8大未解神秘起源

文章来自http://www.sciam.com.cn/html/translate/2009/0828/5919.html

1、流感的季节性

                               
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    在温带，流感和寒冷天气总是如影相随：在北半球，流感高发期是在11月份至次年的4月。但流感病毒自身的活动却没有“周期性”，它们在一年中任何时候都可以在人群间传播。在热带，流感病毒的传播几乎没有季节性，而且在温度较高的月份，还可能产生新的流感病毒，比如今年出现的HINI。

    目前，科学家已提出很多种可能原因，来解释为什么一年中，流感病毒在某些月份更易在人群间传播。寒冷、干燥的空气有助于流感病毒在地表生存，而缺乏维生素D（人体内维生素D的含量与阳光照射量有关，在冬天，阳光照射量偏少），人们的免疫能力就会有所下降，给流感病毒有机可乘。另外，如果天气过于寒冷，人们喜欢聚集在屋里、学校或办公室，更有助于流感病毒的人际传播。房间内的加热系统（如中央空调）也与流感传播有关：一旦有病人咳嗽，他咳出的带有病毒的气溶胶能很快传播到其他房间。

    上述原因听起来都很合理，但实际上，几乎没有相关研究来支持甚至反对这些“假说”。在2007年的“流感季”，美国塔夫斯大学的埃里克 劳夫格伦发表一篇综述，他们认为，流感病毒呈季节性传播的原因很可能是多种因素共同作用的结果。(环球科学编译 褚波）

英文原文：

THE SEASONALITY OF FLU

Influenza and cold weather go hand in hand in temperate zones: In the Northern Hemisphere the flu season typically begins in November and runs to April. But flu viruses themselves circulate year-round. They show little seasonality in the tropics, and new strains can emerge during the warmer months, as the H1N1 swine flu did this year.

Researchers have come up with many possible reasons to explain why nonpandemic flu viruses take hold only at certain times of the year. Cool, dry air seems to help the virus survive on surfaces. Lack of vitamin D, the sunshine vitamin, may leave the immune systems of people weaker during winter, perhaps paving the way for infections. In chilly weather, too, people tend to stay indoors and crowd together in schools and offices, boosting the odds of person-to-person transmission. Indoor heating systems could also play a role, transporting coughed aerosols to distant areas of buildings.

The reasons sound plausible, but little research has actually gone into supporting or rejecting the theories. In a 2007 review on influenza seasonality, Eric Lofgren of the Tufts University School of Medicine and his colleagues wrote that seasonality is likely to be the result of "less-than-straightforward interaction of many different factors."

2、高温超导的起源

                               
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    上世纪80年代中后期，物理学家在对铜氧化物研究时发现了一个令人叹为观止的电学特性。该材料在液氮温度（77K，-196℃）下出现了超导现象。而在此之前，其他超导材料的工作温度都在绝对零度（0K，-273℃）附近。图中所示为一块磁体漂浮在与它极性相反的强磁场中，而这个磁场是由液氮降温的铜氧化物超导体产生的。

    由于铜氧化物超导转变温度（transition temperature）相对较高，它也因此掀起了超导领域的一场革命，促使物理学家重新审视已经被接受的超导理论——BCS理论。BCS理论指出，当电子对形成的时候，就会有超导电流产生。一个电子从物质中间穿过的时候，就会轻微地拉动该物质带正电荷的晶格，它后方的正电荷密度就轻微提高了，这个正电荷密度增大的区域就可以吸引另一个电子的到来。这样一来，这种所谓的“库珀电子对”的联系就变得较弱，不计其数的库珀对就可以没有能量损失地流过晶格。不过，BCS理论还预测，一旦温度超过39K，周围的热量就会导致晶格振动过于剧烈，破坏库珀对的稳定性。

     在高压环境中，铜氧化物甚至可以在164K的温度下进行超导，远远超过了BCS理论39K的极限，因此超导必须一个新的理论来支撑。而铁基超导材料（超导转变温度也远高于绝对零度，但低于铜氧化物）的发现，或许能为破解高温超导之谜带来新的希望。(环球科学编译 申宁馨）


英文原文：


HIGH-TEMPERATURE SUPERCONDUCTIVITY


In the late 1980s physicists were astounded by the electrical behavior of ceramic compounds based on copper oxides. These materials could conduct electricity without resistance well above the temperature of liquid nitrogen (77 kelvins, or –196 degrees Celsius). Previously, superconductivity occurred only in metals cooled to near absolute zero (–273 degrees C). (The image shows a magnet levitated by the powerful magnetic field of opposite polarity generated by a copper-oxide superconductor cooled by liquid nitrogen.)


