What are Waves? (Oscillations – Waves – Physics)

Look around you carefully, and you’ll notice: mechanical waves are everywhere. On the surface of a lake, in the motion of branches, in the shape of clouds, dunes or hills. You can even find waves in the distortion of space time emitted during the collisions of black holes!

But what are these waves exactly? Are these just a shape that humans categorise and therefore, in some way, invent? Or are waves a fundamental construct of nature?

Using classical physics concepts only, I will attempt to discuss the fundamental nature of waves, and even give a shot at a non-exhaustive definition. In other words, don’t expect a straight forward answer, but a bunch of clues that will allow you to pursue your own thoughts on this physico-philosophical interrogation.

At first, I show how a wave is formed by applying a motion to an oscillator bonded with other oscillators (particles in a rope). That’s to show how a wave can emerge. I also discuss briefly the notion of emergent property.

Second, using Newton’s laws, I demonstrate that the motion in time of an oscillator is described by a cosine (or sine) curve, in other words a wave.
I connect the 1st and 2nd parts and realise that what I saw at first as an emergent shape was actually a macroscopic expression of a microscopic natural phenomena. Waves do appear as a fundamental building block of physics!

Finally, I discuss the role of waves in Physics: they transport energy from one point to another. They indeed appear as a crucial phenomenon needed to make the Universe as it is!

#physics #waves #philosophy

**** LINKS ****

**** Content of this video ****
0:00 What is a Wave? Introduction: waves are all round us
1:31 What is a wave? Is it just an emergent shape?
4:22 What is an emergent property?
5:33 What are waves? Are they a fundamental construct of nature?
10:22 Waves and Energy, what’s the link?
14:32 What are waves. Conclusion and food for thoughts.

**** Credits ****
Music by Edouard Reny.

**** More Info ****
This video is produced and presented by Edouard Reny, Ph.D. in solid state chemistry and private tutor in Physical Sciences.

For access to great resources that will help you with your studies of high school Physics, visit and subscribe to the "Physics Made Easy" website:

[Lucidthinking]

Thank you very much for the video.
It brought me some questions:

1) Can we find waves in other phenomena that do not include energy transfer? For example, if I mark a dot on a horizontally spinning wheel, to describe its position in space I need a sine function.
The kinetic energy of the dot does not change (only the direction of its velocity).

2) Can energy be transferred in ways that do not require a wave function to describe them? For example, colliding balls transfer energy. If we treat them as solid objects we don't need a wave function to describe them. If we look at the balls as composed of many atoms we might need a wave function to describe the transfer of energy between them.

3) Can we find phenomena that are described by other types of waves, rather than sin/cos/tan? Like square waves or triangular waves?

4) Why does the sine/cosine functions are so fundamental even, to movements that have nothing to do with circular motion? (like your example of the oscillating spring).

[chadchampion]

That temperature analogy was eye opening

[beyon-limits]

fantastic work Mr Edouard, this is the first time I enjoy physics
please we want more courses like this

[ajayrout]

🙏 Sir, I am from India.Sir as your channel's name suggests, you made physics really easy and understandable rather than practicing things like a robot. I am falling in love with your concepts and calmness while teaching, appreciating your effort sir❤

[Giof]

The way you teach is amazing. I was gradually understanding what your were talking about and then it finally hit me!

[micahlanboney]

You eloquently explained this concept and also showed the philosophy in physics.Thank you!!

[wilsongomes]

Certanly one of the best teacher, I discoverd in my long jorney searching for good material in web .The guy is fenomenal, lucid clear.clever.etc etc

[mcbhunter]

Such a beautiful explanation . Thank you Mr Edouard for your hard work

[tkdzkbc]

Our school system is really failing us, am a undergraduate and today from this video i understood what actually a wave is, watched 100s of video explaining amplitude oscillation etc but no body gave the meaning for a wave, am very thankful for a teacher like you who explains real logic and foundation of fudamental of a topic ❤

[shubhammangalam]

I got some real insight, thanks sir, love from india

[Bugxbounty]

Thank You For Making My Faith More Stronger In Physics! ❤

[IshrakIfti]

Man....this video blew my mind! You just earned a subscriber

[Jeredin]

One of my favorite educational videos. Thanks for sharing

[augijyotbali]

Thank you so much for this. Please keep making these vids sir! ❤️

[robertbates]

great and simple explanation. more please.

[faizazhar]

and now sir, this video of yours is now the video that made my "a-ha" moment of understanding. Thank you!

[Abkuyper]

I just laughed by the way he convinced me into realizing such a difficult concept into a generalization and realization. Thank you so much sir.

[KevinElamMusic]

Excellent video sir, thank you very much!

[harparbeenkaurkhehra]

Hello Sir,
12:31 in the sine wave that is drawn, the particles to whom the energy is given at the first place and the neighbouring particles are tending to reach their maximum amplitudes, by why at the same time the next neighbouring particles going downwards, why are they creating a downward loop?

[ricomajestic]

Enjoyed your lecture on waves and your take on waves as an emergent property. Very interesting!