Doppler shift (split from Cosmological redshift)

[Itoero]

Something else, our atmosphere is filled with particles, which enable sound. When you move through that, then the gravit. field is altered depending on your speed. Your speed changes the concentration of particles(which alters gravit. attraction) around you, which shortens or lengthens sound waves. This is what people call the doppler effect.

 

Edited November 25, 2018 by Itoero

[Strange]

8 minutes ago, Itoero said:

Something else, our atmosphere is filled with particles, which enable sound. When you move through that, then the gravit. field is altered depending on your speed. Your speed changes the concentration of particles around you, which shortens or lengthens sound waves.

Citation needed.

Or should I ask a moderator to move this to Speculations so you are required to defend this nonsense?

[Itoero]

9 minutes ago, Strange said:

Citation needed.

Or should I ask a moderator to move this to Speculations so you are required to defend this nonsense?

For what do you need citation? That our atmosphere is filled with particles?

You are a moderator.

1 hour ago, Strange said:

If you and the police car/radar gun or whatever are on the same stretch of road then the gravity is the same, yes. Moving at a constant speed won't change that.

Which gravity? The particles which enable sound (from police car) have also a gravitational attraction. When a police car drives, then the particles in front of him increase in concentration (which shortens waves) and the particles behind the car decrease in concentration.(which lengtens waves)

This is simple aerodynamics.

[beecee]

1 hour ago, Itoero said:

Something else, our atmosphere is filled with particles, which enable sound. When you move through that, then the gravit. field is altered depending on your speed. Your speed changes the concentration of particles(which alters gravit. attraction) around you, which shortens or lengthens sound waves. This is what people call the doppler effect.

Gravity has nothing to do with sound, rather sound is caused by compressions and rarifications of the atmopshere and the vibration one particle imparts to another.

 

Let me correct that...sound is caused by the vibration of a medium, and sound waves consist of areas of low and high pressures, caused by the compression and rarification of the atmosphere.

Edited November 25, 2018 by beecee

[Strange]

2 hours ago, Itoero said:

For what do you need citation? That our atmosphere is filled with particles?

No. That movement changes gravity, which causes the Doppler effect.

If that were the case, surely a passing cyclist who hears a sound with a different pitch would also affect your perception of the sound?

2 hours ago, Itoero said:

You are a moderator.

We are not allowed to moderate threads we take part in.

2 hours ago, Itoero said:

Which gravity? The particles which enable sound (from police car) have also a gravitational attraction. When a police car drives, then the particles in front of him increase in concentration (which shortens waves) and the particles behind the car decrease in concentration.(which lengtens waves)

While there is some truth in that, it has nothing to do with gravity.

The gravitational effect of a car (moving or stationary) would be hard to measure with precision instruments. It certainly isn't going to compress air enough to change sound.

[Outrider]

2 hours ago, Itoero said:

Something else, our atmosphere is filled with particles, which enable sound.

While worded poorly I think this mostly correct. 

2 hours ago, Itoero said:

When you move through that, then the gravit. field is altered depending on your speed.

This is what you need to cite or better yet retract because its just wrong. AFAIK the only thing that alters a gravitational field is more or less mass.

Also why do you spell gravitational like this "gravit."

2 hours ago, Itoero said:

Your speed changes the concentration of particles(which alters gravit. attraction) around you, which shortens or lengthens sound waves. This is what people call the doppler effect.

 

This is also wrong.

2 hours ago, Itoero said:

Which gravity? The particles which enable sound (from police car) have also a gravitational attraction. When a police car drives, then the particles in front of him increase in concentration (which shortens waves) and the particles behind the car decrease in concentration.(which lengtens waves)

This is simple aerodynamics.

It is simple aerodynamics which is why we can and do ignore any gravitational effects. Your not wrong that particles in the air have a gravitational attraction its just that its so small that we can ignore it.

Cross posted with Strange.

[swansont]

2 hours ago, Itoero said:

Something else, our atmosphere is filled with particles, which enable sound. When you move through that, then the gravit. field is altered depending on your speed. Your speed changes the concentration of particles(which alters gravit. attraction) around you, which shortens or lengthens sound waves. This is what people call the doppler effect.

 

!

Moderator Note

Since you are now proposing some new understanding of science, this is moved to speculations. Let's see your model explaining the doppler shift in therms of speed changing the density of particles.

 

[Itoero]

On ‎25‎/‎11‎/‎2018 at 9:27 PM, Strange said:

No. That movement changes gravity, which causes the Doppler effect.

When you move, you alter the position of particles around you. (doppler effect)When you stand still you hardly alter the position of the particles around you.(no doppler effect)  When you alter the position of particles you change the gravitational attraction.

 

On ‎25‎/‎11‎/‎2018 at 7:49 PM, beecee said:

On ‎25‎/‎11‎/‎2018 at 6:37 PM, Itoero said:

.

Gravity has nothing to do with sound

You need atoms/molecules for sound...the ones in our atmosphere for example have gravitational attraction to other atoms/molecules and to the Earth (which is also a bunch of atoms/molecules)

 

On ‎25‎/‎11‎/‎2018 at 9:29 PM, Outrider said:

mple aerodynamics which is why we can and do ignore any gravitational effects. Your not wrong that particles in the air have a gravitational attraction its just that its so small that we can ignore it.

