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No, OK and that's correct, because each photon of light actually has more energy than is needed to eject an electron.
没有，好，对了，因为每一个光子实际上,都有更多的能量去逐出一个电子。
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So, you might ask then well what is the significance of shooting different amounts of photons at a metal?
所以，你们可能会问向,金属发射不同数量的光子,有什么重要性？
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And so the photons hitting the wall actually put pressure on the wall, but the pressure is so low.
所以光子碰撞墙面,事实上在对墙加压，但只是压力很小。
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Yes. In fact, there is not enough energy in a single photon to go ahead and eject an electron from this zinc surface.
是的，事实上，这里的光子没有足够的能量,去从锌表面逐出一个电子。
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That's sometimes confusing for people, because it seems like okay, is it a photon or is it an electron.
有时候这对人们来说是令人迷惑的，因为它看起来好像是对的，它是一个光子还是一个电子？
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All right. So jumping in to having established that, yes, particles have wave-like behavior, even though no, hey're not actually photons, we can't use that equation.
好的，我们已经承认了，粒子有波动性，虽然它们不是光子，我们不能用这个方程。
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So, if we have a high intensity, we're talking about having more photons per second, and it's important to know also what that does not mean.
所以，如果我们有一个高强度，我们就是在讨论每秒钟,有更多的光子数，同样理解它不代表什么,也是很重要的。
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If a photon which has no mass can behave as a particle, does it follow then an electron which has mass can behave as a wave? 1920.
如果一个没有质量的光子,能像粒子一样运动，那么它能像一个,没有质量的电子那样以波的形式运动吗。
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So for every photon we have 2.84 times 10 to the -19 joules.
每一个光子有,2，84乘以10的-19次方焦耳。
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So this gives you a little bit of an idea of just how many individual photons there are in a laser beam of light. This is a huge number of photons.
这个给你们一点思路关于,一个激光束有多少独立的光子,这是一个巨大的光子数目。
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Because here what we have is some atom that we're studying, in the case, it's going to be a gas, and we hit it with a photon that has some incident energy.
因为这里我们要研究的是一些原子,在这种情况下，一般是气态的，然后我们令一个,具有一定初始能量的光子打上去。
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Well, if I go through that, the wavelength of such a photon is going to be so big that I am back to measuring the dimension of the human hair with the yardstick.
好的，如果我做完了这个，那个一光子的的波长将成为,我将回头测量的,用一个尺度测量出人头发的尺寸。
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And instead of having the electron giving off energy as a photon, instead now the electron is going to take in energy from light and move up to that higher level.
与电子以光子形式施放能量不同,我们现在要从光中,获得能量到一个更高的能级。
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And that's really neat to think about, because photons, of course, are massless particles, they have no mass, so it's neat to think about something that has no mass, but that actually does have a momentum.
而且那真的不容易想明白，因为光子，当然是无质量的粒子，它们没有质量，所以这个真的不容易想明白,一些物体没有质量，但是它们事实上确实有动量。
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If you get some of these in the upper atmosphere, a photon, an ultraviolet photon, has the energy capable of breaking this bond.
如果你把它放到大气层上，一个光子，一个紫外光光子，有能量可以破坏它的化学键。
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People are very comfortable talking about individual photons, but now we can talk about waves of matter.
人们能轻松的,讨论单个光子，现在我们要说物质波了。
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When I am looking at that wall, its photons are hitting the wall and coming back to me.
当我盯着墙看的时候，光子撞击墙面,又回到我眼中来。
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Is there any significance at all, for example, in the number of photons that are hitting the metal or being absorbed by the metal.
举例来说，若干个光子撞击金属,或者被金属吸收究竟是否有意义。
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So that means we're going to need to figure out what is the energy per photon that's emitted by that UV light.
所以那意味着我们将需要,计算出从紫外光源发射出的,每个光子的能量。
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The first that we need to know the energy of the photon that's incident on our gaseous atom.
首先，我们需要知道,入射到气体原子的光子的能量。
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And that will be associated with a wavelength if it releases the energy in terms of a photon.
是用光子的形式放出来的话,它会和光的波长相关。
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So our last question we ask is what's the total number of photons emitted if we give this given intensity for 60 seconds?
最好的问题是如果我们,按照给定的强度照射60秒,那么总的光子数是多少？
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If a proton which has no mass can behave as a particle does it follow that an electron which has mass can behave as a wave?
如果一个没质量的光子能像粒子一样,具有质量的电子能否,表现得像波一样吗？
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So this means that we can go directly from the energy between two levels to the frequency of the photon that's emitted when you go between those levels.
这意味着我们可以直接,从两个能级的能量得到它们之间,跃迁发射出光子的频率。
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If a photon, which has no mass, can behave as a particle --And we know this.
如果一个没有质量的光子，像粒子一样运动--，我们知道这个。
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It's called this just because it's an electron that results when an electron absorbs a photon's worth of energy, so thus it's a photoelectron.
之所以这样称呼是因为,当一个电子吸收,一个光子的能量的结果，因此它是一个光电子。
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And we'll also talk about photon momentum as another example of light behaving up as a particle.
并且我们也会讨论光子动量的问题,这个可以作为光有粒子行为的例子。
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Intensity, if we increase the intensity, we're not increasing the energy in each photon, we're just increasing the number of photons that we're shooting out of our laser, whatever our light source is.
强度，如果我们增加强度，我们增加的不是,每个光子的能量，我们增加的仅仅是,从我们激光源射出的光子数，无论我们的光源是什么。
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Any frequency can't have an energy, you have to -- you don't have a continuum of frequencies that are of a certain energy, it's actually punctuated into these packets that are called photons.
任何频率不能有个能量,你必须要-对某一个能量上,你不会有连续的频率,光子实际上分立的存在。
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So, the take-home message is whether you have three photons or 3,000,000 photons that you're shooting at your metal, if you're not at that minimum frequency or that minimum energy that you need, nothing is going to happen.
所以，这里表明的信息是,无论是向金属发射3个光子,还是300万个光子,如果没有达到所需的最低频率,或者最小能量,什么事情都不会发生。
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