Can you solve the unstoppable blob riddle? - Dan Finkel

8,508,716 views ・ 2019-03-18

TED-Ed


请双击下面的英文字幕来播放视频。

翻译人员: 진영 윤 校对人员: Lipeng Chen
00:07
A shooting star crashes on Earth,
0
7789
2450
一颗流星撞上了地球,
00:10
and a hideous blob emerges.
1
10239
2900
出现了一只可怕的粘液怪物。
00:13
It creeps and leaps, it glides and slides.
2
13139
3886
它会爬行、会跳跃; 它会滑动、会滑行。
00:17
It’s also unstoppable:
3
17025
2160
它也所向无敌:
00:19
weapons, fire, extreme temperatures…
4
19185
2460
武器、火、极端温度……
00:21
no matter what you throw at it,
5
21645
1740
不论你用什么方式攻击它,
00:23
it just regrows and continues its rampage.
6
23385
3890
它总会再生并继续制造暴乱。
00:27
Its expansion is breathtaking;
7
27275
2200
它的扩展能力十分惊人;
00:29
it doubles in size every hour.
8
29475
2660
每小时,它的大小就会增大一倍。
00:32
But there’s one opportunity:
9
32135
2080
但有一个机会:
00:34
after each hour, it goes to sleep,
10
34215
2920
每小时之后,它就会进入睡眠,
00:37
forming itself into a flat triangle
11
37135
2500
让它自己的形状变成扁平三角形,
00:39
and resting for a few minutes
12
39635
2070
休息几分钟,
00:41
before it begins eating and growing again.
13
41705
3710
接着又会开始吃东西成长。
00:45
Your only chance to save the planet
14
45415
2000
你只有一个机会能拯救地球,
00:47
involves a satellite-mounted nano-fission ray that can cut through the blob.
15
47415
5980
要用到装在卫星上的 纳米分裂光束来将它切成两半。
00:53
When the blog is active
16
53395
1476
当怪物在活动时,
00:54
it heals itself within seconds.
17
54871
2230
只要几秒钟时间它就会愈合。
00:57
However, when you break the sleeping blob into two triangles,
18
57101
3780
然而,当你把在睡觉中的 怪物切成两个三角形时,
01:00
you make a critical discovery.
19
60881
2130
你有了重大的发现。
01:03
The acute triangle portion,
20
63011
2410
锐角三角形的部分
01:05
with all angles less than 90 degrees, is inert.
21
65421
4330
也就是所有角都小于90°的 三角形,不再有生命力
01:09
It never “wakes up.”
22
69751
1838
它不再醒来
01:11
The obtuse triangle,
23
71589
1370
至于钝角三角形,
01:12
which has an angle greater than 90 degrees,
24
72959
2580
也就是有一个角大于90°的三角形,
01:15
wakes up as usual and keeps growing.
25
75539
2680
还是一样会醒来并继续成长。
01:18
Similar experiments show that all shapes other than acute triangles,
26
78219
4300
类似的实验结果显示, 除了锐角三角形之外的所有形状,
01:22
including right triangles, will also wake up.
27
82519
3617
包括直角三角形,都还是会醒来。
01:26
For the next few minutes,
28
86136
1370
接下来的几分钟,
01:27
the blob is sleeping in its obtuse triangle form.
29
87506
3960
怪物会以扁平三角形的 形式进入睡眠。
01:31
You can make clean, straight-line cuts
30
91466
2660
你可以针对三角形上 或三角形内指定的任两个点
01:34
between any two points on or inside the triangle.
31
94126
3570
做到精确的直线分割。
01:37
But you’ll only have time to make 7 cuts while the satellite is above you.
32
97696
4660
但当卫星在你上方可以 进行切割的时间只够你切七次。
01:42
By the time it completes its orbit and returns,
33
102356
2910
当卫星完成绕行再回来时,
01:45
the blob will have consumed the entire world,
34
105266
2950
就已经来不及阻止怪物 把整个世界吞噬了,
01:48
