Is it possible to build long-lived macro-scale structures out of non-atomic substances?

Question

A staple of science fiction is substances like 'durasteel' or 'tritanium', which, through generally unexplained means, have vastly superior material qualities when compared to conventional materials. Other common materials for constructing sci-fi vehicles and structures out of are heavy, stable elements, like those proposed to be in the "island of stability" in the periodic table.

However, there are other forms of matter that can exist in the universe, which are not found in the periodic table. Antimatter is the most obvious example, but interacts poorly with matter, limiting its utility as a construction material in a world filled with ordinary matter. More exotic things like pentaquarks also exist. Unfortunately, most of these particles are highly unstable, limiting their utility in the construction of spacecraft and the like. Are there any such exotic, non-atomic forms of matter which would be feasible as futuristic construction material?

Note: I'm concerned with building large-ish (person sized or larger) structures out of such materials which are 'long lived' in the sense that the construction materials won't decay in fewer than a couple of years.

Answer 1

No

There are no known macroscopic structures composed solely of non-Baryonic matter

Antimatter is *atomic* matter

Antimatter is Baryonic matter which forms atoms when positrons ($e^+$) are added. It interacts (reacts) quite vigorously with normal atomic matter. Just like normal matter, it possesses mass, charge, etc. You should consider anti-matter as atomic matter too.

Even "neutronium" the exotic nuclear soup/plasma found in neutron stars are made from Baryonic matter.

Other types of matter don't clump

The problem with other forms of matter (non-baryonic Hadrons and Fermions) is: first, they usually don't clump like the Baryons to form larger structures like nuclei and second, you can't get different non-Baryonic Hadron clumps to stick together in a manner similar to that of the chemical bonds that atoms can form.

Any other possibilities?

It's not impossible that exotic behaviors like what you want could occur in a quark-gluon plasmas under extreme conditions. However, under conditions we encounter every day, those behaviors would not live long enough for what you likely want. Similarly these clumps won't be on the same size scale as you & me. They might get as large as nuclei.

Pentaquarks and other exotic Baryonic matter are probably your best bet. If you could find a Pentaquark with enough stability then from the outside, it would behave similarly to a normal baryon - except more massive.

Since quarks carry +/- 1/3, +/- 2/3, or 0 charge; then you could get a baryon with really weird charges. Many of the possible combinations are likely not stable but since it's your story you can make the rules. Unfortunately, we have no way to tell you what the macroscopic properties of such a material might be.

How about even weirder stuff?

There are a bunch of weirder particles that are not part of the Standard Model (the most widely accepted theory of what particles we should expect) but are not expressly forbidden by other things we know about physics.

Some of these are fairly well known (Tachyons & magnetic monopoles). A lesser known one is negative mass (not anti) matter.

Monopoles at least are predicted to exist by some current theoretical models but would tend to repel each other and not form larger structures. However, we've never directly or indirectly observed these exotic particles and the chances of them being real are very slim.

Tachyons aren't supported by theory but aren't really forbidden either. The main trouble with these is that we could only observe them by their interaction with normal matter. We haven't found any particle interactions which might be accounted for by them.

Negative mass matter is hypothetical only.

Common Sense

If such materials were possible, we would have observed them in nature.

Story trumps Science

If such a material is necessary for your story, then simply invoke it as one of the fictions of your story. Larry Niven needed materials with fantastic properties for his Ringworld so he imagined scrith.

Answer 2

What do we have that's non-atomic matter and is stable at normal temperatures and pressures? That is, what has rest-mass, isn't made of protons and neutrons, and will last longer than a fraction of a second?

Baryons?

These are things made of three quarks. It includes protons and neutrons, but there's other stuff. A quick look at the list of baryons reveals the problem with trying to use them as a building material: except for protons and neutrons they're all wildly unstable lasting, at best, 1/10,000,000,000th of a second.

Mesons?

Mesons are one quark and one anti-quark. They're all unstable. The best you'll get is 1/100,000,000th of a second. Getting better!...?

