One Star Trek concept was so silly it's become a running joke in other franchises

in Star Trek: The Original Series episode 4 of season two, fans everywhere were introduced to the Mirror Universe. The concept is that in a universe just like ours exists totally opposite versions of ourselves. In some cases bad guys become good, but mostly we see good guys become bad. The episode that introduced this concept to the masses was called "Mirror, Mirror" and it became famous for depicting the "evil" version of the Enterprise crew with goatees.

While not technically true, as for the most part only mirror Spock had one, it became a trope that lasted longer than the series did. Yet, it didn't stay with the trend of depicting the evil versions of ourselves with facial hair, instead morphing into a bit of a tongue-in-cheek reference. After all, Star Trek didn't patent the idea of a multiverse concept, so how other forms of media depicted other versions of the same character were largely detached from how Star Trek did so in 1967.

But before the world had The Big Bang Theory to explain concepts like Schrodinger's Cat to the masses, such concepts weren't widely known by the greater public. So shows like Star Trek often had a chance to really leave a mark on scientific concepts. Even if they didn't land after the episode.

So they did, numerrous times. The one that seems to be most tied to Star Trek, however, is the Mirror Universe concept and how we're supposed to be depicted in such a world. Namely, the facial hair.

It was an attempt to make Spock, who already looked quite "devilish" look even more so. This likely plays into the Satanic panic that the character created when he first premiered on the show. Yet, what ended up happening was that the concept became a bit.

More of a comedic expression of love for the series and less about a serious portrayal of such things. While some concepts that Star Trek created came and went, this one lasted. And lasted and lasted.

When it comes to "Mirror, Mirror" we know that the previously mentioned show, The Big Bang Theory, has had nods to that episode. We've seen Sheldon don a fake goatee as an homage to the episode that featured "Evil Spock" in the first episode of season three; "The Electric Can Opener Fluctuation".

That wasn't the only comedy series from that time that did so too. We saw another homage to "Mirror, Mirror" in Communities' fourth episode of season three entitled "Remedial Chaos Theory". In that, the "darkest" timeline saw Abed and Troy, the two sillier characters, dawn fake felt goatees at the end of the episode.

There are more references and shows we could point to but the general gist is clear, that the concept once thought so evil has become a great comedic trend.