The relatively high transition temperature seen in the copper oxides revolutionized the field and forced physicists to reconsider the accepted cause of superconductivity, called the BCS theory. It posited that the supercurrent occurred when electrons paired up. One electron moving through the substance would slightly pull together the material's positively charged crystal lattice, leaving a wake of slightly denser positive charge behind it; a second electron would be attracted to this wake. In this way, these so-called Cooper pairs of electrons became weakly bound together, and a sea of them could flow through the lattice without losing energy. But the theory also predicted that, above about 30 K, ambient heat would cause the lattice to vibrate too much, destabilizing the Cooper pairs.


The copper oxides, which can superconduct at temperatures reaching 164 K under the right circumstances, clearly indicated that a new theory was needed. Cooper pairs were still being formed, but just what brought and kept them together has eluded definitive explanation. The discovery of iron-based superconductors, which also function well above absolute zero but below the copper oxides, could provide some essential clues.

3、语言

                               
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    当600万年前人类和黑猩猩从同一祖先沿不同分支向前发展时，我们人类就开始发展出说话的能力——传播八卦、争吵、抱怨以及装腔作势。然而由于诸如声带、喉、舌头、小舌以及大脑这样的软组织并没能保留在化石当中，所以我们的祖先究竟是在什么时候进化出说话的能力，以及经过多长时间这种能力才最终被人类掌握，我们不得而知。


    其他动物也会交流——土拨鼠警觉的叫声是在警告其他伙伴周围有捕食者；饥饿的猫喵喵地叫是告诉它的主人赶紧把食物放下来给它吃。然而这些动物的“语言”都没有语法，也缺少复杂性。婴儿是如何掌握语言能力的？这一争论从未停歇，然而至今也没有明确答案。或许正如诺姆·乔姆斯基所说，人类天生就具有“万能语法”，抑或语言是我们大脑处理信息的一部分。


    在乔姆斯基的著作《第一个词语：追寻语言的起源》中，她问几个主要研究人员一个问题：如果将婴儿放在一个孤单上生长，它们还能否发展出语言能力？几乎所有人都认为，婴儿会发展出一些交流形式，但是不会形成一套完整“正常的”语言体系。（环球科学编译 曹丽敏）


英文原文：


LANGUAGE


At some point after chimpanzees and humans diverged from a common ancestor six million years ago, we developed the capacity to talk—and to gossip, argue, complain and pontificate. But because soft tissue like the vocal cords, larynx, tongue, uvula and brain are not preserved in the fossil record, we don't know when our ancestors evolved the physical capacity to make speech or how long it took to develop.


Other animals can communicate—the alarm calls of prairie dogs to warn of a nearby predator, say, or the meowing of a hungry cat to tell its owner to put food down. But they lack the complexity and grammar of language. And how babies develop the capacity has been thoroughly debated without clear resolution. Maybe humans have an inborn "universal grammar," as Noam Chomsky asserts, or maybe it emerges as part of the general processing of our big brains and the surrounding culture.


In her book, The First Word: The Search for the Origins of Languages (Viking 2007), Christine Kenneally asked several key researchers if a boatload of babies landed on a desert island, would they develop language? Almost all agreed that they would develop some form of communication, but they disagreed if a fully formed, "normal"  language would emerge.

