user9943: Here is the question: How is the flicker fusion rate interpreted as an on-off rate?
After 2 close-votes were in I edited it to stress it is all about flicker fusion. In my area of research a commonly encountered parameter. As background - retinal implants operate at certain frame rates and when those frame rates are too slow, folks perceive flickering or shimmering images (they indeed often report so).
Anyway - the question itself is about the frequency of light pulses and what the unit Hz means in this regard.
Yes that's Physics, but so are questions on colors and wavelengths in the VIS frequency range of light, e.g. see the 4-answer and 8-upvoted question Is human vision sensitive to frequency or wavelength?.
There is an interesting discussion going on under the question - here is it [partially anonymized] quoted below:

Besides the fly, I don't think the main question has anything to do with biology. I'm voting to close as off topic [TFE]
@TFE - I think questions like this are not Bio per se,
but frequencies and cycle times are so fundamentally important in the
visual and acoustical sciences that I strongly argue to keep this post
alive. Biologists often don't receive training in signal processing,
although it's an essential part of some pretty big disciplines. I have
attempted to make the question biologically more interesting too,
adding the key term 'flicker fusion' in there + a link – AliceD
@AliceD I agree that they are important, and I can see why the OP
asked this question here. However, unless the OP edits in a way to
make the question more biologically relevant, {edit from AliceD - I did!!} I think it's off topic.
This is more for their sake b/c they could likely get good answers if
asked elsewhere. However, I just saw that you provided a perfectly
viable and useful answer (+1), so that seems moot at this point :p.
But even your answer does not mention anything biological. This whole
Q&A would still probably be more appropriate on Physics.SE in my
opinion. [TFE]
If questions about chromatography get closed, I can't imagine how this
one would be on-topic. –[C]
@[C] I think everyone here is biased toward their own
interests. The question here is so fundamentally linked to my areas of
research I find it on topic. Others outside this field think
differently. That's OK. – AliceD 1 hour ago
@AliceD I disagree, it's not okay. If this or any other question is about biology then it shouldn't be closed because some people don't
realize the connection. I'm not sure what can be done about this,
though. – [C]
@[C] - it's not that black and white I'm afraid. I've added
substantial biological context in the question when 2 votes were in,
and despite these efforts it still got closed. – AliceD
@AliceD That suggests to me that we have a problem with the way we
close questions. I would re-iterate my point that if a question is
about biology it should be on-topic on this site. [C]


user16866: Instead of filling in a bunch of comments, I'm just going to write my many comment points as an answer (though it's still very much just discussion).

I definitely agree that we have a problem w/ the way we close questions. Well, perhaps not a problem, but inconsistency based on lack of community agreement/discussion. Also, I would say overall, we've become very trigger-happy with question closing (likely because question quality has noticeably dropped). I think many of us read questions at face value. The question really should be, should we instead put ourselves in the OP's shoes and consider their reasoning for assuming biological relevance? If so, though, I would assume further editing would still usually be needed. 
I think this discussion is very important here -- these types of questions lay on the fringe of what would be on-topic or not, so it'll be good to have multiple folks discuss it. 
I think in the context of the  community discussing such pseudo-mostly-off-topic questions (PMOTQ's) in this Meta post, that C's argument about another question being closed is irrelevant and should not weigh the decision in this case. We need to come to a new agreement about how to handle such PMOTQ instances and only use previous instances as a point of reference for discussion (not decision making per se).
I (the one and only TFE :p) saw that you (AliceD) updated the question, but here was my reasoning: your updates may provide further "weight" to the biological reason for the OP to ask the question (which is great), but your edits do not add further biological focus to the main question itself. In other words, if we removed the entire 1st paragraph, then the question has nothing to do with biology. In fact, the question "how long is each light pulse?" has inherently nothing to do with biology. Further, your answer (though it answered the question superbly) does not discuss any strictly biological principles or information.

