupiter's orbital angular momentum is so large that Jupiter "didn't even notice the change." This is what the phrase "sling-shot effect" means in celetial mechanics (buy the way, this phrase has been misused in "Star Trek" as well). Both spacecraft were then sent to Saturn through this "sling-shot" from Jupiter. Voyager I then was directed out of the solar system's plane at Saturn in order to make a close pass to Saturn's moon Titan. Voyager II used some of Saturn's orbital angular momentum to send it to Uranus, then some of Uranus's orbital angular momentum to get to Neptune, and finally at Neptune to gain even more speed. Right now, Voyager II is the fastest man-made probe in the Galaxy due to its encounters with 4 gas giants (the 3 other interstellar-bound spacecraft interacted with only 2, Jupiter and Saturn).

Your statement "with the Second Law of Thermodynamics...all actions have opposite and equal reactions" is not correct. The statement "all actions have equal and opposite reactions" is a simplified statement of Newton's 3rd law of motion. This 3rd law is nothing more than the conservation of linear momentum and is the basis behind the operation of rockets. The 2nd law of thermodynamics has to do the change of entropy (energy that is no longer available to carry out work) in an isolated (so-called "closed") system. In classical thermodynamics, the 2nd law can be described as follows: in a closed system, entropy always increases (on average). In statistical mechanics (the modern physics version of thermo), the 2nd law deals with probabilities and is a bit too technical to describe here (besides I have bored all of you enough).

Finally, through their various encounters with the Jovian planets (the large gas giants), the two Voyagers, and Pioneers 10 and 11, have exceeded escape velocity with respect to the Sun. However, they still "feel" the gravity of the Sun which is currently (and for tens of thousands of years) the strongest gravity source they "see." Because their velocities are so high, this gravitational force is not strong enough to return them to the inner solar system. Another way of saying this is that their kinetic energy (energy of motion) is greater than the Sun's gravitational potential energy (energy of position). Gravity is an inverse square-law, the Sun's gravitational force will never go to zero as these spacecrafts depart the solar system. However, sometime in tha far distant future, the Sun's gravity will be negligible with respect to the backgound gravitational field of the Milky Way galaxy as a whole (or by another star if they venture too close to one). I'm sorry to go into lecture mode here and I mean no slam against you rjbudz -- I appreciate where you are coming from. This is something I know a little about, I just wanted to offer some helpful corrections.

Thanks for all the finer details, Don. I was generalizing for brevity in the analogy.

 

[Ampdog]

Gee Astrodon,

An unkind reminder of my struggle with Thermodynamics at varsity in the days of yore!! I still have nightmares. That is why I preferred something simple like electronics.

Seriously, thanks for clear explanation, Professor!

Regards.

 

[astrodon]

No problem, now back to audio stuff!

Cheers,
Don

 

[mtrycrafts]

This is something I know a little about, I just wanted to offer some helpful corrections.

A little?
Looked a lot more than little
This is great, learn more than we bargained for. How else would we gain it for free, while doing something we prefer to do

Thanks for sharing. Don't keep this knowledge hidden. Who knows, you might have something more just as appropriate.

 

[zildjian]

You're on the right track, but a few of your statements are not quite correct. Both Voyager I and II were placed in solar orbit with their small "course-correction" rockets firing at the appropriate time in their orbit to get them out to Jupiter's orbit, coincidentally when Jupiter was at the same approximate position. The trajectory past Jupiter was calculated to increase the spacecraft's angular momentum about the Sun at the expense of some of Jupiter's orbital angular momentum through the conservation of angular momentum. Jupiter's orbital angular momentum is so large that Jupiter "didn't even notice the change." This is what the phrase "sling-shot effect" means in celestial mechanics (buy the way, this phrase has been misused in "Star Trek" as well). Both spacecraft were then sent to Saturn through this "sling-shot" from Jupiter. Voyager I then was directed out of the solar system's plane at Saturn in order to make a close pass to Saturn's moon Titan. Voyager II used some of Saturn's orbital angular momentum to send it to Uranus, then some of Uranus's orbital angular momentum to get to Neptune, and finally at Neptune to gain even more speed. Right now, Voyager II is the fastest man-made probe in the Galaxy due to its encounters with 4 gas giants (the 3 other interstellar-bound spacecraft interacted with only 2, Jupiter and Saturn).

Your statement "with the Second Law of Thermodynamics...all actions have opposite and equal reactions" is not correct. The statement "all actions have equal and opposite reactions" is a simplified statement of Newton's 3rd law of motion. This 3rd law is nothing more than the conservation of linear momentum and is the basis behind the operation of rockets. The 2nd law of thermodynamics has to do the change of entropy (energy that is no longer available to carry out work) in an isolated (so-called "closed") system. In classical thermodynamics, the 2nd law can be described as follows: in a closed system, entropy always increases (on average). In statistical mechanics (the modern physics version of thermo), the 2nd law deals with probabilities and is a bit too technical to describe here (besides I have bored all of you enough).

