- Look at the night sky, find the moon, work out (by looking at the side of the moon that is lit up) where the sun is, try and visualise the sun, the earth, the moon, particularly the orbits of the moon and earth. Focus on this image as hard at you can while looking at the sky. If you relax your eyes you can sometimes see the earth and the moon as they really are. This works even better if you can also see a planet. Mars is very visible at the moment so give that a try. http://space.jpl.nasa.gov/ is good for looking these things up.
- Next time you're on a plane, look at the horison, this is the kind of sight you've seen before many times. Next time tilt your head.
The world is a planet. It's really round. Watch powers of 10, then look at anything at all.
Have a profound day.