4、物质战胜反物质

                               
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    我们在对称中发现美，但如果不是一个关键的不对称，我们都不可能有机会来欣赏这些美好事物。在粒子碰撞和量子过程中，反物质和普通物质一样，经常被产生出来。事实上，大爆炸产生的物质和反物质数量应该相等——这可不是一件好事，因为每一块反物质都会毁灭等量的物质。因此，大爆炸应该产生一个只有光和能量的宇宙，不存在任何固体、液体和气体。

       有可能大爆炸确实创造了足够多的反物质，它们形成了反恒星、反行星、反星系等等，只不过它们存在于宇宙中与我们隔离的另外一块区域。不过几十年来的深空观测表明，这样的可能性极小。

       因此，一定发生了某种不对称，让宇宙的演化朝着物质一方倾斜。这种倾斜并不过分——每出现10亿个粒子－反粒子对才会多出一个物质粒子。研究人员已经在物质和反物质的性质之间发现了一种不对称，称之为电荷宇称不守恒，可能已经让事物的演化偏向了我们的物质世界这一边。不过，要把这种微小的偏差转化为过剩的物质，原始宇宙必须经历一段环境极不平衡的错乱时期，现在还没人知道这一过程是如何发生的。（环球科学编译 虞骏）


英文原文：


ATTER OVER ANTIMATTER


We find beauty in symmetry, but without a key piece of asymmetry, we wouldn't be around to appreciate the finer things. In the realm of particle collisions and quantum processes, antimatter is produced as often as ordinary matter. In fact, the big bang should have produced equal amounts of both—not a good thing, because each piece of antimatter would destroy an equal amount of matter. The big bang should thus have created universe of only light and energy, free of any solids, liquids or gases.

It's possible that the big bang did indeed create enough antimatter to create anti-suns, anti-planets, anti-galaxies and the like, and that they exist somewhere in separate pockets of the universe. But decades of observations of deep space make that possibility seem unlikely.

So, some sort of asymmetry occurred that skewed the universe's evolution toward matter. It would not have taken much—just one extra matter particle for every billion particle-antiparticle pairs. Researchers have discovered an asymmetry between the behavior of matter and of antimatter, called charge–parity violation, which could have skewed things to our side of the material world. But for this subtle bias to translate into an excess of matter, the primordial universe would have had to go through a wrenching period of imbalanced conditions, and so far no one knows how that might have happened.

5、超高能宇宙线

                               
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       通常我们认为，亚原子粒子是微小而无害的。但在1991年10月15日，天文学家发现，一颗击中地球大气层的粒子携带的能量，竟然跟砸到你脚面上的保龄球不相上下。从那时起到现在，一共有好几十颗如此“强悍”的粒子击中地球。不管是什么东西发射了这些粒子，与它们相比，世界上最强大的粒子加速器——大型强子对撞机与它们相比，简直就像是孩子手里的玩具枪。甚至连一颗超新星爆炸都无法完成这样的粒子加速任务，无论如何，如此高能的粒子应该会在传播过程中损失能量。

       因此，已经有物理学家推测，它们可能涉及到物质的奇异形态及已知物理规律的失效。不过2年前，阿根廷西部的Pierre Auger宇宙线观测站发现，这些粒子似乎来源于邻近星系。那些星系中的超大黑洞或超级超新星能够产生激波，给这些粒子狠狠“踢上一脚”，而且它们距离我们足够近，粒子还不至于损失太多能量。不过，具体细节仍然不明。（环球科学编译 虞骏）

英文原文：

ULTRAHIGH-ENERGY COSMIC RAYS

Normally we think of subatomic particles as small and innocuous. But on October 15, 1991, astronomers saw a particle strike Earth's atmosphere with the energy of a bowling ball dropped onto your foot. Several dozen others have hit us since then. Whatever shoots them out makes the Large Hadron Collider, the world's most powerful particle accelerator, look like a pop gun. Not even a supernova explosion is up to the task and, anyhow, particles of such potency should lose their energy in transit.

So physicists have speculated about exotic forms of matter and failures of the known laws of physics. But two years ago the Pierre Auger Cosmic Ray Observatory in western Argentina found that the particles appear to come from nearby galaxies. Giant black holes or super-supernovae in those galaxies could set off shock waves that give the particles a good kick, and they are close enough for the particles to retain most of their energy. The details, though, remain sketchy. —George Musser

6、左右手使用习惯

                               
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    通常有机分子的中心是一个碳原子，这个碳原子与其他4个原子或者原子团相连。如果至少有两个这样的原子（或者原子团）是一样的，那么这一结构就是镜像对称，它的镜像就是它自己。如果这4个原子各不相同，这一分子就不对称，它就会形成截然不同的两个形态，就像我们的左右手。通常来讲，这些不同的形态具有相同的化学机制，然而地球上的生命都只使用其中一个。这并不难理解：形态对于生化反应来说至关重要，不同形态的个体要提供两种截然不同的镜像，这对于大脑来说太复杂了。


