In my story, there's a stable isotope of carbon with 217 neutrons (it doesn't have to be 217, I just like the number). Based on humanity's current observations of the universe, could this isotope exist with the following properties:

  1. Exergy (usable energy) manipulation
    • Carbon-223 slightly increases entropy in the area surrounding it, decreasing usable energy around it
    • It releases this usable energy in an invisible field, similar to some types of electromagnetic radiation
    • This exergy can be absorbed and used by people or machines containing carbon-223
  2. Bonds into the same molecules as normal carbon isotopes
  3. Interacts with dimensions perpendicular to the 3D space we live in
  4. Forms unevenly throughout the universe, so that some solar systems are rich with it and others (such as Earth) have little to none.

This is the basis of a system by which "magic" could work on another planet in the future.

Edit: To be clear, I'm not asking if it contradicts scientific models, i'm asking if it directly contradicts scientific observations. I'm aware that such a particle is impossible under current models of particle physics.

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    $\begingroup$ There isn't such thing as a nucleon that measurably decreases exergy in a given region - that would involve abnormal manipulation of the electromagnetic and strong lagrangian. That isn't to say that a similar particle with positive electric charge and high mass could also participate in an as-of-yet unknown fundamental force whose quanta decrease exergy. It would behave chemically like a nucleon with positive charge, binding electrons to it, and it doesn't involve insanely-high mass numbers like 217 neutrons and only 6 protons. $\endgroup$ Commented May 13 at 1:28
  • $\begingroup$ On Earth it would not be possible, but in an environment of extreme gravity I don't know. After all if we have neutron stars it means that in some cases you can pack neutron together. However I decided to downvoted because the accepted answer creates further confusion about the concept of dimensionality. Too much sci-fi is abusing it. $\endgroup$
    – FluidCode
    Commented May 13 at 8:28
  • $\begingroup$ According to currently known science, nothing exists that "Interacts with dimensions perpendicular to the 3D space we live in", nor could anything like that exist - as no perpendicular dimensions are known of or reasonably suspected to exist. $\endgroup$
    – zovits
    Commented May 13 at 9:33
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    $\begingroup$ Whose observations? Are those made up? Because if you tag it as science-based, all ludicrous, made-up, or sci-fi assumptions are to be dropped. $\endgroup$ Commented May 13 at 13:24
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    $\begingroup$ The stability of nuclei is calculated as the difference between the current state and any other state, as compared to the weak force binding energy. This has been measured literally billions of times, to the point that it's reliable enough for industrial purposes. The difference in energy between carbon 14 and carbon 15 is adequate to lower the half-life by nine orders of magnitude. You wouldn't be able to get extra neutrons to even stick to a carbon nucleus much larger long enough to call it an atom. Yes, they've tried. $\endgroup$ Commented May 15 at 19:37

3 Answers 3


Carbon-223 can certainly not exist, a carbon atom with a mass number of 223 would not behave chemically like normal carbon (the bonds might be the same, but the kinetics would be very different), and there's no reason why piling neutrons together would access other dimensions or affect entropy.

However, none of the reasons for this say say there can't be some unknown particle that has basically the described effect. Perhaps instead of 197 neutrons, it's some higher-dimensional analogue of a molecule that protrudes into our 3 spatial dimensions at 197 points, manifesting with fields that allow bonding to a carbon atom at each one.

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    $\begingroup$ You can use the standard in story excuse of 'it isn't fully understood how it works, but it does' and 'observations indicated that the Carbon-223 isotope isn't truly an isotope, but the naming stuck.' If you are set on the name. $\endgroup$
    – vinzzz001
    Commented May 14 at 11:39
  • $\begingroup$ Alternatively, the Hyperdimensional Particle (HP) somehow causes the residual strong force in a region to increase the number of neutrons that can bind to the nucleus, while creating a negative mass field and lowering the effective mass of 223C to something reasonable. We know that the HP causes the magic we know about, but it always manifests in the material world as 223C so that’s just what we call it. $\endgroup$ Commented May 14 at 17:49
  • $\begingroup$ You can change a bunch of basic aspects of physics in a perfectly coordinated way to allow C-223 to exist without being instantly fatal, or you can add multidimensional magic particles. I would consider the former to be contrived to the point of breaking suspension of disbelief. $\endgroup$ Commented May 14 at 21:20

Atomic mass of the isotope

In my story, there's an isotope of carbon with 197 neutrons.

