The Great Filter 大筛选——我们在其中走了多远？[中英对照翻译]-推荐下载

【注1：文中出现的中括号指的是引用的其他作者的言论，中括号中内容是作者名字及文章发表年代】
【注2：文中小括号是原文带括号的内容，黑括号是本人自己做的注释】
The Great Filter - Are We Almost Past It?
大筛选【大过滤】——我们在其中走了多远？【这个翻译是最符合文中意思的】
Sept. 15, 1998
1998年9月15日
by Robin Hanson
Robin Hanson著
Humanity seems to have a bright future, i.e., a non-trivial chance of expanding to fill the universe with lasting life. But the fact that space near us seems dead now tells us that any given piece of dead matter faces an astronomically low chance of begating such a future. There thus exists a great filter between death and expanding lasting life, and humanity faces the ominous question: how far along this filter are we?
人类似乎有着光明的未来，这里对“光明未来”的定义是：有着不错的机会（而非渺茫的机会）不断扩张到整个宇宙并永续文明。

但事实是，我们附近的宇宙一片死寂。

这事实告诉我们，从无生命的物质进化出生命并走向这样的光明未来的几率是如此之低。

在无生命与持续扩张的生命之间存在着这样一张大的筛网，而人类也面临着一个严峻的问题：我们在这场大筛选中已经走了多远？
Combining standard stories of biologists, astronomers, physicists, and social scientists would lead us to expect a much smaller filter than we observe. Thus one of these stories must be wrong. To find out who is wrong, and to inform our choices, we should study and reconsider all these areas. For example, we should seek evidence of extraterrestrials, such as via signals, fossils, or astronomy. But contrary to common expectations, evidence of extraterrestrials is likely bad (though valuable) news. The easier it was for life to evolve to our stage, the bleaker our future chances probably are.
结合生物学家、天文学家、物理学家和社会学家们提出的标准，我们观察到的筛选应该并没那么严苛。

因此应该至少有一个标准是错的。

为了找出哪出错了并为我们的选择提供更多信息，我们应该重新审视每一个领域。

比如说，我们可以通过信号、化石或天文发现等手段去寻找地外生命存在的证据。

但与人们普遍的期望完全相反，发现地外生命的存在可能是坏消息（即使是很有用的消息）。

如果生命越容易进化到我们这个层次，我们的未来前景就越暗淡。

【应该简单理解成“地外文明的存在尤其是等于或高于我们文明等级的文明存在，将占据人类文明未来的生存空间，阻碍人类向宇宙中的扩张”。

】
Introduction
绪论
Fermi, Dyson, Hart, Tipler, and others [Finney & Jones, Dyson 66, Hart 75, Tipler 80] have highlighted the relevance to SETI (the search for extraterrestrial intelligence) of the "The Great Silence" [Brin 83] (also known as the Fermi paradox), the fact that extraterrestrials haven't substantially colonized Earth yet. What has not yet been sufficiently highlighted or adequately analyzed, however, is the relevance of this fact for much bigger choices we now make.
Fermi，Dyson，Hart，Tipler等人都高度重视SETI（地外智慧生物搜寻【组织名，也指寻
找外星人的这项活动】）与“大寂静”的关联（也叫费米悖论），即为什么还没有外星人实
质地接触地球。

而还没有引起人们足够重视或充分分析过的方面是，这一事实与人类文明
将面临的重大选择之间的联系。

【即人类将走向何方？人类现在选择的道路能否挺过大筛选？还是最终逐渐走向自我灭亡？】
The Great Silence must force us to revise a standard view in one or more area of biology, astronomy, physics, or the social sciences. And some of these revisions strongly suggest that humanity be much more wary of possible disasters. To clarify these points, this paper will first review how our standard understandings in these areas would lead us not to expect a Great Silence, and will then consider a variety of possible revisions we might consider.
“大寂静”的事实强迫我们对生物学、天文学、物理学和社会学中的一个或多个领域的标
准观进行修正。

