# 量子力學 1.14

（安：言歸正傳，剛才所講，「量子決定論」的難處在於：

」；

— Me@2013.09.30

# Block spacetime, 6

Clojure 4

fleitz 17 hours ago

Great article on the fundamental problems associated with mutable state. The fundamental problem is that the idea of an object with a set of state that is the same to all observers violates pretty much the whole of information theory. It’s not a problem that will ever be fixed [without] changing the fundamental laws of the universe.

Ditch the mutable data and you can stop asking questions like what do we do if 10 becomes 10.5 before it becomes 11 and start storing values which never change.

jerf 13 hours ago

Information theory does not have a problem, only, as you say, our universe. Mathematicians and their various hangers-on like programming language researchers often prefer to deal with models that have no concept of time, in which the very concept of “observer” is extraneous since there isn’t really anything like a “point of view”. Everything just… is.

— Hacker News

2013.09.29 Sunday ACHK

# 機器 3

= 全部先決條件之容器

= 充份條件之容器

= 缺乏了起碼其中一個先決條件

= 因果網絡有障礙

— Me@2013.09.27 19.30.21

# 量子力學 1.13.2 （外傳）

（安：但是，你又真的可以，從那一千億元的戶口之中，每天提取一百元去用。因為那些一百元，始終是來自那一千億元的，你不能說，那一千億元完全沒有用，完全不屬於你。）

（安：等一等。其實這個例子很有趣，彷彿正在講述「個人潛能」似的。

— Me@2013.09.28

You can do anything, but not everything.

– David Allen

# Godel 12

Consistency and Completeness. We say a formal theory is consistent if you cannot prove both P and ¬P in the theory for some sentence P. In fact, because from P and ¬P you can prove anything using classical logic, it is equivalent that a theory is consistent if and only if there is at least one sentence Q such that there is no proof of Q in the theory.

[]

By contrast, a theory is said to be complete if given any sentence P, either [it] has a proof of P or a proof of ¬P. (Note that an inconsistent theory is necessarily complete).

[]

Hilbert proposed to find a consistent and complete axiomatization of arithmetic, together with a proof (using only the basic mathematics that both camps agreed on) that it was both complete and consistent, and that it would remain so even if some of the tools that his camp used (which the other found unpalatable and doubtful) were used with it.

— Mathematics – Stack Exchange

— Jan 5 ’11 at 3:21

— Arturo Magidin

2013.09.27 Friday ACHK

# The Neverending Story 3

The ended stories, such as novels, movies, and computer games, can be the backgrounds or plug-ins of the never-ending story of your real life.

— Me@2011.04.30

# Always make new mistakes, 7.4

（TK：感受到。）

（CYW：？？？）

（CYW：開學時，不是還有五個月嗎？）

「五個月」，不就是「百多日」嗎？

— Me@2013.09.26

# Logical arrow of time, 5

Otherwise your games with the “definition” of initial and final states and with the sign of t are completely immaterial. “Initial” and “final” states are, according to logic, qualitatively different things, and the usual convention for the sign of t is that t_{initial} < t_{final}. But I have never even used this convention.

Even if I had, it wouldn’t matter. One can easily rewrite all proofs to the opposite convention by replacing t with −t; all those things are physically vacuous. The non-vacuous claim is that the future and past don’t play symmetric roles in logic.

— Physics Stack Exchange

— Jan 25 ’12 at 9:49

— Lubos Motl

2013.09.26 Thursday ACHK

# 受難曲 2

— Me@2013.09.22

.

… 因為，攝影師要離開畫面，才可以拍攝到該個畫面。

— Me@2013.09.23

.

.

# 量子力學 1.13

「量子決定論」可信而不可用。可信而不可用，還有資格叫做「可信」嗎？

（安：但是，你又真的可以，從那一千億元的戶口之中，每天提取一百元去用。因為那些一百元，始終是來自那一千億元的，你不能說，那一千億元完全沒有用，完全不屬於你。）

— Me@2013.09.25

# Logical implication 3

The paradox ceases to exist the moment we replace informal logic with propositional logic. The Tortoise and Achilles don’t agree on any definition of logical implication. In propositional logic the logical implication is defined as follows:

P ⇒ Q if and only if the proposition P → Q is a tautology

[H]ence de modus ponens [P ∧ (P → Q)] ⇒ Q is a valid logical implication according to the definition of logical implication just stated. There is no need to recurse since the logical implication can be translated into symbols and propositional operators such as →. Demonstrating the logical implication simply translates into verifying that the compound truth table is producing a tautology.