if even a single portion that will wake up remains.
35
108216
4540
即使只剩下怪物的一小部分也是如此。
01:52
How can you cut the blob entirely into acute triangles
36
112756
3698
你要如何把怪物切割成锐角三角形,
01:56
and stop it from destroying the planet?
37
116454
2630
阻止它摧毁地球?
01:59
Pause the video now to figure out for yourself
38
119084
2190
如果你希望自己 尝试解题,请在此暂停。
02:01
Answer in 3
39
121274
1333
答案即将公布:3
02:02
Answer in 2
40
122607
2700
答案即将公布:2
02:05
Answer in 1
41
125307
2160
答案即将公布:1
02:07
While this seems doable at first,
42
127467
2128
虽然一开始会觉得这个方法可行
02:09
there’s a hidden difficulty when it comes to avoiding obtuse and right angles.
43
129595
4910
其实若想避免钝角和直角三角形, 会碰到一个隐藏的困难处。
02:14
Every time you make a cut that reaches an edge,
44
134505
3320
每当你做的切割有接触到边缘,
02:17
it either makes an acute and an obtuse angle, or two right angles.
45
137825
4960
就会制造出一个锐角三角形和一个钝角三角形, 不然就是两个直角三角形。
02:22
That makes it seems like you’re doomed to keep creating obtuse angles.
46
142785
4890
看起来似乎你注定会 一直制造出钝角三角形。
02:27
But as with so many of life’s problems,
47
147675
2680
但是,就像许多人生难题一样,
02:30
we can look to pizza for inspiration.
48
150355
3130
我们都能从披萨上找到灵感。
02:33
Imagine squaring off the outside of a pizza,
49
153485
3350
想象一下,把披萨的外缘切平,
02:36
so that instead of a circle, it’s an octagon.
50
156835
3140
披萨现在变成八角形,不再是个圆。
02:39
When we cut it into slices,
51
159975
1830
当我们把它切片,
02:41
each of the eight triangles is acute.
52
161805
2540
这8个三角形都是锐角三角形
02:44
This works with larger polygons too.
53
164345
2350
对于边数更多的多边形, 这招也一样可以。
02:46
Importantly, it also works for some polygons with fewer sides,
54
166695
4960
重要的是,对于边数 更少的多边形仍然可行,
02:51
including heptagons, hexagons, and pentagons.
55
171655
4130
包括七角形,六角形,五角形。
02:55
That’s good news,
56
175785
1007
那是好消息,
02:56
because if you cut off the sharp corners of the blob triangle,
57
176792
3950
因为如果你把怪物 三角形的尖角切除,
03:00
a pentagon is exactly what you’ll be left with.
58
180742
3650
你就会得到一个五角形。
03:04
And just like a pizza,
59
184392
1840
就像披萨一样,
03:06
you can cut the blob pentagon into five acute triangles.
60
186232
4550
你可以把怪物五角形 切成五个锐角三角形。
03:10
That’s 7 cuts, and it renders the blob completely inert.
61
190782
5026
一共要切七次,结果是 怪物完全不再有生命。
03:15
You’ve saved the day!
62
195808
1500
你拯救了世界!
03:17
Now you just need to figure out what to do
63
197318
2000
现在,你只要想办法处理
03:19
with all of these giant, practically indestructible triangles.
64
199318
3630
这些巨大且刀枪不入的三角形了。
关于本网站

这个网站将向你介绍对学习英语有用的YouTube视频。你将看到来自世界各地的一流教师教授的英语课程。双击每个视频页面上显示的英文字幕,即可从那里播放视频。字幕会随着视频的播放而同步滚动。如果你有任何意见或要求,请使用此联系表与我们联系。

https://forms.gle/WvT1wiN1qDtmnspy7


This website was created in October 2020 and last updated on June 12, 2025.

It is now archived and preserved as an English learning resource.

Some information may be out of date.

隐私政策

eng.lish.video

Developer's Blog