The Schwarzschild radius is proportional to c^-2, so this would mean the Schwarzschild radius of the Earth would be about 400 billion km, and the Earth would be a black hole.
The Schwarzschild radius is proportional to c^-2, so this would mean the Schwarzschild radius of the Earth would be about 400 billion km, and the Earth would be a black hole.
If you're allowed to change the speed of light, you can also change the gravitational constant G to compensate since the Schwarzschild radius is r = 2GM/c^2, where M is the mass of the object.