I've been patiently waiting for Sabine to make a video on this topic. It's about time.

The past haunts me every day, whether it still exists or not.

Also notice that our memories can have differences in this manner. My memories of 50 years ago ( I am 80 ) are in a distant past...but the things I did, that I wish I hadn't, such as being rude as a teenager to someone, and we never forget, is as if it was yesterday.

Not exactly sure about what you said but i did enjoy the way you said it.

This is the first video I see on this channel. This is very refreshing to have explanations without all the usual background music, hyperactive ton of speech, or lots of graphics moving around! The calm tone of the video is very good for learning!

This video made me realize how often we are watching the past. All KZfaq videos we watch in the present were made in some recent or distant past and can be played actively as if they are now in the present. All media and entertainment that’s recorded is that way. I think that’s why stories play such an important role in human development - story is time travel.

Even though I watched a lot of science videos it is the first time I heard about the block universe. Well explained. And now I am mindblown.

I followed your Quantum Mechanics course in Brilliant, it was truly a gem :)

I do love the dry humor woven into the ‘story telling’ and then referred to again randomly…a stand up comic schtick that amazingly turns a physics lecture into a conversation between friends. Brilliant.

This starts to make sense when you think about how we percieve stars. If we observe one star that goes supernova 5 million light years away, and then another star that goes super nova 6 million light years away, each of those events happened a million years apart, and we just happen to be at the oberservable point to witness each at the same time.

The block universe idea has comforted me for years. All the dead people we know, are still doing things with us "now".

This video made me go back to an open evening I went to weeks ago with my children at a potential school which had a small farm on site.

What blew my mind is that when Sabine gave examples of 'now', she knew I was watching the video. Amazing, great video.

Yes, it does! I'm sitting here in the English countryside, on a dark winter's night, looking high above me, into a sky full of stars; many of which are now dead - but because of my unfathomably distant vantage point, are still up there shining, still ‘alive’. It then follows that an alien being sat on the other side of the galaxy, looking our way through some kind of ‘advanced super telescope’, could maybe - just maybe, see my late mum and dad, meeting for the very first time on that dizzy late summer's evening they used to tell me all about. Believe it; somewhere, everything is still alive.

.. I am puzzled by time too.. having a nice memory is a divine gift and actually works like a time machine.. I am 54 now but one mental step back I am in a moment of time when I was 4 years old...and know how I felt on that moment... that is really really a gift... that is the only time travel we are capable of doing I think, but...let's listen to Sabine !

I just have to say. I LOVE your sense of humor. Your videos are great regardless, but this just adds so much more. The frosting on the cake.

This woman can literally talk about anything and my concentration will never break

It's so clear when you explain it. I think I'll be coming back to this video often. The idea that (at least) the past always exists is the only way I've been able to cope with the loss of my loved ones.

Luv the content, gunna buy her book, also yeah she so adorable

Once again you have hit it out of the park. Grateful for the clear way you explain the observer. It leaves a straight path forward. Or maybe this is it. Thank you so much.

The strange things about getting old is that the intimate identification of here and now are slowly lost.One feels transposed into infinity more or less are alone.No longer in hope or fear, only observing.

Long ago a thought occurred to me about those films my teacher showed our class in grade school that being that the roll of film was all of time past and if you could pick a point or place along that roll is being a point in the past which you could hypothetically look at or even experience. Now it's interesting to see a smart person talking something in those same terms or similar thought exercise. Thank you for your 'films'.

Dr Sabine I graduated grade 9 With flying colors I can build a building from the Anchor bolts to the puripute You are so awesome Gary from Winnipeg

Thanks Sabine!❤ Your videos are very nice. They make me feel like I have an understanding of the topics you cover

As a working class layman, thank you for making this topic more accessible to me.

Sabine good to see you back

Got it, it makes perfect sense, the theta of trigoviani seens to hold true the way you explained but only works for nth tunnel d-1.

I just bought your book, “Existential Physics”. I can’t wait for it to arrive! You are such an inspiration to me.

When Sabine casually covers the question you have always been wondering about. 😁

There does exist some memory from the past, that is shared between people. Things that i didnt experience personaly, but have a feeling for. Or i know the attitude for it. Hard to explain. But there is something, when you are born that gives over as an understanding. But i didnt expwrience it personaly. Like the shared peoples memory.

