Would you dare bring extreme sports to the next level?
你敢挑战更刺激的极限运动吗？
Do a bungee jump with no strings attached?
比如没有绳索的蹦极？
Don’t worry, we won’t let you hit the ground.
别怕 我们不会让你摔到地上的
We’ll use science to catch you with some big magnets.
我们将用大磁铁以科学的方法来抓住你
How would it work?
这是怎么做到的呢？
How many magnets would you need.And…
要用多少磁铁呢？
What are the chances that this could end up badly for you?
这样使你受伤的几率又是多少呢？
This is What If
这里是《自然无常》
And here’s what would happen
接下来会为你展示
If you did a wireless bungee jump with magnets
你用磁铁进行一次无绳索蹦极会发生什么
You’ve probably seen these thrill-seekers
你可能见过这些寻求刺激的人
jumping off cliffs and bridges.
从悬崖或桥上跳下来
But their “extreme” doesn’t come close
但他们的“极限运动”
to what we have in mind.
跟我们想的不一样
Bungee jumping usually means that
在正常的蹦极运动中
you’re attached to an elastic rope.
你会绑有一条弹性绳
You’re also secured by a harness,
还绑有安全带
and protected from colliding with the bungee cord by soft padding.
还有软垫垫着防止被蹦极绳勒伤
What we propose is a bungee jump
而我们试想的是在蹦极的时候
minus the rope,
去掉绳子
plus a couple of massive magnets.
加上几个强力磁铁
Could it work
这样可以吗？
Theoretically, this could be possible.
理论上说 这是有可能的
Magnets have north and south pole
磁铁有南北两极
and they produce magnetic fields around them.
它们在周围产生磁场
The opposite poles are attracted to each other,
磁铁异极相吸
and the similar poles produce a force of repulsion.
同极相斥
What you’d need for a wireless bungee jump
你在进行无绳索蹦极的时所需要的
is a magnet strapped to your harness,
是在安全带上绑一块磁铁
with its south pole facing downwards.
它的南极朝下
You’d need another magnet on the ground,
你需要另一块在地上的磁铁
with its south pole facing upwards.
南极朝上
You’d also need to think hard before you agree to do this
不过在去做这件事前 你应该好好想想
because I wouldn’t recommend trying i t at all.
因为我一点也不推荐你去做这件事
One thing I would recommend is to learn more about magnets
我建议你到brilliant上我们朋友那里
among other things with our friends at brilliant.
学习更多关于磁铁的知识
the sponsor of this episode
他们是本期节目的赞助商
I never thoughs doing math could be fun
我从没想过做数学会很有趣
but brilliant totally change my mind .
但brilliant改变了我的看法
if you’ve ever felt like taking a deep dive into the world of math fundamentals but
如果你曾想深入研究数学的基本原理
we’re afraid of long formulas and big birds like me
但你应该能看出来 像我这样的笨蛋很害怕长公式
Well, you should check out brilliant .
你应该去看看brilliant
I went to brilliant to see what they had on magnets
我去brilliant看他们有没有磁铁相关的
and I ended up learning a whole lot more about axe-throwing gymnastics and my fridge
结果学了很多关于飞斧体操和我的冰箱的东西
you should try to go to brilliant.org/ what if to sign up for free
你可以到brilliant.org/what if免费注册一下
oh and also the first 200 people who go to that link will get 20% off
前200名点击链接订阅的用户优惠20%
the annual premium subscription for more interactive courses,
年费订阅还有更多互动课程
daily challenges and quizzes.
每日挑战和测验
Now that you’re all geared up you’re ready to take the jump
现在你已经做好准备 准备蹦极了
the reason why bungee jumpers aren’t splashed all over the ground after the jump
蹦极运动员跳完后不会溅得到处都是
is that the elastic rope slows them down to a stop
是因为弹性绳使它们减速到停止
and then pulls them back up
然后把它们拉回来
then down then up then down then up
然后向上 向下 向上
until all the energy from the jump is spent
直到所有能量在跳跃中被消耗掉
With magnets it’s a little trickier
用磁铁的话有点棘手
when you’re in freefall the gravitational force pulls you down
当你在自由落体的引力把你拉下来
and increases your speed by 9.8 meters per second every second
以9.8m/s²加速
that you fall after 3 seconds of freefall you’d reach a speed of almost 30 meters per second
自由落体3秒后你会达到近30m/s的速度
Only you wouldn’t have a stretchy rope to soften your claw
只是你没有弹力绳来减速
here’s the thing about magnets
这里用的是磁铁
when they’re apart from each other they’re repulsive force is close to zero
它们彼此分离时排斥力接近于0
but as they get closer together the repulsive force
但当它们靠近时
increases very rapidly
排斥力迅速增加
as you jumps down
当你往下跳的时候
the magnets would stop you just a few centimeters from the ground
磁铁会让你在离地面几厘米的地方停下来
but because of the forces involved in stopping you so fast,
但由于你受到的阻力力太大
you feel as if your body got smashed by a drug.
你会觉得你的身体好像被某种药物击碎了
I know I promised you wouldn’t get squashed into the ground
我知道我保证过你不会被地压扁
but I didn’t say you wouldn’t get crushed by the repulsive force between two magnets
但我没说过你不会被两块磁铁之间的斥力压扁
if you’re wondering if this could get any worse but it could
如果你想知道情况会不会变得更糟
if you move slightly out of line during your fall
如果你在下落过程中稍稍偏离直线
you’d risk flipping together with the magnet attached to you
你就有可能和磁铁一起翻转
now instead of facing the opposite poles to each other
现在把磁体相反的两极
the magnets would be facing the same poles
换成面对相同的两极
and what do magnets do when they face similar poles
当它们面对相似的两极时会发生什么
yeah
是的
not even your body caught in between
甚至你的身体也不例外
the jump with magnets was a bad idea
用磁铁蹦极不是什么好主意
sorry about that
抱歉
looks like falling from an airplane could be safer than that under the right conditions
看来在合适情况下从飞机坠落都比这安全
but that’s a story for another
但那就是另一回事了
What If
《自然无常》