Exploring the Magic of Iridescence
653
post-template-default,single,single-post,postid-653,single-format-standard,bridge-core-3.0.8,qi-blocks-1.2.7,qodef-gutenberg--no-touch,qodef-qi--no-touch,qi-addons-for-elementor-1.7.0,qode-page-transition-enabled,ajax_fade,page_not_loaded,,qode-title-hidden,qode_grid_1300,qode-content-sidebar-responsive,qode-theme-ver-30.4.1,qode-theme-bridge,disabled_footer_top,disabled_footer_bottom,qode_header_in_grid,wpb-js-composer js-comp-ver-6.10.0,vc_responsive,elementor-default,elementor-kit-145

Exploring the Magic of Iridescence

By Scout Lebedis

Have you ever gazed at a soap bubble or a delicate butterfly wing, and found yourself contemplating the reason behind the captivating and constantly morphing array of colors you see? The explanation for this visual phenomenon, known as iridescence, lies in wave interference.

The color of an object arises from the absorption of certain wavelengths of light while others are reflected. Iridescence happens when light waves interact with one another and with the surface or layers of an object. This interaction of light waves is called interference. Such interference can be constructive or destructive. Constructive interference occurs when two or more wavelengths reinforce each other, with the peaks of one wave meeting the peaks of another; in this type of interference, the waves reinforce each other, leading to an overall increase in amplitude and a more intense (brighter) output. Destructive interference occurs when the peaks of one wave align with the valleys of another, and the wave patterns cancel each other out. When light strikes an object such as a bird feather or gasoline puddle, different wavelengths (colors) experience different levels of constructive (brightening) and destructive (dimming) interference, which causes iridescence and a shimmering variety of colors.

Specifically, iridescence is influenced by how materials are arranged. Materials arranged in a repeating pattern with a crystalline structure are more likely to contain band gaps, areas where electrons cannot exist within certain energy levels inside atoms. When light strikes a surface with a band gap, certain wavelengths are absorbed while others are reflected. The specific wavelengths that are absorbed or reflected depend on the structure of the band gap and the angle at which light hits the gap. So as you view the surface of the object at different angles, the colors you see will also change. By tailoring the properties of band gaps in different objects, engineers and designers can create a wide variety of iridescent items! 

Iridescence is an incredible natural phenomenon. Next time you gaze at a peacock feather, examine how a bubble catches the light, or admire a magpie’s tail, you’ll be experiencing the joy and wonder of iridescence firsthand!


References

Bernard, B. A. (2003). Hair shape of curly hair. Journal of the American Academy of Dermatology, 48(6), S120–S126. https://doi.org/10.1067/mjd.2003.279

Cloete, E., Khumalo, N. P., & Ngoepe, M. N. (2019). The what, why and how of curly hair: a review. Proceedings. Mathematical, physical, and engineering sciences, 475(2231), 20190516. https://doi.org/10.1098/rspa.2019.0516

Hair Bonds 101: What They Are and How to Repair Them. Living proof. (2022, July 22). https://blog.livingproof.com/hair-bonds-guide/ 

Michelle K. Gaines, Imani Y. Page, Nolan A. Miller, Benjamin R. Greenvall, Joshua J. Medina, Duncan J. Irschick, Adeline Southard, Alexander E. Ribbe, Gregory M. Grason, and Alfred J. Crosby Accounts of Chemical Research 2023 56 (11), 1330-1339DOI: 10.1021/acs.accounts.2c00740

Understanding Curly Hair Mechanics: Fiber Strength. (2020). Journal of Investigative Dermatology, 140(1), 113–120. https://doi.org/10.1016/j.jid.2019.06.141

Westgate, G. E., Ginger, R. S., & Green, M. R. (2017). The biology and genetics of curly hair. Experimental Dermatology, 26(6), 483–490. https://doi.org/10.1111/exd.13347