Part of the Case Study Series

As before, this is a series of my own top-rated questions; I'll give my own opinions about whether or not they are on-topic, and anyone else can give their own opinions. I encourage everyone to provide their own answer, even if they agree with the ones already posted.

How many nanobots can I have in my blood?

About Worldbuilding? I would say that this is about worldbuilding. I wanted to know about a near-futuristic technology so I could use it in a sci-fi world where its applications could have large and far-reaching effects.

Risking Off-topic? I don't know about this one, I think it's on-topic but maybe I could have asked it on Biology SE.

How could I scientifically explain ice breath?

About Worldbuilding? Again, I think this one is on-topic. It's about how dragons would work.

Risking Off-topic? I can see this as being idea-generation, but for some reason it doesn't seem too idea-generation. I think my intention was for answers to draw upon real-world evolution and choose the solution that was... the most plausible (I think I get it now, Tim B). This goes along with what some people have been saying, that idea-generation may not actually be a bad thing as long as its scope is thin enough.

What Time is it IN SPACE?

About Worldbuilding? How to tell time in an interstellar society definitely seems about worldbuilding to me.

Risking Off-topic? Again, this could be idea generation, and I think it's an even bigger culprit than the last one. I don't think I have a defense for this one.

Can you shoot someone with a bullet... from orbit?

About Worldbuilding? It has applications in military strategy, and the military is pretty important for changing worlds, so yeah, I'd say it's about worldbuilding.

Risking Off-topic? Well, this one was closed as not about worldbuilding, so maybe I have a skewed perspective. But I think orbital ballistics is way more on-topic than some of the other stuff we've had recently, so please, if I'm wrong, explain how.

That's no Moon: Planet-sized Plants Possible?

About Worldbuilding? I'm building a world out of plants. I think it's definitely about worldbuilding.

Risking Off-topic? Nah, I think this is cut-and-dry on-topic. 'Can it be done' is way narrower than 'how can it be done' or 'why would it be done'.

  • $\begingroup$ Thanks for volunteering these - they were interesting questions to think about. $\endgroup$
    – Avernium
    Feb 9, 2016 at 18:31
  • $\begingroup$ What about some examples that are not on topic? $\endgroup$
    – frеdsbend
    Feb 9, 2016 at 20:19
  • $\begingroup$ @fredsbend That's sort of what we're trying to figure out. You tell me what is and is not on-topic, and we'll see if people agree. Also, the fourth one listed was closed as off-topic, so maybe take that one as an example. $\endgroup$ Feb 9, 2016 at 20:29
  • $\begingroup$ Definitely agree that narrowly-defined idea generation questions are some of the most interesting and best questions we have. $\endgroup$
    – Josiah
    Mar 5, 2016 at 23:32

5 Answers 5


Overall, I agree with your assessments, but I do have some additional thoughts on the orbital bullet question.

As an aside, it seems like “Idea Generation” has become somewhat of an evil phrase around here. Idea generation seems fundamental to the site, but we need a better way to describe and identify the difference between proper narrowly scoped idea generation and the looser variety.

  1. How many nanobots can I have in my blood?

About Worldbuilding? Yes, I think it is. Nanobots are a traditional sci-fi topic and this question is foundational to anyone trying to keep some realism in a world with nanobots in people.

Risking Off-Topic? I don't think so. The question suggests that an answer will require some knowledge of biology, but the sci-fi component makes WB a more reasonable home for it than Biology SE. It probably could have used a science-based tag though.

  1. How can I scientifically explain ice breath?

About Worldbuilding? It definitely seems to be. Questions dealing with creature design are solidly in scope.

Risking Off-Topic? This is idea generation. But I believe this is the exact type of idea generation that belongs on this site. The scope is quite narrow and, while there could be multiple correct answers, there is a metric on which all answers can be evaluated (how closely does the scientific solution match the proposed ice breath?).

  1. What time is it IN SPACE?

About Worldbuilding? As someone who has personally used this question to inform his own world design, it definitely seems in scope to me.

Risking Off-Topic? This is once again idea generation, but like the previous question, the scope is narrow enough that good answers can be separated from the bad.

  1. Can you shoot someone with a bullet... from orbit?

About Worldbuilding? I don’t think so. The text of the question makes this read like a hypothetical and it’s just not clear how it relates to world building at all. The ability to fire a bullet from orbit, while possibly having implications on the world, seems to be more related to a plot point or the actions of one character (or multiple).

Risking Off-Topic? Other than reading like a what-if hypothetical, I think there is an instruction in the question that may have also made it a little too broad:

if there's something that makes it impossible for a regular sniper rifle, please consider a bigger or more specialized gun that can get the job done, if one can exist.

That instruction seems to expand what was originally a narrowly scoped reality check question (focused on a 50-caliber weapon) into also being a loosely-bounded idea generation question.

