Chen Shouyi took a breath of air filled with methane ice crystals and sized up this massive planet.
Neptune was called a gas giant, but because of the ultra-low temperature, its surface was just like Pluto's, as if it were a gigantic ice ball.
Ever since Pluto had been devoured, this place had already become the outermost boundary of the Solar System, this miniature universe.
Of course, that was from a four-dimensional scale.
From a three-dimensional perspective, you couldn't tell at all that this was a boundary region.
Generally speaking, zero dimensions is a point, one dimension is a line, two dimensions is a plane, and three dimensions is a body.
On a blank sheet of paper, we can easily draw mutually perpendicular X and Y axes, and by imagination draw a Z axis perpendicular to both X and Y—this is also the three-dimensional coordinate system humans commonly use.
So where is the S axis of the fourth dimension?
