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I posted this question.

Is running in a zigzag helpful in avoiding being shot by an arrow?

It has at least 7 upvotes, and the answer has at least 6 upvotes. I want to give the answerer a bounty.

I can't because my question is off-topic.

How can I revise my question to be on-topic?

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  • $\begingroup$ I read the question and also upvoted as interesting, but it truly was off topic because it had to do with logic and pure math rather than physics. I would try to bring it back to physics: maybe use vectors and describe your zigzag motion as a "sawtooth" function, it will already look like more physics! $\endgroup$ – M Barbosa Jun 24 '16 at 12:47
  • $\begingroup$ @MBarbosa but the answer may have to do with physics? Or not? Gravity, cosine, terrain, friction, air resistance, weather? $\endgroup$ – BCLC Jun 24 '16 at 12:50
  • $\begingroup$ Well if you wanted to get that specific, sure. But with an arrow's aerodynamics the way they are, things like air resistance can generally be ignored unless it's being shot from a cannon. I would think the nicest answer would come from a vector stand point. You can model all the possible places the arrow can land as a vector field, and use the magnitude as the probability, for example. $\endgroup$ – M Barbosa Jun 24 '16 at 12:56
  • $\begingroup$ Someone on there also suggested that an even more interesting question would be: when would the straight line option be better? And the answer may be when you're being showered by arrows, but don't take my word for it. $\endgroup$ – M Barbosa Jun 24 '16 at 12:57
  • $\begingroup$ @BCLC, maybe you should ask this at Game Development SE... $\endgroup$ – Graviton Jun 27 '16 at 10:22
  • $\begingroup$ As Emilio Pisanty suggested in a comment to your Zig-Zag question, try reposting in Mathematics SE, where it should get a better reception and be less likely to be voted off topic. $\endgroup$ – sammy gerbil Jul 11 '16 at 20:09
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As someone who voted to close, I would say you cannot make this question on-topic because it is inherently not about physics - it is about choosing some model for how an archer aims/shoots/hits a target and then computing the outcomes of that model for the two different paths.

But it is not apparent what the physical aspect of this question is, and specifically what physics is being asked about. I would think the primary aspect is actually whether or not human beings can reliably aim such that they hit a zig-zagging object, and I don't consider human archery ability to be an aspect of physics.

As minor supporting evidence of this not being about physics, the existing answer does not actually use any specific physics to develop a model of probability for the archer hitting the target: A certain way of determining the probability of whether the archer hits or not is chosen, and then the outcomes computed. The model of probability just says "assume an inverse square law", and then purely geometrical considerations lead to the result.

But many other models are possible, including or excluding certain physical and unphysical factors (like wind, gravity, the archer's eyesight, the archer's tiredness, the (un)balancedness fo the arrows,...) will give rise to different models. So the question is not only about something of dubious physical constant, but also too broad: Regardless of how physical the answers are, how do we determine the correct one?

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  • $\begingroup$ I agree that the question is, in fact, inherently off-topic according to site policy - because it is not about any specific physics concept, it is about problem-solving. My answer does use physics (kinematics) in developing a model, and points towards a more realistic model which incorporates projectile motion. Your final point might be significant in distinguishing what is on/off-topic according to PSE policy. A question about a physics concept will have one correct answer; a question about problem-solving can have many equally correct answers. $\endgroup$ – sammy gerbil Jun 27 '16 at 0:17
  • $\begingroup$ @sammygerbil: Read the last para. $\endgroup$ – user36790 Jun 27 '16 at 12:13
  • $\begingroup$ @MAFIA36790 : I have read the last para, but I am not able to read your mind. $\endgroup$ – sammy gerbil Jun 27 '16 at 12:59
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Fortunately I posted an Answer before your question was put On Hold. This allowed me to develop it further without competition (or interest) from anyone else. The challenge of the question is its own reward : I do not feel robbed without the bounty you would like to offer, particularly since I had no competition.

