陶拉里亞大學院時間操縱緒論期末考 - 魔法風雲會

"If yesterday was two days ago tomorrow,
will the day after tomorrow be today or yesterday?"
—Temporal Manipulation 101 final exam, Tolarian Academy

"如果說昨天到了明天會變成兩天前，試問後天應該是今天或昨天？"
~陶拉里亞大學院時間操縱緒論期末考


我想應該不少人看過這題
之前我照自己的理解，覺得答案是都不對，不是今天也不是昨天，而是明天。

今天=D
昨天=D-1
前天=D-2
明天=D+1
後天=D+2

如果昨天到了明天會變成兩天前，這句的意思是如果到了D+1時，再看D-1，中間的差距會
變成2。試問後天(the day after tomorrow，也就是D+2)應該是今天或昨天？這句話其實
是陷阱，因為第一句的關係，目前的時間是D+1，而由D+1來看D+2，中間的差距是1天，也
就是說，這題的答案是「明天」。


但最近有人丟給我一個2005的FAQ
老實說我不太理解...

http://archive.wizards.com/Magic/magazine/
(接上面)article.aspx?x=mtgcom/askwizards/1105




November 9, 2005

Q: "I was flipping through the Ninth Edition spoiler on Gatherer, and I came
across Temporal Adept's flavor text. After about 20 minutes of critical
thinking, all I had was a headache. Is that question actually solvable?
Thanks!"
--Rick
Richmond, VA, USA

A: From Devin Low, Magic R&D:

"If yesterday was two days ago tomorrow, will the day after tomorrow be
today or yesterday?"
-Temporal Manipulation 101 final exam, Tolarian Academy

"Thanks for the question Rick. There is an answer to this exam question.
You're almost there. Let's look at the first phrase first: 'If yesterday was
two days ago tomorrow.' For the purposes of argument, assume it's Wednesday
today. Then the phrase says: 'If yesterday (TUESDAY) was two days ago
tomorrow (THURSDAY)…' When it's Thursday, Tuesday was indeed two days ago.
In fact, for any 'tomorrow', two days before that will clearly be
'yesterday.' So the first part of the question is just always true. It's like
it said 'If bananas are yellow, will the day after tomorrow be today or
yesterday?' That's the same as just asking, 'Will the day after tomorrow be
today or yesterday?'

So now consider the second part of the question: 'Will the day after tomorrow
be today or yesterday?' Again, assume it's Wednesday today. Then the question
says 'Will the day after tomorrow (FRIDAY) be today (WEDNESDAY) or yesterday
(TUESDAY)?' Clearly, Friday is neither Wednesday nor Tuesday. Likewise, 'the
day after tomorrow' is never 'today' or 'yesterday.' So the correct answer to
the question is 'Neither.' Best of luck on the rest of the exam.


照FAQ的意思來說，
"如果說昨天到了明天會變成兩天前"這句和後面的問題完全沒關係嗎？



--
League of Legends ∕◣(﹎▁▄ _▆▃ ◢▂▄▄▂=◣ ▄▇_▇▄▁ ,◢/'}
◥◣◣▁,="﹊ ▁▕ , ︻▇◣-◣◣ ▁﹊"～,▁ ◤◢◤
Sona, Maven of the Strings ◥▅︼▁▃▅ ▕,{◤ ◥◥█\ \◥ ▅▂`=◥▇ ◤
▆ ▲{| ● ◥▼▍}▲ ▇▆▄﹊
"Only you can hear me Summoner, ◣◣ ︺ ◢/▎▅ cycefa修改
what masterpiece shall we play today?" ﹊`/●●\ ◤﹊ vcfsvjf原作

--