what i love about this is that it starts with mathematics with the kids but by the end it gradually turns into a philosophical discussion

Could they add a fetus level of explanation for me?

Love how he started with the child by asking how old they were. Just instantly relevant and on the child’s level.

“How remarkable is it that we have this brief moment that allows us to think, feel, love, explore and illuminate. How wonderful is that.” Made me sob

I'm a professional astronomer, have a bachelors in astrophysics and a masters in astronomy. He explained the derivation of the time difference between moving and stationary clocks better than any of my textbooks and professors have...

I felt like a kid watching this guy explain things. learned a lot in a short amount of "time" Well Done!

I’m constantly in awe of people like Massimo Porrati. Imagine being so intelligent you can communicate such high concept thoughts in your second language.

I was surprised how simple the conversation in the fifth level was. Super easy to follow.

I was *totally* lost in the "teenager" explanation but bits and pieces with the adults made total sense to me

So lucky to have had Dr. Greene as my professor, such a great lecturer and educator. I recently asked him a question about relativity, and his answer was so well articulated despite being almost instant. I’m really glad to see him featured in this series!

I love how both the experts have crazy socks on 😂

This ability to communicate on a single topic at all these levels is like watching art

"It might be a brief flicker on a single moat of dust floating in a cosmic eternity. But it's everything." Such a great way to put it.

The grad student could play Einstein in his younger years.

Dr Greene's body doesnt change in regards to who hes talking. A good teaching to every layman --check the ego and speak wholefully and earnestly no matter the external factors or people or pressures or even moods. Really inspiring conversation!

I'm aspiring to be a theoretical physicist and watching this really has broadened my knowledge more. He's amazing at explaining things.

As a student in Brian Greene’s Origins and Meanings of the Universe at Columbia, every lecture was existentialist like that - I sobbed in his last lecture

This dude is the teacher we all wish we had at each level.

If I had a teacher like him, I believe I would have enjoyed the sciences more and pursued it further.

I love how when he gets to the expert it becomes more of a conversation then a teaching

Brian Greene can explain the most sophisticated and complicated theories into the most basic simple terms, and that makes him the greatest gift to all fans of physics.

I read The Elegant Universe as a kid. Watching Prof. Greene walk through this was nostalgia and pure adult nerd joy all in a short half-hour. Really appreciate his love and dedication to our existence.

I like how he explains to the nine year old: if you travel in a spaceship around the world and come back, everyone else will be dead. His intense look almost make it looks like a death threat.

What smart kids though! I pulled it off but it was a challenge to really follow even at level 2 -that's how rusty the brain gets as you get older. Very endearing to see Mr Greene actively trying to understand someone else in the end, for a change. Wonderful video, than you!

Dr Greene is a great example of a scientist who also knows and understands how people learn science

These physicists sure have a great sense of style

This makes me think about the difference between the empirical measurement of time and the subjective measurement of time. When my children were young they would often get injured as young children do - by falling, tripping, all those simple things that children do. It wasn't uncommon for these incidents to happen in a room where both my husband and myself were with them, and often they were closer to my husband than me. When these accidents- incidents happened and the children would fall and cry, if they were closer to my husband I would wait for him to offer consolation to them. And so often, in my experience, he would let them sit there and cry and cry and not react. I would get so angry, until I would finally get up, walk across the room, and pick up one of our children and hold them and make sure that nothing was wrong. My husband would always say that I was overreacting, that he was about to help them. And, of course, I would think that he was making excuses for his inattention to these upset little humans in our care. Until the day a friend of ours was at the house when one of these events happened. Once again, one of our children fell, and they were closer to my husband thannto myself in a room where the three adults were talking. And again I waited, and waited, for my partner to check on our child. And again, he ignored them continuing on on his train of thought until I finally got up, crossed the room, and picked up our son. At this point, our friend commented that she had never seen me move so fast. In her experience, our son had fallen and before he had really started to cry, I was there picking him up. Yet, in my experience, you've been crying for quite some time. So, apparently, this may have been what was happening all along? My experience of time when one of our children was in distress was faster (or would you say slower?) than the people around me. I had all the time in the world to wait, get frustrated, then cross the room, and pick up our child while the other adults in the room had enough time to experience the child beginning to cry and me arriving almost concurrently. Which, to me, shows the real-life experience of the subjective nature of time as an experiential phenomenon in our physical universe. If our brains' ability to twist the experience of time so subjectively on a personal level, how can we trust anything empirically? All our our interactions with so-called reality are indeed relative to our personal observations of that 'reality.' Hence, how parenting - for me - made the theory of relativity make sense on an gut level.

High quality video in general, but especially I notice it's beautifully lit and edited. Much sensitivity. Well done, gaffer/camera dept and editor.

That nine yo girl is sooooo smart for her age!! Love her enthusiasm. Most adults won’t even get what the prof was telling her! ❤

When he was doing the calculation with the second student, I was practicing my knowing thoughtful nod I like to do, when I don't understand anything a person is saying.

