555: Two Mirrors

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Two Mirrors
If you actually do this, what really happens is Douglas Hofstadter appears and talks to you for eight hours about strange loops.
Title text: If you actually do this, what really happens is Douglas Hofstadter appears and talks to you for eight hours about strange loops.


In folklore, Bloody Mary is a legendary ghost or spirit conjured to reveal the future. She is said to appear in a mirror when her name is called multiple times (mainly 3). The Bloody Mary apparition may be benign or malevolent, depending on historic variations of the legend. The Bloody Mary appearances are mostly "witnessed" in teenage group participation games, often as part of a game of truth or dare. This is Bloody Mary's first appearance in xkcd, the second being 2364: Parity Conservation.

In this comic, Megan sets up two mirrors facing each other, in which reflections bounce back and forth between the mirrors until the mirrors absorb all the light. She then says "Bloody Mary" three times (as in the folklore) before ducking, conjuring an infinite number of spirits who jump from the mirror towards each other. It's not clear if they simply collide, or pass into the opposing mirror. Megan may be attempting an experiment either in particle physics upon colliding mirror matter or bridging Mirror Universes by enabling Bloody Mary’s opposing characterizations to interact with each other, or both.

Douglas Hofstadter (also referenced in 917: Hofstadter) is the author of Gödel, Escher, Bach and I Am a Strange Loop. In the former book, among many other discussions of infinite loops, he points a television camera at the screen on which its image is projected, forming an endless series of screens similar to panel 2 of this comic. In the latter book he focuses on the idea of minds being self-referential. "In the end, we are self-perceiving, self-inventing, locked-in mirages that are little miracles of self-reference". This blends with the idea of the images of the person looking in the mirror being reflected endlessly.


[Megan sets up a full mirror facing a bathroom-counter mirror.]
[Megan looks through the bathroom counter mirror to see the infinite reflections.]
Megan: Bloody Mary, Bloody Mary, Bloody Mary.
[Megan ducks as the infinite Bloody Marys pop out between the two mirrors above her head.]
Bloody Marys: RAAGHHHHH


In the right-most panel, Megan can still be seen standing in the right mirror even though she had ducked down at that point.

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Am i the only one who think of the ne555? 21:46, 11 December 2012 (UTC)

No idea. What I was thinking was who reads books like that?

(There again who responds to sites like this?) And: Shouldn't the mirrors be at a slight angle to one another? I used Google News BEFORE it was clickbait (talk) 18:06, 30 January 2015 (UTC)

He refers to the NE555, the most famous IC, used mainly to create timers and oscillators. Its use matches perfectly the comic's theme. In fact, I came to this Discussion section expecting a reference to the NE555. Ajgelado (talk) 05:33, 1 September 2016 (UTC)
A slight angle would amplify with each reflection breaking the chain. It would make more sense for them to be parallel but off-center from one another. flewk (talk) 07:38, 5 January 2016 (UTC)
What difference does it make where the centre of the mirror is? I don't get it. Jkshapiro (talk) 01:50, 26 September 2021 (UTC)

In the last frame, you can see her reflection still standing in the right-most mirror. (talk) (please sign your comments with ~~~~)

Thank you for mentioning that! I had missed it until I read your comment. DeeJaye6 (talk) 08:23, 10 February 2024 (UTC)