You always have to watch science teachers on recess duty–it can be VERY tempting to make a Newton’s Cradle with the children on the swings.
World at Your Fingertips: This badge is essentially the Around the World badge, but we tell you the names of all the countries. In exchange, you have to know where they all are. 100% or better on Find the Countries of the World is all it takes to earn this.
As always, check the badge page for the latest updates.