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