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Yes, by conservation of momentum if light is refracted in a way that's not symmetric, momentum must be imparted to the lens. It doesn't even need to be a single pulse - a prism will refract light asymmetrically, and an off-axis section of a spherical-surfaced lens will do it.

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I did a PhD involving this. Yes, light passing from one medium to another gives the interface a momentum kick. (Edit: example video, not mine.)

Yes! This effect is used for laser cooling. The momentum from a photon can be imparted to an atom; if done in the right way a cloud of atoms can be cooled to a few billionths of a degree above absolute zero. One cool application of this technology is optical clocks, which form the most precise clocks in existence.

Does it mean that the reflected (or refracted) photon has a longer frequency (less energy)?

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Fixed link: http://john.maloney.org/Papers/Mechanical%20fluidity%20of%20fully%20suspended%20biological%20cells%20(Maloney%20et%20al%202013).pdf

Or for markdown http://john.maloney.org/Papers/Mechanical%20fluidity%20of%20fully%20suspended%20biological%20cells%20%28Maloney%20et%20al%202013%29.pdf

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Thank you! I always forget to escape the parentheses on Reddit.

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As I recall, the energy is split between absorption, reflection, and refraction. The frequency of the light wave stays the same; its speed changes. Remember that we’re talking about light interacting with matter, rather than lone photons in a vacuum.

This answer got me wondering, if a photon could somehow enter an atmosphere, pass through water, then head back into the vacuum of space, does it “re-accelerate” to “full” lightspeed? How does that work?

No one thing is decelerating or accelerating. The photon–matter interaction propagates slower than c.

See the discussion here and the links within, for example.

So when the light speeds up when it leaves the medium, where does that come from? The medium? So the net force on the medium is 0 because if gives it back up to the light when it leaves?

The medium plays a part in the momentum transfer, yes.

The net force on a spherical body isn't zero for a single beam because the beam changes shape moving through it, so the refractive details are different on either side.

But for two counterpropagating beams, which is what I used, the left–right forces do balance out, leaving an internal tensile load that stretches a compliant medium. You don't notice this in everyday situations with macroscale objects because they're stiff and the light is weak.

Honestly, this made me think of the emdrive from a few years ago. Interesting phenomenon.

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Does this mean that the light leaving the medium is of a lower frequency? Can this be setup in a way to increase the frequency and take energy from the medium?

The frequency is the same everywhere. (The easiest way to see this may be to note that the electric and magnetic fields must be in sync everywhere, including the interfaces.)

The light must give some of its energy to the medium so if the frequency doesn't change then where does this energy come from.

Well, what's different about monochromatic light that's passed through a filter?

I don't know. I am a normal dude in IT that spends too much time on the internet. I have a middling understanding of this stuff and am curious. If a refractory medium like a lens behaves differently than a filter that would be interesting. 😁

I was just looking for “It’s dimmer.” That’s what provides the energy that’s absorbed in the medium, not any change in frequency.

Could this be a potential propulsion system in a vacuum? Like I know solar sails are a thing, but could it be plausible to emit a high lumen light directed through a prism for propulsion from the craft itself?

You don’t need a prism. A directional light source produces a recoil force. For a near-perfect beam like a laser you need 300 megawatts per Newton.