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And these rings are indicative of the crystal structure of nickel and can be explained only by invoking wavelike properties of light.
这些光圈,表明了了镍的晶体结构,而且只能通过,光线中波的特征来解释。
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If you take one of those individual grains of sodium chloride, look at it carefully, you will see the edges look like this.
如果你拿起,氯化钠晶体的一粒，仔细观察，你可以看到这样的棱角。
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And that's consistent with other things that we've seen, Remember the whole thing about the perfect crystal at zero degrees Kelvin has zero entropy It's completely ordered.
这和我们看到的其他东西自洽吗？,想想零摄氏度下的,完美晶体的熵为零,这是完全有序的。
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And at first this was done by Davidson and Germer, and they were American scientists who tried diffracting electrons from a nickel crystal.
这个实验首先是由，美国科学家Davidson和Germer完成的,他们尝试从镍晶体中衍射电子。
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And then, if you go the real sodium chloride crystal and you do this same calculation but in three-dimensions.
接下来，如果回到实际的氯化钠晶体中,你们做同样的计算,但是是在三维中。
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We looked at pressure change before, actually, in discussing the third law, the fact that the entropy goes to zero as the absolute temperature goes to zero for a pure,perfect crystal.
在讨论热力学第三定律的时候，我们讨论过压强变化,即对于纯净的完美晶体,随着温度下降到绝对零度熵也变成零。
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But look at the lattice energy, the Madelung energy component is huge which tells you that when ions form they really want to continue to glom onto one another and form that giant crystal.
看看晶格能，马德龙能很大,这告诉我们，当形成离子是,它们如果要继续的话,需要从另外一方夺取电子，形成巨大的晶体。
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Crystal is an ordered solid, as opposed to a disordered solid.
晶体是一种有序的固体，和无序固体相反。
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And what that corresponds to, if you recall, is the idea that in a perfect crystal at zero degrees Kelvin then you have no disorder at all.
如果你们能回忆起来的的话，这就意味着,绝对零度下的完美晶体,一点无序状态也没有。
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You can consider this line a one-dimensional crystal because it is ordered.
你可以考虑这一列为一维的晶体,因为它是有序的。
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It'll go to the lowest energy state.
所以晶体会具有最低的能量。
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And that is how come he got involved in this, obviously this is talking about crystal formation.
这也是为什么他会出现在这里，结晶学就是研究晶体的形成。
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I know table salt is white, but that is because you have power and you have multiple surfaces scattering, but a large crystal of sodium chloride is clear and colorless.
我知道食用盐是白色的，但这是因为你让它成了粉末,因为有了多个散射面，但是一个大的氯化钠晶体,是无色透明的。
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And you will form a crystal of sodium chloride as a result of this need to form crystal expressed through the Coulomb's Law.
你能得到氯化钠晶体,因此，形成晶体所需要的条件,在库伦定律中通篇都有表达。
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So this is simply the energetics of crystal formation.
这就是简单的晶体形成的静电原理。
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This is a three-dimensional crystal.
这是一个三维的晶体。
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It's going to be a one-dimensional crystal.
它将是一维的晶体。
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I want an ordered solid.
我们需要有序的晶体。
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that's one way to think about it, and there's also another way, and this is the way that your book presents it. If you, in fact, have two of the same atom right next to each other, let's say you have a crystal, or let's say you're talking about a metal, what you can do is just look at the distance between the two nuclei, and split that in 1/2, and take the atomic radius that way.
这只是一种定义的思路，另外还有其它方法，也就是你们课本上的方法，如果你，事实上，有两个相同的原子彼此靠在一起，比如说你有一个晶体，或者说你讨论的是一个金属，你所要做的就是,看看这两个原子核之间的距离，然后将距离除以二，就得到了这个原子的半径。
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The question is can I show you, from an energetic standpoint, that the crystal is favored over having the discrete set of pairs?
我展示你的问题是，从能量的观点出发，晶体倾向于,形成分散的一系列的对？
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We started with this hypothesis of octet stability and I'm talking about properties of ionic crystals.
我们从八隅律的稳定性假设开始,我们讨论到了离子晶体的性质。
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There is no way that you could irradiate a crystal of nickel with a single beam of x-rays and get that circular ring pattern if the electron beam were behaving as a particle beam only.
没有什么其他的途径,可以让镍晶体发射,单束X光来,继而得到环状图案,如果电子束,是以粒子束形式出现的。
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If de Broglie is correct, let's irradiate the nickel crystal with a beam of electrons where the wavelength of the beam of electrons is identical to the wavelength of the x-rays that were used and see what we get.
如果德·布罗意是正确的，那么镍晶体放出,电子光束,电子束的波长,和原来讲过的X光的波长是相等的,再看看得到了什么。
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Last time we reach the third law which is telling us that we can't quite get to zero degrees Kelvin .but that as the temperature approaches zero degrees Kelvin, the absolute entropy of a pure substance in perfect crystalline form is zero.
上次课我们得到了热力学第三定律,这个定律告诉我们我们无法,达到0K的温度,但是在我们接近绝对零度的过程中，以完美晶体形式存在的纯物质的绝对熵,也趋向于零。
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They took a crystal, this is a single crystal of nickel that has regular planes of atoms, and those planes are spaced on the order of an angstrom or less apart, and they irradiated this with x-rays.
他们取了个晶体,一个具有规则原子平面的，镍晶体,这些面间距差不多也是一埃或者更少，它们放射出X射线。
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