👉 The term "underrealm" is commonly used in various fields, including mathematics, physics, and engineering. It refers to a region of space or an object that lies below another more dense region or object. For example, in a vacuum chamber, if you push a balloon into the air, it will rise above the surrounding atmosphere. Similarly, in a vacuum tube, a thin piece of wire may be used as a source of high-frequency electromagnetic radiation to produce a low-frequency signal. This is an