有些修正会强调对于潜藏的大灾变的警惕。

为了解释清楚这些观点，本文
会先检视一遍这些领域里现有的标准观能否导向一条避免“大寂静”的路径，然后提出一
些可供考虑的修正方案。

Life Will Colonize
生命的本能是扩张【三体2中提出的宇宙文明公理：文明不断增长和扩张】
So far, life on earth seems to have adapted its technology to fill every ecological niche it could. Previously stable populations and species have consistently expanded into newly-opened frontiers. All known life seems to have a "dispersal phase" to encourage colonization, with non-trivial mutations and sexual mixing to encourage exploration of new technologies [Tipler 80].
到目前为止，生命已经通过自己的适应调整能力占满了地球上每一个能被占据的生态位。

【楼主正解】已有的稳定的物种和种群会不断向新的疆域扩张，直至其数量与生存空间再
次达到平衡。

所有已知生命物种都有一个“扩张阶段”，这一过程中会出现重大的变异、重组来获得更强的生存能力。

Similarly, humanity has continued to advance technologically, and to fill new geographic and economic niches as they become technologically feasible. For example, while imperial China closed itself to exploration for a time, other competing peoples, such as in Europe, eventually filled the gap.
相似地，人类也在不断进化【生理方面和科技方面】，并随着不断提高的适应力和科技水平不断填充新的“地理位”和“经济位”【即地理上的和经济上的生存空间】。

举个例子，当年中华帝国【清政府】选择了闭关锁国，一段时间后，其他的竞争者如欧洲人，逐渐占据了这些生存空间。

This phenomenon is easily understood from an evolutionary perspective. In general, it only takes a few individuals of one species to try to fill an ecological niche, even if all other life is uninterested. And mutations that encourage such trials can be richly rewarded. Similarly, we expect internally-competitive populations of our surviving descendants to continue to advance technologically, and to fill new niches as they become technologically and economically feasible.
这一现象很容易用进化论的观点解释。

总的来说，要试图填充一个生态位只需要一个种群中的几个个体就足够了，即使没有其他任何生物物种一起来填充。

而基因突变将为这种尝试带来巨大的有利因素。

相似地，我们可以预期未来的人类后代也会在内部竞争的推动下继续发展科技，并在科技和生态条件的允许下填充新的“位”。

Colonization has been a consistent experience with life on Earth over the long run, and our best understanding of human social systems suggests this will continue. While humans evolve within complex co-evolving organizational, cultural, memetic, and genetic systems, all of these systems show long-term tendencies to make use of reproductively-useful resources.
殖民扩张是地球生命长期以来一直延续的行为，而基于我们对人类社会系统发展的理解，这样的趋势仍然会继续下去。

随着人类的进化发展而演化出来的复杂的组织结构、文化、模因以及基因遗传系统，都会显示出利用对繁衍有利的资源的长期趋势。

Thus we should expect that, when such space travel is possible, some of our descendants will try to colonize first the planets, then the stars, and then other galaxies. And we should expect such expansion even when most our descendants are content to navel-gaze, fear competition from colonists [Benford 81], fear contact with aliens, or want to preserve the universe in its natural state. At least we should expect this as long as a society is internally-competitive enough to allow many members to have and act on alternative views. After all, even navel-gazing virtual reality addicts will likely want more and more mass and energy (really negentroy) to build and run better computers, and should want to spread out to mitigate local disasters [Zuckerman 85]. A million years is a cosmologically short period, yet it is much more than enough for historic population growth rates (> .001%/yr.) to overwhelm fundamental physical limits on the amount of computation possible within the observable universe [Zaslavskii 96]. This remains true even using black holes for negentropy and quantum computers for computation, each of which squares the available resources relative to standard approaches. Thus we have good reasons to expect unused resources to be colonized on cosmological time scales, even if we find other civilizations to communicate with or to "teleport to" [Scheffer 94].
因此我们可以预期，只要宇航条件允许，我们的后代一定会试图向外进行殖民扩张，首先征服其他行星，然后是其他恒星，再然后是其他星系。