Wow!! Beautifully presented and explained video!! 🌟☀️🚀✨️

I love the joke about Alice agreeing to be friends with you said with such seriousness 😂 Little things like this make this video even more amazing

OMG this is a truly incredible video, best one I have seen on the subject. This really is an incredibly good lecture. I have been studying this subject for many years, back then most of what I worked with was in Physical Review D and books. Some great books out there got me interested in physics and math, but I am very impressed by this video and the deep subjects you talk about. I was a math physics major, though the truth is that most of these fascinating concepts can be understood through thought alone. The math is certainly interesting. I had to see how it worked. The Tipler cylinder was my first interest, in the math model it is infinite in length so it does not collapse into a black hole. Anyway we know that time like coordinate becomes spacelike and spacelike becomes timelike, but I had to see the math. I used to talk to Tipler, and Gott on the phone way back, then later I got into Caltech though I did not go. In any case I study this stuff for fun, and this video is magnificent. BRAVO.

Loving her detailed explanations.

According to physics, Black Holes can and do warp space-time. So, were we able to determine the x,y,z where we need to enter and then amount of time we need before exiting we could effectively go back or forth in time. Quite a bit different to physically move in time, back and forth, than Observing ( t=d/v only works for linear time and only present)

I will have to watch this multiple times to understand my own example of this to confirm that this video is correct. I love this type of content.

I love the way you tell this and the subtle humor you put in between.

Every instance exists, but each version of us experiences it ONCE and as the moment changes so do we with it .... SO A DIFFRENT VERSION OF US , IS ALWAYS EXPERIENCING THAT MOMENT ...

I changed my mind Dr hosesenfelder I love your channel

thank you for simplifying these things. i almost feel like i vaguely see how these things fit toghether

I very much love your method for explaining things to us. Great job, and keep up the excellent work!

“What the hell am I looking at??” “You’re looking at now, sir. Everything you’re seeing is happening now”

just when I thought I had it Sabine hits me with a "Anything exists now, elsewhere. all obervers viewpoints are equally valid = Everything exists now".

Great video Sabine. Thanks for the added perspectives on things.

Immediately after watching this, I watched a documentary about Kurt Vonnegut, the author of "Slaughterhouse Five" and numerous other excellent novels. If for some reason you are unfamiliar with this book, it is about a man who becomes "unstuck in time". I read it many years ago. And it is the perfect literary accompaniment to Sabine's lecture.

I was watching something about quantum entanglements and trying to communicate faster than the speed of light. I don't know quantum mechanics. But how fast does a frequency travel in the frequency domain? She was showing some kind of 1 or 0 step function with quantum entanglements where one is always the opposite but the event itself is random. well I do know that a 1 or 0 would be modeled as a step function in the time domain. But then to solve those kinds of problems you have to use some kind of inner product to put them in the frequency domain where time doesn't make sense, and then it poops out an answer for you when you convert it back. That's how explain it at least. I understand the setting up the equations from physics. but i've never heard anyone explain the la place transform or other transforms pooping out answers. The professors talk about it like they don't understand it. they're just saying stuff. poles, zeros, eigenvalues, matrices, K values, and then it poops out an answer. Then you learn that the math was invented in the 1600 by people sitting alone monastery not even talking to other humans. Everyone gets on youtube trying to b.s. about things faster and slower and usain bolt and olympic medals or something and that's not how it is, and the nazis winning the olympics. If you're thinking about speed you're thinking about velocity and already choosing a direction. That's already an application and not science. You didn't discover anything to apply to create a device where you can intentionally create an event that is faster than time. So experiments that "prove" einsteins theories are correct are not really proofs. it's really an application of his theory. You for example apply a theory on making a prediction of where you will see light after it is bent by a planet. experiments in physics don't really prove anything. You can't prove physics. You can only have mathematical proofs. you can't prove postulates. and you can apply math in physics. You're illustrating an application of the theory of relativity for example with an experiment.

Wonderful explanation. It's the first chapter of her book 'Existential Physics', which is one of the best books I've read.

The information earned a thumbs up. Sabine's sense of humor earned a subscription. Sharing this with my software dev buddies.

