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Since light imparts momentum to an object that it comes in contact with, and since a magnifying glass bends light that passes through it, I am wondering if this would mean that if a magnifying glass is placed in outer space within our solar system, and it is held in position towards the Sun, it should be accelerated away from the Sun as it gains more and more momentum by continuously bending sunlight that is passing through it.

I am neither a physicist nor a scientist and I am asking this question simply out of scientific curiosity.

Would a magnifying glass be an effective solar sail?

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Since the lens would be redirecting originally parallel rays, conservation of momentum dictates that it would experience a force and would indeed be effective as a solar sail.

Consider the ray diagrams shown below. Entirely leftward momentum is replaced for each ray with momentum with some upward or downward character (which cancels out). The leftward momentum difference is imparted to the lens. The force scales up with the curvature of the lens, approaching an asymptotic limit in which the rays are all redirected toward the side, which is equivalent (in momentum-transfer terms) to absorbing them.

enter image description here

(Better still, though, would be a mirror, which redirects the rays back toward their source for maximum momentum-generating efficiency and is also much easier to fabricate, requiring only a thin shiny layer rather than a relatively thick and carefully shaped dielectric. In other words, image fidelity—the advantage granted by a lens—isn’t important in this context.)

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    $\begingroup$ Conservation of momentum dictates that the momentum that the light carries will be partially tranfered to the lens, the effect will be nearly non-existent and even more so for high-quality, optically-clear lenses. A mirror would be more effective as a solar sail, but there is an even better option: thin mirrors with orbital lenses which target huge quantities of light at a regular solar sail. $\endgroup$
    – Gerald
    Commented Dec 20, 2022 at 21:54
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    $\begingroup$ "the effect will be nearly non-existent" On the contrary; the stronger the lens curvature (i.e., the shorter the focal length), the more the results will approach the outcome of complete absorption, which is that the object assumes the complete momentum carried by the light. I agree, though, that making the lens clearer is a complete waste of time in this context, serving only to decrease the (momentum-transferring) efficiency. $\endgroup$
    – Chemomechanics
    Commented Jan 3, 2023 at 19:28

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