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If the Earth were 3x heavier, birds wouldn't be able to fly, at least not the way they are now. Sparrows can barely get airborne when they're full, let alone at triple their weight.

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Air density would be three times higher though. So they might still be able to fly.

Ooo, that's a good point!

> at least not the way they are now.

Yeah, but they wouldn't be, because the extra mass would have influenced their evolution.

Extra weight. If gravity is the only thing changed, mass would remain constant.

Since the discussion is about "earth's gravity", I'm assuming the change would be in its mass, not in the universal gravitational constant, which is not Earth-specific.

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