这个预期是有理由的，即使我们的后代大多数都满足于地球上这狭促的空间，害怕殖民者之间的竞争，害怕与外星人接触，
或者想保持宇宙原本的样子。

但只要这个社会的内部竞争是足够的并能够允许大量的成员产生不同的想法并付诸实践，那这种期望就是可能实现的。

毕竟，即便那些沉迷于网络虚拟现实的非常眼光狭隘的人也需要更多的物质和能量（真正的负熵过程）来建造和运行更好的电脑，也需要迁徙以减轻区域性的灾祸带来的损失。

一百万年在宇宙尺度上是很短的一瞬，但也远远足够让人类的数量以历史平均增长速度（高于十万分之一每年）增长到超过在可观测的宇宙内的计算量的物理上限。

这还是考虑到了用黑洞的降熵作用，以及量子计算机所能达到的计算量【本人的理解和楼主有些出入，不能保证正确】，这两点都分别最大化地利用了所有可能的资源。

因此我们有足够理由期待在宇宙时间尺度上【即长达数亿年的时间范围内】，人类将殖民并开发宇宙中还未被我们利用到的资源，即使我们发现了其他的外星文明并与之发生了交流。

Evolutionary theory even suggests [Hansson & Stuart 90] that competitive pressures among colonists should encourage a maximum feasible economic growth rate, as those who travel too slow, linger too long, or choose not to replicate [Stephenson 79] become outnumbered by others. Increasingly fast and high risk colonization probes may be sent on increasingly long journeys, all for a chance at being the first to colonize vast virgin territory.
进化论告诉我们，殖民者之间的竞争压力能带来可行范围内最大规模的经济增长，因为一旦谁走得慢了、犹豫太久或选择不进行扩张的，就会被其他人超越。

在不断延长的宇航旅程中将会有不断变快和高风险的殖民探测器被发射出去，一切就是为了尽早开拓那广阔的处女地。

Technically, such space colonization seems feasible, even if it is well beyond our current abilities, since even now we can envision the enabling technologies. Slow self-sufficient interstellar boats would be nearly feasible now, if we were rich enough to construct them. And fast less-than-kilogram-sized [Forward 85,87] self-reproducing [Tipler 80] nanotech-based [Drexler 92b] space-traveling machine intelligences (artificial or uploaded [Hanson 94]) seem possible within a few centuries.
技术上说，这样的宇宙殖民是可行的，即使它要求远远超过我们现在所达到的科技水平，但至少现在我们已能展望一些使能技术。

低自循环的恒星际飞船现在几乎都能实现，只要我们有足够的钱去建造。

而快速的1kg级纳米自我修复宇航机器（人工操作的或上载式传输的【这里不太确定】）在未来几百年内也能实现。

There are no obvious limits to spacecraft speed (other than lightspeed), given sufficient resources. And with full (nanotech-based) control over the atomic structure of matter [Drexler 92a], colonists should mainly be interested in the atoms and negentroy they can extract from a colonization site [Dyson 66,79], and the convenience of its location.
宇宙飞船的速度似乎也没有明显的限制（除光速外），只要有足够的能源驱动就行。

况且，有了对物质的原子结构的（纳米级）完全控制能力，殖民者对殖民地的要求只需要能提供原子和降熵过程的条件就行，当然，也要考虑到到达其方位的便捷程度。

The Data Point
数据点【即预测出数据变化曲线并给出数据发生重大变化的关键点】
Within the next million years (at most) therefore, our descendants seem to have a foreseeable (greater than one in a thousand) chance of reaching an "explosive" point, where they expand outward at near the speed of light to colonize our galaxy, and then the universe, easily overpowering any less developed life in the way. FTL (faster than light) travel would imply even faster expansion.
至多在未来一百万年内，我们的后代将有可能（大于千分之一）到达一个“爆炸”点，届时人类将以接近光速的速度殖民整个银河系，然后是整个宇宙，并在这过程中征服所有低技术文明。

