For those that want more in depth information on some of the subjects I talked about in this video, here are some detailed videos I made: 1) Newton's Law of universal gravitation: kzfaq.info/get/bejne/g6egoclosZrLZGg.html - 2) Entropy: kzfaq.info/get/bejne/ipxzq7dlpqu3c4U.html 3) Electromagnetism and the speed of light: kzfaq.info/get/bejne/fLl1fZeKsb7YpGw.html 4) Special Relativity: kzfaq.info/get/bejne/kKeWaqmJzs6Repc.html 5) Einstein's General Relativity: kzfaq.info/get/bejne/quCBdpamvrKaZ4k.html 6) Quantum mechanics basics: kzfaq.info/get/bejne/nLZih6SonLTShok.html 7) Extra Credit: 4 fundamental forces of nature: kzfaq.info/get/bejne/bJxphLh716yYpWQ.html

Well if your going to teach physics you gotta start from the beginning, it’s a warm summer evening in Ancient Greece

I like how he explains the speed of light at the speed of light.

It’s insane that the same subject I hated and was forced to learn in school is the same subject I am up at midnight binge-watching for fun 🤩

I'm late to this party but I wanted to let you know that your explanation of relativity and the graphic of the two trains has helped more of my physics students than any thing else I have come across. Simple. Elegant and accessible. Thanks for the great videos.

5 yrs of engineering and I still don't really get entropy

As a physics PhD student, I gotta say, your videos are some of the best I’ve seen at explaining physical phenomena. Thank you for making these to have more people interested in physics, everyone should appreciate the beauty of this subject.

This is exceptionally explained. I was also a student of physics and can somewhat understand the complexities involved. I only wish that he should have taken half an hour instead of 15 minutes. Hats off to you Sir and thanks.

First day of 2022 and I’m sitting here with a Blunt digging deep into this. Quantum Mechanics has peak my interest heavy. Thanks for the content ! Science is life.

When your final Physics exam is in 15 mins and you barely studied anything:

Physics is not about remembering , Physics is about Concept - Walter Lewin

4 years of engineering and i have to say he got most of the useful stuff for anyone in here. It's always nostalgic seeing how easy some of those equations look at first glance XD

I never truly understood the difference between weight and mass until I heard your explanation. Thank you.

Still a very underrated channel.

Duuuuude. For years and years I never understood why time slows down when you move faster. Your diagram with the two flashlight beams completely cleared it up! Subscribed.

Arvins videos should be mandatory learning for fundamental physics courses taught in our educational institutions. They are similar to the mechanical universe series video courses and describe various principals of physics with astonishing simplification and clarity. Bravo Arvin.

you explained physics in 15mins better than my professors did the whole year !!! total support

I’m an art student who slept through almost all of those classes, failed miserably on both math and physics in high school, yet somehow youtube is making me fascinated by them rn.

Here we go boys. I'm about to become a physicist.

You're one of few people who can give me a headache and still make me smile and like your videos.

The chillest, most informative, coolest KZfaq channel! Really good when one once had more detailed knowledge but it faded. This brings back a framework of context. Reflecting on it, I then begin to piece the details into place. Love it!

Newton: “Okay let’s just use this small apple as an example of one Newton for this demonstration on my theory” Physicists hundreds of years later: 1 Newton = one small apple

Me: I feel like I know everything Exam: “*gets 0 score*”

its 1:42am and i have to go to work at 7:00am, but thats a good video bro

Years of physics and never understood why time slows down but this video made me finally understand it

He is expressing all phenomena better than my professor.

Excellent. This is the most important thing we have: science and knowledge, not money

As professional in subject and being skeptical about 15 mins of physics want to say big thank to author - good job.

THis was pretty epic. I love where he is coming from with this. His heart is in a great place.

Arvin, You do NOT know how thankful I am for this video. I've always been interested in physics since my childhood, but gave it up later as a rather foolish act of rebellion against the forceful insistence of my parents that I become a doctor. (They themselves are both doctors and I am from an Indian family, so you can imagine what pressure I was in) Anyhow, since the education system in our country is structured such that all science graduates must go on to become doctors, I gave up the sciences, and having done so, I pursued Law at University. These details about my life, youth and interests will no doubt bore you, but the reason I state these is that as a practicing lawyer who never had this interesting of a science teacher as you clearly demonstrate yourself to be at any period of my school life, I feel forever indebted and grateful to you from the bottom of my heart for so artfully piquing my long lost interest in science once again, to the point where I have now decided to expand my knowledge in the sciences in the duration of these rather unexpected days of pandemic where I am mostly at home with little to no clients in my practice. Thanks a lot once again!

Always gets me hyped when he says "...that's coming up right now!". Well played Mr. Arvin, well played.