I'll also just note that the "Is human vision sensitive to frequency or wavelength?" question you link to explicitly asks the main question within a biological context. However, the post under question (even after your edits) has a brief intro providing biological context, but the main question lacks any explicit biological focus. As a result, I think these 2 questions represent different degrees of on-topicness within the PMOTQ spectrum. 

I still feel that the question and answer appear to be off topic based on both the focus of the question and the entire answer having little inherent relevance to biology without providing further context. However, as you mention, this information can be hugely relevant to certain subfields of biology. And as I noted, you provided a reasonable and useful answer to the question. So in that regard, the Q&A seem to fit ok on Bio.SE. 
So this leaves the question: how to determine if these PMOTQ's are on topic (or relevant) enough to not be closed? 

Should a seemingly off-topic question (as voted by 4 other users) be closed even if it receives a very good and useful answer? (assuming some argument can be made for biological relevance).
Conversely, If a reputable Bio.SE user answers the question and acknowledges biological relevance, should it be left open?
Should that answerer be responsible for editing the question to make it seem more biologically relevant?
Should that answerer also be responsible for trying to explicitly mention the biological relevance of the topic / their answer if the question does not explicitly do so?
Overall, does biological relevance have to be implicit or explicit?? 


I guess overall I have not thought up or included any major answers here, but I wanted to discuss my original thinking in this specific case as well as acknowledge the importance of having this discussion. 

9943: <p>Here is the question: <a href="https://biology.stackexchange.com/questions/57030/how-is-the-flicker-fusion-rate-interpreted-as-an-on-off-rate">How is the flicker fusion rate interpreted as an on-off rate?</a></p>
<p>After 2 close-votes were in I edited it to stress it is all about flicker fusion. In my area of research a commonly encountered parameter. As background - retinal implants operate at certain frame rates and when those frame rates are too slow, folks perceive flickering or shimmering images (they indeed often report so).</p>
<p>Anyway - the question itself is about the frequency of light pulses and what the unit Hz means in this regard.</p>
<p>Yes that's Physics, but so are questions on colors and wavelengths in the VIS frequency range of light, e.g. see the 4-answer and 8-upvoted question <a href="https://biology.stackexchange.com/questions/21812/is-human-vision-sensitive-to-frequency-or-wavelength">Is human vision sensitive to frequency or wavelength?</a>.</p>
<p>There is an interesting discussion going on under the question - here is it [partially anonymized] quoted below:</p>
<blockquote>
<p>Besides the fly, I don't think the main question has anything to do with biology. I'm voting to close as off topic [TFE]</p>
<p>@TFE - I think questions like this are not Bio per se,
but frequencies and cycle times are so fundamentally important in the
visual and acoustical sciences that I strongly argue to keep this post
alive. Biologists often don't receive training in signal processing,
although it's an essential part of some pretty big disciplines. I have
attempted to make the question biologically more interesting too,
adding the key term 'flicker fusion' in there + a link – AliceD</p>
<p>@AliceD I agree that they are important, and I can see why the OP
asked this question here. <strong>However, unless the OP edits in a way to
make the question more biologically relevant</strong>, {edit from AliceD - <strong>I did!!</strong>} I think it's off topic.
This is more for their sake b/c they could likely get good answers if
asked elsewhere. However, <strong>I just saw that you provided a perfectly
viable and useful answer</strong> (+1), so that seems moot at this point :p.
But even your answer does not mention anything biological. This whole
Q&amp;A would still probably be more appropriate on Physics.SE in my
opinion. [TFE]</p>
<p>If questions about chromatography get closed, I can't imagine how this
one would be on-topic. –[C]</p>
<p>@[C] I think everyone here is biased toward their own
interests. The question here is so fundamentally linked to my areas of
research I find it on topic. Others outside this field think
differently. That's OK. – AliceD 1 hour ago</p>
<p>@AliceD I disagree, it's not okay. If this or any other question is about biology then it shouldn't be closed because some people don't
realize the connection. I'm not sure what can be done about this,
though. – [C]</p>
<p>@[C] - it's not that black and white I'm afraid. I've added
substantial biological context in the question when 2 votes were in,
and despite these efforts it still got closed. – AliceD</p>
<p>@AliceD <strong>That suggests to me that we have a problem</strong> with the way we
close questions. I would re-iterate my point that if a question is
about biology it should be on-topic on this site. [C]</p>
</blockquote>
 16866: <p>Instead of filling in a bunch of comments, I'm just going to write my many comment points as an answer (though it's still very much just discussion).</p>