The gravitational attraction between particles can probably be ignored but the one between particles and you and between particles and the Earth can't.

 

On ‎25‎/‎11‎/‎2018 at 9:29 PM, Outrider said:

On ‎25‎/‎11‎/‎2018 at 6:37 PM, Itoero said:

 

This is what you need to cite or better yet retract because its just wrong. AFAIK the only thing that alters a gravitational field is more or less mass.

When you are on the move you change the gravit field since you have mass. Atoms/molecules in the atmosphere also have mass, your motion alters the position of many atoms/moleculles which changes the gravit field.

 

On ‎25‎/‎11‎/‎2018 at 9:29 PM, Outrider said:

Also why do you spell gravitational like this "gravit."

Because I like to shorten words.

[Strange]

2 hours ago, Itoero said:

When you move, you alter the position of particles around you. (doppler effect)

The Doppler effect is not caused by altering the position of particles around you.

2 hours ago, Itoero said:

When you alter the position of particles you change the gravitational attraction.

Citation needed.

2 hours ago, Itoero said:

The gravitational attraction between particles can probably be ignored but the one between particles and you and between particles and the Earth can't.

Well, I suppose we can't ignore the gravitational attraction between the molecules of air and the Earth otherwise we would have no atmosphere and no sound.

However, you need to show, qualitatively, that this gravitational attraction is relevant to Doppler shift (which as every schoolboy knows is only due to relative motion).

But, as we know the cause of the Doppler effect, you seem to be claiming a new "molecular gravitation redshift (MGR) effect". You need to show us the mathematical model for how large this effect is, and then evidence that it exists.

If you claim that this MGR effect produces what we currently call the gravitational effect, then you also need to explain why moving through wavefronts does not make you experience them more frequently. (Which would appear to require that you challenge basic arithmetic.)

 

2 hours ago, Itoero said:

When you are on the move you change the gravit field since you have mass. Atoms/molecules in the atmosphere also have mass, your motion alters the position of many atoms/moleculles which changes the gravit field.

Citation needed.

Just repeating this doesn't magically make it true.

 

[beecee]

3 hours ago, Itoero said:

You need atoms/molecules for sound...the ones in our atmosphere for example have gravitational attraction to other atoms/molecules and to the Earth (which is also a bunch of atoms/molecules)

Essentially gravity has nothing to do with sound. Does a sealed road make a car go?

[Ghideon]

3 hours ago, Itoero said:

When you are on the move you change the gravit field since you have mass. Atoms/molecules in the atmosphere also have mass, your motion alters the position of many atoms/moleculles which changes the gravit field.

I've a few naive questions:

Question 1: Does speed of sound differ horizontally and vertically? I think answer is no but I'm not sure. 

Question 2: Suppose gravity is involved*, does direction, according to you, change the dopler effect? What should happen if gravity is involved and source of sound and any relative movement is vertical? For instance if you in the top of a building, listening to an approaching elevator. Can it be measured? Can you provide references?

Question 3: If you move to a location where gravitational constant is slightly different, how will the dopler effect change? Can it be measured? Are there any measurements available?

 

*) No, I do not think gravity is involved.

[studiot]

1 hour ago, Ghideon said:

I've a few naive questions:

Question 1: Does speed of sound differ horizontally and vertically? I think answer is no but I'm not sure. 

Question 2: Suppose gravity is involved*, does direction, according to you, change the dopler effect? What should happen if gravity is involved and source of sound and any relative movement is vertical? For instance if you in the top of a building, listening to an approaching elevator. Can it be measured? Can you provide references?

Question 3: If you move to a location where gravitational constant is slightly different, how will the dopler effect change? Can it be measured? Are there any measurements available?

 

*) No, I do not think gravity is involved.

Q1 1, theoretically yes.

Q2 You don't need gravity for this to happen, and it also happens horizontally with vehicles, whose engine sound chages as it approaches, passes and then recedes. Elevators tend to make broad band noise, not fixed frequency engine noise.

Q3 Why should it?

 

I think that in air, as in water, thermal effects that cause rays  of sound to adopt curved paths will be orders of magnitude greater than any gravitational effect.

 

https://www.acs.psu.edu/drussell/demos/refract/refract.html

Edited November 30, 2018 by studiot

[Ghideon]

2 minutes ago, studiot said:

Q2 You don't need gravity for this to happen, and it also happens horizontally with vehicles, whose engine sound chages as it approaches, passes and then recedes. Elevators tend to make broad band noise, not fixed frequency engine noise.

I was rather unclear with the intentions, sorry for that! I intended Itoero to try to answer from the point of view that gravity is involved (which it is not). I had the idea that the questions should trigger some new thoughts.

Anyway, good point regarding Q1, I did not know that.
And of course I agree on Q2 & Q3. 

[studiot]

1 hour ago, Ghideon said:

I was rather unclear with the intentions, sorry for that! I intended Itoero to try to answer from the point of view that gravity is involved (which it is not). I had the idea that the questions should trigger some new thoughts.

All I was really observing is that air is not an isotropic medium because of gravity as the pressure drops with height.

 

[Strange]

Combining the Doppler effect with gravitational redshift is the basis of the Pound-Rebka test of GR. I think this also rules out any interaction with the medium (the air in the tower) changing the frequency significantly. Thus disproving Itoero's claims.