Actually, gravity may not work the same for the Traveler. You'll realize that all the inner planets now have the same gravitational pull. That means that some alteration occurred when the Traveler made Luna, Mercury, Venus, and Mars habitable. What I can assume is that the basic concept of more mass = more gravity may not apply in destiny. Plus, he made a rough assumption on some of the materials so the margin for error is drastically increased. Point is the Traveler may be close to 300,000 times more massive than Earth but may only exert a fraction of a fraction of a fraction of that gravitational power. Even if the Traveler lacks that capacity, what's to say she's not using another force to counteract gravity. That's the entire premise of a star. High grade fusion could be occurring that powers the Traveler (would be enough energy) and it is used to warp the basic laws of physics as we understand them. There's too many variables to contemplate. If what you said is true and there is no change in the laws, the Traveler should be close to the density of a singularity by now. And the actual size of the Traveler isn't proportional to the law of celestial bodies taking spherical shapes. And the Traveler would have crushed both U.S. and even make the Sun groan and probably collapse