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Hian-Kun Tenn
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嘖嘖嘖~
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我想如果要票選最討人厭的第三勢力,這位大姐應該可以得到相當靠前的名次吧......
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I haven't read the article yet, but this looks fun.
 
This image by wavegrower [1] has been circulating, together with the question: "Will these jellyfish ever make it back to their original place?" +Kimberly Chapman pointed out the obvious "yes, because it's an animated GIF and those loop." But here's something you might not expect: even if it weren't an animated GIF, even if these jellyfish were being moved around by a program using random numbers, I could guarantee that they always repeat.

(Or to be a bit more careful, if you watch it long enough, you'll always see a repetition. It might not be the very first position that repeats [2])

Why? Let's imagine a simpler case for a moment, involving a 2x2 grid of jellyfish, each of a different color so we can tell them apart. There are 24 possible ways we could arrange the jellyfish: if you start with an empty grid, there are four places to put the red jellyfish; for each of those places, there are three remaining possible places to put the blue one; for each of those, there are two remaining possible places to put the green one; and once you've chosen those three, there's only one place the yellow one could go. So there are 4*3*2*1=24 possible jellyfish patterns. (Written 4!, "4 factorial")

Each time the jellyfish move, we move from one of these 24 configurations into another. As it happens, the motions below are very limited -- each jellyfish has to move onto a dot next door -- but that turns out not to matter, because even if the jellyfish could teleport, they'd still have to repeat.

Why? Imagine that we look at the first 25 moves. The jellyfish will end up in 25 configurations, but there are only 24 different configurations total, which means that at least one configuration had to happen twice!

This is called the pigeonhole principle: if you have N+1 pigeons in N pigeonholes, at least one hole has to contain two pigeons. (In this case, you have 25 configurations in 24 distinct slots)

If the rule going from one configuration to the next is deterministic -- that is, if the next move depends only on where the jellyfish are right now -- then you know that once a single repetitive loop happens, that loop will continue to repeat forever, because you're back at the first stage of the loop and will then have to go on to the second one, etc.

If the rule isn't deterministic -- say, if each time the jellyfish move randomly -- then a single repetition doesn't guarantee infinite repetition, but you still know that at least one pattern will appear at least twice in any sample of 25 patterns.

The same thing is true for this bigger grid; you just need to wait a bit longer. The 16x16 grid below has 256 jellyfish, so you need to wait for 256!+1 steps -- that's 256*255*...*3*2*1 + 1 steps, or about 8*10^506 steps [3] -- but no matter what, the jellyfish are absolutely guaranteed to repeat.

What's even more interesting is that this may apply to more than just jellyfish. One set of rules that we know are deterministic are the laws of physics. [4] Now, an interesting open question in physics is: is there a minimum granularity of spacetime, so that we can think of the entire universe as being on some kind of extremely fine grid? (When I say "extremely fine," I mean a grid size of the Planck length, about 1.6*10^-35 meters. For comparison, that's as much smaller than a proton as a proton is smaller than the San Francisco Bay Area.)

There are some reasons to believe that this may actually be true (although the geometry is a lot more complicated than a simple grid, and in fact "geometry" isn't even the right word for it; the whole expansion of the universe, from the big bang on, is part of it). If it is, then there's something interesting: we could imagine the entire universe as a gigantic grid, and the current state of the universe is given by deterministic laws about what's on that grid, then we know that the state of the universe itself must ultimately repeat.

Of course, "ultimately" is a pretty long time horizon: if you think the number below is big, that's what we got with only 256 jellyfish. The total number of "jellyfish" needed to describe the universe is going to be something like 10^245, and so the number of moves it would take would be unimaginably huge.

But if this repetition is real, then it has some very interesting consequences. For example, it's one way to explain why we happen to observe physical constants in our universe that are consistent with the existence of human life. [5] If those "constants" are actually controlled by the state of the universe, and the universe ultimately steps through all possible states, then it isn't surprising that we'll look out the window and see the constants that we could survive in; when the universe was in all of those other possible states, we weren't around to see it.

If, on the other hand, the universe has infinitely many states in it, then no recurrence need ever happen; it can keep changing indefinitely, and the entire argument above falls apart. This is one of the very few times that "finite but very big" and "infinite" are meaningfully different in physics.

This sort of analysis is called an "anthropic" analysis, and while it seems unsatisfying in some ways -- it doesn't explain the values of the constants, after all, or tell us what other constants might allow us to exist, it just tells us why they happen to be that right now -- it's a real possibility that this is what's actually going on. The entire debate over this, whether these recurrences (they're called Poincaré Recurrences, after the French mathematician who first described the math above) occur in nature and whether Anthropy is an explanation for the world, is a major open question in fundamental physics today.

So whether the jellyfish are moving in an animated GIF or powering the basic laws of physics, remember this: Finite patterns must always repeat; infinite patterns don't have to.

And now, you may return to staring at the GIF to your heart's content.

[1] Circulating uncredited, mind you. Wavegrower's work can be found at wavegrower.tumblr.com, and is full of great math images like these. Those who like such things can also find some great ones at beesandbombs.tumblr.com. Thanks to +Don Yang for finding the original!

[2] Actually, for this picture we can prove that every state repeats, but the math gets a lot more serious. You can check out this post if you want to know more:
https://plus.google.com/+YonatanZunger/posts/h7aaNSANgVq
Among the things proved in that discussion was that if you have a system with finitely many states, and the rule that maps one state onto the next state is reversible -- that is, you can always tell from any state what the previous state must have been -- then every state is periodic and will repeat infinitely many times.

