Wednesday, November 20, 2013

Unnecessary Superpowers: Seeing Polarized Light

“Once you see it, you can’t unsee it”*

Earlier this fall, I conversed with my coworker, Julie, about what superpower we would choose. She mentioned that she and another coworker, Rob, were interested in learning how to see different types of light. I immediately grew excited because this seemed like an attainable superpower. I decided to focus on seeing polarized light.

During my search, I even found a website that listed seeing polarized light as a useless superpower. My search ended with Haidinger’s Brush, the manifestation of how humans see polarized light.

Figure 1: Open source image of Haidinger’s brush from Wikipedia

Haidinger’s brush is a visual phenomenon seen in polarized light that looks like a yellow bowtie with a blue bowtie perpendicular to it (see Figure 1). People do not usually see it naturally, but most can train themselves to detect it. The easiest way to see the brush is on the white screen of an LCD monitor (for example, you could use the computer that you reading this blog post on). Be warned though, once you train yourself to see it, you will probably see it on every future computer that you look at.

After this initial research, I quickly coerced my study group (Raquel and Hartley) into investigating this phenomenon. We initially tried staring at blank Safari tabs on iPads. Hartley was the first to reach success, but Raquel and I needed some extra help. We decided to go on a search for polarizing filters in the museum.

During our trip to the shop with senior Explainer, Kate, we fortuitously ran into the museum’s neuroscientist, Richard Brown. He immediately knew what we were talking about and agreed to help us out. He gave us some tips on ways to train our eyes, and he also mentioned that some light-eyed people might never be able to see the brush (take that recessive genes).

Richard’s main tip was to try rotating the iPad smoothly while looking at it from a distance. We achieved this by using a turntable provided by Kate and standing on the Explainer Hub table. Soon Raquel, Kate, and I were able to see a rotating yellow brush. Hartley claimed that he could also see the blue bowtie as well, but this claim has yet to be verified.

We decided to share our new-found powers with the other Explainers during our Friday meeting. Although I had to miss that training, Raquel and Hartley reported back that some Explainers were able to see the brush. Unfortunately, Julie was not one of them; she’ll have to find her own superpower.

Overall, I am ecstatic that I have succeeded in turning myself into a superhero. The next challenge is training myself to see Haidinger’s brush in the sky. And like every superhero, I've already obtained a supervillian: the rain in San Francisco is deliberately thwarting my attempts to see the brush in the sky.

*This post was originally posted at http://explainers.wordpress.com/. It's based on a study group that I was part of at the Exploratorium.

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