    那么为什么地球上的生命会选择其中之一呢？有些人认为这只是几率问题，但也有人认为，这种选择是我们追寻生命起源的一个线索。水晶能够将这两种形态分开，那么或许水晶可以为我们研究原始生命提供一个支架。抑或生命的架构来自于外星世界，不同形态是由偏振光筛选出来的。（环球科学编译 曹丽敏）

英文原文：

HANDEDNESS

Organic molecules are commonly built around a carbon atom attached to four other atoms or groups of atoms. When at least two of these atoms (or groups of atoms) are the same, the structure is mirror-symmetric; its mirror image is itself, only rotated. When all four are different, however, the molecule lacks this symmetry; it comes in two distinct varieties, like your hands. In general these varieties behave the same chemically, yet life on our planet uses only one of them. That, in itself, is not mysterious: shapes are crucial in biochemical reactions and providing for both mirror images might have been too complicated.

Yet why did life choose the variety it did? Some think it was mere chance, but others think the choice is a clue to the origin of life. Perhaps crystals, which can separate the two varieties, provided a scaffolding for protolife, or perhaps the building blocks of life came from outer space, where polarized starlight had sifted out the varieties. —George Musser

7、性别的起源

                               
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    性别为什么会存在？换句话说，男性为什么会存在？若不是Y染色体（Y染色体只包含数十个基因，而X染色体则包含2,000到3,000个基因）引起了男性特征，所有的人类胚胎都将成为按一个固定默认的发展，最后都变成女性。


    最早的生命都是无性繁殖的，但是，至少在10亿年前，性别就出现了。今天，我们很难找到一种多细胞机体不是有性繁殖的。当然，有些生物同时具备两种生殖方式，比如生长在印度尼西亚科莫多岛巨蜥（Komodo dragon）就具备单性生殖能力。但是，性别是如何产生、进化并一直延续下来，其中的原理还没有完全破译。如果所有生命都是平等的，那么无性生殖的生物的发展肯定要快过与其竞争的有性生殖的生命，直至这些有性生殖生命灭绝。因为，无性生殖的生命不需要花费时间来和能量来寻找伴侣，并设计出更好的方法来吸引异性。


    幸亏所有生物并非完全平等，有性生殖的生物要在生存竞争中活下来，就必须具备更高的适应性。毫无疑问，有性生殖可以更好地混合基因库，但是目前科学家还不清楚这些混合是如何进化出适应性的。也许这种混合在清除或者屏蔽基因突变方面比无性生殖的生物更强，而这些被屏蔽的突变中的绝大部分都是有害的。或者，性别使机体具备具备防御基因，因此可以更好的避免寄生虫以及它们带来的疾病。(环球科学编译 申宁馨）

英文原文：

SEX

Or put another way, why do males exist? Were it not for the maleness program set off by that scrub of a chromosome called Y (it contains a few dozen genes, compared with the X chromosome's 2,000 to 3,000), all human embryos would proceed down a default developmental path and become female.

The earliest life reproduced asexually, but at least one billion years ago, sex emerged. Today, it would be hard to find a multicellular organism that does not reproduce sexually (although some can reproduce both ways, like the Komodo dragon and its parthenogenic ability). But why sex evolved and persists is not entirely clear. All things being equal, a group of clonal reproducers should proliferate faster than competing sex mavens and drive them extinct. After all, asexuals don't have to spend time and precious energy looking for mates and thinking up better witticisms than, "Come here often?"

Thankfully for sexual creatures, all things are not equal—and considering how wildly successful it is, sex must be highly adaptive. Certainly, sex efficiently mixes the gene pool, but just how that mixing improves evolutionary fitness is not entirely clear. Perhaps it weeds out or masks mutations, most of which are deleterious, better than cloning does. Or maybe sex equips organisms with defensive genes to better fend off parasites and the diseases they bring.

