4分钟揭秘永动机骗局！Why Don’t Perpetual Motion Machines Ever Work?

4分钟揭秘永动机骗局！Why Don’t Perpetual Motion Machines Ever Work?
Imagine a windmill that produced the breeze it needed to keep rotating.
设想一个风车，能够制造出它转动所需的微风。
Or a lightbulb whose glow provided its own electricity.
或者一个灯泡，其发光足以为自己供电。
These devices have captured many inventors' imaginations because they could transform our relationship with energy.
这些设备深深吸引了众多发明家的想象，因为它们有潜力彻底转变我们与能源的互动方式。
For example, if you could build a perpetual motion machine that included humans as part of its perfectly efficient system, it could sustain life indefinitely.
例如，如果能构建一台包括人类在内、作为其完美高效系统一部分的永动机，那么它就能无限期地维持生命。
There's just one problem.
但是，存在一个问题。
They don't work.
永动机行不通。
Ideas for perpetual motion machines all violate one or more fundamental laws of thermodynamics, the branch of physics that describes the relationship between different forms of energy.
所有关于永动机的想法都至少违反了一个热力学基本定律。热力学是物理学的一个分支，专门研究不同形式的能量之间的关系。
The first law of thermodynamics says that energy can't be created or destroyed.
热力学第一定律表明，能量既不能创造也不能消灭。
You can't get out more energy than you put in.
你得到的能量无法超出投入的能量。
That rules out a useful perpetual motion machine right away because a machine could only ever produce as much energy as it consumed.
这立即排除了实用永动机的可能性，因为任何机器产生的能量都不会超过其消耗的能量。
There wouldn't be any left over to power a car or charge a phone.
这意味着不会有多余的能量用于驱动汽车或为手机充电。
But what if you just wanted the machine to keep itself moving?
但如果你仅仅是想让这台机器自持续运作呢？
Inventors have proposed plenty of ideas.
发明者们提出了众多创意。
Several of these have been variations on Bhaskara's over-balanced wheel with rolling balls or weights on swinging arms.
其中一些是巴斯卡拉的过重平衡轮的改良版本，摆臂上连接了滚动的球体或配重。
None of them work.
没有一个行得通。
The moving parts that make one side of the wheel heavier also shift its center of mass downward below the axle.
让轮子一侧变得更重的移动部分，也使得其重心下移，位于轴心之下。
With a low center of mass, the wheel just swings back and forth like a pendulum, then stops.
重心较低的轮子仅仅会像钟摆一样摇摆几下，随后便停止了。
What about a different approach?
如果采取另一种方法呢？
In the 17th century, Robert Boyle came up with an idea for a self-watering pot.
在17世纪，罗伯特·波义耳发明了一种自动添水的花瓶。
He theorized that capillary action, the attraction between liquids and surfaces that pulls water through thin tubes, might keep the water cycling around the bowl.
他推论，通过毛细作用，一种液体与表面之间的吸引力将水通过细小管道拉动的现象，可以实现让水在花盆中循环流动。
But if the capillary action is strong enough to overcome gravity and draw the water up, it would also prevent it from falling back into the bowl.
但如果毛细作用足够强，能够克服重力吸引水分上升，同样也会阻止水回落到花盆里。
Then there are versions with magnets, like this set of ramps.
接着是带有磁铁的类型，例如这种斜坡。
The ball is supposed to be pulled upwards by the magnet at the top, fall back down through the hole, and repeat the cycle.
球被设计为被顶端的磁铁吸引向上移动，然后从孔中落下，如此循环往复。
This one fails because like the self-watering pot, the magnet would simply hold the ball at the top.
这种设计失败了，原因与自动浇水的花盆相似，磁铁仅仅会把球停留在顶端。
Even if it somehow did keep moving, the magnet's strength would degrade over time and eventually stop working.
即便它能够某种方式持续移动，磁铁的磁力也会随时间减弱，最后失去作用。
For each of these machines to keep moving, they'd have to create some extra energy to nudge the system past its stopping point, breaking the first law of thermodynamics.
要保持这些机器的持续运作，它们需要产生额外的能量，以推动系统越过其停止点，这将违反了热力学第一定律。
There are ones that seem to keep going, but in reality, they invariably turn out to be drawing energy from some external source.
有些似乎能够不停地运转，但实际上它们总是从外部源头获取能量。
Even if engineers could somehow design a machine that didn't violate the first law of thermodynamics, it still wouldn't work in the real world because of the second law.
即便工程师能够设计出一种不违背热力学第一定律的机器，在现实世界中它还是因为第二定律而无法正常工作。
The second law of thermodynamics tells us that energy tends to spread out through processes like friction.
热力学第二定律指出，能量会通过摩擦等方式散布开来。
Any real machine would have moving parts or interactions with air or liquid molecules that would generate tiny amounts of friction and heat, even in a vacuum.
在现实中，所有机器都会有移动的部件或者是和空气或液体分子之间的相互作用，这会在任何情况下，即便是在真空环境中，也会产生一些微小的摩擦和热量。
That heat is energy escaping, and it would keep leeching out, reducing the energy available to move the system itself until the machine inevitably stopped.
这种热量是正在逸散的能量，它会不断地流失，导致推动系统本身的可用能量减少，直至机器最终不得不停止运作。
So far, these two laws of thermodynamics have stymied every idea for perpetual motion and the dreams of perfectly efficient energy generation they imply.
迄今为止，这两条热力学定律已经使所有关于永动机以及它们所代表的完美高效能源生成的梦想无法实现。
Yet it's hard to conclusively say we'll never discover a perpetual motion machine because there's still so much we don't understand about the universe.
不过，我们很难断定永远不会发现永动机，因为关于宇宙，还有太多未知之处。
Perhaps we'll find new exotic forms of matter that'll force us to revisit the laws of thermodynamics.
或许我们将会发现一些新奇的异种物质，使我们不得不重新考量热力学定律。
Or maybe there's perpetual motion on tiny quantum scales.
或许在微观的量子尺度上，永动现象确实存在。【贝贝英语网】