user24: We discussed this before at Are "anime-physics" questions a good fit for our site?. There I answered that anime-physics isn't a very good tag in my opinion. This is a followup to that with the intent to either clarify or delete the tag.
anime-physics is, in my opinion, very vague. It seems to deal with almost any in-universe mechanics for any series, as well as certain tropes which exist in multiple universes (see e.g. this page). The tag wiki seems to me to imply it's for this latter category, in which case I think it's entirely covered by tropes, but a lot of the current questions in the tag don't fit that. I don't really know when I'm supposed to apply it. I don't understand why Why is Steins Gate in the Beta Attractor Field? isn't tagged with it, but Why do some anime characters never grow old? is. 
To me it seems like a meta tag. I can't imagine anyone actually being an expert on anime physics, at least as broadly as it's being defined here. It has all the problems of character-abilities which we removed earlier for much the same reason.
Should we remove this tag? If it is going to stay, what objective criteria can be used to make the tag clear, useful, not a meta tag, and not a duplicate of tropes?

user24: The consensus seemed to be strongly in favor of removing anime-physics, and I haven't heard any strong opposition to this or attempted clarifications of the tag's purpose and scope. Hence, I've removed it from all questions that had the tag. The tag should be removed from the system within 24 hours.

user1908: Quite frankly, I have no idea what "anime physics" even is. Unless someone can provide a good definition of what things are and are not covered by the anime-physics tag, the lack of a solid definition for the topic is reason enough to do away with it. 

Regarding David Starkey's discussion of being an expert on various things (which I would comment on, but this is a bit long for a comment):

identification-request - you're right, one cannot be an expert on "identification requests". As long as we allow questions on the topic, though, we kind of have no choice but to allow this tag as an exception.
tropes - I think one can, in fact, be an expert on "tropes". This expertise comes from wide-ranging experience consuming anime and related media, and understanding what commonalities exist in many different anime, and why they exist. This is, admittedly, a bit difficult to characterize, but I think we can agree that somebody who has watched a lot of anime understands why the protagonist sits in the back row by the window, or what the "anime sweatdrop" means, or whatnot. 
anime-physics - until I know what this actually means, I have no idea whether or not one can be an expert on it.


24: <p>We discussed this before at <a href="https://anime.meta.stackexchange.com/questions/541/are-anime-physics-questions-a-good-fit-for-our-site">Are &quot;anime-physics&quot; questions a good fit for our site?</a>. There I answered that <a href="https://anime.stackexchange.com/questions/tagged/anime-physics" class="post-tag" title="show questions tagged &#39;anime-physics&#39;" rel="tag">anime-physics</a> isn't a very good tag in my opinion. This is a followup to that with the intent to either clarify or delete the tag.</p>

<p><a href="https://anime.stackexchange.com/questions/tagged/anime-physics" class="post-tag" title="show questions tagged &#39;anime-physics&#39;" rel="tag">anime-physics</a> is, in my opinion, very vague. It seems to deal with almost any in-universe mechanics for any series, as well as certain tropes which exist in multiple universes (see e.g. <a href="http://www.cs.utah.edu/~duongsaa/more_htm/jk_100animeRules.htm" rel="nofollow noreferrer">this page</a>). The <a href="https://anime.stackexchange.com/questions/tagged/anime-physics">tag wiki</a> seems to me to imply it's for this latter category, in which case I think it's entirely covered by <a href="https://anime.stackexchange.com/questions/tagged/tropes" class="post-tag" title="show questions tagged &#39;tropes&#39;" rel="tag">tropes</a>, but a lot of the current questions in the tag don't fit that. I don't really know when I'm supposed to apply it. I don't understand why <a href="https://anime.stackexchange.com/questions/6876/why-is-steins-gate-in-the-beta-attractor-field">Why is Steins Gate in the Beta Attractor Field?</a> isn't tagged with it, but <a href="https://anime.stackexchange.com/questions/6854/why-do-some-anime-characters-never-grow-old">Why do some anime characters never grow old?</a> is. </p>

<p>To me it seems like a meta tag. I can't imagine anyone actually being an expert on anime physics, at least as broadly as it's being defined here. It has all the problems of <a href="https://anime.stackexchange.com/questions/tagged/character-abilities" class="post-tag" title="show questions tagged &#39;character-abilities&#39;" rel="tag">character-abilities</a> which we removed earlier for much the same reason.</p>

<p>Should we remove this tag? If it is going to stay, what objective criteria can be used to make the tag clear, useful, not a meta tag, and not a duplicate of <a href="https://anime.stackexchange.com/questions/tagged/tropes" class="post-tag" title="show questions tagged &#39;tropes&#39;" rel="tag">tropes</a>?</p>
 24: <p>The consensus seemed to be strongly in favor of removing <a href="https://anime.stackexchange.com/questions/tagged/anime-physics" class="post-tag" title="show questions tagged &#39;anime-physics&#39;" rel="tag">anime-physics</a>, and I haven't heard any strong opposition to this or attempted clarifications of the tag's purpose and scope. Hence, I've removed it from all questions that had the tag. The tag should be removed from the system within 24 hours.</p>
 1908: <p>Quite frankly, I have no idea what "anime physics" even is. Unless someone can provide a good definition of what things are and are not covered by the <a href="https://anime.stackexchange.com/questions/tagged/anime-physics" class="post-tag" title="show questions tagged &#39;anime-physics&#39;" rel="tag">anime-physics</a> tag, the lack of a solid definition for the topic is reason enough to do away with it. </p>

<hr>

<p>Regarding David Starkey's discussion of being an expert on various things (which I would comment on, but this is a bit long for a comment):</p>

<ul>
<li><a href="https://anime.stackexchange.com/questions/tagged/identification-request" class="post-tag" title="show questions tagged &#39;identification-request&#39;" rel="tag">identification-request</a> - you're right, one cannot be an expert on "identification requests". As long as we allow questions on the topic, though, we kind of have no choice but to allow this tag as an exception.</li>
<li><a href="https://anime.stackexchange.com/questions/tagged/tropes" class="post-tag" title="show questions tagged &#39;tropes&#39;" rel="tag">tropes</a> - I think one can, in fact, be an expert on "tropes". This expertise comes from wide-ranging experience consuming anime and related media, and understanding what commonalities exist in many different anime, and why they exist. This is, admittedly, a bit difficult to characterize, but I think we can agree that somebody who has watched a lot of anime understands why the protagonist sits in the back row by the window, or what the "anime sweatdrop" means, or whatnot. </li>
<li><a href="https://anime.stackexchange.com/questions/tagged/anime-physics" class="post-tag" title="show questions tagged &#39;anime-physics&#39;" rel="tag">anime-physics</a> - until I know what this actually means, I have no idea whether or not one can be an expert on it.</li>
</ul>