FTL（超光速）旅行如果可能，那么殖民的速度将会更加迅速。

We expect such an explosion to fill most every available niche containing usable mass or negentroy resources. And even if the most valuable resources are between the stars or at galactic centers, we expect some of our descendants to make use of most all the matter and energy resources they can economically reach, including those in "backwater" solar systems like ours and those near us.
我们预测，这次爆炸式扩张将填满所有以有用物质或负熵过程为资源的生态位。

而且，即使大部分可用的资源都存于恒星之间或银河的中心，也依然会有人会考虑所有能获取到的物质和能量资源的地方，包括像太阳系附近这样边缘、荒凉的空间，只要经济条件上允许。

Once an explosion goes beyond the scale where a single disaster, such as a supernovae, could destroy it, to become a "lasting" explosion of advanced life, it should only be stopped by meeting another explosion of similarly-advanced life. After that, if disaster befalls some long-established colony, others should soon return to try again.
一旦人类文明的爆炸式扩张达到了一次大灾变——如超新星爆炸——所不能完全摧毁的程度，它就能“永恒地”作为一个高等智慧生命文明扩张下去，直到遇到另一个类似的扩张中的高等文明，才有可能停下来。

扩张停止之后，一旦有长期性的殖民地被灾祸摧毁，其他人会很快回到这里并且再度上演一次爆炸式增长。

Without FTL travel to mediate conformity, we would also not be surprised by a great diversity among the different parts of an explosion, and especially among different explosions [Hoerner 78]. We would expect, for example, different cultures, languages, and body form details. We expect much less diversity, however, regarding choices which would put a civilization or entity at a strong competitive reproductive disadvantage.
如果没有超光速旅行的技术来协调这么广阔的空间中的均衡态势，那么在这种爆炸式发展中不同地区呈现出的巨大差异就不足为奇了，尤其是不同一阶段文明的爆炸式发展。

我们可以预计这种不平衡发展将会带来不同的文化，语言以及体貌特征。

但对于整个文明或群体面对生存竞争所作出的选择上，倒是不会有太大的差异。

For example, while one can imagine predatory probes sent to search and destroy other life [Brin 83], it is harder to understand why such probes would not also aggressively colonize the systems they visited, if such colonization were cheap. Aggressive colonization would give them all the more probes to work with, and deny resources to competitors. If this colonization effort could hide its origins from those who might retaliate, what would they have to lose?
比如说，如果你能想象到用捕猎型探测器去搜寻和摧毁其他生命，那么用这样的探测器去直接武力殖民整个恒星系也就不难想象了，只要这样做的代价并不太昂贵。

这样的直接武力殖民能解放出更多的探测器去别的目的地，并且断绝其他竞争者的资源。

如果探测器能掩藏其行踪来源以避免可能的报复行动，那么殖民者们还有什么好担心的呢？
Similarly, while some groups might plausibly leave some places "fallow" as information-generating "nature preserves" [Fogg 87], it is much harder to imagine that most places would be so preserved. There should be diminishing returns to such information, and groups that use more of their resources should be at a competitive advantage. And given the vastness of space, substantial resources should be required to keep "poachers" from slipping in to colonize such a preserve.
相似地，尽管有些高尚的群体希望将某些地方像“自然保护区”一样保护起来，保持其原始形态不去干涉，只获取和研究其信息资料，但很难想象大部分地区会是这样。