Degenerate Matter?

Sounds cool! It's how neutron stars can be so dense! ...but it's a special form of plasma at either extremely high densities or extremely low temperatures. So it's atomic.

And it will fly apart as soon as it's not held together by extreme gravity or is given even the slightest amount of energy.

Quark Matter?

Quark matter, which includes ideas like strange matter, is so energetic the quarks themselves are free to move around. Unfortunately this requires overcoming the strong force which, you guessed it, is very strong. It is the strongest force. Keeping quarks from bonding requires temperatures in the area of 1,000,000,000,000 K.

Pentaquarks?

These are particles with four quarks and one anti-quark bound together. They're theoretically possible, and two might have been observed in 2015 at the LHCb which should give you an idea how unstable these things are.

Sorry, it's atoms or nothing.

Answer 3

Alright! So You want not-periodic table matter..

Let's see. As some have said the problems with these things is that they do not clump together and they last uhm... nothing.

We can make them last longer using the quantum zeno effect (here). For example my Jupiter airships are filled with Muonium gas, which has about 10% the density of molecular Hydrogen and therefore provides very good lift and is stabilized by a special laser light. QZE can also be used to give longer life to "normal" unstable stuffs like superheavy elements and things like Astatine.

To make them clump together we have to mix them with normal matter and make exotic atoms. These boys can form molecules and stuffs and therefore can have a very diverse range of qualities (here).

In general Oniums are "atoms" made by a particle and an antiparticle, alternatively you can replace electrons with muons (results in smaller, heavier atoms) and proton with hyperons (chemically similar to normal elements but with different nuclear qualities)

EDIT: Forgot to mention that some of these even have symbols and naming convention. So you can make some pretty cool sounding names for your compounds! here

Answer 4

There is a concept known as strange matter which has been theorized based on our mathematical models of nuclear physics, though never observed. It would be a sort of "liquid" made of quarks which aren't confined to protons and neutrons, and it's been theorized that forms of it could be stable at low temperatures and pressures--for example, this paper says "Witten has pointed out that strange quark matter might be stable at a zero temperature and at a zero external pressure."$\text{*}$ (In fact, the analysis indicates it should be more stable than ordinary matter under these conditions since as mentioned here it would be the 'ground state' of matter made of quarks, meaning it would have lower potential energy than quarks confined to protons and neutrons. As discussed in this answer from the physics stack exchange, the idea is that ordinary matter is "metastable", having a potential barrier that tends to prevent it from decaying to strange matter unless it temporarily gains enough energy to hop the barrier, or unless you wait a sufficiently huge time for it to get through the barrier via quantum tunneling)

This PhD thesis on strange matter in astrophysics has a section on p. 22-27 where it divides strange matter into some categories based on size, the largest being "bulk strange matter" with mass equivalent to over $10^{44}$ protons, which would again be "stable at zero temperature and pressure" along with very small strangelets with mass comparable to "isotopes of super-heavy elements" and an intermediate size with mass less than $10^7$ protons but larger than the very small category, which would have a radius of the order of a few hundred femtometers (a femtometer is a millionth of a nanometer). It's mentioned that for the intermediate size, "The electrons will now be found ‘orbiting’ the strangelet as in an atom", so maybe there could be a sort of "chemistry" with materials made up of multiple strangelets of this size bonded into "molecules" of a sort, although maybe the attraction would be too weak given their large mass or maybe they would just group together into bulk strange matter under these conditions, I couldn't find any info on this. Either way, bulk strange matter might have the features you're looking for.

