Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to CuriousKidsUS@theconversation.com. What is Bluetooth? – Henry, age 13, Somerville, ...

Shreyas Sen is the Founder and CTO of Quasistatics, Inc. (dba Ixana), which develops Wi-R, a wireless body-area communication technology. He owns shares in the company. How do headphones, toys, ...