— Wikipedia on What the Tortoise Said to Achilles

2013.09.25 Wednesday ACHK

# Forever Young, 2

Young people have passion on almost everything, because the opportunity cost they have to pay is so low. It is profitable to do almost everything.

— Me@2011.04.29

# Always make new mistakes, 7.3

（CYW：但是，我又真的很想溫完書才做。）

（CYW：但是，如果做 past paper 時，大部分題目也不懂的話，那不會好像是，浪費了那份 past paper 嗎？）

— Me@2013.09.24

# Quantum Mechanics 4

Instead, it is a lesson that string theory has clearly taught us. If we want to talk about exact observables only, it’s simply not true that physics may be thought of as being composed of sharply localized objects in a predetermined classical geometric background, at least not in a uniquely specified way.

The very assumption that there exists a black hole interior (and the strict event horizon that separates it from the rest of the Universe) is an approximation. Exact stringy rules of evolution don’t allow such a conclusion to be 100% certain, ever. The probability may converge to 100% for a star collapse but the remaining deviations from 100% are always necessary to restore the unitarity and guarantee other high-precision consistency conditions.

— String theory is a complete theory of quantum gravity

— Lubos Motl

2013.09.23 Monday ACHK

# 量子力學 1.12

宇宙隨著量子物理定律演化，一切事件皆是必然的。

「量子決定論」的第二個問題是，在任何一次的實驗之前，你都要知道整個宇宙狀態的所有數據，才可以百分百準確地，預測到該個實驗的結果。

「量子決定論」可信而不可用。

— Me@2013.09.22

# Idea babies 4

On why failing in the startup world is normal

“In the startup world, ‘not working’ is normal … You might wonder why ships have [bilge] pumps [to remove water from below the deck] … Why don’t they just make one that’s waterproof, right? And the fact is, one way or another, all ships take on water … and one way or another, practically all startups internally are disasters. And they just hide this from the outside world.

— Paul Graham

— Failure: The F-Word Silicon Valley Loves And Hates

— NPR Staff

2013.09.22 Sunday ACHK

# David Attenborough

In a December 2005 interview with Simon Mayo on BBC Radio Five Live, Attenborough stated that he considers himself an agnostic. When asked whether his observation of the natural world has given him faith in a creator, he generally responds with some version of this story, making reference to the Loa loa parasitic worm:

My response is that when Creationists talk about God creating every individual species as a separate act, they always instance hummingbirds, or orchids, sunflowers and beautiful things. But I tend to think instead of a parasitic worm that is boring through the eye of a boy sitting on the bank of a river in West Africa, [a worm] that’s going to make him blind. And [I ask them], ‘Are you telling me that the God you believe in, who you also say is an all-merciful God, who cares for each one of us individually, are you saying that God created this worm that can live in no other way than in an innocent child’s eyeball? Because that doesn’t seem to me to coincide with a God who’s full of mercy’.

He has explained that he feels the evidence all over the planet clearly shows evolution to be the best way to explain the diversity of life, and that “as far as [he’s] concerned, if there is a supreme being[,] then he chose organic evolution as a way of bringing into existence the natural world.”

— Wikipedia on David Attenborough

2013.09.21 Saturday ACHK

# Always make new mistakes, 7.2

（TK：更大的問題是，probability（機會率）課題之中，老師教了的部分，其實我仍然不明白。）

（TK：有呀。）

（TK：來不及完成那麼多年的 past paper？）

（TK：為什麼呢？）

（CYW：但是，我又真的很想溫完書才做。）

（CYW：但是，如果做 past paper 時，大部分題目也不懂的話，那不會好像是，浪費了那份 past paper 嗎？）

— Me@2013.09.21

# Inner and outer, 6

Onion self 8

In a sense, the fewer qualifiers you give to yourself, the smaller “you” are.

As you have fewer unnecessary qualifiers, “you” are purer. For example, when you label yourself as “a person” rather than “a thin person”, “you” are purer. Furthermore, if you label yourself as “an animal” rather than “a person”, “you” are even purer.

In the most extreme case, you label yourself just as “a thing”. You are just a being. You are just you.

In another sense, the fewer adjectives you give to yourself, the bigger “you” are.

As you have fewer unnecessary adjectives, “you” are more complex. For example, when you define yourself as “a human” rather than “a thin human”, “you” are greater, because there are more objects satisfying the condition of “being a human” than “begin a thin human”. There are more “humans” than “thin humans”.

Furthermore, when you define yourself as “an animal” rather than “a human animal”, “you” are even greater.

In the most extreme case, you define yourself just as “a thing”. In other words, as everything is “a thing”, you are “everything”.

The smallest possible you is “nothing”. The biggest possible you is “everything”, aka “the universe”.

— Me@2013-09-17 10:15 PM