Shadowing Practice: If You Don't Understand Quantum Physics, Try This! - Learn English Speaking with Video
Ders oluşturuluyor...
1
Quantum physics is a mystique of being complicated and hard to understand.
2
In fact, Richard Feynman, who won the Nobel Prize for his work on quantum electrodynamics said, If you think you understand quantum physics,
3
you don't understand quantum physics.
4
Which is kind of disheartening for us because if he didn't understand it, what chance do the rest of us have?
5
Fortunately, this quote is a little misleading.
6
We do in fact understand quantum physics really In fact,
7
it's arguably the most successful scientific theory out there and has let us invent technologies like computers,
8
digital cameras, LED screens, lasers, nuclear power plants.
9
You know, you don't really want to build a nuclear power plant if you don't really understand how it works.
10
So quantum physics is the part of physics that describes the very smallest things in our universe.
11
Molecules, atoms, subatomic particles, things like that.
12
The things down there don't quite work the same way that we used to up here.
13
This is fascinating because you and everything around you is made from quantum physics, and so this is really how the whole universe is actually working.
14
I've drawn these protons, neutrons and electrons as particles, but in quantum mechanics we really describe everything as waves.
15
By the way I'm using quantum physics and quantum mechanics interchangeably, they're the same thing.
16
So instead of an electron looking like this, it should look something like this.
17
This is called a wave function.
18
But this wave function isn't a real physical wave like a wave on water or a sound wave.
19
A quantum wave is an abstract mathematical description.
20
To get the real world properties like position
21
or momentum of an electron we have to do mathematical operations on this wave function.
22
So for the position we take the amplitude and square it, which for this wave would look something like this.
23
This gives us a thing called a probability distribution which tells us
24
that you're more likely to find the electron here than here.
25
And when we actually measure where the electron is, an electron particle pops up somewhere within this area.
26
So with quantum physics we don't know anything with infinite detail.
27
We can only predict probabilities that things will happen.
28
And it looks like this is a fundamental feature of the universe, which was quite a departure from the clockwork deterministic universe in classical physics,
29
the kind of thing Newton derived.
30
This wave function model predicts what subatomic particles will do incredibly well, but weirdly we've got no idea if this wave function is literally real or not.
31
No one's ever seen a quantum wave, because whenever we measure an electron all we ever see is a point-like electron particle.
32
So there's like this hidden quantum realm where the waves exist, and then the world we can see, which is where all the waves have turned into particles,
33
and the barrier between these is a measurement.
34
We say that a measurement collapses the wave function, but we don't actually have any physics to describe how the wave collapses.
35
This is a gap in our knowledge that we've dubbed the measurement problem, and this is one of the things that Feynman was referring to with his quote.
36
Another confusing thing is how exactly to picture an electron.
37
It seems to be a wave until you measure it, and then it's a particle.
38
So what actually is it?
39
This is known as particle wave duality and here's an example of it in action, the famous double slit experiment.
40
Imagine spraying a paintball gun at a wall with two openings in it.
41
You'd expect to see two columns of paint go through and hit the wall behind.
42
But if you shrink this all down to the size of electrons you see something quite different.
43
You can fire one electron at a time at the slits and they appear on the back wall,
44
but as they build up over time you get a whole pattern of stripes instead of just two bands.
45
This pattern of stripes is called an interference pattern, something you only see with waves.
46
The idea is that it's the electron wave that goes through both slits at the same time, and then the waves from each slit overlap with each other,
47
and where the waves add together you've got a high probability of the electron popping up at the wall, but where the waves cancel out the probability is very low.
48
So actually on the back wall, the highest probability of finding the electron is in the middle of the slits
49
and then it goes down and then up again and down and up again and this is the interference pattern.
50
So when you fire one electron after another they follow this probability distribution
51
and this interference pattern starts building up and that's exactly what we see in experiments.
52
So this shows that electrons behave like waves in this experiment.
53
The question is what actually happens to this spread out electron wave when you do a measurement.
