Shadowing Practice: We Know More About Time Than You Think - Learn English Speaking with Video
Choose a practice mode
Each mode opens a full-screen practice room.
197 sentences
If sentences are too short or too long, click Edit to adjust them.
1
We have learned a lot about the nature of time.
2
We've learned about how time elapses at different rates if you're moving or in a different gravitational field.
3
We've gained insight into trying to understand why the future is different from the past.
4
But the deep questions that continue to puzzle me and many of my colleagues is, what is time?
5
Isaac Newton was one of the first people to try to come to grips with the nature of time.
6
And he kind of took the easy way out.
7
He basically hypothesized that there is this thing called time.
8
And he says that it flows equably in equal intervals, regardless of where you are or what you're doing.
9
He basically introduced the idea of a grand cosmic clock that relentlessly ticks forward, moment after moment after moment,
10
kind of dragging us all forward in time at exactly the same rate,
11
squaring his ideas of time with the everyday experience of time.
12
Before Isaac Newton, people basically understood time from their own experience.
13
We all have agreement on what it means to meet at a certain location at a certain moment in time.
14
And so people just took it for granted that there is this quality of the world called time.
15
And it is what allows us to impose an order on our experiences, right?
16
Time is what allows us to talk about past and present and future.
17
And those are useful concepts when we try to make sense of our common experience.
18
We find it very useful to divide time into certain intervals, right?
19
I mean, the Earth, it spins around one rotation in a day.
20
So that's where the notion of breaking time into days comes from.
21
The moon, it has certain phases as it goes in orbit around the Earth.
22
And that's what gives rise to the notion of the lunar calendar, the month.
23
And then, of course, the Earth itself goes around the sun once per year.
24
And that gives us our natural definition of what we mean by a year.
25
And so we use these natural rhythms in our everyday experience to break time down into natural intervals.
26
When Isaac Newton was trying to figure out the basic workings of the universe,
27
he recognized that a key idea is that motion is simply an object occupying different locations over different moments in time.
28
And so his laws of motion that that he ultimately developed, tried to write down a correlation between where something is and when it is at that location.
29
So the great achievement of Isaac Newton was he was able to write down equations that allowed him to predict
30
where the planets should be at any given moment.
31
And the wonderful thing is, Newton made those predictions using mathematics.
32
And then when people looked up into the night sky, the planets, the moon, just at the locations where Newton predicted.
33
That is the triumph of Newton's ability to understand how things move through space over the course of time.
34
When Newton said that time is absolute, he simply meant that it elapses at the same rate for everyone everywhere.
35
According to Einstein, the answer to that question is no, No, it depends on the motion of the object.
36
That's only true or approximately true
37
if you're not moving really quickly or if you are not in the vicinity of a powerful source of gravitational pull.
38
But if you are, according to Einstein, time is not absolute.
39
Time is relative.
40
When Albert Einstein was about 16 years old, he wondered what would it be like to travel at the speed of light?
41
You know, imagine that he gets on his bicycle and he zips along at the same speed as light itself.
42
Well, he realized that if he could go at light speed, when he looked over at that beam of light, it would hover right next to him.
43
The light itself would appear stationary.
44
Now, the problem is when he looked at the mathematics that describes the motion of light, the math does not allow light to be stationary.
45
Light can't hold still. And
46
so Einstein faced this puzzle of trying to square his expectation
47
of how light would look with what the mathematics described in terms of how light itself actually would appear.
48
He came up with a simple sounding idea that is one of the most profound insights in the history of our species.
49
He put forward the notion that the speed of light is constant, a fixed, absolute, un - changing number.
50
This is so different from any other speed of any object in the world, right?
51
I mean, if I throw a baseball toward you, right, the speed at
52
which you will think the ball is approaching you will depend on whether you're standing still
53
or if you're moving away or if you're moving toward the ball.
54
You move toward it, the speed will be faster.
55
You move away, the speed will be diminished.
56
But Einstein said, if I replace the baseball with a laser and I fire the laser toward you, regardless of whether you move toward the laser or away,
57
the speed at which it will approach you is one fixed and unchanging number, 299 ,792 ,458 meters per second,
58
a fixed, absolute, unchanging speed that is the same regardless of your motion.
59
Speed of light, absolute, constant, unchanging.
60
The idea that the speed of light is constant is
61
so profound because speed is a measure of how far something goes divided by how long it takes it to get there.
62
It therefore is a measure of distance, space, divided by duration, time.
63
And so if the speed of light is behaving weirdly, that must mean that space and time behave weirdly at very high speeds.
64
And this is what intrigued Einstein.
65
And this is what drove him to determine the weird, unexpected qualities of space and time that only emerge at very high speeds.
66
Einstein did his experiments not in the laboratory with equipment, but rather in his brain.
67
He was able to simply think through scenario after scenario,
68
allowing him to extract deep insights into the nature of the world.
69
And then he was able to put mathematics to describe these thought experiments in quantitative detail, allowing him to write down,
70
formulate mathematical equations that describe the new strange properties of space and time.
71
He found that space and time themselves cannot be constant, but rather they must change in exactly the right way so that the ratio,
72
which is what speed is, is itself constant.
73
And so, if you're talking about space and time in the Einsteinian framework,
74
they become radically unlike what Newton had in mind.
75
For Newton, space and time are absolute.
76
For Albert Einstein, space and time are relative.
77
According to Albert Einstein, if you and I have two wristwatches and they're completely synchronized, I go off into space in this direction,
78
and you and I continue to compare the rate at which time elapses on our wristwatches, we will find that they no longer agree.
79
Scientists actually do this.
80
They need to use highly precise atomic clocks.
81
And this was done back in the 70s.
82
Two scientists, they took two atomic clocks, they left one on the tarmac to put the other in a jet, and they flew that jet around the world, took the clock off the plane,
83
and compared it to the clock that they left on the tarmac.
84
And they showed different amounts of elapsed time.
85
And the differences were exactly what the equations of Albert Einstein predicted.
86
So there is no longer a universal notion of now once
87
Albert Einstein gets through with his reworking of the nature of time.
88
In Einstein's general relativity, this is his discovery in 1915,
89
he realized that there's another influence that can affect the passage of time.
90
He basically found that gravity can be thought of as pulling on time, slowing its passage.
91
And so the stronger the gravitational pull you experience, the slower time itself will elapse.
92
In fact, if you're near the edge of a black hole,
93
the gravitational pull there can be so powerful that a clock seems to freeze at a fixed moment in time.
94
Now, these are deep and profound insights, but they do not answer the question that has to do with another quality,
95
a common quality of our experience of time, which is that time seems to move toward the future.
96
It seems to have an arrow from the past toward the future.
97
Where does that arrow of time come from?
98
Entropy is a concept in physics that describes the amount of disorder in a physical system.
99
Now, what in the world does that mean?
100
Let me just give you an example.
101
Imagine a child's bedroom that's completely ordered in the morning, but then in the evening,
102
that bedroom is a total mess because the child has made use of the toys
103
and books and they're all scattered across the room.
104
Now, why is it useful to talk about order and disorder?
105
Well, that example makes clear.
106
It takes much more concerted effort to create an ordered arrangement, and it's very easy to create a disordered arrangement.
107
And because of that, left to their own devices, the room tends to go from order toward disorder.
108
And we call that going from low entropy to high entropy.
109
Everything in the universe tends to go from order toward disorder.
110
I mean, we can even do an example.
111
If we were to take these two liquids, so we have an orderly collection of coffee molecules, an orderly collection of milk molecules,
112
and if we pour the milk into the coffee,
113
we get a mixture, a disorderly mixture in which the milk and coffee molecules intermix among each other.
114
That's going from lower entropy to higher entropy.
115
And that move from order toward disorder, low entropy to high entropy is something that we recognize throughout the cosmos.
116
So a deep puzzle in physics is that But
117
when we look at the fundamental equations that we use to describe the universe, those equations,
118
regardless of whether you're looking at the ones from Newton or from Einstein or from Maxwell's describing the motion of light,
119
all of those equations share the property that they don't distinguish between forward in time and backward in time.
120
And yet our experiences are anything but agnostic
121
when it comes to the direction of time everything we experience seems to point from past toward future.
122
How do we explain that?
123
Well, one idea is to use this notion of entropy.
124
What does it mean to go into the future?
125
It means for entropy to increase.
126
And so there was a time when physicists thought that that might be the answer.
127
Where does the arrow of time come from?
128
It comes from the relentless increase in disorder.
129
Perhaps that's what distinguishes the future from the past.
130
So many things in the world appear to be irreversible, happening in one temporal orientation, right?
131
I mean, if I were to take an egg and I smash it on the ground, right, it splattered.
132
None of us have ever seen an egg unsplatter.
