I understand to get the effect of the one-way, one side needs to have light to produce the mirror, leaving the darkened side with the ability to see through.

I would like to know if there is a way to reverse this. I would like the side with the light to see through and the side with the darkness to block the image.

Could this be done by somehow utilizing other mirrors? I am at a loss here.

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    $\begingroup$ I think what you want is an optical isolator: en.wikipedia.org/wiki/Optical_isolator. I am not aware that one can make really good ones for your purpose, but at least in theory true one way devices are possible. Why the down votes, by the way? How to make a one way optical mirror or other device is a legitimate physics question and it's probably a hundred million dollar industry. $\endgroup$ – CuriousOne Apr 30 '15 at 1:25
  • $\begingroup$ Thank you for your help! I will research that and hopefully have the ability to make a connection. I am not sure why the down votes. I have only been here for 45 minutes and already getting booed! :) $\endgroup$ – Kenna Apr 30 '15 at 1:41
  • $\begingroup$ Don't worry about the down votes. The question is legitimate, I just can't give you a better answer because I have never worked with these devices. I rather not say anything in detail about them than tell you the wrong thing but in principle one can make real "one way" optics, just not with mirrors alone. $\endgroup$ – CuriousOne Apr 30 '15 at 1:44
  • $\begingroup$ You are very kind, I really appreciate your time. Thank you for reaching out to me! $\endgroup$ – Kenna Apr 30 '15 at 2:02

Have a look at the question How does a one-sided glass work?. The effect is due to the limited ability of the human eye to handle large contrast ranges and not to the effect of light intensity on the reflectivity of the glass.

So without replacing the human eye with something else there is no way to achieve what you're asking.

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  • $\begingroup$ How about an optical isolator with a Faraday rotator? I am not aware that they exist as technological components for imaging applications, but in principle? Is there a reason why it couldn't work? $\endgroup$ – CuriousOne Apr 30 '15 at 10:47
  • $\begingroup$ @CuriousOne: you'd have to provide more info (as a new question) because I'm not familiar with the technology you describe. Note however that the equations that describe light propagation are time reversible, and reversing time turns a ray going from light to dark into one going from dark to light. $\endgroup$ – John Rennie Apr 30 '15 at 11:32
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    $\begingroup$ You are right, maybe one should post this as a new question. The reason why these devices do not violate the reversibility (which naively makes the true one-way mirror impossible) is because of their use of a magnetic field. Having said that, I am awful with optics, especially when non-trivial material effects and magnetic fields are involved, so I don't want to write some nonsense about this myself. Maybe I will post this as a new question myself. Let me think about an intelligent way of phrasing it. $\endgroup$ – CuriousOne Apr 30 '15 at 11:42

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