The excitement on that kid's face is precious. Maybe she'll pursue science because of this

I'm a physics graduate. And the way we derive those formula that lead to the E=mc^2 took us a a whole 50 leaves ordinary notebook to completely finish it, well including the graphs and the like. It's just amazing that he simply illustrate it in a way that even ordinary viewers.can understand.

0:27 Child [Level 1: Kayla Martini] 4:05 Teen [Level 2: Maria Guseva] 10:09 College Student [Level 3: Zain Kamal] 16:16 Grad Student [Level 4: Alexander Novara] 23:56 Expert [Level 5: Massimo Porrati, PhD]

I love this series! I would love to see more, with different topics in theoretical science and humanities.

I know we all get old, but Brian Greene is someone I wish could stay young forever. It's no exaggeration to say he's one of the best humans who have ever lived.

wired's finally feeding us with physics fr

He lost me after the 9 year old and I'm a college student:)

Im so glad that Brian Green writes on a chalkboard crooked. That makes my heart happy. Im a crooked chalkboard writer teacher too. It means he is more interested in the content of his writing than the superfluous standard of how to write.

this guy has such amazing energy. I love listening to him explain.

It would be cool to see a philosopher explaining a concept episode!

omg, it is such a privilege to be taught theoretical physics by Dr Greeene

Brian is so passionate about his subject, and communicates so well -- at all levels. I love reading his books for the same reason -- he's such a great writer as well as a great scientist.

I thoroughly enjoy watching his videos and hearing his lectures. He explains things very well and is easy to follow!

I think its crazy that the expert Mr. Greene spoke to had to learn all of these ideas and information in his native language and also how to explain and express these ideas in almost flawless English.

0:48: 🕰 Time is a fundamental quality of the physical universe, and understanding it helps us understand reality. 4:27: ⏰ The concept of time is manmade, but it is still relevant in understanding the universe and its changes. 9:24: 🕒 The laws of physics do not distinguish between forward and backward in time, but our subjective experience does. 14:23: 🌌 The ultimate source of order is believed to be the Big Bang itself, and time behaves differently with speed and gravity. 18:38: 🔍 The laws of physics may prevent free will and time travel to the past, but there may be a preferred frame of reference in the universe. 24:30: 🕰 Time is a parameter measured by clocks that allows us to talk about change and causality. 28:08: 🕰 Time is a complex concept that exists as a continuum and is treated on an equal basis with space. Recap by Tammy AI

As a teen the explanation he gave to the teen was really interesting, and I learned a lot!

@22:55 That answer brought a tear to my eye. Beautiful 😭❤️

My professor told that those who have higher proficiency and comprehension in one thing, will likely simplify the explanation more easily. That's why I love this content. I can even understand physics even if I am a linguist.

Brian Green has always been so underrated. Everything he does is incredibly informative.

honestly big fan of this man - his passion is infectious

I always think of the saying “the smartest people are teachers who can share their intelligence with all levels”. Something along those lines. I love these videos, especially the science/outer space ones.

Wow I'm a mechanical engineer and I always love learning more about time dilation. His explanation of Einstein's equation was AMAZING

I understood the graduate student conversation way better than the 16 year old conversation

Anyone else find this to be so calming? This was joyful to listen to really.

Seeing Kayla get exited while learning gives me hope for our future ❤

The whole time the grad student just looked like he was really vibing out to some good jazz, lmaoo

I love this format so much! Great to learn things and at the same time how to explain them clearly and simply, which is often as difficult. Thanks!

Whats important to point out to people unfamiliar with this topic is that the perception of time passage never varies for an observer. If you travel near the speed of light while a second observer remains stationary relative to you...there will be time dilation ... time will pass more slowly and hence you will travel into the future of the second observer. But for you time on your wrist watch....on your speceship....always passes normally. Five seconds always feels like 5 seconds with a few heart beats. Its only in relative comparison does the rate of time reveal itself to have changed.

This is so sweet. Brian is such a brilliant observer in omniology. Very good at presenting difficult ideas. Not to mention very patient with his given audience. A very blessed human being. Mad respect.

I am fascinated with gravity and time and study on my free time. I'm going to change careers to pursue theoretical physics. God just watching this gives me so much purpose. Dr Greene's passion is so overt and I love it. Brings tears.

Brian is an amazing communicator and teacher. I loved this video. 30 minutes of nerdy joy.

I've been watching Brian most of his career and hes still one of my favorite science educators. Its a bit sad to see him getting older yet so am i. 😮

This series gives me hope because I’m always surprised by how advanced the kids are. I expected him to give a Blues Clues style explanation but that was actually pretty advance 😂

I've just started learning Astrophysics and watched some of his lectures on different topics and I must say that no words would ever be enough to describe how elegantly and greatly he explains science! I fell in love with Astrophysics because of him and a couple of other great people like Neil degrasse Tyson, Michio kaku & Bill Nye!

