What the Heck is "Glowy" Skin? Answer=Physics

     I can't count the number of times I've heard a beauty guru or sales person recommend a product because it will "make your skin glow!" Or my other favorite (not) phrase: this uber expensive cream/foundation/lotion/powder/serum will make you look "lit from within." Excuse me? What. Does. This. Mean? Are these things even measurable? "Try this cream, it will increase your glow by 35 lumens!" Um, no. As with most things pertaining to skincare and makeup, it's all marketing lies and fake science to get you to buy products. Sort of. We are able to perceive "glow" on skin, but it's not really light coming from inside your face. It has to do with Physics. So, in the words of Rhett and Link: Let's talk about that.

     What do professionals mean when they say that your skin is glowing? Short version: it means your skin is very healthy and hydrated with a smooth and even texture. It doesn't mean oily, shiny. greasy, or covered in frosted highlighting powder, although you can use these things to fake a glow for pictures. Long version that includes physics: your skin, like all surfaces, reflects light. The smoother a surface, the more the reflected light resembles the original image. Think of a mirror. The smooth metal coating beneath the glass is a perfectly smooth surface that reflects all light back at a uniform angle (the angle of incidence to normal is the same as the incidence of refraction to normal blah blah blah). This is called "specular reflection" and it produces images, just like what we see in a mirror. If the surface the light is bouncing off of is not perfectly smooth, we end up with "diffuse reflection." This reflection does not produce an image because the light rays reflect off of the surface at all different angles. This is due to the uneven surface, where tiny irregularities in the surface cause the reflection of light to be scattered. This is what happens on your face. The smoother the surface, the more light rays are reflected uniformly back at the viewer. More reflection angled toward the viewer=more light given off or "glow" that you see coming off of the person's face. Get it? Science!

     If you skipped the last few sentences, don't worry. Start reading again now: the way to achieve more glow is to "feed" your skin with the antioxidants and cell-communicating ingredients it craves, give it plenty of moisture so it stays hydrated, and to exfoliate frequently to remove the build-up of dead cells that cause rough skin. The healthier and smoother your skin, the more glow (reflected light bouncing off your skin). Easy, peasy. Physics FTW!