From Flatland to the Fourth Dimension: Perception and Possibility of Higher-Dimensional Beings

To the point

It explains how a four‑dimensional being could enter our 3D world and appear only as slices, using Edwin A. Abbott's Flatland and the Sphere for intuition, noting higher dimensions in string theory and 2018 two‑dimensional experiments hinting at 4D behavior, describing that a 4D observer would see us all at once or enter as a changing 3D slice, with the tesseract as a visualization and Toby Hendy’s explanations plus games like Miegakure and 4D Miner to illustrate, while acknowledging such aliens remain hypothetical but could observe us closely by slipping through hidden dimensions.