679: Christmas Plans

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Christmas Plans
Physicists who want to protect traditional Christmas realize that the only way to keep from changing Christmas is not to observe it.
Title text: Physicists who want to protect traditional Christmas realize that the only way to keep from changing Christmas is not to observe it.

[edit] Explanation

This comic centers around a joke about Quantum Entanglement in physics - if you don't observe something, it has all possible states, not a specific one. It is a double-entendre with the word observe meaning both "look at" (physics sense) and "celebrate" (a holiday). One of the most famous examples on this is the Schrödinger's cat paradoxon.

The title text refers to another principle in physics where the act of measuring something must also change it in some way. If one drops a thermometer into into a mug of water, energy spent (or released) when heating (or cooling) the mercury in the thermometer changes the temperature of the water in the mug by a small amount. The only way not to interfere with the temperature of the water in the mug is not to measure it.

[edit] Transcript

[Cueball is standing behind a friend, who is sitting at a computer.]
Cueball: Hey, will you be in town the day after Christmas?
Friend: Couldn't say—
Friend: I'm Jewish.
Cueball: But... how does being Jewish keep you from knowing your plans?
Friend: I know my plans—
Friend: I just don't know when Christmas is.
Cueball: Really? Why not look it up?
Friend: Well, I'm also a physicist.
Cueball: So?
Friend: I believe that since I don't observe Christmas, it can't have a definite date.
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Discussion

Interestingly, the comic text could be interpretted as dealing more with classical physics (only by observation do we actually know something) while the hover text is definitely referencing the fact that observing does something to a quantum system. 178.98.207.61 12:57, 17 May 2013 (UTC) A bit of theology: Jews are still waiting for Christ to be born, which makes 'I just don't know when Christmas is.' even more true. 94.232.40.18 06:05, 29 October 2013 (UTC)

Strictly speaking, we're waiting for the Messiah to be born. With any luck, he or she won't get crucified, so it won't be proper to refer to him/her as "Christ". 108.162.219.209 07:25, 23 November 2013 (UTC)
Loosely translated, "Christos" means messiah in (transliterated) Greek. It's descended from "chriein" meaning "annoit". So, yes, Jews are still waiting for Christ. The proper term is still "messiah", though, as it is the equivalent Hebrew term (parallel etymologies even! See Merriam-Webster for both). Anonymous 18:26, 4 December 2013 (UTC)


Does the idea the title text references also apply to infrared thermometers? 108.162.250.217 (talk) (please sign your comments with ~~~~)
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