Wait... they're hard to move? That means that gravity can't move them as easily, which means they fall slower, which is absolutely not how the world works.
A little bit of an explanation: All things fall at about the same rate in a vacuum because the heavier something is, the harder it is to move, even for gravity. It's like pushing a car vs. pushing a book: it's easier to move the book because it's lighter. Gravity just follows those rules.
But let's go with it.