Well, this was a curious little word I stumbled upon last night as I was doing some editing. Steradian comes from the Greek "stereos" for solid and a derivative of the Latin "radius" for "a staff, spoke of a wheel or beam of light". So what does that mean for a "solid ray"? Well, in the technical geometrical sense of the word, it means a unit of area of a sphere proportioned to its radius. For those who don't remember their high school calculus, this can visually look like the rind of a wedge or pyramidial slice of a melon. The oceans represent 9 steradians of the earth surface. Probably. The Sydney Opera House is based on recombining all the sterandians of a sphere. Possibly. The astrophysicist was only able to view a fraction of a steradian of the North Ecliptic Pole due to the unusual telescope mount. Yes. But doesn't anyone really understand that, other than my husband, my husband's friends, my friends... Back to reality. How can I use this word in every day conversation? Well, the flashlight illuminated a steradian of light on the dark alley wall. hmmm. After our wonderful Chinese meal, we left steradian orange wedges on the plate? Throw out the blueberries if they are more than 2 pi steradian covered in mold. Accurate, but incomprehensible. I cut the cantaloupe into steradian slices to put down the garbage disposal? As I sat outside one hot sunny day, licking my Ben & Jerry's oatmeal cookie dough crunch ice cream, I contemplated the percentage of chocolate pieces that were visible in a given steradian of the scoop. If I can't see the chocolate, how do I know I got my money's worth??? She cut a steradian swath of grass on the hill? If pressed, and only if the hill is a hemisphere. His mohawk was nearly a perfect steradian of hair shooting from his head.
Well, that was fun to explore its application to spheres and spherical like things, but I think we can agree that even in the absurd, this word has no practical usage. It would confound and confuse the average listener. So, I'll leave this one to my scientist friends, who should be working now, and save its usage for me for those rare esoteric moments when I don't want to be understood.