It's mentioned on p. 29 of this paper that negatively charged bulk strange matter would have disastrous consequences in the real world, since "ordinary atoms would be attracted to it and absorbed" (converted into strange matter themselves), but that for positively charged bulk strange matter, "a Coulomb barrier prevents this system from absorbing the nuclei or ordinary atoms" (and there are theoretical and observational arguments against negatively-charged strange matter being stable enough to 'infect' ordinary matter in this way). It's also mentioned that "since it is very dense even small chunks cannot be supported by material forces at the Earth's surface." This would suggest a problem with using such matter for construction on planets, and would also greatly add to a spacecraft's mass which would increase the fuel needed to accelerate it, but perhaps one could imagine using it to plate space stations as a form of armor (and I'm also not sure how thick a layer of strange matter could potentially be, perhaps thin enough that the mass wouldn't be so large even for a largish area being plated). Another interesting science-fictional use for very small bits of strange matter could be to create some form of ultra-tiny machines much smaller than nanotechnology, the notion of "femtotechnology" discussed in this article, which could function at low pressure and temperature.

$\text{*}$That quote only mentions stability at zero temperature, which is apparently simpler to analyze mathematically, but I found this paper which discusses stability at higher temperatures. I don't really understand what parameters are being graphed on the horizontal and vertical axes in the bottom left part of Fig. 1 on page 3, but it appears qualitatively as if "stability window"--the range of values of the parameters for which strange matter is stable--changes only slightly between T=0 and T=10 MeV, and according to the conversion here a temperature of 1 Kelvin corresponds to 0.0000862 eV, so 10 MeV = $10^7$ eV would be about 116 billion degrees Kelvin, suggesting you only have to worry about temperature affecting stability in extremely high-temperature cases. Page 120 of this book mentions that understanding how stability changes with temperature "is important since we shall in fact be looking at nuggets in hot environments such as the Big Bang and supernova-explosions."

Answer 5

Overview

We have durasteel and tritanium because nano-structured material science is a very new field, and writers could not have reasonably predicted it over the history of sci-fi. The kind of nano-engineering we are used to comes from biology, which we all know is "squishy", not solid. However, the strongest materials we are able to make today do not involve finding magical metals. Rather, they are discovered at the nano-scale, from building things up at the molecular level.

Examples

Carbon nanotubes are currently one of the strongest materials we know about. Aerogel is one of the best insulators, as well as some of the lowest-density material we know how to make. And, of course, graphene is the current poster child of nano-engineering awesomeness. Then there are metamaterials, which can provide a kind of cloaking.

Theory

What these examples teach us is that nature is not interesting because there are 100+ elements on the periodic table. 100 is a very small number, atomically speaking. It is interesting because a mole is a very large number: ~$10^{24}$. If you take just a small handful of those 100 elements (or, in the case of carbon, just one) and combine $10^{24}$ of them in different ways, how many interesting things can you produce? The answer: a mind-boggling number.

Biology is the first proof of this. But biology has an agenda: it's trying to make successful replicators, which limits the kinds of materials it can produce. Biology doesn't produce aerogels because most creatures do not need to insulate themselves from 1000 C flames. Humans, on the other hand, have all kinds of uses for an insulator this effective.

Other examples involve energy storage. In the past, we would make batteries, optimize them, and then ask: "How do we make the battery hold more energy?" And the answer was usually: "Find a different material to store it." So we moved from lead-acid to NiCd to NMH to LiIon to LiPo. Well, chemistry-wise, LiPo seems to have the best energy density we can find, so how can we squeeze more performance out of LiPo? The answer is to stop doing macro-scale chemistry, and zoom down to the micro- and nano-scale.

8th Century Metallurgy

A simple iron sword is better than a rock as a weapon, but iron is relatively soft as metals go. So add some carbon, and you get steel. Now, most of us think of steel as a fairly uniform material. Just a bunch of iron with a tiny bit of carbon mixed in. The strength is surely just a function of how much carbon is included, right? Well, not quite. In fact, steel quality varies quite a bit depending on the process used, and as far back as the 8th century, blacksmiths were using nanostructures to make Damascus steel. Of course, they didn't know that carbon nanotubes were part of the secret to making really tough steel, but that is apparently the case.

So, instead of looking to a magical element on the periodic table to give you exceptional new properties, start with the $10^{24}$ lego bricks in a kg of common elements, mix, match and rearrange them in novel ways, and you can probably derive almost any kind of extreme property imaginable.