54
Seems like it goes from this spread out wave to this localized particle.
55
But like I said there's nothing in quantum mechanics that tells us how the wave function collapses.
56
And this is not only true for electrons but everything in the universe.
57
So this double slit experiment has huge consequences for our model of the universe.
58
And it was very surprising the first time it was done.
59
Physicists are still grappling with this question today
60
and have come up with many interpretations of quantum mechanics to try and explain these results and explain how reality actually works.
61
Ok, let's go back to the wave function.
62
We can now use this picture to explain other features of quantum physics that you may have heard about.
63
So this is just one possible wave function for an electron, but there's many others, like this one for instance.
64
This says that the electron has a probability of being over here and a probability of being over here, and very little probability of being in the middle.
65
This is perfectly allowable in quantum physics, and this is where the phrase things can be in two places at once comes from.
66
This is known as superposition, which comes from the fact that this wave can be made by adding these two waves.
67
The word superposition just means the adding together of waves, and we already saw this in the double slit experiment.
68
And it's not really a very special phenomenon.
69
You can even see superposition by dropping two pebbles into a pond where the ripples overlap.
70
Now for entanglement.
71
Let's say two electron waves meet.
72
Their waves interfere with each other and become mixed up.
73
This means that mathematically we now have one wave function that describes everything about both electrons and they're inextricably linked, even if they move far away from each other.
74
A measurement on one of the particles, like measuring if it's spin up or down, is now correlated with a measurement on the other, even if they move billions of miles away.
75
Einstein was very uncomfortable with this idea because if you measure one of the particles here, you instantaneously know what the other will be, even if it's billions of miles away.
76
And that's got a sort of whiff of faster than light communication, which is not allowed by the theory of relativity.
77
But it turns out you can't actually use this to communicate information because the measurements give you random results.
78
But the fact that they are correlated means that somehow there is a link that stretches over that distance.
79
This is called non-locality.
80
Quantum tunnelling.
81
Quantum tunnelling is where particles have a probability of moving through barriers, essentially allowing things like electrons to pass through walls.
82
When a wave function meets a barrier, it decays exponentially inside the barrier.
83
But, if the barrier is narrow enough, the wave function will still exist on the other side, meaning that there's a probability of the particle being found there when a measurement is made.
84
In fact, the only reason you're alive is because of quantum tunnelling in the Sun, which makes the Sun shine.
85
Protons normally repel each other, but they've got a small probability of quantum tunnelling into each other, which is what turns hydrogen into helium and releases fusion energy.
86
All life exists on Earth because of energy from the Sun except for life around hydrothermal vents.
87
Now onto the Heisenberg uncertainty principle.
88
I said at the beginning that this wave function contains all of the information like position and momentum of the electron.
89
We just have to do some maths on it.
90
The position is given by the amplitude or height of the wave, and the momentum is given by the wavelength of the wave.
91
But for this specific wave, the position gives us a probability distribution, so we don't know exactly where the electron is.
92
Also, there's an uncertainty in the momentum, because this wave is made of many different wavelengths.
93
But we can reduce that uncertainty.
94
Let's have a wave that only has one wavelength, so a sine wave.
95
Now we know the momentum exactly because the wavelength has a single value.
96
But look at the position.
97
There's an equal probability of the electron being found anywhere in the universe.
98
Ok, let's do the opposite.
99
Let's make a wave that has only one position.
100
Now we know exactly where the electron is, but what's the wavelength of this wave?
101
Now the wavelength is very uncertain.
102
Basically only a sine wave gives you a precise momentum.
103
And any wave that isn't a perfect sine wave, you have to build out of multiple different sine waves.
104
And each of those multiple different sine waves has got a different wavelength, and hence you have a range of the possible different values of momentum for the particle.
105
This is Heisenberg's uncertainty principle.
106
You can only know certain things precisely, but not everything.
107
Either you've got a definite value of momentum, and don't know anything about position, or you know the position very well, but don't know anything about the momentum.