I watched a dozen videos dozens of times on time dilation.. from your very simple explanation I think I finally get it a little.

Sir, you are no bald ape. Do not sell yourself short. :-) you are a gentleman and a scholar. Such eloquent video delivery. Bravo thank you

If any Indian students are seeing this , then remembered and learn this whole video line by line because whatever in this video says this is a summary of class 11th and 12 th physics in India...by understanding this video properly can lead u to feel easy to understand class 11 and 12 th physics.

Key takeaway from this video: I weigh about 712 apples.

14:10 - Say my name.

Every single movement of life can be explained by physics and that’s the magic of physics and you prove it very well ..

8 years of physics lesson in just 17 minutes

i like how my physics teacher kept coming up with more complex fornulas from a very basic equation like f=ma

I can’t figure out what science I want to study for college, so I’m exploring physics, geology, chemistry, ecology, etc. through this! It’s hard when you have an interest in everything, bc it’s all connected anyways. Thank you for this!

Author: “Your weight is a force, not a mass” Me:

Outstanding graphics! The Professor we all wish we had.. A pleasure to watch Arvin.. The ONLY regret I Have is that there's nothing controversial to debate in the comments..Thanks.

I swear you are a hero and a savior to students world wide. thank you for helping a new generation of future physicists and others, find joy in the topic youre passionate about

Wow, first time it made sense to me that time is in fact relative... great job in explaining it!

Physics makes me happy! Seeing the connections of the universe is just amazing!

Really a video worth watching. Whenever I feel really negative about physics being attacked always by the odds in "classrooms " and "exams", this video heals me! Though I watch, I can't understand all of them,hope to understand in the near future!

When it’s 15min before the physics exam

Studying for 13 years just to forget it and see a man in KZfaq explaining it in 15 mins.

At 3:19 (for those who are actually studying from this video) the distance is taken from the centres not the boundaries of the objects! Probably it was a editing glitch but nice explanation! Loved it❤️❤️

Ha! Watching this video increased the entropy in my brain....I think. lol

I'm a bachelor of physics and I'd just like to say this video is great, what an excellent way of explaining these phenomena! I wish there were more videos like this that were shown to me in high school or in primary education. I feel that people don't realise how truly fascinating the universe is until learning these concepts. Great job 👍🏻

When he started listing the 5 main branches of physics I paused after the first one and guessed the rest 4/4. I'm now slightly proud of myself

*He is explaining stuff that professors and teachers have failed to explain over the years, again and again*

I'm a physicist myself, but I really love your discriptions and like your approaches to different phenomena. Great video again 👍

the best explanation for time slowing down when you move faster I have ever seen.

The apple 🍎 as a reference of unit force and unit work is brilliant!

I have a Master's in Physics and I'm a civil engineer. Always nice to have refreshers.

Because of the efforts of you men the quality of my life is profoundly enhanced. When I graduated high school I didn’t understand algebra. I was so incredibly weak in mathematics for most of my life. KZfaq did something for me that college lectures never could. I don’t know what it is but I just learn from KZfaq. Thank you.

This is something id watch at 4:00 in the morning when i am supposed to be asleep way before that

As an engineering student this went above and beyond as a brief introduction to physics and I learned a good bit

I wish I had a teacher like Arvin. Thanks again, I wish to meet you in person someday.

I really wish I took physics in high school! I wasn’t interested, fast forward 30yrs, I can’t get enough! Thanks for your videos man!

Astounding. I think every individual with any interest in science should watch this video once a year, starting at age 10. Initially, this will serve as a sort of baffling introduction; later, as a review and something tying everything together. Congratulations on this.

3 years of being engineering and Thermodynamics still fucks me over

Why this channel is so underrated. He is explaining so nicely

I wish my teachers made physics as clear and as interesting as you just did.

Thank you so much for your insight and for how you rendered these deep and hard concepts palatable!

Of all the studies in school, physics seems the most obvious and natural...I think we innately understand it even before we start school.

First time learning about physics a month ago. I got A’s in all quiz and tests so far. This video made me understand WAY MORE than I did earlier. Thank you

If only all teachers could explain like this I would deffo not be bored

This video truly lives up to its title, condensing an enormous amount of information on physics into a 15-minute video is no easy task, but the creator has done an admirable job. The explanations are concise and to the point, making it easy to grasp even for those with little prior knowledge on the subject. The visual aids used in the video are excellent, they help to explain the concepts in a way that text alone cannot. It's a valuable resource for students, educators and anyone looking for a quick and easy way to understand the basics of physics. I highly recommend It. As an engineer who has always been passionate about math and physics, I was intrigued by modern physics, despite neither relativity nor quantum mechanics were part of any course syllabus at my university. I studied these subjects on the side and found them really inspiring, I would go as far as to say that they gave me a novel perspective on life itself. That prompted me to create some online courses on Udemy on Quantum Mechanics, Quantum Field Theory, special and General Relativity. It’s not my job of course, but I love talking about these topics ans showing the "intution" behind the mathematics.

This was so incredibly informative and easy to follow. In this day and age, I wonder how I managed to stay fully concentrated at a 17 minute video. Absolutely beautiful

Thanks for the refresher. It's like being in a high school physics class again. Your channel has become reference material.

It’s summer. I don’t know why I find myself watching this stuff.

If only everyone, in every subject in school had teachers like this, we would be a much better educated humanity. Of all the teachers I had from K through 12 I don't remember a single one, so little was their impact. I certainly never had one like this guy. This video should be played on a loop to newborn babies as they are growing up.

feels gratifying when you already know the basics of the subjects mentioned :)

whoa. i really should use KZfaq back when i was studying.

Arvin you are the clearest physics instructor on KZfaq - you deserve millions of views.

what i learned in 6 year just resumed in 17mn and its actually pretty good ,it made many thing clear

Thank you so much for the Videos. Greetings from India , from the State of Odisha. I am running for orphan in Odisha for Poor Children, we are learning Lot of Information from This Video

This needs to be recommended to action filmakers..lol😂

you need more subs man. I'll be starting my physics journey in university 5 months from now and you explain all sorts of phenomena so simply so we can understand it better and faster. thank you

Im stoned asf and ngl this changes my view of life, view more videos on KZfaq! Not even schools and colleges explain it so easy that it makes sense. These videos ate underrated

The video starts by saying it's impossible to teach physics in less than 20 minutes but I think what he meant was... 20 years. Kudos to anyone born gifted enough that they don't find this stuff incredibly complicated, because most of us do!

i'm in 11th and now i finally feel that all those years of studying were worth it!

