Are forces subject to the doppler effect?

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SUMMARY

The discussion centers on the effects of the Doppler effect on forces exerted by massless gauge bosons, specifically photons impacting a solar sail. It is established that as a solar sail accelerates relativistically, the force exerted by incoming photons diminishes from the sail's frame of reference due to energy loss from Doppler shifting. The conversation confirms that this phenomenon applies to both massless and massive particles, although the extent of reduction varies. The frames of reference—Earth, co-moving inertial, and accelerating frames—are critical in analyzing energy conservation and force dynamics.

PREREQUISITES
  • Understanding of relativistic physics and frames of reference
  • Knowledge of gauge bosons and their role in fundamental forces
  • Familiarity with the Doppler effect and its implications in physics
  • Basic principles of energy conservation in accelerating systems
NEXT STEPS
  • Study the implications of the Doppler effect on energy transfer in relativistic systems
  • Explore the role of gauge bosons in quantum field theory
  • Investigate the dynamics of solar sails in varying frames of reference
  • Learn about energy conservation challenges in relativistic motion
USEFUL FOR

Physicists, aerospace engineers, and students of relativistic physics interested in the interactions of light and matter, particularly in the context of solar sails and energy dynamics in relativistic systems.

kmarinas86
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I know that photons hitting a solar sail can add energy to that sail.

I know that photons are gauge bosons.

I know that gauge bosons are thought to be the carriers of fundamental forces.

If a solar sail were gaining speed to a point where it reached relativistically with respect to the power source, I know that an observer on a solar sail would observe a reduction of the force on that solar sail.

Is not the same essentially true for any massless gauge boson?

It seems that the work done on the sail by previous photons reduced the amount of work that future photons coming from the same source and direction could add to it, that is, from the frame of reference of the sail.

It would seem that the actual amount of work done on the sail, from the frame of reference of the sail, would be less than the energy expended by the source which produced the photons.

Is this all correct?
 
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kmarinas86 said:
Is not the same essentially true for any massless gauge boson?
It's true for any massless particle. It's also true for massive particles, although the amount of reduction would be different.

kmarinas86 said:
It seems that the work done on the sail by previous photons reduced the amount of work that future photons coming from the same source and direction could add to it, that is, from the frame of reference of the sail.
Yes, this is correct in an inertial frame that's momentarily co-moving with the sail (but not in the Earth's frame).

kmarinas86 said:
It would seem that the actual amount of work done on the sail, from the frame of reference of the sail, would be less than the energy expended by the source which produced the photons.
You could define three frames: E = the frame of the earth, C = an inertial frame that's momentarily co-moving with the sail at some later time, S = a frame accelerating along with the sail.

In C, there is no mismatch between the sun's energy output and the work done on the sail, since the sun is emitting photons that are Doppler-shifted to a lower energy.

In S, we have much bigger issues with conservation of energy than the ones involved in the solar sail. For instance, the sun is rapidly gaining huge amounts of kinetic energy.
 
bcrowell said:
It's true for any massless particle. It's also true for massive particles, although the amount of reduction would be different.


Yes, this is correct in an inertial frame that's momentarily co-moving with the sail (but not in the Earth's frame).


You could define three frames: E = the frame of the earth, C = an inertial frame that's momentarily co-moving with the sail at some later time, S = a frame accelerating along with the sail.

In C, there is no mismatch between the sun's energy output and the work done on the sail, since the sun is emitting photons that are Doppler-shifted to a lower energy.

In S, we have much bigger issues with conservation of energy than the ones involved in the solar sail. For instance, the sun is rapidly gaining huge amounts of kinetic energy.
In the Earth frame wouldn't the acceleration derived from the photonic reflection energy also drop off as the sail approached c ,?? to the point where there would be no measurable increase in v from further light reflection?
On the increase in the Sun's relative kinetic energy isn't this a sort of ubiquitous problem? Inherent in any accelerating system from a relativistic perspective?
Or am I just not getting your point??
 

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