108
Or you're in some intermediate state.
109
And this isn't a limit of our measuring apparatus, this is a fundamental property of the universe.
110
And finally, where does the name quantum come from?
111
Well, a quanta is a packet of something, like a chunk of something.
112
And one of the first quantum effects people saw were atomic spectra, which is where atoms give off light with specific discrete energies.
113
It works like this.
114
Imagine a string that's tied at both ends, like a guitar string.
115
If you pluck it, only certain waves can exist because the ends are tied down.
116
In this situation we say that the wavelengths are quantised to certain values.
117
The same thing happens if you tie the ends of the string together because the waves have to match up.
118
They can only vibrate in certain restricted And this is what's happening to an electron in an atom.
119
The electron wave is constrained by the atom and quantized to certain wavelengths.
120
Short wavelengths have got a high energy and long wavelengths of a lower energy.
121
This is why the light emitted by an atom looks like a barcode, because each bar of light corresponds to an electron jumping from
122
a wave with a high energy to one with a lower energy
123
and at the same time emitting a quantized photon of light when it does this.
124
where the light from an atom is quantised to discrete packets of energy.
125
Ok, so that's all the basics of quantum physics.
126
Here are some technical notes which aren't essential to know, but pause the screen now if you're interested in a little bit more mathematical detail.
127
So to round up, in quantum physics objects are described with wave functions, but when we measure them, what we see are particles.
128
So this leads to particle wave duality and also the measurement problem.
129
And the consequence of these wave functions are the quantum phenomena superposition, entanglement, quantum tunneling, the Heisenberg uncertainty principle, and energy quantization.
130
So if you understand these things you've got a good basic understanding of quantum physics.
131
Despite its reputation I think that quantum mechanics isn't too difficult for most people to get the basics of what's going on.
132
In the past I've relied on analogies to try and explain it, but here I've just described what's actually going on, which I think might be more helpful.
133
But if you've got more questions I'll be on the comments below, so ask away.
134
For me the weird thing about quantum physics is that on the one hand it's incredibly accurate and predictive, but also it's got giant holes in it like the measurement problem,
135
which we just don't understand.
136
So we can wonder, will we ever actually understand quantum physics, or is it just too abstract for our human brains to comprehend?
137
Well I hope this video has helped you understand a little bit more about how quantum physics works.
138
And thanks to the sponsor of this video, brilliant.org, who have just launched their daily problems which you can dip into if you've got a spare five minutes each day.
139
Each problem teaches you some interesting facts that you can then use to solve the problem.
140
And if you enjoy that specific problem there are links to more on the same topic
141
so you can develop your framework of knowledge around that subject.
142
And as ever if you're confused and need more guidance then you can join with the community discussions.
143
So this is a simple fun way to keep learning more.
144
If that sounds interesting go to brilliant.org slash dos
145
or click on the link in the description below
146
and the first 200 to do
147
so will get a 20% discount off the annual subscription which unlocks all of their premium content.
148
Well that's it from me, thanks for watching and I'll see you next time.
📺 Aynı Kanal
C12
The Map of Mathematics
British AccentBusiness EnglishUniversity StudentsWorking Adults
C15
The Map of Physics
British AccentIELTS PrepTOEFL PrepUniversity Students
C14
Map of Science (and everything else)
British AccentIELTS PrepTOEFL PrepUniversity Students
C1The Map of Engineering
British AccentBusiness EnglishUniversity StudentsWorking Adults
✨ Video Öner
C16
57 cümleler
Einstein’s beef with quantum physics, explained | Jim Al-Khalili for Big Think
IELTS PrepTOEFL PrepUniversity Students
B23
380 cümleler
Understand Native English Speakers with this Advanced Listening Lesson
British AccentIELTS PrepTOEFL PrepUniversity Students
C12
155 cümleler
Let There Be Light: Maxwell's Equation EXPLAINED for BEGINNERS
IELTS PrepTOEFL PrepUniversity Students
C13
80 cümleler
FINALLY: A Proof that Particles Take All Paths At Once?