Finally, through their various encounters with the Jovian planets (the large gas giants), the two Voyagers, and Pioneers 10 and 11, have exceeded escape velocity with respect to the Sun. However, they still "feel" the gravity of the Sun which is currently (and for tens of thousands of years) the strongest gravity source they "see." Because their velocities are so high, this gravitational force is not strong enough to return them to the inner solar system. Another way of saying this is that their kinetic energy (energy of motion) is greater than the Sun's gravitational potential energy (energy of position). Gravity is an inverse square-law, the Sun's gravitational force will never go to zero as these spacecrafts depart the solar system. However, sometime in tha far distant future, the Sun's gravity will be negligible with respect to the backgound gravitational field of the Milky Way galaxy as a whole (or by another star if they venture too close to one). I'm sorry to go into lecture mode here and I mean no slam against you rjbudz -- I appreciate where you are coming from. This is something I know a little about, I just wanted to offer some helpful corrections.

Wow, now your username makes a lot of sense...

 

[Tomorrow]

You're on the right track, but a few of your statements are not quite correct. Both Voyager I and II were placed in solar orbit with their small "course-correction" rockets firing at the appropriate time in their orbit to get them out to Jupiter's orbit, coincidentally when Jupiter was at the same approximate position. The trajectory past Jupiter was calculated to increase the spacecraft's angular momentum about the Sun at the expense of some of Jupiter's orbital angular momentum through the conservation of angular momentum. Jupiter's orbital angular momentum is so large that Jupiter "didn't even notice the change." This is what the phrase "sling-shot effect" means in celestial mechanics (buy the way, this phrase has been misused in "Star Trek" as well). Both spacecraft were then sent to Saturn through this "sling-shot" from Jupiter. Voyager I then was directed out of the solar system's plane at Saturn in order to make a close pass to Saturn's moon Titan. Voyager II used some of Saturn's orbital angular momentum to send it to Uranus, then some of Uranus's orbital angular momentum to get to Neptune, and finally at Neptune to gain even more speed. Right now, Voyager II is the fastest man-made probe in the Galaxy due to its encounters with 4 gas giants (the 3 other interstellar-bound spacecraft interacted with only 2, Jupiter and Saturn).

Your statement "with the Second Law of Thermodynamics...all actions have opposite and equal reactions" is not correct. The statement "all actions have equal and opposite reactions" is a simplified statement of Newton's 3rd law of motion. This 3rd law is nothing more than the conservation of linear momentum and is the basis behind the operation of rockets. The 2nd law of thermodynamics has to do the change of entropy (energy that is no longer available to carry out work) in an isolated (so-called "closed") system. In classical thermodynamics, the 2nd law can be described as follows: in a closed system, entropy always increases (on average). In statistical mechanics (the modern physics version of thermo), the 2nd law deals with probabilities and is a bit too technical to describe here (besides I have bored all of you enough).

Finally, through their various encounters with the Jovian planets (the large gas giants), the two Voyagers, and Pioneers 10 and 11, have exceeded escape velocity with respect to the Sun. However, they still "feel" the gravity of the Sun which is currently (and for tens of thousands of years) the strongest gravity source they "see." Because their velocities are so high, this gravitational force is not strong enough to return them to the inner solar system. Another way of saying this is that their kinetic energy (energy of motion) is greater than the Sun's gravitational potential energy (energy of position). Gravity is an inverse square-law, the Sun's gravitational force will never go to zero as these spacecrafts depart the solar system. However, sometime in tha far distant future, the Sun's gravity will be negligible with respect to the backgound gravitational field of the Milky Way galaxy as a whole (or by another star if they venture too close to one). I'm sorry to go into lecture mode here and I mean no slam against you rjbudz -- I appreciate where you are coming from. This is something I know a little about, I just wanted to offer some helpful corrections.

Don,

You might be interested that I worked on the Voyager projects and have a large print from one of the original sepia close-up photos of the rings of Saturn.

 

[astrodon]

Don,

You might be interested that I worked on the Voyager projects and have a large print from one of the original sepia close-up photos of the rings of Saturn.

Cool! Were you at JPL? I worked at NASA/Goddard in Greenbelt, MD for a few years (I worked on the IUE and SoHO programs).

Added after post: In case anyone is interested, IUE is the short-hand name for the International Ultraviolet Explorer, a space-based telescope placed in geosynchronous orbit back in the late 70s. Originally it was designed to last 3 years, but it was designed well and lasted 17 years. SoHO is the NASA short-hand name for the Solar Heliographic Observatory which continuously monitors the Sun. This telescope is still in operation and resides in a so-called halo orbit about the Lagrangian point (a gravity equilibrium point) between the Earth and Sun.

 

[Tomorrow]

Cool! Were you at JPL? I worked at NASA/Goddard in Greenbelt, MD for a few years (I worked on the IUE and SoHO programs).

No, I worked at a little high-tech company in San Diego named Linkabit (founded by Andy Viterbi and Irwin Jacobs...who spun off to develop Qualcomm!). We contracted some work from JPL on the original Viterbi codecs. Later we morphed into M/A-Com Linkabit where I was assistant Program Mgr. on our Star Wars programs, and program managed the (hated) VideoCipher encryption device, and other engineering programs/projects. (I was on the business...not the technical side of things.)

NASA/Goddard has always been a place near heaven, IMHO. LOL. Good on ya.

 

[majorloser]

Has it been that long?

Boy, I go away for a week and you guys get all "intelligent" on me!

 

[mtrycrafts]

Boy, I go away for a week and you guys get all "intelligent" on me!

Isn't that the best time for it? LOL