  1. That's no moon: planet sized plants possible?

About Worldbuilding? In addition to quite literally being about world building, I think it fits into the scope adequately.

Risking Off-Topic? There are some sub questions added, but they lead answers along the path to showing whether it’s possible or not. I think the scope remains pretty narrow and invites positive idea generation. It seems on topic to me.


How many nanobots can I have in my blood?

I agree this seem plenty on topic for world building. Its a matter of what a human can take given a loss of blood volume to nano bots. You could potentially ask the question on Biology sure but that doesn't make it off topic here.

How could I scientifically explain ice breath?

Creature design questions are pretty universally accepted as on topic and I see no issues with this question that would make me want to VTC.

What Time is it IN SPACE?

No issues here. I apparently missed this question when it was asked. +5 rep for you.

Can you shoot someone with a bullet... from orbit?

Interesting question, and an utterly amazing answer but when I read it I don't feel like I am helping you build a world so much as a plot point. VTC, Not related to world building.

These are admittedly tough...ironically I think it falls in line with my mad scientist question...so I would have to say that question is OT as well.

That's no moon: planet sized plants possible?

This one seems really borderline to me. It is asked well but it starts feeling too broad toward the end. I think asking about fewer aspects (provide them yourself as part of the scenario) would make this cleanly on topic.


I think 1, 2, 3, and 5 are on-topic for reasons already given in other answers. I want to address #4, which I mod-closed after a few days (and several flags). FYI, it later received a reopen vote, went to the review queue, and got four "leave closed" votes there. I say all that just to report the data.

The question asks about a weapon to be used under a specialized circumstance by a single character. That makes it feel less about the world and more about the plot, though I can see opposing argument too. It further says "assume this is possible" and then asks how to design the bullet, so it's built on a fuzzy foundation. Taken together, I think that places the question out of scope.

If you explained more about how sniping from space would work in general, that could firm up the foundation and make it more about the behavior of things in your world. Things like gravity, atmospheric properties, metallurgy, and probably lots of other factors could be brought to bear on the question at that point. But right now it's almost like a magic question where the magic system isn't specified -- on what basis can people answer a question about a detail in a system that seems impossible to begin with?

It did get an amazingly thorough answer, and several highly-voted answers. Sometimes that happens, and I'm glad you got the information you were looking for.

I don't think I was wrong to close this, but if the consensus here is that it should be reopened, I won't oppose that.

  • $\begingroup$ This definitely clears up my confusion on that question. I can now agree with its closure, though I still wonder if there are other similar questions that have remained open. $\endgroup$ Feb 10, 2016 at 19:29
  • $\begingroup$ There probably are (this sort of review is highly imperfect). If you see things you think should be closed, use your votes/meta/chat accordingly. Also, I apologize for leaving you a mystery all this time; nobody should be left to wonder why his question was closed. $\endgroup$ Feb 10, 2016 at 19:41
  • $\begingroup$ I think Orbital Bullets is on topic (see my answer) but it's definitely a very useful case study. $\endgroup$
    – Tim B
    Feb 17, 2016 at 23:21

I think I mostly agree with everyone else on these ones with one big exception.

Nanobots: On topic. The fact that it could be asked on biology does not make it off topic here.

Ice breath: On topic since we've established that creature design is on topic.

Time: On topic

Orbital Bullets: On topic. In my opinion this question should be allowed it does not ask "will" someone do this, it does not ask "should" someone do this. It asks "can" someone do this. Would and Should are not Worldbuilding, Can is.

Planet plants: On topic

  1. Nanobots

    1. About worldbuilding? Yes. Exploration of the limits of a speculative technology seems to be about world-building. While not explicitly about the mechanics of a world, the question does ask about limitation on a possible mechanic.
    2. Risking off-topic? No. I think this one is pretty clear.
  2. Ice breath

    1. About worldbuilding? Same as the first question. I think it's on-topic because it talks about the mechanics in a world. The accepted answer outlines clear limitations on frost-breath that the author will need to work with/around.
    2. Risking off-topic? No.
  3. Keeping time in space

    1. About worldbuilding? Yes. This question discusses how to organize time keeping in an intergalactic empire. Time keeping is a fundamental mechanic.
    2. Risking off-topic? No.
  4. Bullets from Orbit

    1. About worldbuilding? Edgy. If this question is off topic, then the nanobots and ice breath questions are also off topic since they both address limitations of an environment involving a highly speculative premise. Besides, the question was good enough to get a supremely good answer with graphs (and everything!)
    2. Risking off-topic? No. I don't think this question is off topic.
  5. Plant Planets

    1. About worldbuilding? Yes. Literally, this question addresses the construction of a planet.
    2. Risking off-topic? No.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .