跟读练习: Revealing 5 Secret Magic Tricks With Science - 通过视频学习英语口语
正在创建课程...
1
Today we're gonna be teaching you five magic tricks you can do yourself at home to impress your friends.
2
Actually even better than magic tricks because they use science like a levitating orb.
3
Oh Emma needs her ladle back.
4
These are tricks that I've never seen before
5
and they're gonna be performed by our former middle school science teacher and even former-er middle school magician, Science Bob Flugfelder.
6
Here we go.
7
Trick number one involved nothing more than a metal ring, Bob's finger and some uncomfortable prolonged eye contact.
8
Ready?
9
Yeah.
10
What the heck was that?
11
There's no hinge on here.
12
Let me just try it.
13
One, two...
14
Okay, maybe there's...
15
Oh no!
16
So this is a trick to use as persistence of vision.
17
We have build box toys that utilize persistence of vision.
18
That's true.
19
The coin spinner.
20
You spin the coin and it looks like Saturn has rings, but really it's just a circle on one side and rings on the other.
21
I'm literally just pushing my finger.
22
So at one point my pinky looks like that, but you don't see that.
23
You can do it just right.
24
One, two, three.
25
Wow.
26
Resistance of vision relies on the fact
27
that your eyes can only send a limited number of visual pictures to the brain each second.
28
Because the pinky bend happens so fast, there's a good chance your eyes never sent that part of the trick to your brain.
29
Which means your brain has to assume the ring just went through your finger, even though it knows that's really not possible.
30
And that's how you can pull out this mind-blowing trick like I do.
31
Huh?
32
Huh?
33
Nate's laughing, so I don't think it worked after maybe a bit more practice.
34
Oh dang it, stop laughing!
35
For trick number two, Bob threw down not one, not two, but three cups, and then filled just one of them with water, at which point he gave me a challenge.
36
I will scramble up the cup, try to remember which one has the water in it.
37
Easy.
38
In this one, here we go, and mixing, and mixing, and mixing, and mixing, and mixing.
39
Okay, one, two, or three.
40
Easy, one.
41
Let's see if you are right.
42
You are, hopefully you got that at home.
43
That means we're going to the next level.
44
It's in this thinner one.
45
Okay, yeah.
46
Here we go, and there we go, there we go.
47
Mixing, mixing.
48
Let's do that.
49
One, two, three.
50
I feel like that was even easier, Bob.
51
Number two, thank you very much.
52
If you're right, you are.
53
One more time, one more time.
54
It's in this one.
55
Okay.
56
Going, going, going, going.
57
All right, one, two, or three.
58
Two!
59
Let's see if you're right.
60
What?
61
One or three.
62
Three?
63
Are you right?
64
No. So here's the weird thing, there never was any water.
65
Believe it or not, the science behind this is the same science that's used in diapers.
66
Whoa.
67
You need to get your hands on some diapers.
68
Go and say, hey, can I borrow a diaper?
69
Yeah, that's not weird.
70
You will immediately see all this white powder coming out of that.
71
And this white powder turns out to be a liquid absorbing polymer, which explains why it's in diapers.
72
So Bob grabbed some clear cups to show me the secret
73
was putting a little bit of the polymer into just one of the cups.
74
And then after transferring water between the two empty cups, poured it into the polymer cup.
75
After which...
76
That water absorbing polymer starts going to work.
77
And after just a little bit of time, no water in there.
78
No water in that one and no water in that one.
79
Whoa.
80
That is wild. And magic.
81
And after a quick clean up of the mess Bob's diaper left, we got to trick number three, which involved a big bottle of water containing a tiny packet of ketchup.
82
Bring your hand near it and it will drop.
83
It takes the warmth from your hand and it will change the density.
84
There it is.
85
Bob, that's not a valid explanation.
86
Are you saying I was lying?
87
Yes, I'm saying you were lying.
88
Traditions lie a lot.
89
It has nothing to do with the heat from your hand.
90
Totally made that up.
91
What it does have to do with is water pressure.
92
So if I want this to sink, all I gotta do is actually squeeze this.
93
Almost imperceivable squeeze will make that go down.
94
This is called the Cartesian diver.
95
Water can't compress, but the little air bubble inside of the ketchup can compress.
96
So when I squeeze this, that changes the density and that causes it to sink until I release it.
97
So that means the combination of the ketchup, the packet and that air bubble is really close to the density of water.
98
It's almost neutrally buoyant, right?
99
Almost.
100
It turns out there's a secret ingredient to this trick.
101
Because if you put the ketchup packet in regular water...
102
You can see how this one's not floating the way you eat it.
103
Yeah, it's not really floating.
104
So you just add some salt and shake it up.
105
Yeah.
106
It's gonna increase the density of the water.
107
Sure.
108
Oh, now it definitely floats.
