能量从哪里来？分子运动与能量守恒的奥秘
字幕摘录
| 时间 | 英文 | 中文 |
|---|---|---|
| 0:00 | Energy is not easy to define. | 能源不容易定义。 |
| 0:02 | Things have energy, but you can't hold a bushel of energy in your hands. | 事情是有能量的,但你不能 手握一束能量。 |
| 0:06 | You can see what it does, but you can't see it directly. | 你可以看到它的作用,但不能直接看到它. |
| 0:10 | There are different types of energy, | 有不同种类的能量, |
| 0:12 | but the differences between them are manifested only in how they make stuff behave. | 但他们之间的分歧 仅仅表现在 他们如何使事物的行为。 |
| 0:17 | We do know that the total amount of all the different types of energy in the universe | 我们知道宇宙中所有不同种类的能量总量 |
| 0:21 | is always the same. | 总是一样。 |
| 0:23 | For chemists, two important types of energy are chemical potential energy | 对于化学家来说,两种重要的能源类型是化学潜在能源. |
| 0:26 | and kinetic energy. | 和动能。 |
| 0:29 | Potential energy is energy waiting to happen. | 潜在的能量是等待发生的能量。 |
展开字幕全文（74 条）
| 序号 | 英文 | 中文 |
|---|---|---|
| 1 | Energy is not easy to define. | 能源不容易定义。 |
| 2 | Things have energy, but you can't hold a bushel of energy in your hands. | 事情是有能量的,但你不能 手握一束能量。 |
| 3 | You can see what it does, but you can't see it directly. | 你可以看到它的作用,但不能直接看到它. |
| 4 | There are different types of energy, | 有不同种类的能量, |
| 5 | but the differences between them are manifested only in how they make stuff behave. | 但他们之间的分歧 仅仅表现在 他们如何使事物的行为。 |
| 6 | We do know that the total amount of all the different types of energy in the universe | 我们知道宇宙中所有不同种类的能量总量 |
| 7 | is always the same. | 总是一样。 |
| 8 | For chemists, two important types of energy are chemical potential energy | 对于化学家来说,两种重要的能源类型是化学潜在能源. |
| 9 | and kinetic energy. | 和动能。 |
| 10 | Potential energy is energy waiting to happen. | 潜在的能量是等待发生的能量。 |
| 11 | Think of a stretched rubber band. | 想想一个拉长的橡皮筋。 |
| 12 | If you cut it, all that potential energy gets converted to kinetic energy, | 如果你切断它, 所有潜在的能量 被转换成动能, |
| 13 | which is registered by you as pain. | 被你记录为疼痛 |
| 14 | Like a stretched rubber band, chemical bonds also store energy, | 像一个拉长的橡胶带, 化学债券也存储能量, |
| 15 | and when those bonds are broken, | 当那些盟约破裂的时候, |
| 16 | that potential energy gets converted to other types of energy, | 潜在能量被转换成其他类型的能量, |
| 17 | like heat or light, or gets used to make different bonds. | 喜欢热或光, 或者习惯 制造不同的债券。 |
| 18 | Kinetic energy is the energy of motion, | 动能是动能 |
| 19 | and molecules are always moving. | 分子总是在移动 |
| 20 | They're not necessarily going somewhere, though they could be, | 他们不一定去某个地方 虽然他们可能去 |
| 21 | but they are vibrating, stretching, bending, and or spinning. | 但他们震动、伸缩、弯曲、旋转。 |
| 22 | Take methane, which is four hydrogens attached to a central carbon as an example. | 以甲烷为例,甲烷是四个附着在中心碳上的氢. |
| 23 | Drawn on paper, it's just a still tetrahedron. | 画在纸上,它只是一个仍然四面体。 |
| 24 | But in real life, it's a jiggling mess. | 但是在现实生活中,这是一团乱糟糟. |
| 25 | The kinetic energy of molecules is exactly the same type of energy | 分子的动力学能量完全一样 |
| 26 | as the energy you have when you're moving around, | 就像你移动时的能量一样 |
| 27 | except that you can be still and molecules can't. | 只不过你可以静静地,分子不能。 |
| 28 | If you suck the kinetic energy out of a group of molecules, | 如果你吸出一组分子的动能, |
| 29 | they'll move less, but they'll never fully stop. | 他们会少移动,但他们永远不会完全停止。 |
