Daily Archives: September 1, 2012

Planck units

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Originally proposed in 1899 by German physicist Max Planck, these units are also known as natural units because the origin of their definition comes only from properties of nature and not from any human construct. Planck units are only one system of natural units among other systems, but are considered unique in that these units are not based on properties of any prototype object, or particle (that would be arbitrarily chosen) but are based only on properties of free space.

— Wikipedia on Planck units

2012.09.01 Saturday ACHK

Push-ups

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Being able to do more push-ups doesn’t mean that you can endure more pain. Instead, it means you have stronger muscles so that you can feel less pain for the original number of push-ups.

— Me@2011.09.05

2012.09.01 Saturday (c) All rights reserved by ACHK

蘋果 與 Apple, 2.1

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Electric Field and Electric Potential, 2.1

這段改編自 2010 年 6 月 9 日的對話。

「Field」（場）貌似是一個抽象的概念。實質可以很簡單容易。究竟什麼是「field」（場）呢？

空間上，每一點有一個數字，就為之有一個「field」。例如，這兒的空間有溫度。這一點是 26 度、那一點是 27 度、另一點是 26.5 度 等等。你發覺在這兒空間上的每一點，都可以標籤一個數字，用來代表溫度。所以我們說，這裡有一個 temperature field（溫度場）。　

— Me@2012.09.01

2012.09.01 Saturday (c) All rights reserved by ACHK