IELTS PrepTOEFL PrepUniversity Students
C14
39 cümleler
Why Walls STOP Light Waves But Not Radio Waves?
IELTS PrepTOEFL PrepUniversity Students
C13
353 cümleler
Something Strange Happens When You Look Inside an Atom (Feynman Was Right)
IELTS PrepTOEFL PrepUniversity Students
C1182 cümleler
The Uncertainty Principle: What Does It Mean, How Does It Work?
IELTS PrepTOEFL PrepUniversity Students
C13
32 cümleler
What if quantum physics could eradicate illness? | Jim Al-Khalili for Big Think
IELTS PrepTOEFL PrepUniversity Students
C1552 cümleler
The Professor Who Taught People How To Think (1962)
IELTS PrepTOEFL PrepUniversity Students
C14
135 cümleler
String Theory
IELTS PrepTOEFL PrepUniversity Students
C1204 cümleler
Polarization of light, linear and circular | Light waves | Physics | Khan Academy
IELTS PrepTOEFL PrepUniversity Students
Bu dersin kelimeleri ve konuşma notları
Bu videoda gölgeleme çalışması için 148 cümle ve 2339 kelime var. Konuşma bölümü 12:35 sürüyor. Konuşmacı hızlı konuşuyor, dakikada yaklaşık 186 kelime; bu yüzden birbirine bağlanan ve zayıflayan sesler duyacaksınız. Kelimelerin yalnızca %79’i İngilizcede en sık kullanılan 3.000 kelime arasında, bu yüzden kelime dağarcığı zorlayıcı.
Bu videodaki önemli kelimeler
Videodan daha az kullanılan 15 kelime, telaffuzu ve anlamıyla:
- quantum /ˈkwɑntəm/ (isim) — kuantum, nicem. The total amount of something; quantity.
- electron /ɪˈlɛk.tɹɑn/ (isim) — elektron. The subatomic particle having a negative charge and orbiting the nucleus; the flow of electrons in a conductor constitutes electricity.
- physics /ˈfɪz.ɪks/ (isim) — fizik, doğam (doğa kuramı). The branch of science concerned with the study of the properties and interactions of space, time, matter and energy.
- particle /ˈpɑɹtək(ə)l/ (isim) — parçacık. A very small piece of matter, a fragment; especially, the smallest possible part of something.
- measurement /ˈmɛʒ.ə.mənt/ (isim) — ölçüm. The act of measuring.
- momentum /ˌmə(ʊ)ˈmɛntəm/ (isim) — itki, momentum. Of a body in motion: the tendency of a body to maintain its inertial motion; the product of its mass and velocity, or the vector sum of the products of its…
- atom /ˈætəm/ (isim) — atom. The smallest possible amount of matter which still retains its identity as a chemical element, now known to consist of a nucleus surrounded by electrons.
- experiment /ɪkˈspɛɹ.ə.mənt/ (isim) — deney (n), tecrübe. A test under controlled conditions made to either demonstrate a known truth, examine the validity of a hypothesis, or determine the efficacy or likelihood of…
- tunnel /ˈtʌn(ə)l/ (isim) — tünel. An underground or underwater passage.
- uncertainty /ʌnˈsɜːtənti/ (isim) — belirsizlik, muğlaklık. Doubt; the condition of being uncertain or without conviction.
- mechanic /mɪˈkænɪk/ (isim) — mekanikçi, makineci. Someone who builds or repairs machinery, a technician; now specifically, someone who works with and repairs the mechanical parts of a motor vehicle, aircraft…
- string /stɹɪŋ/ (isim) — ip, tel. A long, thin and flexible structure made from threads twisted together.
- principle /ˈpɹɪn.sɪ.pəl/ (isim) — prensip, ilke. A fundamental assumption, fundamental law or guiding belief.
