Momentum transfer dependent on distance?

In summary, the amount of momentum transferred by an EM wave to a particle is proportional to the intensity of the light and the number of photons colliding with the particle. Distance and the spread of the wave may affect the intensity, but it does not change the basic principle of momentum transfer. The double slit experiment measures waves, not particles, and interference is a property of waves while momentum is a property of particles. To accurately explain momentum transfer, a particle paradigm can be used. However, in cases such as a laser, where all particles are flying in the same direction and do not spread out, distance does not affect the momentum transfer. For the double slit experiment, the wave nature of light must also be considered in addition to its particle properties
  • #1
jaketodd
Gold Member
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Does the amount of momentum transferred by an EM wave to a particle differ by how far away the particle is from the EM wave emitter? The more spread out the EM wave is, the less momentum transfered? I'm not talking about a collision between a photon and a particle; I'm talking about the momentum transferred to a particle by the wave nature of an EM wave.

Thanks!
 
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  • #2
jaketodd said:
Does the amount of momentum transferred by an EM wave to a particle differ by how far away the particle is from the EM wave emitter? The more spread out the EM wave is, the less momentum transfered? I'm not talking about a collision between a photon and a particle; I'm talking about the momentum transferred to a particle by the wave nature of an EM wave.

Thanks!

Waves don't have momentum, particles do. So you can think of the problem as having a shotgun-like source spraying photons everywhere, each with their own momentum. The total momentum transferred will be proportional to the number of photons colliding with your particle. It will be proportional to the intensity of the light where you're measuring.
 
  • #3
kote said:
Waves don't have momentum, particles do. So you can think of the problem as having a shotgun-like source spraying photons everywhere, each with their own momentum. The total momentum transferred will be proportional to the number of photons colliding with your particle. It will be proportional to the intensity of the light where you're measuring.

Actually waves do have momentum. If it were a multitude of particles then you would get particles all over the place from one EM wave emission in the double slit experiment, for example. An EM wave is a wave and then collapses to a particle. And that wave transfers momentum to everything it touches (even the things that the wave don't manifest as a particle on). So would someone else please answer my question? I do appreciate your message though, Kote. I agree that the intensity of the wave would be proportional to the momentum transfered, but I'm wondering if distance and how much the wave has spread out makes a difference in how much momentum is transferred to the particle.
 
  • #4
jaketodd said:
Actually waves do have momentum. If it were a multitude of particles then you would get particles all over the place from one EM wave emission in the double slit experiment, for example. An EM wave is a wave and then collapses to a particle. And that wave transfers momentum to everything it touches (even the things that the wave don't manifest as a particle on). So would someone else please answer my question? I do appreciate your message though, Kote. I agree that the intensity of the wave would be proportional to the momentum transfered, but I'm wondering if distance and how much the wave has spread out makes a difference in how much momentum is transferred to the particle.

There is no momentum involved in the double slit experiment. That experiment measures waves, not particles. Interference is a property of waves; momentum is a property of particles :). A photon is neither a wave nor a particle persistently, but in certain interactions it will manifest the properties of either a wave or a particle. A particle paradigm can be used to explain the momentum transfer interaction accurately because momentum is a property of particles.*

What you said is exactly correct. The distance is proportional to the intensity (and momentum) of the light from a normal light bulb type source by an inverse square relationship. If you have a laser then the distance will not change the momentum at all since the intensity is the same at any distance. All of the particles in a laser are flying in the same direction and don't spread out.

*Now, if you want to know the intensity and related momentum on the other side of a 2 slit setup, you've got a little more work to do. That would involve a step where you consider the light to be a wave and then a step where you consider light's particle properties.
 
  • #5
kote said:
There is no momentum involved in the double slit experiment. That experiment measures waves, not particles. Interference is a property of waves; momentum is a property of particles :). A photon is neither a wave nor a particle persistently, but in certain interactions it will manifest the properties of either a wave or a particle. A particle paradigm can be used to explain the momentum transfer interaction accurately because momentum is a property of particles.*

What you said is exactly correct. The distance is proportional to the intensity (and momentum) of the light from a normal light bulb type source by an inverse square relationship. If you have a laser then the distance will not change the momentum at all since the intensity is the same at any distance. All of the particles in a laser are flying in the same direction and don't spread out.

*Now, if you want to know the intensity and related momentum on the other side of a 2 slit setup, you've got a little more work to do. That would involve a step where you consider the light to be a wave and then a step where you consider light's particle properties.

In the double slit experiment, there is a tiny amount of momentum transferred to the wall in between the slits and everywhere the wave touches. It is a wave until it changed into a particle on the detector array behind the slits. If it were a bunch of particles or a wave and a bunch of particles at the same time, then you would get significant momentum transfer to everything it touches.
 

Related to Momentum transfer dependent on distance?

1. How does distance affect momentum transfer?

Distance affects momentum transfer because as distance increases, the force acting on an object decreases, resulting in a decrease in the rate of change of momentum. This means that a smaller amount of momentum is transferred over a longer distance compared to a shorter distance.

2. Is momentum transfer always dependent on distance?

No, momentum transfer can also be dependent on other factors such as the mass and velocity of the objects involved. However, distance is an important factor in determining the amount of momentum transferred between two objects.

3. What is the relationship between distance and momentum transfer?

The relationship between distance and momentum transfer is inverse. This means that as distance increases, momentum transfer decreases and vice versa. This relationship can be described by the formula: Momentum transfer ∝ 1/distance.

4. Can momentum transfer occur without any distance between objects?

No, momentum transfer requires a distance between objects. This is because momentum transfer involves the transfer of forces between two objects, and for forces to act, there must be a distance between the objects.

5. Why is understanding momentum transfer important in science?

Understanding momentum transfer is important in science because it helps us to explain and predict the motion of objects. It is also essential in many real-life applications, such as designing safer cars and improving the efficiency of machines.

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