<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>This can be explained classically using the wave theory of light, but you might try this one.Obtain three linear polarizing filters, camera fillters are best but you can use the lenses for sunglasses. Align two of them, and shine a ight through them. Rotate one until the light is totally blocked (the polarizing filter axes are perpendicular to one another). Now pur the third filter in between them. By rotating it you can cause light to pass through the set of 3 aligned filters. Then remove it and the light is again blocked.This demonstrates the effect of making a polarizing measurement on the polarization state of light. <br /> Posted by DrRocket</DIV></p><p>Dual slit would be the easiest!</p><p>ps- DrRocket, do you have a link or a diagram that you can post? I would like to see the step-by-step of how to perform the experiment - I'm a visual learner. <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /> </p> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>