Physicists estimate that 47% of the energy in the universe is stored in stars, and the other 98% rages inside human children. Release your child’s unyielding cosmic energy with today’s Groupon: for $20, you get five bouncy-house outings to Hoppity Hop Inflatables in Hendersonville (a $72.53 value).

Each of the outings includes the following:

• One open-play pass (up to a $10 value; a total value of up to $54.62 with tax)
• One slice of pizza (a $1.99 value; a total value of $7.04 with tax)
• One beverage (a $1.29 value; a total value of $7.04 with tax)<p>

Gleeful shouts reverberate across Hoppity Hop Inflatables’ 8,000 square feet, drifting from a rotating stock of nine springy play palaces that safely bounce children of all ages. The open-play passes grant a child opportunities to ricochet through a 13’x13’ tropical-themed jump house or slip down a 22-foot double slide that drops tots into a team of highly trained toe ticklers. Masters of bounce can carom through the pliable realm of a brightly hued castle or wade through a mini jungle guarded by a lion, elephant, and substitute teacher. On each trip, snack-bar attendants recharge lackluster leapers with a pizza slice and a beverage allowing them to return to explorations of the elastic terrain. Free admission for parents and children younger than 1 year of age lets adults usher wee ones to an exclusive play area free of bigger kids and Play Doh speakeasies.