Carbon (as all light elements) is generally intolerant to high molecular mass isotopes. The "nuclear magic numbers" describe an empirical relation between the atomic mass $A$ and number of protons $Z$ in an isotope: the higher the $A/Z$ ratio, the higher its instability and the more prone it is to radioactive decay. This translates to a shorter half-life. Roughly speaking, such an isotope has a higher probability of decaying.

$\mathrm{^{223}C}$ would have a very high $A/Z$ ratio (around 37.2), which largely defeats every other known isotope. The weak and strong nuclear forces would not be able to hold the nucleus in place. For instance, the heaviest known isotope for carbon, $\mathrm{^{22}C}$ ($A/Z$ = 3.7) decays to half its population in about 6.2 milliseconds. This means that $\mathrm{^{223}C}$ would be astronomically unstable.

[Carbon-233] bonds into the same molecules as normal carbon isotopes.

Moreover, the number of neutrons in an atom affects the strength of its bonds with surrounding atoms (Curr Opin Chem Biol. 2007; 11(5): 529–536), and in this case, the extremely larger size of $\mathrm{^{223}C}$ could severely weaken bonds around it.

Interaction with its surroundings

Carbon-223 slightly increases entropy in the area surrounding it, decreasing usable energy around it. It releases this usable energy in an invisible field, similar to some types of electromagnetic radiation.

You would have to define this fantasy field and explain why it doesn't interact with other (electromagnetic, gravitational, etc.) fields. Moreover, since an increase in the entropy of the surroundings does not mean an increase in the entropy of the universe, your property could well be in conflict with the second law of thermodynamics.

interacts with dimensions perpendicular to the 3D space we live in

would require building fictional science around it in your story, since the only dimension we are aware of besides space is time. I am not sure if this is what you have in mind, since you asked for scientific feasibility, and $\mathrm{^{223}C}$ existing would require heavy justifications outside of science.

  • $\begingroup$ Is it possible that there could be undiscovered laws of physics that would allow this particle to exists and are consistent with our observations, or does this directly contradict experimental evidence? $\endgroup$
    – le_chat
    Commented May 12 at 23:26
  • $\begingroup$ @le_chat I think that experimental evidence contradicts even the (detectable) existence of this isotope. If you want scientific precision in your story, this might not be the best approach. $\endgroup$ Commented May 12 at 23:35
  • $\begingroup$ @le_chat However, as C. J. Huff suggested above, your story could include a new, fictional particle with these properties, albeit at the cost of losing scientific precision. It is up to you. $\endgroup$ Commented May 12 at 23:36
  • $\begingroup$ It would indeed increase the entropy of the surrounding region, and release useable energy, but not through some strange effect - just like every other highly radioactive element. $\endgroup$
    – g s
    Commented May 12 at 23:40
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    $\begingroup$ I agree with 100% of your logic. If there is an as-of-yet undiscovered particle that interacts with an as-of-yet undiscovered fundamental force whose quanta naturally reduce exergy (some kind of "tension" field), then maybe, but you're right in that no such particle or field has ever been detected. $\endgroup$ Commented May 13 at 1:35

Carbon-223 possible? no.

Nuclear drip line The drip line being the point passed which it is energetically favorable to reject the neutron or undergo beta decay.

So anything beyond Carbon 22 will fall apart faster then it can be put together. And it will take more energy to put together beyond that and release more energy when falls apart.

If drip line ignored:

Points 1,3,4 would all require additional exceptions.

Point 2 bond fomentation would require least exceptions. Formation of bonds would be as expected, but the bond behavior would not. c223 is 12x as massive which is enough to alter bond behavior. eg deuterium bonds vs hydrogen produces measurably different behavior.

Should keep it simpler

carbon-223 requires multiple exceptions to make work as desired. Yet is not the end goal. If the end goal is a magic system. Better to have one exception being the magic system.

  • $\begingroup$ "Better to have one exception being the magic system.": This is essentially what I was getting at. C-233 requires multiple things to work in ways that go against how they work in reality, which can cause a jarring break of suspension of disbelief that wouldn't be present if you created something new. Another example: the common trope of quantum entanglement allowing instant communication, when quantum mechanics specifically shows it can't be used for this. Some vaguely defined "ansible" doesn't have this problem. $\endgroup$ Commented May 13 at 23:38

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