Viewing a single comment thread. View all comments

haysoos2 t1_ixwpnks wrote

Reply to comment by fliguana in How would one calculate the gravity of a planet? by LoreCriticizer

And the strength of that field is determined by your distance from the center of that mass.

Y'all are making this far more complicated than it needs to be. For pretty much all important considerations, the only number you need to know is a planet's surface gravity. This will govern such things as the escape velocity, and anything actually relevant to living or adventuring on that planet, like how far you can throw a grenade, how high you can jump, or how many puppies you can carry.

My formula will give you a close enough measure of that surface gravity for any planet.

Edit: changed "calculation" to "formula", which is a more accurate description

1

fliguana t1_ixwq0dy wrote

>For pretty much all important considerations, the only number you need to know is a planet's surface gravity. This will govern such things as the escape velocity

Incorrect. Two planets with identical surface gravity can have different escape velocities.

Simplification is good to a point, dumbing down leads to errors.

2

haysoos2 t1_ixwrzrc wrote

Ok, admittedly escape velocity will be a little different. In my examples above the escape velocity on the iron planet will be 1.7 times higher than on Earth, and on the water planet it will only be about 20% that of Earth's escape velocity, but it's close enough that for say, a fiction based on the Star Wars universe it will be much closer than anything actually used in the series.

1