8、质子自转

                               
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       质子有一个属性叫做自旋，这一量子物理量对应到我们日常生活中，就是人们更为熟悉的旋转。不过，质子自旋不同于陀螺自转，它决定着质子和其他粒子之间的磁相互作用，正是这一性质让磁共振成像技术（MRI）得以实现。

    质子自旋的大小总是相同的，按归惯例被设定为1/2。为了理解这一点，你可以认为质子的自旋直接来源于构成质子的三个夸克：两个上夸克（每个自旋为1/2）和一个下夸克（自旋–1/2，因为它的自旋指向相反方向）。把这些夸克的自旋加在一起，就得到了质子自旋1/2。与此类似，中子自旋也可以通过类似方式相加得到（中子由一个上夸克和两个下夸克构成）。

       不过，粒子加速器实验证明，上面这种简单的说法是错误的。20世纪80年代，物理学家用高能电子和其他粒子来撞击质子并反弹回来；这些粒子的偏转角指明了每个质子内部的自旋。这些实验证明，夸克自旋最多只占质子自旋的30%。为了解决这一“自旋危机”，物理学家开始检验其他可以产生自旋的因素，比如将压克粘在一起的胶子、夸克在质子内部的轨道运动，以及瞬间出现的虚夸克等。多亏了几年来的实验和计算，许多线索正变得越来越清晰，但物理学家仍然无法完全解释质子自旋从何而来。（环球科学编译 虞骏）

英文原文：

PROTON SPIN

Protons have a property known as spin, a quantum physics counterpart to the more familiar, everyday kind of rotation. But unlike the spin of a top, proton spin governs the magnetic interactions between protons and other particles, a property that permits magnetic-resonance imaging (MRI).

The magnitude of a proton's spin is always the same and is conventionally set to be 1/2. To account for that, one might think that the spin came solely from the three quarks that make up the proton: two up quarks (1/2 spin each) and one down quark (–1/2, because its spin points in the opposite direction). Totaling those quark spins yields the proton's spin of 1/2. Similarly, the spin of the neutron (one up, two down quarks) could be summed in a similar fashion.

But particle accelerator experiments disproved that simple picture. In the 1980s physicists bounced energetic electrons and other particles off protons; measuring their deflection indicated the spins inside each proton. The experiments showed that quark spins make up less than 30 percent of the proton's spin. To resolve this "spin crisis," physicists began examining other factors that can contribute to spin, such as the gluons that hold quarks together, the orbital motion of the quarks inside the proton, and the momentary appearance of virtual quarks. Many features are becoming clearer thanks to years of experiments and calculations, but physicists still have not completely accounted for protonic spin.

看一下，好奇中.............

这些。。。。不好说！
应该说不好解释！

好啊，我没法解答

8、质子自转

       质子有一个属性叫做自旋，这一量子物理量对应到我们日常生活中，就是人们更为熟悉的旋转。不过，质子自旋不同于陀螺自转，它决定着质子和其他粒子之间的磁相互作用，正是这一性质让磁共振成像技术（MRI）得以实现。

    质子自旋的大小总是相同的，按归惯例被设定为1/2。为了理解这一点，你可以认为质子的自旋直接来源于构成质子的三个夸克：两个上夸克（每个自旋为1/2）和一个下夸克（自旋–1/2，因为它的自旋指向相反方向）。把这些夸克的自旋加在一起，就得到了质子自旋1/2。与此类似，中子自旋也可以通过类似方式相加得到（中子由一个上夸克和两个下夸克构成）。

       不过，粒子加速器实验证明，上面这种简单的说法是错误的。20世纪80年代，物理学家用高能电子和其他粒子来撞击质子并反弹回来；这些粒子的偏转角指明了每个质子内部的自旋。这些实验证明，夸克自旋最多只占质子自旋的30%。为了解决这一“自旋危机”，物理学家开始检验其他可以产生自旋的因素，比如将压克粘在一起的胶子、夸克在质子内部的轨道运动，以及瞬间出现的虚夸克等。多亏了几年来的实验和计算，许多线索正变得越来越清晰，但物理学家仍然无法完全解释质子自旋从何而来。东写西涂 发表于 2010-5-23 09:50

                               
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不管怎么说，在讲微观粒子的自旋时还是喜欢用自转/旋转类比，这里连标题都直接用自转了。深层次的物理现象和实际生活相差太远，当在实际生活中找不到对应，再聪明的物理学家也只能如此了，反复的使用不伦不类的比喻。

是啊，宇宙如此之大，什么奇妙的事都有可能发生。虽然有些不能解释，但我们还是应该以科学的角度出发。