Is the Dual-Vector Foil Physically Possible?

The Dual-Vector Foil is the most visually striking weapon in the Three-Body universe — a seemingly harmless transparent film that, once activated, collapses three-dimensional space into two dimensions at light speed. But setting aside the sci-fi veneer, could such a weapon exist in reality?

In theoretical physics, dimensions aren't abstract concepts. String Theory requires 10 or 11 dimensions (10 spatial + 1 time). In our macroscopic world, only 3 spatial dimensions are observable — or "unfolded."

If extra dimensions really exist, they must be "curled up" — like how a hose looks like a line (1D) from afar but is actually a cylinder (2D) up close. These curled dimensions are extremely small (~Planck length, 10^-35 m).

Dimensions can change state — they can switch between "unfolded" and "curled"

Matter can carry dimensional state changes — like the sophon's 11D unfolding

Dimensional weapons can "infect" — once an area is 2D-ized, surrounding areas are also dragged into 2D

These assumptions aren't ruled out by existing physics, but they're also not confirmed — they fall under "reasonable extrapolation" in hard sci-fi.

A short-distance jump phase initiated by the foil's internal energy source

Once deployed, the foil's surface becomes a "phase boundary" between 3D and 2D space

The 2D region expands at light speed — the maximum rate of information propagation

This is analogous to a phase transition — like how ice crystals "infect" liquid water during freezing. Except here, "water" is 3D space itself, and "ice" is 2D space.

Not compression: It doesn't "squish" objects like flattening paper — it changes the dimensionality of space itself

Information preserved: The book mentions neural activity continues briefly after 2D-ization — meaning all information is preserved in 2D structure

Aesthetic effect: The 2D solar system looks like Van Gogh's "Starry Night" — because the complexity of microstructure creates unexpected aesthetic patterns macroscopically

Strangelet: A hypothetical particle that could convert normal matter into strange matter on contact

Vacuum Decay: If our universe is in a "false vacuum" state, a single vacuum bubble could destroy everything at light speed

Spacetime Tear: Under extreme energy conditions, spacetime itself could tear

The Dual-Vector Foil is neither confirmed nor ruled out by existing physics. It's a "reasonable extrapolation" — pushing known theories (dimensions, string theory, cosmology) to their extremes. This is the beauty of hard science fiction.

And Liu Cixin told a great story with it — that's enough.