- collapse /kəˈlæps/ (fiil) — çökmek. To break apart and fall down suddenly; to cave in.
- mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/ (sıfat) — matematiksel. Of, or relating to mathematics.
Duyacağınız deyimsel fiiller
- go on /ˈɡoʊˌɒn/ (fiil) — devam etmek, sürmek. To continue in extent.
- give off /ɡɪv ɒf/ (fiil) — yaymak, saçmak. To emit; to produce and send forth; to come across in some manner.
- look at (fiil) — bakmak. To observe or watch.
- turn into (fiil) — dönmek. To become.
Dikkat edilecek telaffuzlar
Konuşmacı don't, you're, you've gibi kısaltılmış biçimleri 39 kez kullanıyor. Bunları duyduğunuz gibi kısa söyleyin.
- “th” sesleri: mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/, mathematics /mæθ(.ə)ˈmæt.ɪks/, wavelength /ˈweɪvˌlɛŋ(k)θ/
- “sh” ve “zh” sesleri: measurement /ˈmɛʒ.ə.mənt/, reputation /ˌɹɛpjʊˈteɪʃən/, essentially /ɪˈsɛnʃəli/, interpretation /ɪnˌtɜːpɹəˈteɪʃən/, shine /ʃaɪn/
- Uzun kelimeler — vurguyu doğru yere koyun: probability /ˌpɹɑ.bəˈbɪl.ə.ti/, momentum /ˌmə(ʊ)ˈmɛntəm/, experiment /ɪkˈspɛɹ.ə.mənt/, uncertainty /ʌnˈsɜːtənti/, mathematical /ˌmæθ(.ə)ˈmæt.ɪ.kəl/
Bu videoyla nasıl çalışılır
- Videonun tamamını konuşmadan bir kez dinleyin ve bilmediğiniz kelimeleri not edin.
- 0,75× hızla başlayın, cümle cümle tekrar edin ve kolaylaşınca normal hıza dönün.
- Kendinizi kaydedin ve orijinaliyle karşılaştırın; quantum, electron, physics gibi kelimelere özellikle dikkat edin.
Bu videodaki dil bilgisi
Konuşmacının en çok kullandığı yapılar, videodaki sözcüklerin aynısıyla:
| Yapı | Videoda |
|---|---|
| Koşul cümleleri if + cümle, will/would + fiil — bir koşul ve sonucu | if you've got more questions I'll be |
| Edilgen yapı be + fiilin üçüncü hâli — kimin yaptığı değil, ne olduğu önemli | being complicated · is made · is called |
| Present perfect have/has + fiilin üçüncü hâli — geçmişte olan ama şimdi de önemli olan bir eylem | has let · I've drawn · have turned |
| İlgi cümlecikleri who / which + cümle — bir kişi ya da şey hakkında ek bilgi | universe, which was · see, which is · communication, which is |
Gölgeleme Tekniği Nedir?
Gölgeleme, başlangıçta profesyonel tercüman eğitimi için geliştirilen ve çok dilli Dr. Alexander Arguelles tarafından popüler hale getirilen, bilim destekli bir dil öğrenme tekniğidir. Yöntem basit ama güçlüdür: ana dili İngilizce olan bir sesi dinler ve hemen yüksek sesle tekrar edersiniz — konuşmacıyı 1-2 saniye gecikmeyle takip eden bir gölge gibi. Pasif dinleme veya dilbilgisi alıştırmalarının aksine, gölgeleme beyninizi ve ağız kaslarınızı gerçek konuşma kalıplarını eşzamanlı olarak işlemeye ve yeniden üretmeye zorlar. Araştırmalar, telaffuz doğruluğu, tonlama, ritim, bağlı konuşma, dinleme anlama ve konuşma akıcılığını önemli ölçüde geliştirdiğini göstermektedir — bu da onu IELTS Konuşma hazırlığı ve gerçek dünya İngilizce iletişimi için en etkili yöntemlerden biri yapar.