While I was writing a SF story last week, I realized I had problems with my spaceship battles, travel distance, etc. So I thought about changing the story and pulling the ships out of space. I experimented with ships that just fly in the sky, or on the surface of a habitable planet. I thought if I scaled down my story's world from space to just one planet, I would solve my problems.<br /><br />The thing is, I didn't want Earth. I wanted another planet. I wanted larger oceans, larger continents, stronger winds, a bigger sun, etc. So I thought "Hey, I'll just make the planet bigger than Earth!" But then I realized this made no sense because of gravity. If I'm not mistaken, a bigger planet means heavier gravity, right? So even though I want breathable air, cool temperatures, clear skies and water to sustain life, nothing could work on a bigger planet because of increased gravity. My human characters couldn't walk normally, the ships couldn't fly, etc. Am I correct in thinking I can't write a planet that's "like Earth, just bigger"? Or am I missing something?