这些信息资料的收益回报是递减的，这些群体要耗费大量的资源，因此必须是在竞争中的优势者。

而对于广阔的空间，还需要源源不断地投入以阻止“偷猎者”溜入保护区进行殖民行动。

Finally, we expect advanced life to substantially disturb the places it colonizes. Whenever natural systems are not ideally structured to support colonists, we expect changes to be made. And unless ideal structures always either closely mimic natural appearances or are effectively invisible, we expect advanced life to make visible changes.
最终，我们预测高等文明一定会对其殖民地产生实质性的干扰。

只要该地原始的自然系统并不能提供完美宜居的环境，改变就会发生。

而除非完美宜居的环境与自然状态看起来几乎一样，或者其对自然状态的改变完全不可见，那么我们一定能看到可视性的变化。

For example, it only takes a small amount of nuclear waste dropped into to visibly change its spectra [Whitmire & Wright 80.] And a civilization might convert enough of a star's asteroids into orbiting solar-energy collectors to collect a substantial fraction of this star's output, thereby substantially changing the star's spectral, temporal, and spatial appearances. Even more advanced colonists may disassemble stars [Criswell 85] or enclose them in Dyson spheres well within a million years of arrival. Galaxies may even be restructured wholesale [Dyson 66].
比如说，只需要少量的核废料就可以改变一个星球的光谱。

一个文明可以将小行星带变成环绕其恒星的太阳能收集器来收集其整个恒星输出功率的可观的一部分，这样就能明显地改变恒星的光谱和时空上的运行规律。

技术更高的殖民者还有可能将百万年尺度内的恒星直接拆解或用类似“戴森球”这样的结构来包裹起来。

整个银河系都有可能被重新构造。

If such advanced life had substantially colonized our planet, we would know it by now. We would also know it if they had restructured most of our solar system's asteroid belt (though much smaller colonies could be hard to detect [Papagiannis 78]). And they certainly haven't disassembled Jupiter or our sun. We should even know it if they had aggressively colonized most of the nearby stars, but left us as a "nature preserve".
如果这么高等的生命已经实质性地殖民了我们的星球，我们现在已经发现了。

哪怕他们只是改造了我们太阳系的小行星带，我们也能发现。

而他们肯定也还没有分解过我们的木星和太阳。

甚至是哪怕他们现在已经殖民了我们周围大部分恒星，而保留了太阳系作为“保护区”，那也应该是有迹可循的。

Our planet and solar system, however, don't look substantially colonized by advanced competitive life from the stars, and neither does anything else we see. To the contrary, we have had great success at explaining the behavior of our planet and solar system, nearby stars, our galaxy, and even other galaxies, via simple "dead" physical processes, rather than the complex purposeful processes of advanced life. Given how similar our galaxy looks to nearby galaxies, it would even be hard to see how our whole galaxy could be a "nature preserve" among substantially-restructured galaxies.
我们的行星和太阳系，并没有被来自星星的其他高等竞争者们殖民，我们能发现的宇宙其他地方也没有类似迹象。

相反地，我们极其成功地解释了我们的行星和太阳系、附近的行星、银河系乃至其他星系的运行规律。

这些只需要简单的几个死公式，没有任何被高等智慧有目的地干预过的迹象。

而且我们的银河系和周围的其他星系也是如此相似，我们也很难认为整个银河系都只是众多被改造过的星系中的一个“保护区”。

These considerations strongly suggest that no civilization in our past universe has reached such an "explosive" point, to become the source of a light speed expansion of thorough colonization. (That is, no civilization within the past light cone of a million years ago for us; see Technical Appendix below). Much follows from this one important data point [Hart 75, Tipler 80].
所有这些迹象都表明，我们的宇宙中还没有出现过一个文明能达到这个“爆炸点”，成为一个光速扩张的殖民之源（也就是说，在过去一百万年的光锥里还没出现过这么一个文明）。

