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Thanks to Skillshare for supporting this episode of SciShow.
感谢Skillshare对本节目的支持。
Many of us learned that electricity can be dangerous back when we were toddlers.
大部分人在小时候就知道电是危险的东西。
You know, that time you tried to stick a fork in an electrical outlet and all the adults in the room freaked out.
当你试图把叉子插进插座里，房间里所有的大人都会惊慌。
Compared to a standard outlet, overhead power lines carry a lot more electricity, so touching them is an even bigger no-no.
和标准电源插座相比，架空电力线路携带更多电流，所以触摸它们更是危险的不要不要的。
But that doesn't explain how birds perch on power lines all the time without getting zapped.
但这无法解释鸟类是如何一直栖息在电力线上却不被电到的。
Besides being way more dangerous, overhead power lines usually aren't even insulated like the cords on appliances.
除了更加危险之外，架空电力线路甚至不像那些家电线一样是绝缘的。
Well, it's not because birds have some sort of superpower.
这并不是因为鸟类有某种超能力。
Instead, it turns out that the reason they can sit on power lines has to do with how electric currents and circuits work.
相反，其它们可以坐在电线上的原因和电流与电路的运作方式有关。
Electric current is just the movement of electrons. Specifically, from an area with a lot of electrons to one with fewer.
电流仅仅是电子的移动，具体来说，是从带有大量电子的区域移动至电子较少的区域。
Scientists describe that as moving from lower to higher potential.
科学家将其描述为从较低电位移动至较高电位。
If someone were to stick their finger in an electrical outlet,
如果有人将手指戳进插座里，
electrons would travel through their body to get to a spot with higher potential usually, the ground.
电子将流过他们的身体来到高电位的地点，通常是地面。
Which is why sticking your finger in a socket is a terrible idea. But when a bird perches on a wire, they're totally fine.
所以将手指插进插座里是个非常可怕的想法。但当小鸟栖息在电线上时，它们还好好的。
That's because both feet are on the same wire they're not in contact with an area of higher potential, like the ground.
那是因为它们的两只小脚同时站在电线上，没有和更高电位，比如地面，接触。
The electrons in the wire can't get to an area of higher potential by passing through the bird's body, so they don't.
电线中的电子无法通过小鸟的身体流到更高电位的地方，所以它们没事。
And since no current flows through the bird, it's unharmed. But say a bird moves one foot to a different wire with a different potential.
没有电流流过它们的身体，所以它们不会受到伤害。但如果一只鸟将另一只脚搭在另一根电位不同的电线上。
Now, their body has formed a path for the electrons to move from low to high Potential, also known as a circuit.
现在，它们的身体形成了让电子从低电位流向高电位的通道，即电路。
Current flows through the circuit, and it's Bye Bye Birdie.
电流穿过电路，那就拜拜啦，小小鸟。
Now, thankfully, most birds don't have a problem with power lines. But some do get electrocuted.
现在还好大部分鸟类都不会栽倒在电线上，但是一些鸟类还是会被电死。
Typically, these are larger raptors, like eagles, hawks, and owls.
比如那些有代表性的大猛禽，老鹰、隼和猫头鹰。
Often, these birds will perch on an electrical pole, then stretch out a wing and brush it against a power line.
通常，这些鸟类会栖息在电线杆上，然后伸展翅膀，扫过电线。
That completes a circuit between the power line and the pole, which leads to the ground.
这样就完成了电线和电线杠之间的电路，最后电流流到了地面。
Electrocution is usually fatal for birds, and scientists estimate that millions of them are electrocuted by power lines each year in the U.S.
通常触电对鸟类来说是致命的，并且科学家估计美国每年有百万只鸟被电线电死。
To protect larger birds, many utility companies are now implementing raptor-safe power pole designs.
为了保护这些大型鸟类，很多公用事业公司现在都使用猛禽安全电线杆设计。
These include structures that discourage birds from perching on poles or that leave more space between the pole and charged wires,
其中包括阻止鸟类栖息在电线杆上或是在电线杆和电线之间留出更多空间的设计结构，
so birds are less likely to touch both at the same time.
这样鸟类就不太可能同时触碰到电线杆和电线了。
Electricity allows us to do amazing things, like reheat yesterday's pizza in under a minute or watch SciShow!
有了电，我们可以做很多奇妙的事情，比如一分钟热好昨天的披萨或是观看《科学秀》！
But it can also kill us and our feathered friends, so it's always better to leave the power lines to the professionals.
但电对我们和我们的鸟类朋友也是致命的，所以最好把电线的工作交给专业人士。
Speaking of professionals, Skillshare is packed with classes taught by the pros, and you can learn about everything from circuits to watercolors.
说到专业人士，Skillshare里有很多专业人士教授的课程，从电路到水彩画，什么课程都有。
There's even a class about how to paint birds, taught by watercolor artist Amy Giglio.
甚至还有教你画小鸟的课程，老师是水彩画艺术家艾米·吉利奥。
Amy has lots of tips for beginners, from picking out brushes to choosing a reference image.
艾米有很多给初学者的建议，比如选画刷和选参考画。
So even if you've never painted before, it might be a fun chance to spread your wings and try something new, all while supporting SciShow.
即便你从没学会画画，你也有可能展开双翅尝试新的东西，同时也是在支持《科学秀》。
Right now, Skillshare is offering SciShow viewers 2 months of unlimited access for free.
现在Skillshare为《科学秀》的观众提供两个月的免费使用权限。
There are more than 20,000 classes to choose from, and you can follow the link in the description to check it out!
上边有两万多种课程供你选择，你可以点击下方链接查看！
