Hard Science usually entails being as realistic to reality as we know it as possible. One problem though, is that we do know that science advances. Also, most of our worlds are fictional.

I'm wondering if there is a way to add fictional science while still feeling like science fiction. Some ideas I have:

  • Don't use new science to automatically solve problems. Create the new science first, and then see if it solves problems.
    • This also means that new science is equally like to cause problems (I don't mean new technology, but where science shows that certain things we thought were possible are actually impossible.)
  • Instead of focusing on implications and then rationalizing, make minor technical changes to science.
    • Although the world of Orthogonal seems incredibly different from our world, all the author did was change a - sign to a + sign, which isn't a huge change.
  • Use past, debunked scientific theories as a base (considering what if they were supported by evidence, and the true theory was false.)

Are these ideas good. Are there any other things to keep in mind. Should adding fictional science just be outright avoided?

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    $\begingroup$ Changing the metric signature of spacetime is hardly a "minor technical change". It's huge on a par with "replace relativity with Aristotelian mechanics". $\endgroup$
    – Mark
    Sep 15, 2015 at 1:38
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    $\begingroup$ @Mark Even though the implications are huge, the change itself is not. Indeed, that type of change communicates that you are really trying new science, not just trying to make teleporters $\endgroup$ Sep 15, 2015 at 1:59
  • 1
    $\begingroup$ Try changing the sign of the amount on your bank account. Are you really of the opinion that this is a small change? How large a change is is not related to how much effort it takes to write it down. For example, changing a mass from 1mg to 1kg is just a change of one letter. But it's a change of mass by a factor of a million. I would consider changing a sign to be one of the largest changes you can do to a quantity. $\endgroup$
    – celtschk
    Sep 16, 2015 at 18:58

6 Answers 6


This is a question about hard sci-fi.

Therefore I feel confident to say this:

Add whatever fictional science you need to advance your plot but obey two rules:

1. Do not break the second law (or first and third laws, but mainly the second law) of thermodynamics.

2. Do not muck about with time. So no FTL.

Stick to these two rules and you'll have a plausible hard science background as long as it is internally consistent and socially plausible. Breaking either of the above will result in multiple hard sci-fi (and likely basic fictional) plot holes.

Get out clause:

If you must break one of the above rules then break the time rule. Do not under any circumstances break the thermodyamics rule if you expect any vaguely scientific plausibility and hole-free plot.

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    $\begingroup$ +1 for emphasizing the importance of thermodynamics. Take that away, and there's no coherence to existence. (David Brin, in The Practice Effect, swung for the fence on that. It was fun but ultimately unconvincing, because he dealt only with first-order effects. Really: it's thermodynamics all the way down.) $\endgroup$ Sep 15, 2015 at 4:42

I'm wondering if there is a way to add fictional science while still feeling like science fiction.

What you are searching for is to make your fictional science plausible. I mean, to make your fictional science feel like real science, you do not really care if it will be possible or not, you just should make your reader believe it, while reading.

With that idea in mind, I will stress a couple of points, but note they are mainly based on my experience as a reader and are probably not universal. My reflection is based on the fact that there is fictional science that we are inclined to believe, and other that is problematic in our mind. I will try to make clear the difference between the two.

Do not explain what does not need to be

As long as your reader does not question himself about the reality of the science you are talking about, everything feels like real science. It is way more convincing to have a teleportation device, without explanation, than to have a teleportation device transmitting you through wires or waves, or anything. If you speak about wire, the reader will start to think about how is it possible to do it through wire, and the feeling that you are handwaving may arise.

Focus on details that impact the scenario

For Star Wars, and the destruction of the Death Star, the main point risen against plausibility (in my experience) is the fact that by shooting in a hole with a tiny spaceship you can destroy it, meaning the design of the Death Star is terribly bad. Questioning it is natural, since otherwise the rebels would have no way to win (more or less).

From a science point of view it is merely a detail, compare to the fact that the baddies just build a ship the size of a moon, that just destroyed a planet by firing green laser. Or the fact that a spherical ship would be a nightmare to cool down. Of the fact that it appears to be artificial gravity inside every ship.

But all this does not impact the scenario, so you are not pushed to question this point, so you will probably not.

Human stupidity is more unrealistic than fictional science

If at some point your reader think "they are all stupid, with that science they could just do that thing and it will be over", it will totally destroy the plausibility of your story. It destroyed Harry Potter for me : sorcerers could just merge science with magic but they do not because of... reasons. On the other hand I never questioned the possibility of magic while reading (this example is not exactly about science, but it illustrates my point quite well, I hope).

This point is also related to the fact that you should heavily investigate the consequences of the new science you introduce.

  • $\begingroup$ Teleportation is actually a nice example because Star Trek fell exactly into that trap: They explained that the transporter measured position and momentum of each particle, and regenerated the state at the destination. Then someone made them aware that this would violate the Heisenberg uncertainty principle, so they invented the Heisenberg compensator. Then later real science discovered quantum teleportation, which, while not a teleporter in the Star Trek sense, actually solves that very problem without violating Heisenberg uncertainty, by passing the quantum state using measurements … $\endgroup$
    – celtschk
    Sep 16, 2015 at 19:09
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    $\begingroup$ … that do not reveal anything about the state. Had the Star Trek makers remained silent about the mechanism, they now could claim that this is exactly what the Star Trek transporter uses. But now they are stuck with the Heisenberg compensator that explicitly violates known physics. $\endgroup$
    – celtschk
    Sep 16, 2015 at 19:10
  • $\begingroup$ Star Wars is not hard scifi. If it claimed to be, the suspension of disbelief would have been destroyed. $\endgroup$ Sep 17, 2015 at 23:49

As I see it, genuinely science fiction can include fictional engineering advances, but no major fictional scientific advances.

  • You can have fusion reactors, despite the fact that we couldn't make them work so far.
  • You can't have artificial gravity except for rotating sections.
  • You might be able to bluff the reader regarding timescales and efficiency.

This is like the "Is Pluto a planet?" question. The question suggests that there may be legal implications or something here (like you get tax breaks for writing hard science?) but in the end, it doesn't matter to anyone except the taxonomists.

So is your question should really be: "If I introduce a fictional science into my hard science work, will it still appeal to fans of hard science?" or "Could I live with myself if I did this?" or something similar. (I don't know the answer to either)

Pluto is the exact same whether we call it a planet or not, as will your work be whether we call it hard science or not. It's ultimately up to your conscience whether you are still writing a work of hard-science, there's no need to ask us for permission.

(But maybe if you preface your story with a sort of "paper" on the new discovery it might help)


Almost every hard science fiction book I've read has fictional science in it. So I would say that yes you can add fictional science into a hard science fiction book. The primary issue is to give it a fairly believable science 'discovery' for how it works. That is the most important part, believable background for the science that can't be immediately debunked by the average person.


Your first point is key. Scientific progress isn't always making things better. It's just enabling people to make things different.

It's down to the individual, and their morals, to decide if they use scientific knowledge for their own benefit or for the benefit of others.


  • Splitting the atom. We could have cheap and abundant energy for everyone, but instead we have the most destructive weapon ever created.
  • Genetics and microbiology: We can sequence the genes of major viruses and diseases, find their weaknesses and eliminate them. But instead, we weaponise them and make them worse.

You can never forget the human component of a piece of hard-science literature.

Some of the best hard scifi I've read is basically people encountering something very unexpected and then following their process of trying to figure out what the hell is going on?


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