除了这一重要数据点，“大筛选”过程中还包括很多其他的数据点
The Great Filter
大筛选
Consider our best-guess evolutionary path to an explosion which leads to visible colonization of most of the visible universe:
对于到达爆炸点并实现最终殖民整个可见宇宙的进化路径猜想，分为如下几个阶段：
The right star system (including organics)
正确的恒星系（含有有机物）
Reproductive something (e.g. RNA)
产生可自我复制的物质（如RNA）
Simple (prokaryotic) single-cell life
简单（原核）单细胞生物
Complex (archaeatic & eukaryotic) single-cell life
复杂（古生代的和真核的）单细胞生物
Sexual reproduction
有性繁殖生物
Multi-cell life
多细胞生物
Tool-using animals with big brains
能使用工具的脑容量较大的动物
Where we are now
我们现在所处的阶段
Colonization explosion
爆炸式殖民
(This list of steps is not intended to be complete.) The Great Silence implies that one or more of these steps are very improbable; there is a "Great Filter" along the path between simple dead stuff and explosive life. The vast vast majority of stuff that starts along this path never makes it. In fact, so far nothing among the billion trillion stars in our whole past universe has made it all the way along this path. (There may of course be such explosions outside our past light cone [Wesson 90].) The fact that our universe seems basically dead suggests that it is very very hard for advanced explosive lasting life to arise. And if there are other radically different paths to expanding lasting life [Shapiro & Feinberg 82], that only makes the problem worse, by implying that the filter along our path must be even larger.
（这个列表并不一定是完整的。

）“大寂静”的现实暗示我们或许这其中某些步骤是很难跨越的，在一片无生命的死寂环境与爆炸式的生命增长之间有一张巨大的筛选网。

绝大部分的生命或文明走在这条路径上却永远无法最后通过。

事实上，在过去宇宙中的数亿亿亿计的恒星都没能通过这个筛选（当然也有处在我们的光锥之外的爆炸的可能）。

我们的宇宙看起来基本上是一片死寂的这个事实，似乎是在暗示这样持续永生的文明并不存在。

如果生命还有其他大不相同的路径走向持续扩张的方向，那只能让事情更糟糕，因为这意味着在我们路径上的筛选强度更大。

Someone's Story is Wrong
有人弄错了
Biologists and others have been working hard for a long time to come up with plausible explanations for each of the evolutionary steps listed above, explanations which make each step seem not especially improbable. Plausible models have been offered of how RNA evolved to
reproduce, how simple (prokaryotic) cells grew around it, how cells became more complex (eukaryotes), how cells came together into organisms, how brains and hands evolved from simple control mechanisms, and how our brains and hands lead to tool use and scenario generation, which led us to where we are today.
生物学家和其他科学家努力了很多年并对以上提出的每个进化阶段提出了貌似合理的解释，而这些解释都让每一步进化都显得不是特别的难以逾越。

对于诸如RNA如何进化出自我
复制的能力，简单（原核）细胞如何生长出来，如何产生更复杂的（真核）细胞，细胞如何组成组织，大脑和手如何从简单的控制机制演化而来并掌握使用工具和情景生成的技能，最终达到我们如今这个进化层次，都有合乎情理的模型来演示。

Together these plausible explanations have persuaded countless teams to construct relatively high estimates of the probability that any one planet will eventually produce intelligent life such as ourselves, by estimating relatively low values for each filter term in the famous "Drake Equation" [].
总之，这些看似合理的解释已经让无数的研究小组相对高估了任意一个随机的星球都能像我们地球一样最终演化出智能生物的可能性，因为他们相对低估了“德雷克方程”中的每一个筛选因子。

Similarly, technological "optimists" have taken standard economic trends and our standard understanding of evolutionary processes to argue the plausibility of the story I gave above, that our descendants have a decent chance of colonizing our solar system and then, with increasingly fast and reliable technologies of space travel, colonizing other stars and galaxies. If so, our descendants have a foreseeable chance of reaching such an explosive point within a cosmologically short time (say a million years).
相似地，技术乐观派依据标准经济学趋势和我们对进化过程的标准理解来探讨我之前提到的故事的可能性，即我们的后代是否有机会殖民太阳系进而向附近的恒星系乃至银河系外进行扩张。

