It goes up, but at the same time goes down. Up toward the sky, and down toward the ground. It's present tense and past tense too, come for a ride, just me and you. What is it?
I can flutter and take your breath away. I cantake a beating, but do not bruise. If I stopped you would be sure to lose. Everyday I am with you. What am I?
NASA was considering sending canaries into space to study them under zero gravity. The project was scrapped when someone realized that in spite of having sufficient water supplies, they could die of dehydration within a few hours. Why?