1. it is difficult to search for it . Because infrared rays will never penetrate through earth atmosphere.
2. we are unaware of how it looks like and we only know it is red and will glow . A damaged star also looks like this.
3. Dust also makes is hard to detect Dyson spheres . So we will get confused between Dyson sphere and a star surrounded by dust.
Solve the equation.it is hard to see
Solid metal is all different types of metals or some thing that a magnet can pick up that's a full hard solid
but a non metal is everything not metal that's a solid like plastic a hot glue gun can burn throught plastic and not metal
so in conclusion metal is stronger and thicker than non modal things
