Do any of these ideas correspond to your own thinking? If so, which one and why do you think so? If not, describe your own ideas about what you think causes gravity. STEP 2. Now consider some observations that could be used to support or refute some of these ideas. Suppose the Earth's magnetic field was the cause of gravity. If this were true, what materials would you expect to be attracted to a magnet: all materials, or only some types? Explain your reasoning