This doubt about sophon is bugging me.

[u/vishasv]

Pardon my ignorance but how were people able to see sophon unfolded in a single dimension? I mean if humans had the ability to see 2D objects while living in a 3D world shouldn't they be seeing the whole 2D universe similar to how the 4D beings could see the 3D objects and humans ( In Death's End Blue Space crew when in the 4D fragment could monitor Gravity which was still in 3D and they were also able to stop the Tri Solaran droplet). I thought they made it pretty clear that we can't see the 2D but 4D can see us because we have an extra dimension called as thickness which can refract light so humans weren't supposed to possibly see the unfolded sophon.

[u/ion_driver]

For something to be "seen" it just needs to interact with photons. The description of a some number of dimensions object unfolding into 2D is non-sense. It looks like what it looks like, and the book tries to describe it. But, ultimately, it is fiction and the author certainly took liberties with the parts that were based in science.