尋貓題

今有屋一排五間, 一貓匿其中, 夜夜潛移鄰屋, 或左或右. 問: 日訪一屋, 何由相遇?

(youtube The Hiding Cat Puzzle)

* * *

解: 屋編以號, 左起一至五.

貓所在之屋號, 非單即雙.

設單日在雙號屋, 首日訪屋二不遇, 是日必在屋四. 次日訪屋三不遇, 則該日必在屋五, 翌日必在屋四. 猶不遇, 則原設有誤.

原設有誤, 則雙日應在雙數之屋.
第四日起，依次重訪屋二三四.
如是者, 三日內必遇. 前後通共六日.

*

推廣: 一排 N 間屋, 可有通解?



(延伸: 五匣藏一寶)

五匣藏一寶

某 youtube 短片 談一推理題, 略謂:
主與二客對坐, 出五匣, 形各異, 色不同, 中藏一寶. 一匣方而藍. 兩匣圓, 一黃一綠. 餘兩匣三角形, 一藍一綠.

一客知藏寶匣之形, 一知其色.
主問, 藏寶者何匣? 二君相對默然.
再問, 復默然.
三問, 俱起而曰, 知之.

問: 何匣?

* * *

解: 論形: 方圓角. 論色: 藍黃綠.
一匣方, 一匣黃, 餘皆藍綠圓角雜然.
首問俱嘿, 故知非方, 亦非黃.

去方去黃, 餘者唯一藍, 唯一圓.
再問亦嘿, 故知非藍, 非圓.

去藍去圓, 是必 綠三角 無疑.


(延伸: 尋貓題)

Lucian

(Fowler tr.)

Nigrinus (p.26):

A person who has been bitten by a mad dog not only goes mad himself, you know, but communicates his madness to any one whom he bites whilst he is in that state, so that the infection may be carried on by this means through a long succession of persons.

徙木立信

史記卷六十八商君列傳:

孝公既用衛鞅, 鞅欲變法, 恐天下議己. 令既具, 未布, 恐民之不信己, 乃立三丈之木於國都市南門, 募民有能徙置北門者予十金. 民怪之, 莫敢徙. 復曰:「能徙者予五十金」, 有一人徙之, 輒予五十金, 以明不欺. 卒下令.

今人則反其道而行之, 打疫苗而後罹疾身亡者, 輒曰無關. 所諾之救助金, 猶信口雌黃. 或曰予則坐實謠言. 異哉, 然則何必設之.

Six good questions

Opinion: Why vaccine passports won't slow COVID spread, will hurt the poor and threaten medical ethics

By Alanna Golden, Gil Nimni, Sandra Rao and Neil Rau (National Post, Sep 09, 2021)

Six good reasons to rethink vaccine certificates

1. What is the intent and what are the end points?

2. Can we stop transmission with vaccine certificates?

3. What are the logistical considerations of such a program?

4. What are the unintended consequences?

5. Why are people vaccine-hesitant?

6. Are vaccine certificates ethical?

很好的思考框架

sites

https://www.tec-science.com/thermodynamics/temperature/richmanns-law-of-final-temperature-of-mixtures-mixing-fluids/

https://courses.lumenlearning.com/physics/chapter/14-2-temperature-change-and-heat-capacity/

https://tex.stackexchange.com/questions/81842/creating-a-drop-shadow-with-guassian-blur

Ovid's Metamorphoses

(Charles Martin tr.)

1.916--919 (p.42)

Nor can I end this suffering by death:
it is a hamful thing to be a god,
for the gates of death are firmly closed against me,
and our sorrows must go on forever.

2.170--172 (p.96)

But `fortunate'? A judgement best reserved
for a man's last day: call no one blest, until
he dies and the last rites are said for him.

6.4-7 (p.189)

To praise is insufficient, she reflected: we will be praised---and we will not permit
those who belittle our divinity
to go unpunished!

tum secum: 'laudare parum est, laudemur et ipsae
numina nec sperni sine poena nostra sinamus.'

於是她自言自語道: 僅僅稱讚別人是不夠的, 我自己也應受人稱讚才是, 我不能讓人隨便輕視我而不給他們懲罰. (楊周翰)

她這麼思量: 開口讚美不如受人讚美, 萬萬不能縱容凡人在我們面前囂張. (呂健忠)


7.800-804

Ungovernable plague! The doctors die,
their arts a harm to their practitioners,
and those who are the closest to the sick,
who serve most faithfully, are first to fall!

None can offer help, / ease the disease; the plague is pitiless, / assailing even those who try to heal--- / the doctors’ craft rebounds against their selves. / For he who stays more close to the diseased / and cares for them most faithfully will meet / his fate more speedily. (Mandelbaum, in [523--54])