<ol>
<li><p>I definitely agree that we have a problem w/ the way we close questions. Well, perhaps not a problem, but inconsistency based on lack of community agreement/discussion. Also, I would say overall, we've become very trigger-happy with question closing (likely because question quality has noticeably dropped). I think many of us read questions at face value. The question really should be, should we instead put ourselves in the OP's shoes and consider their reasoning for assuming biological relevance? If so, though, I would assume further editing would still usually be needed. </p></li>
<li><p>I think this discussion is very important here -- these types of questions lay on the fringe of what would be on-topic or not, so it'll be good to have multiple folks discuss it. </p></li>
<li><p>I think in the context of the  community discussing such <strong>pseudo-mostly-off-topic questions</strong> (<strong>PMOTQ</strong>'s) in this Meta post, that C's argument about another question being closed is irrelevant and should not weigh the decision in this case. We need to come to a new agreement about how to handle such PMOTQ instances and only use previous instances as a point of reference for discussion (not decision making <em>per se</em>).</p></li>
<li><p>I (the one and only TFE :p) saw that you (AliceD) updated the question, but here was my reasoning: your updates may provide further "weight" to the biological reason for the OP to ask the question (which is great), but your edits do not add further biological focus to the <em>main question itself</em>. In other words, if we removed the entire 1st paragraph, then the question has nothing to do with biology. In fact, the question "how long is each light pulse?" has inherently nothing to do with biology. Further, your answer (though it answered the question superbly) does not discuss any strictly biological principles or information.</p>

<ul>
<li>I'll also just note that the "Is human vision sensitive to frequency or wavelength?" question you link to <strong><em>explicitly</em></strong> asks the <em>main</em> question within a biological context. However, the post under question (even after your edits) has a brief intro providing biological context, but the main question lacks any explicit biological focus. As a result, I think these 2 questions represent different degrees of on-topicness within the PMOTQ spectrum. </li>
</ul></li>
<li><p>I still feel that the question and answer appear to be off topic based on both the focus of the question and the entire answer having little inherent relevance to biology <em>without providing further context</em>. However, as you mention, this information can be <em>hugely</em> relevant to certain subfields of biology. And as I noted, you provided a reasonable and useful answer to the question. So in that regard, the Q&amp;A seem to fit ok on Bio.SE. </p></li>
<li><p>So this leaves the question: <strong>how to determine if these PMOTQ's are on topic (or <em>relevant</em>) <em>enough</em> to not be closed</strong>? </p>

<ul>
<li><p>Should a seemingly off-topic question (as voted by 4 other users) be closed even if it receives a very good and useful answer? (assuming some argument can be made for biological relevance).</p></li>
<li><p>Conversely, If a reputable Bio.SE user answers the question and acknowledges biological relevance, should it be left open?</p></li>
<li><p>Should that answerer be responsible for editing the question to make it seem more biologically relevant?</p></li>
<li><p>Should that answerer also be responsible for trying to explicitly mention the biological relevance of the topic / their answer if the question does not explicitly do so?</p></li>
<li><p>Overall, does biological relevance have to be implicit or explicit?? </p></li>
</ul></li>
</ol>

<p>I guess overall I have not thought up or included any major answers here, but I wanted to discuss my original thinking in this specific case as well as acknowledge the importance of having this discussion. </p>
