OK, here's a thread on something good.
For those who don't know, "AB matter" is a hypothesized state of femtotechnology matter that is essentially a form of degenerate matter that is stable in Earth-like conditions, and would essentially consist of a mesh of nuclear matter.
It's hypothesized that AB matter would have a range of incredible properties. For instance, it would be a million times stronger than any material made out of conventional matter. The list of categories in which it would be superior to conventional matter include: "tensile strength, stiffness, hardness, critical temperature, superconductivity, supertransparency, zero friction". And then there are the seemingly magical properties that this would instill upon such materials: "invisibility, ghost-like penetration through any walls and armour, protection from nuclear bomb explosions and any radiation flux, etc.". Essentially, you could use AB matter to make stuff that's practically indestructible and can, well, do magic. In a Clarke's Third Law sense.
Do you think it'd ever be possible to manufacture such a material, and if so, when? I would guess maybe synthesis in the lab around 2500 and use in the military and other specialized applications around 2600, though this is literally a guess given the timeframes involved here.
The quotes come from here.