[3] If you want to be precise about it, it's 857,817,775,342,842,654,119,082,271,681,232,625,157,781,520,279,485,619,859,655,650,377,269,452,553,147,589,377,440,291,360,451,408,450,375,885,342,336,584,306,157,196,834,693,696,475,322,289,288,497,426,025,679,637,332,563,368,786,442,675,207,626,794,560,187,968,867,971,521,143,307,702,077,526,646,451,464,709,187,326,100,832,876,325,702,818,980,773,671,781,454,170,250,523,018,608,495,319,068,138,257,481,070,252,817,559,459,476,987,034,665,712,738,139,286,205,234,756,808,218,860,701,203,611,083,152,093,501,947,437,109,101,726,968,262,861,606,263,662,435,022,840,944,191,408,424,615,936,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,001 steps.

[4] You may have heard something about "quantum randomness," but this isn't actually randomness; the actual evolution of wave functions is completely, 100%, deterministic, even in quantum mechanics.

[5] The Standard Model of particle physics is controlled by about 20 basic constants, like the mass of the electron and the strength of gravity. Our world is weirdly sensitive to some of them: if the down quark were 10% heavier, say, then stars would never form, and neither would nearly any other kind of matter. What controls these 20 values? Good question. We don't know yet.
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希望有中文版,關於粒子運動模式/隨機與不隨機性,它的內容頗有趣…
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Hian-Kun Tenn

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黨主席裁示教育部。
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國民黨中常會今天下午聽取教育部長吳思華專題報告「課綱微調爭議及後續處理情形」,黨主席朱立倫最後裁示時,要教育部依據8月4日立法院朝野協商結論,立刻展開12年國教綱改寫,在教育中立法的基礎,或是未來訂定教育中立法的原則上,好好訂定課綱,化解所有存在的爭議。朱立倫強調,國民黨從一開始立場,就是堅持在法律基礎上,尊重教育,尊重所有專家、史實,希望教育部秉持原則,呈現多元包容史觀,而8月4日立院朝野協商結論,就是國民黨的立場。
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Hian-Kun Tenn

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昨天因為突然連不上 Google,改用 DuckDuckGo,比印象中上次的使用經驗好很多。

先認真使用一陣子,看看結果如何…
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我都用來搜尋比較多。資料量雖然比不上google,但是至少不會一言堂。
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一時好奇去 google 了一下,還以為看到偽基百科:

林智賢(1969年3月8日-),應該是好萊塢回來的不紅路人。善於模仿及模仿還有模仿跟模仿,代表人物是吳宗憲吳宗憲還有吳宗憲;

XDDD
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我以為我的婦產科醫師什麼時候變成藝人了....
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Hian-Kun Tenn

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重點:環境與人際連結才是核心。

看著這演講的過程,我不斷地想到死刑的問題。
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上癮的原因是什麼 - 包括從古柯鹼到智慧型手機之類的一切,我們該怎麼克服它?約翰海利從他最愛的人身上,觀察到現有的方式為何會失敗。他開始思考為什麼我們這麼對待癮君子,同時也開始思考另一種更好的方法。在這個深刻私人的演講中,他的疑問帶領著他走遍了世界,並且找到了一些令人驚喜並充滿希望的思考方式來面對這個古老的問題。
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最左邊加一。
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附和!
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引用內文:
在畫作損毀的當下,ROSSI第一時間是先安慰那個嚇傻的小男童,並透過翻譯開玩笑的說“現在你是唯一親手碰過真跡的人”。

我突然想起 YouTube 的新聞影片下方,那些幸災樂禍,甚至咒罵闖禍者的留言。
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目前正在“手術中”的畫作 (圖片由主辦單位提供) 今天有個不大不小的新聞,就是“真相達文西特展”中一幅保羅波爾波拉(
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引用內文:

警鴿故事停滯了非常長的一段時間,事實上我一直在想我到底要走什麼方向和路線而無法下筆。

我不是官媒,也不是警察,我是暴民,每次光是要從什麼角度切入、切什麼議題,都讓我苦惱,但我會繼續照著我自己的想法做下去,這是我的故事,無可取代也無從複製。

我從來都不說床邊故事,溫柔與夢幻在我這裡找不到,我會告訴你什麼是現實和真人真事。

果然是有靈魂的創作者。
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警鴿故事91
「COVER」
∆本系列故事皆為虛構,如有巧合純屬雷同。

警鴿故事停滯了非常長的一段時間,事實上我一直在想我到底要走什麼方向和路線而無法下筆。
我不是官媒,也不是警察,我是暴民,每次光是要從什麼角度切入、切什麼議題,都讓我苦惱,但我會繼續照著我自己的想法做下去,這是我的故事,無可取代也無從複製。
我從來都不說床邊故事,溫柔與夢幻在我這裡找不到,我會告訴你什麼是現實和真人真事。
(Line貼圖)
蠢羊與奇怪生物
https://store.line.me/stickershop/product/1113494/zh-Hant
鴿是傳說
https://store.line.me/stickershop/product/1117222/zh-Hant
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Poor drones (see the video links in the post).

Actually, I worried about the attacking animals which might be injured due to the hight speed rotors.

Another one taken down and examined by chimps... XD
https://www.youtube.com/watch?v=Z_zw8h4epQM
 
Watch this majestic eagle swoop in and take down a drone http://cnet.co/1UDYFKt
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I love comic, programming, and reading.
Introduction
I am an engineer of itri.org.tw. Although my major works were about UAV when I was in school, I am now working on HCI (human-computer interface/interaction), especially on the vision based applications.

My hobbies include flying R/C helicopters, viewing and drawing comic, keeping fishes, reading novels, ..., and the list are growing. :-p

Programming is another interesting thing to me. Python is my favorite. I always appreciate the contributors who devote to open source software and tools.
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