Eigenstates 2.3.2

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eigenstates

~ classical states

~ definite states

— Me@2012-04-15 11:42:10 PM

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The concept of eigenstate is relative.

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First, you have to specify the eigenstate is of which physical observable.

A physical system can be at an eigenstate of one observable but at a superposition state of another observable.

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Second, you have to specify the state of that observable is eigen with respect to which observer.

— Me@2018-06-16 7:27 AM

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eigenstates

~ of which observable?

~ with respect to which observer?

— Me@2018-06-19 10:54:54 AM

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2018.06.19 Tuesday (c) All rights reserved by ACHK

大學經濟

這段改編自 2010 年 4 月 18 日的對話。

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我猜想,當一個人改變存在型態時,會立刻或者將會,知道很多生時不知道的東西。但是,那些新知識,未必包括你想知道的東西。

比喻說,由中學升到大學,你將會學到,很多超過中學程度的知識。但是,如果你中學時,沒有讀過經濟科的話,單單是「升大學」本身,並不會令你,立刻獲得經濟科的知識。

大學生「由零開始學經濟學」,都同樣要花時間;分別是,通常而言,比中學生「由零開始學經濟學」,速度會高一點。

(問:不一定呀。中學生比較年青,腦袋理應高速一點。)

無錯。

方便起見,暫時用同一個人來比較,例如你。

「中學的你」可以因為腦袋較年青,學習新事物比「大學的你」較快。「大學的你」可能因為知識和經驗較多,學習新事物比「中學的你」較快。

視乎情況,因人而異,沒有一定的答案。

但是,至少你會同意一點:

如果你中學時,沒有讀過經濟科,在大學時要「由零開始學經濟學」的話,你會立刻看大學程度的經濟書,而不是由中學教科書開始學。

— Me@2018-06-05 11:54:51 AM

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2018.06.07 Thursday (c) All rights reserved by ACHK

Plato

trowawee 4 months ago

I’m a little frustrated at the tossed-off reference to Plato and Aristotle at the beginning – “The good life may have sufficed for Plato and Aristotle, but it is no longer enough.” – because I feel like that ignores the fact that both Plato and Aristotle, along with a lot of philosophers, actually had a lot to say about physical fitness. Plato was a champion wrestler, and both he and Aristotle viewed physical education as a fundamental component to living the good life. Xenophon quotes Socrates saying this:

“For in everything that men do the body is useful; and in all uses of the body it is of great importance to be in as high a state of physical efficiency as possible. Why, even in the process of thinking, in which the use of the body seems to be reduced to a minimum, it is matter of common knowledge that grave mistakes may often be traced to bad health.”

The whole article feels a little too mired in presentism, and ignorant of the history of self-improvement ideas.

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coldtea 4 months ago

>Plato was a champion wrestler

And the name Plato is a nickname — meaning “the broad/wide one” given to him for his broad shoulders because of that training and physical appearance. Real name: Aristocles.

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kernelbandwidth 4 months ago

It’s funny to consider that one of the canonically great philosophers in history is known essentially by the equivalent of his WWE wrestling name. It’s like if in the future there were classes taught on the philosophical ideas of “The Rock”.

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coldtea 4 months ago

Some other amusing related stuff: so, Plato, was called for for the ancient greek word for broad/wide.

Modern [English] words that stem from the same root: plateau, platitude, plat, plate — via French and Latin (plattus) from Greek (platis “flat, wide, broad”).

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danohu 4 months ago

Well, the first Pope was literally called The Rock (Peter). Jesus appointed him by saying “you are The Rock, and I’ll build my church on this rock”.

Exactly what he meant has led to centuries of debate between protestants and catholics.

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acangiano 4 months ago

“No man has the right to be an amateur in the matter of physical training. It is a shame for a man to grow old without seeing the beauty and strength of which his body is capable.”

― Socrates

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— Improving Ourselves to Death

— Hacker News

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2018.06.01 Friday ACHK