109
And now it's floating.
110
See, there it goes.
111
Wow.
112
And because salt water is denser than regular water, ketchup will float on it as long as the air bubble stays big.
113
But when you squeeze the bottle, water pressure pushes all those little molecules of air in the bubble closer together.
114
And that slight change in volume increases the density of the ketchup packet compared to the water around it, and just like magic, the packet sinks.
115
Force.
116
Now that Bob had busted out the force, it was time for trick number four, where he was going to show off further Jedi powers using a balloon,
117
a ring cut from a plastic bag, and his own hair.
118
What this is doing is putting a negative charge on it.
119
And it's making your hair look cool.
120
And then, if all goes well, they will.
121
Isn't that cool?
122
Oh, it's a balloon halo!
123
Isn't that neat?
124
You don't need to be a Jedi to pull this off, thanks to electrons.
125
All materials in the world contain tiny particles called electrons, which have a negative charge.
126
Certain materials, like plastic bags and wiffle ball bats, are able to pick up negative charges from other materials, like your hair, which gives away the charge easily.
127
But it turns out that negative charges absolutely don't like hanging out together, And so they'll repel away from each other just like negative sides of a magnet repel each other.
128
And so if one of those objects with a negative charge is light enough, like say a ring cut from a plastic bag,
129
the repelling force is strong enough relative to gravity to push it away and make it float.
130
Oh, it's like a UFO.
131
Can I try?
132
Yeah.
133
Do I gotta use your hair?
134
Sure.
135
Cut!
136
Oh yeah!
137
There ya go.
138
No way.
139
I can move it up and down.
140
I go to left, I go forward, I come back.
141
I am an actual wizard.
142
That or its electrons repelling each other.
143
And feel free to get creative with the shapes you cut out.
144
It's a jellyfish.
145
Alright jellyfish, we're going for a walk.
146
After taking a brief intermission so Bob could tend to my jellyfish thing.
147
My face!
148
We moved on to the next trick which only involves a pen and a water bottle.
149
This doesn't always work.
150
I'm gonna try it without the cap this time, see if it works better.
151
Alright, here we go.
152
One, two, three.
153
Whoa!
154
Check it out.
155
What the heck just happened?
156
Okay, if you squeeze it, that must be it.
157
You squeeze it.
158
Wait, nothing's happening.
159
Bob!
160
So this was a brain trick.
161
Let's talk a little bit about light diffraction.
162
This works because the sides are round.
163
And so this acts as a lens.
164
And so, when we tip it over, I can't see that pen at all.
165
Then we bring the pen up, I can turn it.
166
Your eyes are now on the pen.
167
So you're not even thinking about one being behind.
168
Now I take advantage of light diffraction the other way.
169
So I can slip this away and all of your attention is on that.
170
But let's see if the final trick could beat it, which started promisingly with another balloon.
171
Now, if I can put this very pointy skewer through this balloon without popping it, will you buy me an ice cream?
172
I'll buy you 12 ice creams, Bob.
173
Excellent.
174
Alright, here we go.
175
Whoa.
176
What?
177
Here we go.
178
What the heck?
179
Maybe I'll go chocolate?
180
What the heck?
181
That feels like it shouldn't be possible.
182
True, because your brain says, hey, if there's a hole in something, it's probably leaking.
183
Yeah.
184
But now we're using, once again, the power of the polymer.
185
Can I make a guess?
186
I noticed you didn't fully fill this up.
187
Correct.
188
So it's like the rubber's a little bit thicker, and it almost creates a seal.
189
You also poked it at the bottom, where I know the rubber's thicker.
190
Yeah.
191
And then if you don't want to spoil it, you can just take it out.
192
There you go.
193
They never have a chance to check it out.
194
Bob, show me this trick could also be performed with a big freezer bag and an absolute rainbow's worth of colored pencils.
195
Pick whatever spot you want.
196
Really?
197
Relatively fast and confident.
198
I can be fast and confident, Bob.
199
Okay.
200
The way you stepped to the side, though, that was not a confident sidestep.
201
I'm not moving.
202
Alright, here we go.
203
Three, two, one.
204
Pukka!
205
Spoiler alert, this was fun.
206
That's trippy.
207
It's because your brain thinks if something is full of water and it has a hole in it, it's supposed to leak.
208
The polymers are sealing that off.
209
In fact, oh no. Maybe it was too fun.
210
Oh no!
211
We've tried to leak!
212
Alright, so that means I moved a little on that one.
213
For our viewers, see how many of these you can get in a single bag without that.
214
Tag us at Crunch Labs.
215
Winner gets 12 ice creams.
216
Alright, well there's a bunch of science tricks that are better than magic, and now I have a final science trick of my own.
217
Back to work, Bob.
218
Yes, sir.
