The meaning of Bobbie Gentry’s 1967 hit “Ode to Billie Joe” has long been a topic of musical debate. To some listeners, the song refers to a secret teenage pregnancy in the conservative Deep South. To ...

Mary Hall is a editor for Investopedia's Advisor Insights, in addition to being the editor of several books and doctoral papers. Mary received her bachelor's in English from Kent State University with ...

Lucas Downey is the co-founder of MoneyFlows, and an Investopedia Academy instructor. Samantha (Sam) Silberstein, CFP®, CSLP®, EA, is an experienced financial consultant. She has a demonstrated ...

A differential equation is an equality constraining a mathematical function in relation to its derivatives over one or multiple variables. Such equations may constitute the mathematical model for a ...

Sleep is the balm that soothes and restores after a long day. Sleep is largely driven by the body’s internal clock, which takes cues from external elements such as sunlight and temperature. The body’s ...