Dense atomic material.
According to the proposal Lü Yongchang put forward, its underlying principle was similar to that of dense neutron material, but its strength certainly could not match dense neutron material, which relied on the strong interaction.
First.
The strong interaction was a short-range force.
Its range was within 1.5*10^(-15) meters. At distances greater than 0.8*10^(-15) meters, the strong interaction manifested as an attractive force that weakened as distance increased. Beyond 1.5*10^(-15) meters, it dropped rapidly to almost nothing; at distances below 0.8*10^(-15) meters, however, it manifested as a repulsive force.
Therefore, producing dense materials required overcoming the repulsive strong interaction that arose when the distance between particles fell below 0.8*10^(-15) meters.
Second, even inside a neutron star, gaps existed between neutrons.
Those gaps shrank steadily as the neutron star's density increased.
Without question, the smaller the gaps, the stronger the material.
Under normal circumstances, atoms were "too far" apart for anything but the electromagnetic interaction to act between them.
Dense atomic material, however, was different.
To give a material unprecedented strength, every effort had to be made to compress the gaps between its atoms.
At that point, the strong interaction began to get in the way.
Therefore, both dense atomic material and dense neutron material were, in fact, strong interaction materials.
The greatest difference between them was simply the type of particles and the spacing between them.
Compared with dense neutron material, dense atomic material had much larger gaps between its particles, and correspondingly much lower strength.
Thus, in Lü Yongchang's view, dense atomic material was actually a transitional technology on the path toward strong interaction materials.
Still, anything that qualified as "dense" was a high-strength material beyond the bounds of ordinary matter.
That said, choosing which atoms to use as the raw material was another headache.
Compared