I’m Roger Wood InDepth, underwritten by Northeast Delta Dental. For information on individual and family dental plans, you can click on their sponsorship space on this site.

Light-emitting diodes. I learned about them during a course at the New Hampshire Technical College. What I didn’t know then was how ubiquitous they would become.

First, as small electronics pilot lights. Then as pixels on a TV screen. Now, they seem to be everywhere – in appliances, lamps, vehicle headlights. The next frontier for them looks to be street lamps. The city of Portsmouth is embarking on a potential citywide LED street light project.

Jacob Levenson is coordinator of sustainability and solid waste for the city. I’m Roger Wood for InDepthNH.org