Science Saturday: Gravity's a Downer.

Gravity is the force that holds us to the ground.
If a ball is thrown, the path down is round.
Let go of an apple and watch it fall.
People dive from planes, an activity to enthrall.
To escape gravity, one can use helium to float.
One can't be free from it in the water, so they float on a boat.
Or one can fly in a spaceship that uses thrust.
Impressive propelling rockets are a must.
Gravity is what keeps the air on the Earth.
We owe it to gravity; our life's worth.
For without it, life may simply not exist.
And if gravity disappeared, it would surely be missed.