Life, 3

生命 3


We exist in time because time is change.

Growing is part of the definition of life. Growing is a kind of change.


Also, without time/change, there would be no thinking and no thoughts.

— Me@2017-12-26 11:42 am

— Me@2018-05-23 10:05:03 PM


time ~ change


Time is logically necessary if change is necessary.

— Me@2018-02-04 09:07:48 PM



2018.05.23 Wednesday (c) All rights reserved by ACHK

The language of Change 1.2

Energy conservation, 6.2 | Energy 5.2


time ~ change

energy ~ the ability of _keeping_ changing


constant velocity ~ the amount of an object’s change of position, measured with respect to its observer’s unit of change, is constant

s = \Delta x

v = \frac{s}{\Delta t} = \frac{\Delta x}{\Delta t}


kinetic energy ~ the amount of the ability of keeping changing an object’s position

\frac{1}{2} m v^2 ~ the square of (the amount of change of position, relative to the observer’s unit of change)



Energy difference is _not_ exactly a measurement of the amount of change, time interval is.

— Me@2018-02-20 09:39:30 AM



2018.02.20 Tuesday (c) All rights reserved by ACHK

The language of Change

Energy conservation, 6 | Energy 5


time ~ change

energy ~ the ability of causing change


1. a system of one single particle

2. has only kinetic energy

3. and that kinetic energy is conserved.

conservation of energy ~ an object’s potential amount of change of position, measured with respect to its observer’s unit of change, is constant

s = \Delta x

v = \frac{s}{\Delta t} = \frac{\Delta x}{\Delta t}

— Me@2018-02-15 02:21:20 PM



The above argument has a bug:

If the mass m is constant, the kinetic energy E_K should be proportional to velocity squared v^2, instead of velocity v.

E_K = \frac{1}{2} m v^2


However, the above argument is still technically correct:

When E_K is constant, v^2 is constant. In turn, the magnitude of v also remains unchanged.

— Me@2018-02-19 09:37:24 PM



2018.02.15 Thursday (c) All rights reserved by ACHK


玄悟慧能 1.3

這段改編自 2010 年 4 月 18 日的對話。








— Me@2015.03.20

2015.03.20 Friday (c) All rights reserved by ACHK


By the definition of “time”, anything in time must be changing. Anything not in time, such as the dead, cannot change.

If you do not keep changing for better (improve, grow), you are effectively dead.

— Me@2011.10.10

Although this paragraph is not 100% accurate, its spirit is useful.

— Me@2014.08.09

2014.08.09 Saturday (c) All rights reserved by ACHK


Energy is the ability of causing change.

Change is related to time.

That’s why energy is related to time.

— Me@2012-10-22 01:45:17 PM

Application of Noether’s theorem allows physicists to gain powerful insights into any general theory in physics, by just analyzing the various transformations that would make the form of the laws involved invariant. For example:

  • the invariance of physical systems with respect to spatial translation (in other words, that the laws of physics do not vary with locations in space) gives the law of conservation of linear momentum;
  • invariance with respect to time translation gives the well-known law of conservation of energy

— Wikipedia on Noether’s theorem

2014.03.25 Tuesday (c) All rights reserved by ACHK


Easy 3

Easy” in Chinese is “容易”, literally meaning “able to change“.

— Me@2012-11-29 10:47:38 AM

It is not the strongest of the species that survives, nor the most intelligent, but rather the one most adaptable to change.

— Charles Darwin misquotation

The definition of insanity is doing the same thing over and over and expecting different results.

— Albert Einstein misquotation

If you are willing to change based on the feedback from the reality, many difficult things will become easy.

— Me@2012.12.17


— 系辭下

— 易經

2012.12.21 Friday (c) All rights reserved by ACHK

Rich Hickey, 2

Like Clojure, Datomic incorporates an explicit model of time. All data is associated with a time and new data does not replace old data, but is added to it. Returning to our previous example, if John later changes his address, a new datom would be added to the database, e.g.

  John, :street, “17 Maple St.”, T43

This mirrors the real world where the fact that John has moved does not erase the fact that John once lived on Swift St. This has multiple benefits: the ability to view the database at a point in time other than the present; no data is lost; the immutability of each datom allows for easy and pervasive caching.

— rjn945 15 days ago

— Hacker News

2012.03.21 Wednesday ACHK

Number, Time, Money, 2.7

Ideal clock 3.7 | 時間定義 13.7


反而,我們是在各個事件發生時,先行從年曆、月曆、日曆 和 時鐘上,獲取時間讀數,然後把各個事件,放在時間軸上的對應位置。那樣,毋須做任何其他動作,所有你要考慮的事件,就會已經自動排列好。

— Me@2011.09.16

2011.09.16 Friday (c) All rights reserved by ACHK

Number, Time, Money, 2.6

Ideal clock 3.6 | 時間定義 13.6


1. 要建構事件序列;

2. 要在原本的事件序列中,加插額外的另一件事;還是

3. 要把兩個事件序列,組合成一個序列,


例如,我們原本的事件序列是「乙(-1)、甲(0)、丙(2)」。如果要額外加上第四件事「丁(1)」的話,你都要先比較(-1, 1)的大小關係、(0, 1)的大小關係 和 (2, 1)的大小關係,才可以知道「丁(1)」發生於「甲」「丙」之間,繼而更新序列為「乙(-1)、甲(0)、丁(1)、丙(2)」。



「十分明顯」的例子有:「甲 = 入大學;乙 = 大學畢業」。因為「入大學」是「大學畢業」的先決條件,所以「入大學」一定先於「大學畢業」發生。

「不十分明顯」的例子有:「甲 = 電燈面世;乙 = 電話面世」。

「十分不明顯」的例子有:「甲 = 地球形成;乙 = 火星形成」。


相反,如果「甲」和「乙」都有數字標籤的話,例如「甲 = 入大學(1999 年);乙 = 大學畢業(2002 年)」,毋須任何其他的解釋,電腦也會立刻知道,「甲」「乙」的先後次序。



— Me@2011.09.14

2011.09.14 Wednesday (c) All rights reserved by ACHK

Number, Time, Money, 2.5

Ideal clock 3.5 | 時間定義 13.5



第一件事(甲)的數字,正如剛才所講,是任意的。所以,你可以選一個對你來說,最方便的數字。因為 0(零)是最簡單的數字,大多數情況下,也是最方便的數字。





— Me@2011.09.14

2011.09.14 Wednesday (c) All rights reserved by ACHK


Number, Time, Money, 2.4

Ideal clock 3.4 | 時間定義 13.4

這段改編自 2010 年 3 月 6 日的對話。






然後,我們考慮第二件事(乙),看看它發生於「甲」的之前還是之後。之前的話,我們就用一個小於「甲」數字的數字來標籤「乙」,例如 -1; 之後的話,我們就用一個大於「甲」數字的數字,例如 +1。在我們的例子中,「乙」發生於「甲」之前。「乙」的數字是 -1。

接著,我們考慮第三件事(丙),根據它分別和「甲」「乙」的先後次序,來決定用哪一個數字來標籤「丙」。如果「丙」發生於「乙」「甲」之間的話,我們就用一個 -1(乙)和 0(甲)之間的數字來標籤「丙」,例如 -0.5。在我們的例子中,「丙」發生於「甲」之後。我們需要用一個大於 0(甲)的數字來標籤「丙」,例如 2。









— Me@2011.09.13

2011.09.13 Tuesday (c) All rights reserved by ACHK