My disappointment with the On Hold decision is that it prevents any alternative solutions and contrary views from being explored, such as M Barbosa's vector approach. Good Answers emerge from healthy debate. The Up Votes show that it is a popular and slightly controversial question (perhaps Game of Thrones fans like you), so I would have expected at least 2 more Answers.

But the consensus even among those who did not Vote to Close seems to be that the question is "off topic". Personally I disagree. It is Applied Mathematics, and requires calculations of speed, time and distance - but so is any question on kinematics or projectile motion, which are "on topic".

Moreover, the broader context of the question requires the development of an appropriate mathematical model, instead of being handed one on a plate. This involves deciding which factors are the most significant, how they can be represented mathematically, and what approximations to make. Seeing the different approaches and solutions that working physicists with different backgrounds bring to modelling the same situation can be very instructive for everyone.

It would be helpful if those who did Vote to Close, or up-voted the "off topic" comment, were more willing to discuss where they think the boundary lies between what is on- and off-topic. Or at least provided Answers to this Meta question. Merely pointing you to the Help Center is not very helpful!

Cynically, I think M Barbosa is right : If you had replaced the Game of Thrones context with an artificial one using a few physics concepts - eg neutrinos being fired at neutrons which can somehow be steered left and right (you don't need to say how, just call it a Thought Experiment) - then I think it would never have been put On Hold! My own Answer goes a little in this direction by mentioning "collision cross-section."

Seriously, you might include gravity in your model (which is already there in the GoT scenario), making it explicitly a question about projectile motion. You might also consider replacing the Newtonian Mechanics tag (which is not strictly applicable) with Applied Physics. Finally, flag the question for Moderator attention, explaining what changes you've made and why you think it is now "on topic".

But I have no evidence that this would be successful. I have appealed against the closure of several questions, without any success.

UPDATE

Since posting the above Answer, I now appreciate why the question is deemed off-topic by those who voted to close it. A change of terminology, or even focussing on projectile motion, would not have altered the decision, for the reasons given by ACuriousMind in his Answer. I think such problem-solving questions should not be off-topic for the site, but I agree that, as a matter of fact, according to the current site policy this one is off-topic.

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  • $\begingroup$ Nice answer. I did think it was a bit off topic but let me correct myself: I did not think it was off-topic enough to be closed. I've had questions that could have been asked in the chemistry forum, but they were still enough on topic that they stayed. I think this question might be similar. $\endgroup$ – M Barbosa Jun 26 '16 at 2:27
  • $\begingroup$ Also, I think what on/off topic generally comes down to (for many users) is the terminology, and I feel the original question lacked the Physics terminology to be considered on-topic by most. $\endgroup$ – M Barbosa Jun 26 '16 at 2:30
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    $\begingroup$ While I also disagree with about everything else you've said in this answer, an objective mistake here is that "flagging for moderator attention" is not the correct way of getting a question reopened. Edited closed/held questions get automatically placed in a reopen queue where they are reviewed. Do not flag for moderator attention to get a question reopened - in general, that flag will just be declined, or at least not be acted upon. Just like they are reluctant to unilaterally close controversial questions, the moderators will also not unilaterally reopen them. $\endgroup$ – ACuriousMind Jun 26 '16 at 21:44
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    $\begingroup$ @MBarbosa : Since posting the Answer above, I now appreciate why the question was deemed off-topic by those who voted to close it. A change of terminology, or even focussing on projectile motion, would not have altered the decision, for the reasons given by ACuriousMind in his Answer. I think it should not be off-topic, but I agree that according to the site policy it is off-topic. $\endgroup$ – sammy gerbil Jun 26 '16 at 23:48
  • $\begingroup$ @sammygerbil Yes, although a very appealing question it just happens to technically be off-topic per website rules $\endgroup$ – M Barbosa Jun 27 '16 at 14:14

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