I love Brian Greene. He is brilliant and is always keen to share his knowledge in such a clear and concise way. Thanks so much!! :)

Brian Green is really amazing, always love to hear him on the incredible notions of science. Time is a central topic. I've studied Relativity and this was so fascinating and also complex. It's not a coincidence of Hawking decided to do his PHD thesis on the nature of time.

OMG that high school explanation just blew my mind.

I first saw Dr. Greene in JRE podcast. His way of explaining things that seems so complex is unmatched. I've been a fan of his interviews and podcasts ever since.

I read The Elegant Universe shortly after it was published being interested in the subject way back then and had no knowledge of who Dr. Greene was. Since then I have sought out and enjoyed what he presents in all manner of media (TV, internet, books, etc) and this is another amazing example !

29:10 made me think about Grant Morrison's description of time at the end of The Invisibles

That derivation of the Lorentz factor (time dilation formula) was so beautiful.

He lost me when the chalkboard came out. I understood everything before it 😂

These videos are a fountain of humility and amazement. I am often tripped up with the teenager level (as I was here) but handle the others fine.

i couldn't understand what he explained to the teen and felt discouraged, but then i realised i found the grad school explainations or conversations much easier to understand?

Thank you for this. I can't comprehend most. But to know that continued curious and open thought can create universes of possibility not confined by our current understanding is deeply moving to me

This makes me so excited! I’m a Sophomore in college just beginning my journey in science. I’ve chosen to do a major in physics and a minor in chemistry. The topic of time is so fascinating. I cannot wait until my job is to study all these fantastically interesting topics and questions. This guy is a legend and an inspiration!

60 years ago I was a "whiz" of an undergraduate physics major, but then I ran into my ceiling in graduate school. The same thing happened again while watching your well conceived video. Thanks for the perspective.

Wow what a beautiful explanation and so eloquent, thank you so much❤

Absolutely brilliant! The emotions when explaining and how the “students” listen with “gimme me more” is incredible. I wish. I’ve had such Professor in my time. Professor Green is exceptional human being!

Wired team i love your content….. keep doing content especially like this….one small request and suggestions make do this 5level of explanation with electrical engineering related 🙂

im 29 yrs old so thanks for this video I know my level now in the first 5mins of the video

The GPS example gets me every time ❤❤

Never imagined that derivation would be so easy to understand

Love this episode 😊 I could have listened to Massimo Porrati and Brian Greene talk all day about physics 😅

Feynmans lecture on time was truly one of best. At the end of the day it’s just conservation of energy?

Brian is one of the best science educators out there. I remember watching a pbs special on string theory as a kid in the early nineties. I Had no way to really understand what he was talking about but he explained things with such wonder and zeal that it fostered my curiosity so much that I’m still watching his videos today. I’m no physicist and have only a high school level physics education, but to this day…I devour as much science content as I can. We were on the couch the other day, I had my iPad and my wife was watching something on TV. She leaned over and said…”No one cares about quantum tunneling but you, please go in the other room and watch that stuff” LOL. Appreciate Brian for sparking my interest all those years ago.

I learned something at the first level … how to visualize the speed of light in relatable terms. Specifically, visualizing going around Earth 7 times in 1 second. It’s crazy fast, but it’s understandably fast.

I think Brian overestimates what highschoolers have learned.

Hi, I've loved your videos and just wanted to say I also love your t shirts :). First Plini and now a Tool t-shirt!!! TesseracT absolutely slaps during a good lifting session too :D

This is one of the BEST videos I have seen on UKposts EVER! 👏👏👏

I value any and all conversations on how understandable and non esoteric they are at conclusion. I have to say that initially I got lost a few times but when it came down to the final conversation I had more comprehension. THANK YOU. This was very illuminating and also comforting to me. I was very very ill in the hospital a couple of years ago and came to terms with one of the concepts you discussed of being amazed that I existed in this time and space and given the life I had been given, upon being told when I went into surgery that I may not come out of it alive , I felt at peace and just fine with it in my own right, although not so for any stress and sadness my family would feel. Ultimately, I experienced a speed up and slow down of time in that very moment. I had only moments before I would be taken into emergency surgery and infinitum to value all I had had, been and connected to. I guess that sounds very hocus pocus and unscientific at best, but listening to this discussion made me realize it probably had more to do with science than I realized.

Brian Greene is one of those scientists who, like Sagan before him, do very well embracing the prosaic qualities of such weighted topics and I love it. That his peer Porrati mentioned Vonnegut just made the video even more wonderful.

23:14 when the grad student said “it’s everything” I just started crying

I really appreciated this. Thanks 🙏 😊

That grad student should help me with my homework

Brian Greene, YOU made my high school science so easy , my teacher were confused as to why i was getting 100% everywhere and asking about Quantum Mecanic all credit goes to you and some fellow famous awesome super cool scientist ! :D much love 😁😁

My understanding stops at the high school level but still am very much exited to watch it all without understanding anything. Does that make me a fan.

Mind blowing talk

I am amazed by how well he did this, wow. Can I keep this video forever, UKposts, never delete this one.

Time on all of those levels still confuses me 😂 but i liked the explanations