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Why does a point mass have no orientation? I'd appreciate it if someone can cite a definition of a point mass (if available), and show how this follows from the definition. An intuitive explanation would also be welcome.

- Thread starter 0pt618
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- #1

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Why does a point mass have no orientation? I'd appreciate it if someone can cite a definition of a point mass (if available), and show how this follows from the definition. An intuitive explanation would also be welcome.

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Svein

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No mass has any orientation. Mass is aWhy does a point mass have no orientation?

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jbriggs444

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But suppose that we make both objects smaller and smaller (keeping their mass constant). As they shrink, the gravitational field at a fixed distance from the dumbbell becomes more and more uniform. The region near the center of mass where gravity behaves differently becomes smaller and smaller for both objects. In the limit, one has a uniform gravitational field following an inverse square law everywhere except exactly at the center of mass and an undefined field exactly at the center of mass.

For purposes of gravitational attraction, a "point mass" is the same as a "mass whose size is small enough to be negligible".

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