1. A real place where things weigh nothing and where there is no up or down 1 2. "Water seeks its own level" 6 3. The sea of compressed air in which we live: Air pressure 10 4. Sinking and floating: Displacement 23 5. How things are kept from toppling over: Stability 29 2. MOLECULAR ATTRACTION 36 6. How liquids are absorbed: Capillary attraction 36 7. How things stick to one another: Adhesion 41 8. The force that makes a thing hold together: Cohesion 44 9. Friction 49 3. CONSERVATION OF ENERGY 57 10. Levers 57 11. Inertia 66 12. Centrifugal force 72 13. Action and reaction 77 14. Elasticity 82 4. HEAT 88 15. Heat makes things expand 88 16. Cooling from expansion 94 17. Freezing and melting 96 18. Evaporation 100 19. Boiling and condensing 107 20. Conduction of heat and convection 116 5. RADIANT HEAT AND LIGHT 122 21. How heat gets here from the sun; why things glow when they become very hot 122 22. Reflection 129 23. The bending of light: Refraction 136 24. Focus 142 25. Magnification 150 26. Scattering of light: Diffusion of light 158 27. Color 161 6. SOUND 174 28. What sound is 174 29. Echoes 183 30. Pitch 185 7. MAGNETISM AND ELECTRICITY 190 31. Magnets; the compass 190 32. Static electricity 196 8. ELECTRICITY 203 33. Making electricity flow 203 34. Conduction of electricity 213 35. Complete circuits 219 36. Grounded circuits 225 37. Resistance 229