133
Why is that?
134
Well, here's the thing.
135
It is the case that entropy increased as the egg splattered.
136
It went from an ordered oval shape to a disordered mess all over the floor.
137
That's the natural progression from order to disorder.
138
But from the standpoint of fundamental physics, if I was to get into the molecules making up the shells
139
and the yolk and the albumin and everything that splattered when the egg splattered on the floor, if I was to reverse all of those motions,
140
then all of those particulate ingredients, they would move toward each other and they would reassemble the egg itself.
141
And so even though it appears to be an irreversible motion from egg to splatter, in principle, that splatter can be undone.
142
It is, according to the laws of physics, reversible.
143
So the hour of time seems like it might be explained by entropy, but that does not quite work.
144
Because once you recognize that the laws of physics, the fundamental laws that describe how things change,
145
if the laws don't distinguish between forward in time and backward in time, entropy, which relies upon those laws, can't explain it either.
146
So where does the argument break down?
147
If you start from any moment in time, the second law of thermodynamics says that disorder, entropy should increase toward the future,
148
but it should also increase toward the past.
149
And that symmetry between past and future is what the laws of physics demand.
150
Now, what would that mean?
151
Well, let me give you an example.
152
Imagine you have a partially melted ice cube sitting on a plate.
153
Well, you all know that as you go toward the future, entropy increases, which manifests as the cube becoming ever more melted,
154
ultimately turning into a little puddle.
155
According to the laws of physics, that same progression should hold when going toward the past,
156
which would mean that the partially melted ice cube did not emerge from a yet more solid ice cube, as our intuition and experience suggests,
157
but rather that partially melted ice cube should have begun as a small puddle of water
158
that then coalesced into that partially melted ice cube.
159
And so future and past, according to entropy and the fundamental laws of physics, on completely equal footing, entropy alone,
160
therefore, does not give us the arrow of time.
161
The best way that we have found to get out of this impasse is to hypothesize that the very early universe, the beginning of the universe,
162
must have been a highly ordered...
163
configuration, and we have been living through the degradation of that order ever since.
164
And so we hypothesize
165
that the beginning of the universe is what anchors the arrow of time by anchoring entropy at a very low value,
166
by anchoring the universe in a highly ordered configuration.
167
What that would mean is when I drop an egg and it splatters on the floor,
168
The fact that the ordered egg exists at all is a reflection of conditions at the Big Bang itself.
169
If the Big Bang wasn't highly ordered, we would never have ordered objects in the world around us.
170
We would never have ordered eggs that could splatter.
171
And so the arrow of time is anchored.
172
It finds its beginning in the beginning of time itself.
173
So that raises the question, why was the Big Bang so ordered?
174
Answer, I have no idea.
175
Nobody on planet Earth has any idea either.
176
We have ideas that we have thrown around,
177
but there is no consensus on what may have imposed this high degree of order on the Big Bang itself.
178
We have learned an enormous amount about time, both from relativity and from thermodynamics.
179
But if you were to ask me what actually is time, I still don't really know how to fully answer.
180
Time is a quality of the universe that allows for change.
181
And we notice that time has elapsed by noticing that things have changed.
182
But is that quality of time a fundamental feature of the universe?
183
Or is it something that we humans impose on the external world in order to organize our perceptions of reality?
184
These are questions that are deeply controversial.
185
And even today, we are not convinced that time itself is a fundamental quality of reality.
186
Most theories of physics that we take seriously simply assume the existence of space and the existence of time.
187
But recently, as we have been examining equations of certain ideas coming out of unified theories and string theory,
188
we're beginning to see the glimpse of a realm of reality where time itself has yet to appear,
189
a kind of timeless realm that may be a more fundamental starting point for understanding how the world exists.
190
There was a period in physics where we simply took for granted
191
that time was a fundamental ingredient in any description of reality.
192
My intuition about where our understanding will go is, I think, in the future,
193
we're going to have a new formulation of fundamental physics in which time itself does not appear.
194
And instead, we will find that time only emerges in certain environments,
195
certain contexts in which time itself becomes relevant.
196
So rather than time being something we impose from the outside into our equations, my suspicion is that in the future,
197
time will emerge from a more basic starting point, that time itself will be an emerging quality of reality.