📺 同频道
✨ 推荐视频
本课的词汇与口语要点
这段视频共有 218 个句子、1767 个单词可供跟读。 讲话部分时长为 8:59。 说话人语速较快,每分钟约 197 个词,会出现较多连读和弱读。 82% 的单词属于英语最常用的 3,000 词,其余的词建议在练习前先学一下。
视频中的重点词汇
视频中 15 个不太常见的单词,附发音和释义:
- trick /ˈtɹɪk/ (名词) — 詭計 /诡计, 騙術 /骗术. Something designed to fool, dupe, outsmart, mislead or swindle.
- float /fləʊt/ (动词) — 浮, 漂浮. To be supported by a fluid of greater density (than the object).
- squeeze /skwiːz/ (动词) — 壓榨, 擠壓 /挤压. To apply pressure (to something) from two or more sides at once.
- polymer /ˈpɑ.lɪ.mɚ/ (名词) — 聚合體 /聚合体. A long or larger molecule consisting of a chain or network of many repeating units, formed by chemically bonding together many identical or similar small…
- density /ˈdɛn.sə.ti/ (名词) — 密度. A measure of the mass of matter contained by a unit volume.
- packet /ˈpæk.ɪt/ (名词) — 包, 小包. A small pack or package; a little bundle or parcel
- bubble /ˈbʌbəl/ (名词) — 泡, 氣泡 /气泡. A spherically contained volume of air or other gas in a liquid, commonly a soapy liquid.
- balloon /bəˈlun/ (名词) — 氣球 /气球. An inflatable buoyant object, often (but not necessarily) round and flexible.
- whoa /woʊ/ — 吁. Stop (especially when commanding a horse or imitative thereof); calm down; slow down.
- finger /ˈfɪŋɡɚ/ (名词) — 手指, 指頭 /指头. A slender jointed extremity of the human hand, (often) exclusive of the thumb, and the corresponding part, irrespective of including a thumb, in many other…
- sink /ˈsɪŋk/ (动词) — 沉, 下沉. To descend or submerge (or to cause to do so) into a liquid or similar substance.
- leak /liːk/ (名词) — 漏洞. A crack, crevice, fissure, or hole which admits water or other fluid, or lets it escape.
- thick /θɪk/ (形容词) — ху, 厚. Relatively great in extent from one surface to the opposite in its smallest solid dimension.
- seal /siːl/ (名词) — 印章, 圖章 /图章. A stamp used to impress a design on a soft substance such as wax.
- powder /ˈpaʊ.dɚ/ (名词) — 粉, 粉末. The fine particles which are the result of reducing a dry substance by pounding, grinding, or triturating, or the result of decay; dust.
视频中出现的短语动词
- turn out (动词) — 原來 /原来. To end up; to result.
- come back (动词) — 回來 /回来, 返回. To return to a place.
- go down (动词) — 下降, 下去. To descend; to move from a higher place to a lower one.
- go through (动词) — 通過 /通过. To travel from one end of something to the other.
- pick up (动词) — 拾取, 撿 /捡. To lift; to grasp and raise.
- show off (动词) — 炫耀, 賣弄 /卖弄. To exhibit the best attributes of something.
需要注意的发音
说话人用了 35 次缩略和弱读形式,例如 don't, gonna, I'm。请按听到的简短形式来说。
- “th” 音: thick /θɪk/, thin /ˈθɪn/, warmth /wɔɹmθ/
- “sh” 和 “zh” 音: explanation /ˌɛkspləˈneɪʃən/, shake /ˈʃeɪk/, jellyfish /ˈd͡ʒɛliˌfɪʃ/, diffraction /dɪˈfɹækʃən/, intermission /ɪntɚˈmɪʃən/
- 长单词——注意重音位置: explanation /ˌɛkspləˈneɪʃən/, uncomfortable /ʌnˈkʌm.fɚ.tə.bl̩/, ingredient /ɪnˈɡɹiːdi.ənt/, intermission /ɪntɚˈmɪʃən/
如何用这段视频练习
- 先完整听一遍视频,不要开口,记下不认识的单词。
- 先用 0.75 倍速逐句跟读,熟练之后再回到正常速度。
- 录下自己的声音并与原声对比,特别注意 trick, float, squeeze 这类单词。
视频中的语法
说话人最常用的结构,并附上视频中的原话:
| 结构 | 视频中的用法 |
|---|---|
| 被动语态 be + 过去分词 — 强调发生了什么,而不是谁做的 | be performed · is called |
| 现在完成时 have/has + 过去分词 — 过去发生但与现在仍有关联的事 | I've never seen · We've tried |
什么是跟读法?
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧,最初开发用于专业口译员的培训,并由多语言者Alexander Arguelles博士普及。这个方法简单而强大:您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同,跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性,语调,节奏,连读,听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。