| 30 | Now, in any group of molecules, some will have more kinetic energy than others, | 现在,在任何一组分子中, 有些分子的动能会比其他分子多, |
| 31 | and if we calculate the average kinetic energy of the group, | 如果我们计算出这个组的平均动能, |
| 32 | we'd have a number mathematically related to temperature. | 我们会有一个数 在数学上与温度有关。 |
| 33 | So the more kinetic energy a group of molecules has, | 因此,一个分子组的动能越大, |
| 34 | the higher its temperature, | 温度越高 |
| 35 | and that means that on a hot day, | 这意味着在炎热的一天, |
| 36 | the molecules in the air around you are spinning, stretching, bending, | 周围空气中的分子在旋转 伸展 弯曲 |
| 37 | and generally shooting around much faster than on a cold day. | 通常在寒冷的一天里射击的速度要快得多 |
| 38 | Now, hot and cold, by the way, are relative terms. | 顺便说一句,热冷是相对的 |
| 39 | They're always used to compare one thing to something else. | 它们总是用来比较一件事和别的东西. |
| 40 | So on that hot summer day, | 所以在那个炎热的夏天 |
| 41 | the air molecules have more kinetic energy than the molecules in your skin. | 空气分子的动能 比你皮肤中的分子多 |
| 42 | So when those air molecules crash into you, | 当那些空气分子撞到你身上时 |
| 43 | they transfer some of their energy to the molecules in your skin, | 它们把能量转移到你皮肤里的分子上 |
| 44 | and you feel that as heat. | 你感觉就像热。 |
| 45 | On a cold day, the air molecules have less kinetic energy | 在寒冷的一天,空气分子的动能更少 |
| 46 | than the molecules in your skin, | 比你皮肤中的分子, |
| 47 | so when you crash into those air molecules, | 所以当你撞到这些空气分子, |
| 48 | you actually transfer some of your kinetic energy to them, | 你实际上把一些动能转移给他们, |
| 49 | and you feel that as cold. | 你会觉得很冷 |
| 50 | You can trace the path of energy around you. | 你可以追踪周围能量的路径。 |
| 51 | Try it at your next cookout. | 试试你的下一场菜 |
| 52 | You burn charcoal, | 你烧炭 |
| 53 | and the release of that chemical potential energy | 以及释放这种化学潜在能源 |
| 54 | shows up as extreme heat and light. | 现身极热光明. |
| 55 | The heat then makes the molecules of your burgers, | 热能让你的汉堡的分子 |
| 56 | your hot dogs, or your vegetables, | 你的热狗,或你的蔬菜, |
| 57 | vibrate until their own bonds break | 震动直到他们自己的债券破裂 |
| 58 | and new chemical structures are formed. | 并形成新的化学结构。 |
| 59 | Too much heat, and you have a charred mess. | 太热了,你还有一团糟 |
| 60 | Just enough, and you have dinner. | 够了,你还有晚餐 |
| 61 | Once in your body, the food molecules in your delicious, | 一旦进入你的身体, 食物分子在你的美味, |
| 62 | or charred, dinner get broken down, | 或被烧伤,或被烧伤, |
| 63 | and the energy released is used to either keep you alive right now, | 而释放的能量 要么用来让你活着 现在, |
| 64 | or it's stored for later in different molecules. | 或者储存在不同的分子中 |
| 65 | As night falls, the hot summer air cools, | 随着夜幕降临,炎热的夏季空气凉爽, |
| 66 | and the flow of energy into you slows. | 和能量的流进, |
| 67 | Then, as the air reaches your skin temperature, | 然后,当空气到达你的皮肤温度, |
| 68 | for the briefest of moments, the flow stops. | 对于最短暂的时刻, 流动停止。 |
| 69 | And then it starts up again in the opposite direction, | 然后它又从相反的方向开始 |
| 70 | as energy leaves the warmer surface of your skin | 当能量离开 你皮肤的温暖表面 |
| 71 | to return to the universe around you. | 回到你身边的宇宙 |
| 72 | That energy neither created nor destroyed, | 能量没有创造或破坏, |
| 73 | but ever shape-shifting, | 但有变形者, |
| 74 | the chameleon phoenix of our physical world. | 我们物质世界的变色龙凤凰 |
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