# Help: I’m on a slippery slope

We do this all the time! I lie to beginning physics students by telling them that gravity is constant (be it 9.81 m/s^2 or just 9.8 or even just 10) depending on context. What they are not ready to hear yet is that actually gravity decreases according to the inverse square law of distance, but that fact makes little difference in the context of “local” gravity and so is neglected so that we aren’t suddenly turning their early physics problems into calculus problems. But then even when we do account for that, I am still lying to them as gravity is really a hopeless many-body mishmash of vectors adding together and not originating from one perfectly uniform sphere. But those new facts make problems hopelessly complicated and besides are unnecessary for their success in basic understandings. Good students come to understand that education is always an accommodating (and therefore technically false - but very useful) oversimplification so that they can actually learn good things and [presumably] come closer to truth.

I never tire of this Asimov quote:

When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical, they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together.

Here is an earlier thread where I wrote more on this very topic.

Probably much more enlightening to you, though, if you take the time to read through all of it is this Ted Davis essay on Galileo, history, and accommodation.

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