A Quark Nugget is a chunk of "strange matter", which is composed of "strangelets", which are composed of roughly equal numbers of up, down, and strange quarks. In technical science speak it is described as Compact Composite Objects (CCOs) nuggets of dense Color-Flavor-Locked Superconducting quark matter created before or during the Quantum ChromoDynamics phase transition in the early universe. Now you know as much as I do.
Suffice to say that it is weird stuff.
Some scientist have become fascinated by the concept because:
•It can explain Dark Matter (or why is there over five times as much gravity in the universe than can be accounted for with observed matter?)
•It can explain the observed cosmological baryon asymmetry (that is, why isn't the universe half matter and half antimatter and thus suffering cosmic explosions every ten seconds?)
•It can explain both of the above within exisiting physics, you do not need to postulate some bizarre new particle.
Thomas Marshall Eubanks examined the concept and wrote a scientific paper about them. You can tell it is relevant to our interests by the title: Powering Starships with Compact Condensed Quark Matter.
He calculates that this stuff is everywhere, left over from the Big Bang. There must be tons and tons of it, because it causes Dark Matter gravity. The point being it should be readily available in our own solar system. Now due to the incredible density of quark nuggets, it is all going to be at the core of various solar system objects. We won't be able to mine any at the core of Sol, the planets, or the moons, but asteroids are a different mattter. Eubanks notes there do exist so-called Very Fast Rotating asteroids, the little whirling dervishes have rotation periods measured in tens of seconds. This is consistent with strange matter asteroids with core masses between 1010
kilograms (50 million metric tons). The cores can be extracted and used (but alas cannot be subdivided, the mutual attraction is too strong). The cores will typically be about one millimeter in radius.
Why do we care?
Because such quark nuggets can be used as SUPER-EFFICIENT ANTIMATTER FACTORIES, that's why.
Using Andreev reflection you could create about 109 kilograms (1 million metric tons) of antimatter before the nugget wore out. You bombard the nugget with a 100 MeV particle stream and some of the particles will transform into their antiparticle (it is actually more complicated than that, but who cares?). Each 1010 kg of quark nugget can produce 109 kg of antimatter.
One the one hand it is far easier to generate antimatter as you need it, instead of trying to carry a million tons of touchy antimatter. Especially since an antimatter containment failure would make an explosion big enough to obliterate an entire solar system.
On the other hand it will be a major engineering feat to drag along a quark nugget with a mass that is a substantial fraction of the weight of Mount Everest. That's why I filed this here in the "Starship" page instead of the "Engines You Can Use Within The Solar System" page
ANTIMATTER AT HAND?
Marshall Eubanks has posited the presence of million tonne masses of stable quark matter inside solar system objects – potentially both matter and antimatter forms of it, with the antimatter version protected from annihilation by a 100 MeV Colour-Force potential well.
Powering Starships with Compact Condensed Quark Matter
While pure antimatter/matter propulsion promises high exhaust velocities (~c) the difficulties of achieving that ultimate performance are considerable. But what if we use something else for reaction mass and use antimatter to energise that? And, instead of using it in a rocket, we use a magnetic scoop to draw in reaction mass from the interstellar medium? This is the Ram-Augmented Interstellar ‘Rocket’ – though technically a rocket carries all its reaction mass – and it promises high performance without all the disadvantages of exponentially rising mass-ratios. Mixing 1% antimatter into the matter flow could, in theory, produce an exhaust velocity of ~0.2 c. Scooping and energising the equivalent mass of ~100 times the mass of the starship would allow a top-speed of 0.999999996 c to be achieved, before braking to a halt using half that mass. This would allow, at 1 gee acceleration, a journey of ~20,000 light-years. The nearby stars would be accessible at a much lower antimatter budget.
Quark Matter in the Solar System : Evidence for a Game-Changing Space Resource
Very Rapid Rotating asteroids might be held together by the additional gravity of a mm-sized million tonne quark nugget.
Primordial Capture of Dark Matter in the Formation of Planetary Systems
Evidence for Condensed Quark Matter in the Solar System
Observational Constraints on Ultra-Dense Dark Matter
Such quark nuggets would be made in the Big Bang potentially, if antimatter is squirrelled away in such a form, the explanation of the observed lack of free-antimatter in the Universe. The abundance of such ultra-dense tiny specks, to be compatible with microlensing observations, would be in the ‘interesting’ mass-range suggested by the Solar System evidence.
Pondering Marshall Eubanks’s concept of quark nuggets for making antimatter and hunting for such inside NEOs and comets, I thought of what an antimatter starship would require. The difficulty of storing anti-hydrogen led to me reason that carrying an antimatter source, like a quark nugget, made more sense than refining the stuff, then trying to store it safely. Make it as you use it seems the best approach.
That does imply that starships will mass millions of tons, to match the quark nugget. Depending on how the antimatter is mixed into the propellant stream, I suspect an antimatter rocket will be a comet adapted to the purpose, blasting out a jet of energised water as the main reaction drive. I’d hazard to guess the efficiency of such a rocket, since mixing annihilation energy into a reaction stream is incredibly difficult. However an exhaust velocity of 0.1 to 0.2 c seems reasonable.
When drives are power limited, based on the endurance of the engine rather than the energy of the fuel, there’s a simple relationship between the mission velocity, exhaust velocity and cruise velocity, with an overall mass ratio of ~4.42. The cruise velocity – the speed at which the vehicle coasts – would be somewhere between 0.075 c to 0.15 c, while the mission velocity would be 0.05 c – 0.1 c.
In the Oort Cloud there’s about 100 billion comets in far-flung orbits. One for every star in the Galaxy. If each formed around a quark nugget, then that would be 100 billion potential starships. Launching forth to every star in the Milky Way at 0.1 c, they would take ~750,000 years to reach the stars on the opposite side of the Milky Way to us. To reach every Globular Cluster in the Milky Way’s vast halo might take 1.5 – 3 million years.
Not every star has an Oort Cloud, ours being one of the few to keep its Cloud, as passages through Molecular Clouds and tight star clusters can lure the far-flung comets away with their gravity. Yet there are enough Oort Clouds that Others might have done the same before us. If Other Civilizations came to the same conclusion, as my musings above, and launched forth thus-like, what would a Galaxy in the throes of such a “Life Burst” look like from far away? Would we see the unique signs of antimatter annihilation spraying forth from that Galaxy? Could we see it with the right gamma-ray telescopes?