Oh really? Does the paper give any idea about how that might be accomplished and where the energy would come from?

EDIT: Ok, I read the paper (it is pretty short) and now I'm tracking down this reference: [34] G. L. Shaw, M. Shin, R. H. Dalitz, and M. Desai, Growing drops of strange matter, Nature (London) 337, 436 (1989).

As a nuclear chemistry PhD, I am highly skeptical of the practicality of this as an energy source.

The suggestion was (as I understand it) that one could "inject/collide/drop" a neutron onto this matter and the neutron would then fission into it's component quarks, capturing them and releasing the binding energy. So this stable matter is a quark soup held together by the strong force because you've managed to get enough up and down quarks together at a low enough energy?

It isn't a mechanism I'm familiar with and I was interested if there was any experimental results to suggest this stuff would behave the way they hope it would.

Moreover, I'm skeptical because a similar idea may apply in neutron starts, but the current model of neutron starts has a crust of about 100m (300ft) that has different kinds of intermediate structures with a lot of neutrons and protons and is called "nuclear pasta" https://en.wikipedia.org/wiki/Nuclear_pasta

I can't find how much experimental support has nuclear pasta, but IIUC there are some measurements of the density of the layers of the neutron stars https://en.wikipedia.org/wiki/Neutron_star#Density_and_press...

Edit: the difference from fusion (which is a primary energy source) is that in fusion your starting reactants are available. In this case, you'd have to spend lots of energy in a heavy ion collide to create the initial reactants from scratch.

Also, this type of matter is experimentally disfavored in the same way as strange matter: if quark matter was stable, all neutron stars should have converted to quark matter already, but measurements appear to be consistent with them being made from ordinary matter.

Colliding neutron stars spray large chunks of material therefrom, into interstellar space. It is said that this contributes a significant percentage of the gold and uranium on Earth.

If QM were stable, would we not therefore expect to observe it in nature, with abundance at least on the order of gold and uranium? Perhaps there is some factor that depresses its abundance somewhat, but to have gone entirely unobserved, it would have to be many orders of magnitude less abundant than gold. Is there any theory that reconciles stable QM with the observed upper bound on abundance?

I thought that due to relativity, if the elements are travelling close to the speed of light then they could still travel for thousands of years even if their their half lives are much shorter. That's because the element only appears to be thousands of years old from our frame of reference; their age is much less when viewed from their own reference frame. Though given the size and mass of these elements that might be a moot point since it's unlikely they could be travelling at near light speed anyway, due to the enormous energy it would require for them to do so?

In the paper, they're talking about udQM being more stable at zero temperature and pressure, basically "competing" with normal elements. The wiki diagram is useful for reference: https://en.wikipedia.org/wiki/Quark%E2%80%93gluon_plasma#/me...

Apparently wikipedia uses some sort of horrible AJAX crap now; please check that your links work before posting them.

I would guess QM composed of strange quarks in addition to up and down, and/or below the "continent of stability" size of 300 Angstroms[1].

[1] Correction: A, not Angstroms

So they're saying A>300 means "a quark system with >900 quarks"; normal protons and neutrons have three quarks a piece.

If I misinterpreted your comment and the above was already clear to you, please forgive my mistake (I didn't want anyone to confuse A for angstroms here).

[0] https://en.wikipedia.org/wiki/Extended_periodic_table#End_of...

The periodic table is only a useful model (and it is very useful) for nuclear systems acting as a zero-temperature Fermi gas (e.g., nuclei here on Earth). At extremes of temperature and pressure (neutron star merger, say), the idea of a discrete periodic table loses meaning.

We certainly would know we don't understand this matter if we stumbled upon it... right?

As for stumbling upon it, all our measurement techniques are calibrated to hadronic matter, so...

https://www.sciencenews.org

http://www.sciencemag.org

https://www.nature.com

https://www.eurekalert.org

https://physicsworld.com

A new kind of weapon? Renewing the nuclear arms race?

For one, the PRL paper linked here is highly speculative, using a phenomenological model and a lot of assumption and extrapolation. It's full of "may" and "if" and "possibility".

Furthermore, what they suggest appears like it would only work as an (inefficient) energy storage; it's not a primary energy source, since you'd have to spend lots of energy first to create this very hypothetical quark matter,and then regain some of that energy as you feed the quark matter with slow neutrons.

Finally, assuming everything above actually works, this would be a slow energy release, not fast like in a nuke.

What would a bigger boom accomplish ?

It's pretty hard to beat existing nuclear weapons, honestly, and even if you could, existing nuclear weapons will be much cheaper for a long time. The bulk of them is already delivery mechanism rather than the warhead.