Download App
Everything you need to speak fluently
AI PronunciationScore every sentence
IPA PracticeMaster every sound
VocabularyBuild your word bank
Vocab GameLearn while playing
Same Channel
B21
Riverdale Cast Answers the Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B21
Daniel Radcliffe Answers the Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B24
Retired Navy SEAL Explains How to Prepare for Dangerous Situations | Tradecraft | WIRED
Daily ConversationWorking Adults
B2Owen Wilson Answers The Web’s Most Searched Questions | WIRED
Daily ConversationWorking Adults
B21
Jack Black & Paul Rudd Answer The Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B2Former FBI Agent Explains How to Read Body Language | Tradecraft | WIRED
Daily ConversationWorking Adults
B22
Dolly Parton Answers the Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B22
Ricky Gervais Answers the Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B21
Rhett & Link Answer The Internet's Best Questions
Daily ConversationWorking Adults
C11
Body Language Expert Explains How to Show Confidence | WIRED
Daily ConversationWorking Adults
B23
Millie Bobby Brown Answers the Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B23
Biological Anthropologist Answers Love Questions From Twitter | Tech Support | WIRED
Daily ConversationWorking Adults
B13
TXT Answer The Web's Most Searched Questions | WIRED
TeensDaily Conversation
B27
Giancarlo Esposito Answers The Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B22
Chris Evans & Ana de Armas Answer the Web's Most Searched Questions | WIRED
Daily ConversationWorking Adults
B22
Sexuality Professor Answers Dating Questions | Tech Support | WIRED
Daily ConversationUniversity StudentsWorking Adults
B24
Urban Designer Answers City Planning Questions From Twitter | Tech Support | WIRED
Business EnglishUniversity StudentsWorking Adults
B2330
Tokyo’s Vertical Farms - The Future of Farming | WIRED
Daily ConversationUniversity StudentsWorking Adults
B22
History Professor Answers Corruption Questions | Tech Support | WIRED
IELTS PrepTOEFL PrepUniversity Students
B22
Demographics Expert Answers Population Questions | Tech Support | WIRED
Daily ConversationUniversity StudentsWorking Adults
FOR YOU
Recommend Video
C16
89 sentences
What is time?
IELTS PrepTOEFL PrepUniversity Students
C13
28 sentences
Neil deGrasse Tyson: Isaac Newton is #1
IELTS PrepTOEFL PrepUniversity Students
C111
99 sentences
Are There Lost Alien Civilizations in Our Past?
IELTS PrepTOEFL PrepUniversity Students
C12
240 sentences
Why This Is the Most Exciting Time to Be Human | Ken Ono, Axiom Math
IELTS PrepTOEFL PrepUniversity Students
C14
61 sentences
All of Astronomy in 6 minutes
IELTS PrepTOEFL PrepUniversity Students
C112
86 sentences
Who Am I?
British AccentIELTS PrepTOEFL PrepUniversity Students
B2395
35 sentences
SEtalk: Sleep Is Not a Waste of Time
American AccentIELTS PrepUniversity StudentsWorking Adults
C12
249 sentences
The Speed of Light Isn't a Limit. It's a Converter
IELTS PrepTOEFL PrepUniversity Students
C1399
7 sentences
The Cost of worldly purpose. /Ted Talks, Ted Ed/ #discipline #learn #wisdom #manage #meaning #time
IELTS PrepTOEFL PrepUniversity Students
C13
627 sentences
Brian Cox - The Most Mysterious Facts About The Universe
IELTS PrepTOEFL PrepUniversity Students
C18
30 sentences
Technology Made Us Human
IELTS PrepTOEFL PrepUniversity Students
C15
251 sentences
Two Astrophysicists Debate Free Will
IELTS PrepTOEFL PrepUniversity Students
Vocabulary and speaking notes for this lesson
This video has 197 sentences and 2776 words to shadow. The speech runs for 18:20. The speaker talks at a natural 151 words per minute, close to everyday conversation. 83% of the words are among the 3,000 most common in English; the rest is worth studying before you start.
