Explore the natural world around you through camping trips, hikes and regular old walks around the neighborhood. Before you set off exploring, print out an identification table for plants or trees, then walk through it together, step-by-step. Carry guidebooks for birds, insects or animals that you can spot in your area. Identify tracks in the woods. Bring a notebook. If no one in the family can identify something, designate someone to sketch it, take notes about its appearance and behavior, and then go and look it up together.
Learn the constellations as a family. iPhones and Droid phones both offer apps that use their built-in GPSs to show the stars, constellations, planets and even the International Space Station based on your current location.
Through it all, try to remember what interests your child and ask follow-up questions that keep your discussions going and drive them on into new and deeper territory. Look for teachable moments in movies, cartoons and sci-fi television shows. Read fun books like "The Physics of Star Trek" to help you out.
Once you're ready to focus on a subject in greater detail, you can …