Answer Gravy: This isn’t part of the question, but if you’ve taken intro physics, you’ve probably seen the equations for kinetic energy, momentum, and acceleration in a uniform gravitational field (like the one you’re experiencing right now). But unless you’re actually a physicist, you’ve probably never been freaked out by seeing a Lagrangian work. This gravy is full of calculus and intro physics. The “action”, S\left(\vec{x}(t) ight), is a function of the path a system takes, \vec{x}(t)=(x_1(t),x_2(t),x_3(t))=(x(t),y(t),z(t)). More specifically, it’s the integral of the Lagrangian between any two given times: S\left(\vec{x}(t) ight)=\int_{t_1}^{t_2}\mathcal{L}\left(\vec{x}(t),\dot{\vec{x}}(t) ight)dt where t1 and t2 are the start and stop times, \vec{x} is a path, \dot{\vec{x}} is the time derivative (velocity) of that path, and \mathcal{L} is some given function of \vec{x} and \dot{\vec{x}}. If you want to chose a path that extremizes (either minimizes or maximizes) S, then you can do it by solving the Euler-Lagrange equations: \frac{\partial\mathcal{L}}{\partial x_i}=\frac{d}{dt}\frac{\partial\mathcal{L}}{\partial \dot{x}_i} This is called the Euler-Lagrange equations (plural) because this is actually several equations. Each different variable (x1=x, x2=y, x3=z) tells you something different. In regular ol’ calculus, if you want to find the value of x that extremizes a function f(x), you solve \frac{df}{dx}=0 for the value x. Using the Euler-Lagrange equations is philosophically similar: to find the path that extremizes S, you solve \frac{\partial\mathcal{L}}{\partial x_i}=\frac{d}{dt}\frac{\partial\mathcal{L}}{\partial \dot{x}_i} for the path \vec{x}(t). The Lagrangian from earlier, for a free-falling object near the surface of the Earth, is: \mathcal{L}=\frac{1}{2}m\left|\dot{\vec{x}}(t) ight|^2-mgz(t)=\frac{1}{2}m\left[\left(\dot{x}(t) ight)^2+\left(\dot{y}(t) ight)^2+\left(\dot{z}(t) ight)^2 ight]-mgz(t) For z: \begin{array}{l}\frac{\partial\mathcal{L}}{\partial z}=-mg\\[2mm]\frac{\partial\mathcal{L}}{\partial \dot{z}}=m\dot{\vec{z}}(t)\\[2mm]\frac{d}{dt}\frac{\partial\mathcal{L}}{\partial \dot{z}}=m\ddot{\vec{z}}(t)\end{array} So the E-L equation says: m\ddot{\vec{z}}(t)=-mg or \ddot{\vec{z}}(t)=-g In other words, “everything accelerates downward at the same rate”. Doing the same thing for x or y, you get \ddot{\vec{x}}(t)=\ddot{\vec{y}}(t)=0, which says “things don’t accelerate sideways”. Both good things to know. You wanna be even slicker, note that this Lagrangian is independent of time. That means that \frac{\partial\mathcal{L}}{\partial t}=0. Therefore, applying the chain rule: \begin{array}{rl}\frac{d\mathcal{L}}{dt}=&\frac{\partial\mathcal{L}}{\partial t}+\sum_i\left(\dot{x}_i\frac{\partial\mathcal{L}}{\partial x_i}+\ddot{x}_i\frac{\partial\mathcal{L}}{\partial \dot{x}_i} ight)\\[2mm]=&\sum_i\left(\dot{x}_i\frac{\partial\mathcal{L}}{\partial x_i}+\ddot{x}_i\frac{\partial\mathcal{L}}{\partial \dot{x}_i} ight)\end{array} But we have the E-L equations! Plugging those in: \begin{array}{rl}=&\sum_i\left(\dot{x}_i\frac{d}{dt}\frac{\partial\mathcal{L}}{\partial \dot{x}_i}+\ddot{x}_i\frac{\partial\mathcal{L}}{\partial \dot{x}_i} ight)\\[2mm]=&\sum_i\frac{d}{dt}\left(\dot{x}_i\frac{\partial\mathcal{L}}{\partial \dot{x}_i} ight)\end{array} And therefore: \frac{d}{dt}\left(\sum_i\dot{x}_i\frac{\partial\mathcal{L}}{\partial \dot{x}_i}-\mathcal{L} ight)=0 This thing in the parentheses is constant (since it never changes in time). In the case of \mathcal{L}=\frac{1}{2}m\left[\left(\dot{x} ight)^2+\left(\dot{y} ight)^2+\left(\dot{z} ight)^2 ight]-mgz we find that this constant thing is: \begin{array}{rl}&\sum_i\dot{x}_i\frac{\partial\mathcal{L}}{\partial \dot{x}_i}-\mathcal{L}\\[2mm]=&\left[\dot{x}\frac{\partial\mathcal{L}}{\partial \dot{x}}+\dot{y}\frac{\partial\mathcal{L}}{\partial \dot{y}}+\dot{z}\frac{\partial\mathcal{L}}{\partial \dot{z}} ight]-\mathcal{L}\\[2mm]=&\left[\dot{x}(m\dot{x})+\dot{y}(m\dot{y})+\dot{z}(m\dot{z}) ight]-\left[\frac{1}{2}m\left[\left(\dot{x} ight)^2+\left(\dot{y} ight)^2+\left(\dot{z} ight)^2 ight]-mgz ight]\\[2mm]=&\frac{1}{2}m\left[\left(\dot{x} ight)^2+\left(\dot{y} ight)^2+\left(\dot{z} ight)^2 ight]+mgz\end{array} Astute students of physics 1 will recognize the sum of kinetic energy plus gravitational potential. In other words: this is a derivation of the conservation of energy for free-falling objects. A more general treatment can be done using Noether’s Theorem, which says that every symmetry produces a conserved quantity. For example, a time symmetry (\mathcal{L} doesn’t change in time) leads to conservation of energy and a space symmetry (\mathcal{L} doesn’t change in some direction) leads to conservation of momentum in that direction.

Amazing! I'm gonna share this with my classmates.

Thank you, and cool video! I’m definitely going to watch this more than once because, I’m new to most this stuff.

I didn’t think this video would be very interesting for me since i spend a lot of time learning physics already, but your entropy explanation was really great. Def got my thumbs up on the video because of that. -edit This whole video was explained amazingly. You went through all the basic concepts so well, i haven’t seen another video before explained so perfectly. Great job man.

I'm 14 and I live in Holland, I am trying to understand it and I can understand it a bit and people call me stupid in school.

That was awesome being that I am relatively uneducated compared to the people who study this stuff. Kudos to you for an awesome video. Still have to watch each segment a few times before I can grasp them and I still can’t fully wrap my head around it. Lol

His explanation was great I understood concept very well.

The best speech so far of the general concept of physics, thank you!

I don't know anyone else who can cover whole physics so efficiently within 20 mins. Thanks for making this video sir!

Some of this hurts my brain. 😁 I think learning this is great. I also think learning about things and history is great. But I now believe the most important thing to learn is how people think and how their egos warp their thinking. Understanding people would have made a much greater difference in my life than knowing things.

Bruh every classroom everywhere should have a video like this before the course

Arvin - many thanks for this. I’m going to show it to all my engineering students after I’ve shown them where the fundamental units come from.

If you know everything about every single particle in the universe, you can actually predict the future.

I never seen this type of teachers He start. From 9 to 12 hats off sir 🙏🙏

If only school taught physics like this for me. This is so much easier to understand.