Let's go down to the tennis court!
This winter break was the first time that I went home to San Diego since the end of May 2014. I was so thankful to be home and able to spend quality time with my parents. We have a tennis court nearby our house and since we live in Southern California where winter is almost nonexistent, we are still able to play in December.
I'm not a tennis player by any means, but it was still fun to pass the tennis ball back and forth. After a while, I sat down to watch my parents play and was intrigued by the oscillating movements. I took a mental note to design it out later, just for fun, and this is what I came up with.