Large atomic nuclei, containing many protons and neutrons, tend to be unstable. But stable nuclei do exist, and can be seen as an 'island of stability' on a graph of proton number against neutron number. As the number of protons increases, the number of neutrons required for stability increases too. Daedalus now points out that neutron stars are stable, even though they have no protons but enormous numbers of neutrons. So the graph should have a 'cliff' of stable neutron-rich nuclei along the neutron axis, rising out of the sea of instability. DREADCO physicists are now looking for such a cliff.

X-ray spectroscopy irradiates an atom with an energetic photon that ejects an electron from a low energy level. A higher electron then 'falls' into the vacancy. At some frequency the electron should emit all of its energy and fall not just into a lower orbit, but right into the nucleus. This nuclear transformation would create a new element, with one more neutron and one less proton than the original.

The process would absorb or emit large amounts of energy, and would have to be conducted slowly. But hydrogen and its two isotopes deuterium and tritium — which have one and two neutrons, respectively, in addition to hydrogen's single proton — should become pure neutrons if their electrons drop into the nucleus. A single neutron is unstable; how many must come together for them to be stable?

'Nuclear matter' would be so dense it would be hard to handle. But, says Daedalus, a heavy element such as gold could have most of its electrons dropped into the nucleus, and still keep some in orbit to balance the nuclear protons. The resulting large atomic nucleus would be stabilized by its excess of neutrons, although it might slowly acquire orbiting electrons by beta-capture. These orbiting electrons would make it a low-atomic-number element, such as hydrogen. Their vast orbital space would give it a high but controllable density, around a hundred times that of water. This would be 'super-heavy' hydrogen, although you could do the same for helium or lithium, for example.

Daedalus anticipates new chemistry. 'Superheavy hydrogen' should give dense types of water and hydrocarbons, probably incompatible with life. A nucleus of hundreds of neutrons stabilized by a few protons could be taken up the periodic table by a beam of protons until it approached the elusive 'island of stability' from below. And dense anti-tank shells would not need depleted uranium.