Key vocabulary in this video
15 words from the video worth learning, with pronunciation and meaning:
| Word | Pronunciation | Meaning |
|---|---|---|
| physics noun | /ˈfɪz.ɪks/ | The branch of science concerned with the study of the properties and interactions of space, time, matter and energy. |
| disorder noun | /dɪsˈɔɹdɚ/ | Absence of order; state of not being arranged in an orderly manner. |
| fundamental adjective | /ˌfʌn.dəˈmɛn.təl/ | Related to a foundation, base, or basis; serving as a foundation. |
| equation noun | /ɪˈkweɪ.ʒən/ | The act or process of equating two or more things, or the state of those things being equal (that is, identical). |
| clock noun | /klɑk/ | A chronometer, an instrument that measures time, particularly the time of day. |
| arrow noun | /ˈæɹəʊ/ | A projectile consisting of a shaft, a point and a tail with stabilizing fins that is shot from a bow. |
| cube noun | /kjub/ | A regular polyhedron having six identical square faces. |
| notion noun | /ˈnoʊʃən/ | Mental apprehension of whatever may be known, thought, or imagined; idea, concept. |
| mathematics noun | /mæθ(.ə)ˈmæt.ɪks/ | An abstract representational system studying numbers, shapes, structures, quantitative change and relationships between them. |
| melt verb | /mɛlt/ | To change (or to be changed) from a solid state to a liquid state, usually by a gradual heat. |
| emerge verb | /ɪˈmɝd͡ʒ/ | To come into view. |
| regardless adverb | /ɹɪˈɡɑɹd.lɪs/ | Without attention to warnings or indications of bad consequences. |
| insight noun | /ˈɪnsaɪ̯t/ | A sight or view of the interior of anything; a deep inspection or view; introspection; frequently used with into. |
| partially adverb | /ˈpɑɹʃəli/ | To a partial degree or extent, incompletely. |
| anchor noun | /ˈæŋ.kəː/ | A tool used to moor a vessel to the bottom of a sea or river to resist movement. |
Phrasal verbs you will hear
| Word | Meaning |
|---|---|
| write down verb | To produce or set (something) down in writing; to record something. |
| move away verb | To go away from a place, especially when permanently changing one's residence. |
| break down verb | To stop functioning. |
| come up with verb | To manage to produce, deliver, or present (something) by inventing, creating, thinking of, or obtaining it. |
| figure out verb | To come to understand; to discover or find a solution; to deduce. |
| get out of verb | To leave, exit or escape from; to become free of. |
| go around verb | To move or spread from person to person. |
| live through verb | To survive a difficult period or event |
Pronunciation to watch
The speaker uses 21 contractions and reduced forms, such as you're, don't, can't. Say them the short way, as you hear them.
- The “th” sounds: mathematics /mæθ(.ə)ˈmæt.ɪks/, rhythm /ˈɹɪð.əm/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/, hypothesize /haɪˈpɑ.θəˌsaɪz/, thermodynamics /ˌθɜː(ɹ)moʊdaɪˈnæmɪks/
- The “sh” and “zh” sounds: equation /ɪˈkweɪ.ʒən/, notion /ˈnoʊʃən/, partially /ˈpɑɹʃəli/, distinguish /dɪˈstɪŋ.ɡwɪʃ/, configuration /kənˌfɪɡ.əˈɹeɪ̯.ʃən/
- Long words — get the stress right: fundamental /ˌfʌn.dəˈmɛn.təl/, mathematics /mæθ(.ə)ˈmæt.ɪks/, experiment /ɪkˈspɛɹ.ə.mənt/, configuration /kənˌfɪɡ.əˈɹeɪ̯.ʃən/, ingredient /ɪnˈɡɹiːdi.ənt/
How to practise with this video
- Listen to the whole video once without speaking and note the words you do not know.
- Start at 0.75× speed, shadow it sentence by sentence, then go back to normal speed once it feels easy.
- Record yourself and compare with the original, paying attention to words like physics, disorder, fundamental.
Grammar in this video
The structures the speaker uses most, with the exact words from the video:
| Structure | In the video |
|---|---|
| Present perfect continuous have/has been + -ing — an action that started earlier and is still going on | have been living · have been examining |
| Present perfect have/has + past participle — a past action that still matters now | have learned · We've learned · We've gained |
| Passive voice be + past participle — the focus is on what happens, not who does it | will be diminished · can be thought · can be undone |
What is the Shadowing Technique?
Shadowing is a science-backed language learning technique originally developed for professional interpreter training and popularized by polyglot Dr. Alexander Arguelles. The method is simple but powerful: you listen to native English audio and immediately repeat it out loud — like a shadow following the speaker with just a 1–2 second delay. Unlike passive listening or grammar drills, shadowing forces your brain and mouth muscles to simultaneously process and reproduce real speech patterns. Research shows it significantly improves pronunciation accuracy, intonation, rhythm, connected speech, listening comprehension, and speaking fluency — making it one of the most effective methods for IELTS Speaking preparation and real-world English communication.