Question about photons

@humy said
What are you talking about? That's a pretty vague and confused sounding assertion.
What aspect of "sound vibrating the air" is "not a constant"? The speed of sound? If so, nobody here including I said/implied the contrary.
If not, exactly what are you referring to here if not the speed? Be specific.

@Metal-Brain
The speed of sound has nothing to do with audible doppler shift in air.
If you are standing on the ground near a RR track on a calm day there won't be much change in the speed of sound at ground level but if a train approaches the pitch will be higher and when it recedes the pitch will be lower. that is the definition of doppler shift and it happens in air and in light.

@sonhouse said
@Metal-Brain
The speed of sound has nothing to do with audible doppler shift in air.
If you are standing on the ground near a RR track on a calm day there won't be much change in the speed of sound at ground level but if a train approaches the pitch will be higher and when it recedes the pitch will be lower. that is the definition of doppler shift and it happens in air and in light.

@Metal-Brain
BULLSHYTE. c is unchanging and the last 100 years of research has borne that out time after time.
It is only the FREQUENCY of the radiation that changes during doppler shift and nothing else.

@sonhouse said
@Metal-Brain
BULLSHYTE. c is unchanging and the last 100 years of research has borne that out time after time.
It is only the FREQUENCY of the radiation that changes during doppler shift and nothing else.

@metal-brain said
LOL! You clearly do not understand what causes a Doppler effect. Why do you bother posting nonsense? You don't even understand sound is not a constant like light is claimed to be.

@deepthought said
When you say "light is a constant" or "sound is not a constant" what exactly do you mean?

@deepthought said
When you say "light is a constant" or "sound is not a constant" what exactly do you mean?

@sonhouse said
@Metal-Brain
BULLSHYTE. c is unchanging and the last 100 years of research has borne that out time after time.
It is only the FREQUENCY of the radiation that changes during doppler shift and nothing else.

@Metal-Brain
Of course the speed of sound is not constant, it depends on what is in the air att and the pressure, for instance if you breath in a lungful of helium, and you exhale and talk you know you come out sounding like the chipmunks because the speed of sound is higher in helium than N2 and O2, the principle components of our air.
Like I said, the only thing that changes in a changing speed of sound is the resultant change in frequency perceived by the receiver, there is still a change in frequency regardless of the speed of sound in air.
And the speed of light is ALWAYS constant to within a part in a trillion or so now proven by experiments.
Why are you asking US about all this stuff you should have learned in high school?
And why can't you just google for instance, 'is the speed of light constant' or what is doppler effect.

@Metal-Brain
What difference does it make in regards to the frequency shift or 'red shift' in astronomy? One thing that does change is the fact that at a certain frequency there is a certain level of energy in that electromagnetic wave. A shorter wavelength means more energy in that wave so a 1 Ghz radio wave has much less intrinsic energy than a 1 TERAhertz wave.
So if a wave comes at you when you are going half the speed of light, the frequency shifts down by half so a 1 Ghz signal is now seen at 500 Megahertz on your onboard radio.
So that means if you want to convert that into energy, you have lost half the intrinsic energy of the wave due to its lower frequency.
Conversely, if you are approaching a source, that same 1 Ghz signal will now be found on your on board radio at TWO gigahertz and therefore that wave will have a higher intrinsic energy per wave than what was sent.
Also, the red shift thing means the energy level of the original signal has been reduced by the amount of the change in frequency, how deeply red shifted it is.
Close in galaxies like Andromeda would have very little red shift so the colors we see of stars are pretty much the same as stars we would see in our own galaxy.
But for a galaxy way far away, the red shift goes way up and the star color goes to the red if it started out as say green. So that light has less intrinsic energy per wave than the source.

@sonhouse said
@Metal-Brain
Of course the speed of sound is not constant, it depends on what is in the air att and the pressure, for instance if you breath in a lungful of helium, and you exhale and talk you know you come out sounding like the chipmunks because the speed of sound is higher in helium than N2 and O2, the principle components of our air.
Like I said, the only thing that cha ...[text shortened]... why can't you just google for instance, 'is the speed of light constant' or what is doppler effect.

@Metal-Brain
It depends on composition, temperature and altitude, those are the variables.
Why didn't you learn this in high school? I leaned this stuff in 8th grade.
Same altitude and pressure, if it is standard air, then it would be a constant. If it was all helium at the same altitude and pressure the speed of sound would be much higher. What is so hard to understand about that?

@sonhouse said
@Metal-Brain
It depends on composition, temperature and altitude, those are the variables.
Why didn't you learn this in high school? I leaned this stuff in 8th grade.
Same altitude and pressure, if it is standard air, then it would be a constant. If it was all helium at the same altitude and pressure the speed of sound would be much higher. What is so hard to understand about that?

@Metal-Brain
the speed of sound depends on pressure, temperature and composition. If you have sample A and it says the speed of sound is 1200 feet per second, and sample B with the same conditions, the speed in that sample will be the same.
Why did you not learn this in high school?
Did you EVER take a single physics class?