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As usual, I apologize for asking dumb questions, and I hope this isn't one of them.

If we know that photons are the carriers of the electromagnetic force, could we somehow create a device that simply emits these photons directly, in order to attract or repel another object? Similar, for example, to how the Death Star was pulling ships to it, but instead of gravity, using just electricity, and in a single direction.

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  • $\begingroup$ The only way I can think of is that the "target" stimulatedly emits photons into the direction of the photons sent to it. By that a thrust into the direction of the photon-source is created. $\endgroup$ – Quantumwhisp Oct 15 '19 at 9:22
  • $\begingroup$ So then both objects would have to artificially emit photons towards each other? Has this ever been attempted in an experiment? I'm curious if this can be verified to be directional electromagnetism rather than a field, if that makes sense $\endgroup$ – Cosmin A. Oct 15 '19 at 9:36
  • $\begingroup$ Photons have momentum. That is the principle of the Lightsail. $\endgroup$ – Keith McClary Oct 16 '19 at 3:44
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    $\begingroup$ BTW, Quantumwhisp will not get a notification unless you put @Quantumwhisp . You are automatically notified since it's your Question. $\endgroup$ – Keith McClary Oct 16 '19 at 4:20
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    $\begingroup$ A device that simply emits photons? You mean like a light bulb? $\endgroup$ – WillO Oct 16 '19 at 21:42
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It is very important to understand the difference between real photons and virtual photons.

Now when you need to create EM attraction between two objects, to pull, you need to create a static EM field, that might have the effect of attracting other objects. This is caused by the static EM field that the object (charge) would create, and that static EM field is modeled by virtual photons. These are not real photons, just a mathematical model of how the static EM field creates this attraction (or repulsion).

https://en.wikipedia.org/wiki/Electromagnetic_field

We use these virtual photons to describe the effect that the EM field has on certain objects that it interacts with.

Virtual photons, what makes them virtual?

Now you are talking about an object emitting real photons, thus creating attraction. This does not work, because photons that are emitted by the source do recoil the source, and the absorbing object too, thus creating a push effect between them (instead of attraction).

Does an atom recoil when photon radiate?

Thus, the emitting source receives a recoil in the other direction, away from the other object.

And when the photon is going to be absorbed by the object, it will receive a recoil again in the opposite direction, away from the source. This is called radiation pressure.

https://en.wikipedia.org/wiki/Radiation_pressure

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    $\begingroup$ why the downvote? $\endgroup$ – Árpád Szendrei Oct 16 '19 at 21:03
  • $\begingroup$ not sure who gave you the downvote, but I gave you an upvote. Your answer is quite enlightening for me. So in other words in order to create a directional EM field (rather than a spheric one) one would have to, excuse my wording, emit virtual photons. $\endgroup$ – Cosmin A. Oct 25 '19 at 17:38
  • $\begingroup$ @CosminA. thank you! you would have to create a static EM field in a certain direction yes (that is what we model with virtual photons). $\endgroup$ – Árpád Szendrei Oct 25 '19 at 18:38
  • $\begingroup$ Are there any studies, experiments or papers out there on this? Has this been attempted? $\endgroup$ – Cosmin A. Oct 26 '19 at 8:39
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I have heard of something kind of like that.

If I understood the answer correctly, normally linearly-polarized light will tug charges sideways, first one direction and then the other.

And it should be possible to arrange a maser that will tug charges sideways in one direction, and never back the other way. The sideways forces it makes would not cancel out.

That doesn't pull charges toward you or push charges away. It would only be sideways. But that's something.

Possibly it won't work like that in reality. One expert seemed to say it would.

weird light

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