如果是这样的话，人类将很有希望在相对于宇宙尺度来说很短的时间内（比如一百万年）达到“爆炸点”。

Of course many other folks don't consider this scenario particularly "optimistic" - they prefer that our descendants choose a more stable path, less likely to "disturb the universe". But I will continue to use the word "optimistic" to describe this scenario, because even fans of stability should be concerned about the implications of humanity not living long enough or free enough to have even a one in a million chance, for example, that any descendant of ours will escape to colonize space. It would seem that any reasonably non-pessimistic scenario would include a non-trivial chance that at least some of our descendants will choose the explosive path over the next million years.
当然很多人不会认为这个情景是“乐观”的，他们更希望未来的人类走的是一条更加稳妥的道路，不要过多去“干扰宇宙”。

但我仍将用“乐观”这个词来描述人类走向殖民扩张的情景，因为即使再保守求稳的人也会担忧如下的情景的发生，即人类文明因为没有足够的时间或足够的自由，而无法发展出能够殖民宇宙的技术条件——哪怕只有一百万分之一的
机会。

而所有不算悲观的人类前景中，一定都包括了在一百万年内能让至少一部分人选择走上爆炸性扩张道路的可能性。

While all of these stories are at least minimally plausible, our main data point implies that at least one of these plausible stories is wrong -- one or more of these steps is much more improbable than it otherwise looks. If it is one of our past steps, such as the development of single-cell life, then we shouldn't expect to see such independently evolved life anywhere within billions of light years from us. But if it is a step between here and a choice to explode that is very improbable, we should fear for our future. At the very least, our potential would have to be much less than it seems. Optimism (as defined here) regarding our future is directly pitted against optimism regarding the ease of previous evolutionary steps. To the extent those successes were easy, our future failure to explode is almost certain.
尽管每个领域的分析都有一定的道理，但我们的主要数据点告诉我们至少有一个分析错了。

在大筛选中至少有一步或者更多是远比看起来要更难跨越的。

如果这一步是我们已经跨越过了的，比如单细胞生命的产生，那么我们在数十亿光年内都很难找到另一个独立进化出来的外星生命。

但如果这难以跨越的一步是在我们现在的阶段以后的，那么我们对未来的担忧就不是杞人忧天了。

至少，我们永续文明的可能性就没那么高了。

对于能跨过未来这一关的乐观和对于我们已经跨过了这一关的乐观是截然不同的。

相对于我们之前在大筛选中取得的成功的容易程度，我们未来的失败几乎是笃定的。

Note that this cause for concern has a different basis than the simple statistical arguments of Gott [Gott 93] and Leslie [Leslie 96] that all else equal we shouldn't expect many more future humans than there have been past humans. While those arguments shouldn't be ignored, their strength depends much more on the auxiliary assumptions one makes about other relevant information. In contrast, the conclusion that the Great Filter is very large is relatively insensitive to other assumptions.
值得注意的是这种担忧并不同于Gott和Leslie通过简单统计学得出的在其他条件相同的情况下未来人类并不比过去的人类能更有出息的结论。

尽管他们的讨论很重要，但是他们的贡献在于对其他相关的信息的附带分析。

相比之下，大筛选的进程是如此浩繁的结论却显得不那么重要了。

It Matters Who's Wrong
重要的是谁错了
Rational optimism regarding our future, then, is only possible to the extent we can find prior evolutionary steps which are plausibly more improbable than they look. Conversely, without such findings we must consider the possibility that we have yet to pass through a substantial part of the Great Filter. If so, then our prospects are bleak, but knowing this fact may at least help us improve our chances.
除非在我们发现之前的进化阶段其实比看起来要更难，那么理性的乐观的未来是几乎不可。