Why does the first day of summer arrive on December 1 and not December 21 in the southern hemisphere?
• Are there any alternative theories about what causes the seasons on the Earth? • Why is the tilt of the Earth’s axis 23 1/2 degrees? • Was the tilt of the Earth’s axis ever larger than 23 1/2 degrees in the past? • Has El Nino really slowed down the rotation of the Earth? • Does the rotation of the Earth affect the way water goes down a drain in the North and South Hemispheres? • How old is the Earth? • Is the Earth’s pole shifting? • How many different directions does the Earth move in space? • How do we know the speed of the Earth? • Why is the sky blue? • How is the mass of the Earth determined? • Are there differences in gravity from one place on the Earth to another? • Why is the Earth tectonically active and not Mars or Venus? • Over a 10 kilometer run, how high is the Earth’s curvature at the mid- point? • How is the Earth-Sun distance determined? • If the universe is mostly hydrogen and helium, why isn’t the Earth composed the same way? • Is the Earth’s atmosphere thicker at
