<img width="640" height="480" src="https://www.cooperhewitt.org/wp-content/uploads/2018/07/Picture-3-700x525.jpg" class="attachment-large size-large wp-post-image" alt="" style="display: block; margin-bottom: 5px; clear:both;max-width: 100%;" srcset="https://uh8yh30l48rpize52xh0q1o6i-wpengine.netdna-ssl.com/wp-content/uploads/2018/07/Picture-3-700x525.jpg 700w, https://uh8yh30l48rpize52xh0q1o6i-wpengine.netdna-ssl.com/wp-content/uploads/2018/07/Picture-3-300x225.jpg 300w, https://uh8yh30l48rpize52xh0q1o6i-wpengine.netdna-ssl.com/wp-content/uploads/2018/07/Picture-3-170x128.jpg 170w" sizes="(max-width: 640px) 100vw, 640px" data-attachment-id="30680" data-permalink="https://www.cooperhewitt.org/2018/08/14/protecting-the-iridescent/picture-3/" data-orig-file="https://www.cooperhewitt.org/wp-content/uploads/2018/07/Picture-3.jpg" data-orig-size="4032,3024" data-comments-opened="1" data-image-meta="{"aperture":"0","credit":"","camera":"","caption":"","created_timestamp":"0","copyright":"","focal_length":"0","iso":"0","shutter_speed":"0","title":"","orientation":"0"}" data-image-title="Picture 3" data-image-description="" data-medium-file="https://www.cooperhewitt.org/wp-content/uploads/2018/07/Picture-3-300x225.jpg" data-large-file="https://www.cooperhewitt.org/wp-content/uploads/2018/07/Picture-3-700x525.jpg" />Have you ever noticed shimmering rainbows floating along puddles in the road? This bright iridescence is created by oil floating on the water, and is caused by the way light interacts with itself as it travels through the oil film to the water below. We often refer to this phenomenon as interference colors (good explanation...
