Light Color for the Optical Dummy

Filtering colored light

In the nasty old days of internet content farms, almost anyone who could write a coherent sentence... strike that: anyone who could reword a coherent sentence or even pretend to write a coherent sentence... could pick up spare cash writing at sites like Helium.com and eHow.com. The former disappeared (although a site calling itself ActForLibraries is randomly reposting all its content), while the latter lives on, spinning its bullshit into "niche sites" like Sciencing.com Unfortunately, this means the utter bull English and journalism majors visited on the website under a pretense of "information" lives on, too. We've already pointed out one such writer, Jorina Fontelera, twice; she's back again in a new category, misinforming the world about physics in "How do Light Filters Work?"¹

Jorina, who had already demonstrated her ignorance of geology and cars for the Antisocial Network, tipped her scientifically illiterate hand again in the first paragraph of this post, during the DMS-mandated introduction,

"Light filters work by removing or passing wavelength bands ranging in size, from hundreds of nanometers to a single wavelength..."

...to which we can only say, "WTF?!" It's pretty clear that between the two of them, neither Fontelera nor her content editor had the foggiest notion of the meaning of the word "wavelength" in this context (or, for that matter, how to use a comma). It's also likely neither of them recognized "nanometer," either -- perhaps a measuring device for grandmothers? Jorina goes on to tell us that

"Basically, the filter material --be it glass, gel, plastic or some other substance or combination thereof--selectively absorbs, reflects, refracts or diffract specific wavelengths in the visible light spectrum." Ummm, delicious -- non-parallel, but delicious; and cunningly reworded from some source that actually knew how filters work (and probably what wavelengths and nanometers are).  Fontelera continues to mangle the science as she enumerates the different filters. Of absorption filters, she informs us that "...the thicker the material, the more wavelengths it will absorb. By absorbing certain wavelengths, only certain parts of the visible spectrum can be seen. For example, if a filter that is meant to absorb all other wavelengths bar yellow is used, only yellow light will come through and be seen."

"[The] more wavelengths it will absorb"? WTF? once again, Jorina's failure to understand the concept of waves rings through... although the statement contains a grain of truth (a filter less than a wavelength in thickness is ineffective), the idea that gel or colored glass can be manufactured at a thickness of nanometers is ludicrous. Fontelera continues in this vein, saying of refractive filters that,

"The desired wavelengths are directed to a specific optical path whilst the unwanted parts of the lights spectrum are refracted to another direction..."

We think perhaps she meant to say, "light of a specific wavelength," don't you? (we're pretty clear she copy-reword-pasted that one from a British source).

Fontelera continues in this vein, in the process rendering it clear that she has no idea how filters work, what light is, what refraction is, what a wavelength is, or (among other things) what a nanometer is – we're not certain she even knows what a microscope is, even though she blathers at length on the topic. Oh, and she says zip about polarization, too... By the time she's done, Jorina has made it absolutely clear that she is a scientific illiterate attempting to write about science – in other words, a Dumbass of the Day.

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was    ehow.com/about_6304461_do-light-filters-work_.html

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