Editing 2178: Expiration Date High Score

{{comic
| number    = 2178
| date      = July 19, 2019
| title     = Expiration Date High Score
| image     = expiration_date_high_score.png
| titletext = "Wait, we've MOVED since 2010. How on Earth did--" "Look, some of us were just born to be champions."
}}

==Explanation==
[[Randall]] is introducing the rules of the game ''Expiration Date High Score'' hence the title. 

If you find an item which you purchased, but is now past its {{w|expiration date}}, you get a score which is what percent of your lifetime elapsed between when the item expired and when you found it.  

[[Megan]], looking in a cupboard, find a can of beans that expired in 2010 (9 years ago), and that gives her a score of 24.3. Megan's age is thus revealed to be 37, found by substituting 2019 and 2010 into the formula 100*(2019-2010)/<age> = 24.3 and solving for the age. This is consistent with this comic(https://explainxkcd.com/wiki/index.php/630:_Time_Travel) in which Megan's date of birth is given as 1983.

[[Cueball]] then remarks that she will never beat her mom's jar of pickles that was from 1978. Megan then wonders if there are more cans (from 2010 or before) in the cupboard, and asks Cueball to remind her to not look any further until 2030. At that time the can would have been 20 years old and she would be 48, giving such a can a score of 100*(2030-2010)/48 = 41.6. That would thus beat her mom's high score. 

If her mom's jar had expired in 1978 (not clear from the text), and for instance was found last year in 2018, then the formula for the mother's score would be 100*(2018-1978)/<Mom's age>. And this should then not be more than 41, thus revealing the mother age to be around 100 years old today (98 last year). Of course the jar could have had an expiration day some years later, or have been found earlier. Otherwise Megan's mom would have been above 60 when giving birth to Megan. Of course Megan could also just take this extra long wait in case the next can is not from 2010 but only 2013 etc. 

Cueball's final remark is that this is a terrible competition, the worst ever. Because keeping food that can spoil could potentially be dangerous, if not so, at least disgusting when finally trying to get rid of it later.

Many perishable items, such as food, cosmetics, medications, batteries, or condoms, have expiration dates, or sometimes best by dates. The only other rule is, that it has to be something you have purchased yourself, so that heritages or stuff that was left in the basement when one moved in, does not count.  A score of 100 or higher would indicate the item expired when you were born or before you were born, meaning it was already expired when you purchased it.

The joke is, that owning expired items without noticing for a long time, is here getting you a high score, while in reality it is not considered favorable to have food that has expired long time ago.{{Citation needed}}

The other joke is both the items in the comic (a can of beans and a jar of pickles) do not go bad with time but in fact remain edible indefinitely (as long as the jar/can is not opened and is undamaged.)

Food going bad, in the sense that it will make you sick if you eat it, is most often caused by harmful bacteria growing in the food.  Less often caused by fungi or yeast growing in the food and creating a poisonous substance, like methanol (wood alcohol.)  The process of canning food involves boiling it to kill all possible pathogens, then sealing it in a can/jar while the food is still hot, with no air bubble.  As long as this process is done correctly, the jar lid will have an airtight seal, so as long as the can is not punctured, or does not have a hole become rusted through, no bacteria/virus/yeast/fungi can get in and the food cannot spoil.  Some food may discolor over time in the jar/can, or the texture may change, but it cannot go bad in a way that makes it unsafe to eat.

Megan's mom could not have a jar of pickles with a 1978 expiration date because in 1978 jars and cans of food did not have expiration dates. Since then many countries introduced laws and regulations requiring companies to put expiration dates on perishable goods. In some instances this can have the negative effect of people throwing out good food by blindly following the suggested expiration date. This behavior can incentivize companies to adjust the expiration date, or put expiration dates on non-perishable goods, so that people will re-buy the products sooner.

The title text continues the conversation from the comic. Cueball remarks that they moved since 2010... Thus the beans were apparently bought while living in a different home, meaning they were moved along with their other belongings. This is somewhat unusual as many people take moving as an opportunity to go through their old stuff and get rid of things they no longer need. Since the rules clearly states that you have to have bought it yourself, it could not have been in the house when they moved in, they had to have brought it along (unless they later bought something that was already expired). But given Megan's final answer that "some of us were just born to be champions" indicates that she did bring it along, anticipating this game, and thus given her self a great score. And as is clear she is willing to wait 11 years to try to beat her mom's score.

It is not clear why they are keeping items for long periods of time in order to win.  An easier way to win this game would be to buy food that is already expired.  One could obtain a score of 100 simply by buying something that expired when one was born, and finding it the next day.

==Transcript==
:[Title up in the panel:]

:What's the most expired item you've found in your house?

:Calculate your
:Expiration Date High Score
:(must be something ''you'' purchased)

:[Equation in a circle:]

:Score = (year you found item) minus (year item expired) divided by (your age when you found it), multiplied by 100

:[Megan and Cueball talking in a kitchen, with Megan holding a can.] 

:Megan: These beans expired in 2010! That's... let's see... 24.3! New personal best! 
:Cueball: You're never going to beat your mom's jar of pickles from 1978.
:Megan: Maybe there are more cans in there. Remind me not to look until 2030.
:Cueball: This is the worst competition.

==Trivia==
The formula suggests Megans age to be 37, if this comic plays in 2019, when it was released. That puts her birth year to either 1982 or 1981 (depending on whether this plays before or after her birthday in 2019). This is in slight contrast to [[630: Time Travel]], which implies her birth year to be 1983.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Food]]