What is the Doppler Shift of Matter?

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In summary, there is a link between the doppler shift and matter waves, as explained by debroglie's equation and the concept of phase velocity. However, there are still ongoing debates and research regarding the interpretation and understanding of matter waves and their relationship with complex probability amplitudes.
  • #1
teroenza
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Hello all,
I first must state I have very little formal experience or knowledge of physics or mathematics. This is just a random musing that I could not find an answer for.
My question is that if a source emitting waves is moving, and the waves when observed are affected by the doppler effect. If matter itself has a wave-like nature then would it be effected also? Say, an electron gun emmiting electrons moving at high speed.
Again, sorry if I am overlooking many fundamental things as I am merely an inquisitive layman.
Thank you
-ter
 
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  • #2
Matter most certainly can be doppler shifted; but its much less exciting than you would think.
According to debroglie's equation, momentum and frequency are directly related (the equation says wavelength; but for our purposes i think frequency is easier to think about). If the electron is shot out, when the gun is moving towards us, it seems to be higher momentum than it is from the stationary gun frame.
This is exactly the same as throwing a baseball from a moving car - the speed of the car will add to the speed of the baseball from a stationary observer.

The doppler effect allows the debroglie relation to hold in front of relativity.
 
  • #3
Thank you very much. I was afraid I would not be able to understand the answer but that makes sense.
-ter
 
  • #4
lzkelley said:
Matter most certainly can be doppler shifted; but its much less exciting than you would think.
According to debroglie's equation, momentum and frequency are directly related (the equation says wavelength; but for our purposes i think frequency is easier to think about). If the electron is shot out, when the gun is moving towards us, it seems to be higher momentum than it is from the stationary gun frame.
This is exactly the same as throwing a baseball from a moving car - the speed of the car will add to the speed of the baseball from a stationary observer.

The doppler effect allows the debroglie relation to hold in front of relativity.

There are some issues for Doppler Shift on matter waves.
The wavelength is given by :-
[tex] \lambda = \frac{h}{p}[/tex] where p is the momentum.
The phase velocity of the wave is:-
[tex] v_p = \frac{C^2}{v}[/tex] where v is the velocity of the particle.

The wave is super luminal.
There are more fun to it.
What is exactly the source of this wave?
Assuming the particle to be the source, the wavelength measured should already be Doppler Corrected, as the source is moving with a velocity *v*.

There are loads of other fun, namely :-
[tex] \lambda_{compton} = \frac{h}{m_0C}[/tex]


[tex]
\lambda_{DeBroglie} = \frac{h}{mv} = \frac{h}{m_0 v \gamma } = \frac{h}{m_0 \beta C \gamma }
[/tex]

where

[tex]
\beta = \frac{v}{C}
[/tex]

Hence,
[tex]
\lambda_{DeBroglie} = \frac{ \lambda_{compton}}{\gamma \beta}
[/tex]

Assuming that the Compton effect was done in a moving reference frame, [that is the beauty]
[tex]
\lambda_{compton} = \frac{h}{m_0 \gamma C}
[/tex]

And, hence

[tex]
\lambda_{DeBroglie} = \frac{ \lambda_{compton}}{ \beta}
[/tex]

Now, why there is a similarity here?

I am working on this for past 20 days, and I am overwhelmed by the amount of things taken to be granted about matter waves.

Some are linked here:-
http://www.springerlink.com/index/G862M2015L774784.pdf
http://linkinghub.elsevier.com/retrieve/pii/0375960184902913

I personally see, there is some issue with interpretation of matter waves.
In fact, that might unravel the idea why we need a complex probability amplitude for quantum systems.

Why I am saying this?
Consider this:-
[tex]
E^2 = p^2C^2 + {m_0}^2C^4
[/tex]

Assume this energy is a Complex number.
Check that , the last term is Compton effect. I earlier tend to go with the pC term for De Broglie wavelength, but I was wrong.

You can rewrite
[tex]E_{complex} = J pC + m_0C^2[/tex]
J is the complex number `i' . Why I am assigning J to pC ? Because that is dependent on motion of a particle, which can be frozen out. [May be I am dead wrong].

Any thoughts?
 
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FAQ: What is the Doppler Shift of Matter?

What is the Doppler Shift-Matter?

The Doppler Shift-Matter refers to the change in frequency or wavelength of electromagnetic radiation emitted by a moving object. This phenomenon is named after the Austrian physicist Christian Doppler who first described it in 1842.

How does the Doppler Shift-Matter work?

The Doppler Shift-Matter works by changing the frequency of the electromagnetic radiation emitted by an object as it moves towards or away from an observer. This change in frequency is caused by the compression or stretching of the waves due to the relative motion between the object and the observer.

What causes the Doppler Shift-Matter?

The Doppler Shift-Matter is caused by the relative motion between an object and an observer. This can be observed in various scenarios such as a moving ambulance siren, a passing train whistle, or the redshift of galaxies in the expanding universe.

How is the Doppler Shift-Matter used in science?

The Doppler Shift-Matter is used in various fields of science, such as astronomy, meteorology, and radar technology. It is used to measure the speed and direction of moving objects, study the properties of stars and galaxies, and predict weather patterns. It is also used in medical imaging techniques like ultrasound.

How is the Doppler Shift-Matter different from the Doppler Effect?

The Doppler Shift-Matter is a type of Doppler Effect, which refers to the change in frequency or wavelength of a wave due to the relative motion between the source and observer. The Doppler Shift-Matter specifically deals with electromagnetic radiation, while the Doppler Effect can also be observed in sound waves and other types of waves.

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