Great explanation and i have to say you are absolutely stone cold with the jokes they are fantastic. Your stoic delivery is delightful. Perfect❤

Hmm, have been waiting for a video about this subject. perhaps this will put a deferent spin on all theories and other ideas out there. From my personal perspective is that time is interdimensional. Let me explain; I have experienced future-time and time-displacement (time-past, but somewhere else though). Future-time came in many forms, especially as a teenager, either in the form of dreams, premonitions, or simple but limited clairvoyancy. It had jumps, starting from the age of 12, then stronger at 13, and way too strong at 16, which was when i tried to close it down (it became too scary). In my tween ages, 12 and 13, my mom realised i had a "gift", and asked how i knew what was still going to happen. Quite frankly i turned around and told her there were doorways in past and future that opens up to allow us to a glimpse in time-past and time-future. However i said, "mine seems to be limited to time-future because i'm still to young..., or time-past is protected"! To explain further, as a student in Feb 1987, i had a dream so real, a reality of physically being there, blessed with a realty in terms of all my senses. In a dream I experienced the birth of my daughter! However, i had no fiancé, no girlfriend, nothing. It came to me at around 5am on a Saturday morning. It was so real and so shocking, and i felt my subconscious self slamming back into my body, which woke me up. I made a promise to myself not for that to happen ever. Then as time went on i forgot about it, met my wife in Oct 1987, and wow my daughter was born the 20th of Feb 1989. Guess the time, just after 5am. More, i experienced everything as in the dream and even knew what to do when a student nurse could not handle the pressure. The sounds, smells (which should not exist in a dream), even my clothing was 100% as in the dream (i still remember it today still)! So on to time-displacement then, 1996, at work. Just about to finish a Customs clearance and enter the final data. Had a library of info on the item in questions for tariff classification and had all the books placed on my aircon mounted in the window frame. I wrote down the info and turned around to go a few steps back to my desk. My system was not in the same programme and my newly created worksheet was gone! Bewildered i turned around to find the library (cabinet) doors closed, and no books on the aircon unit. However, in my hand i had a piece of paper with all the info i needed. It took me a long time, playing this over and over in my head to realise what had happened. I even asked the airfreight manager in the cubicle next to mine if he played a prank on me. Peter thought i was mad! Righto all, these were a few examples only to explain my own experiences and thus my view on time, but as i say to my students: "you are constantly traveing in time, every time you move from east to west you either loose or win time, depending on speed also, but remember this, time is not limited to this universe only". Cheers all, Rialgo

My heart skipped a beat when I saw that face at 3:35. Didnt expect horror from a science video. it was terrifying. I love it!

This is a beautiful debrief of Einstein's theory of relativity. I love KZfaq and content creators this is amazing

Thank you Dr Hossenfelder … you’ve done a great job of continuing my education.

Thank u for the enlightening! Greetings from Mexico

Time is experienced two ways: Chronologically or simultaneously. If you wish you can look at a clock and not think about anything but the seconds that pass in order, or you can think of a number of things at the same time. To say that the past exists is to say that it exists perfectly, ready to be experienced and/or observed perfectly with nothing missing at all; if even the smallest thing is missing or altered, it's not the past- it's something else. If the past still exists, it would be nice to know how to access it just for entertainment and reflection if nothing else. Great topic!

I once heard the block universe described as the "view from nowhen" and I still think that's once of coolest phrases. The graphics in this video did a great job of showing it along with the concept of time sliced at different angles

Thank you for this. Your presentation is quite enlightening. As well as entertaining. I love your style, your presentation.

I think it is like saying that reality is like a videotape, what happens now is being recorded by the universe and can be seen again from some other part of the universe, like how we can see things that happened a million years ago from other parts of the universe.

3d Representation was amazing

Just discovered Sabine. I love her dead pan humor and style. Being a student of Non Duality (Advaita Vedanta) I find her examples so strikingly similar to the consciousness only model that it helped me understand the notion of consciousness contracting itself via the observer to experience 3rd dimensional reality and how all there is is now and our experience of this now. Thanks

I love your big ole brain and thank you for adding some humor! I actually think I understood this and that’s bc you did a great job of explaining without too much diversion (which takes my small brain off track and then I can’t get back there.)

I find it easy to understand time as it relates to me but you mentioned space , I need further understanding of what you’re referring to . Is it distance ?

Love the videos, hard to ignore the eyes. The look right through you.

I have pre-ordered your book, Sabine. Your first book is simply amazing. A real page-turner. I can hardly wait for your new one to come. Only a few days now!

What an amazingly clear, concise, uncluttered, unmuddled description. You truly are ‘brilliant’!

I bought your book. You are amazing.

Whether it still physically exists, or not, much of my past will haunt me forever. But I try to stay positive. 😎

Just found your channel, such a fresh breath of air, love it! Thanks!

I was watching this and had a thought about "now", as it regards to time. Since nothing moves faster than the speed of light and when we flip a light switch we see the light instantly, I think that means time moves forward at the speed of light.

Sabine you are fascinating

Its 3.00am and I couldn't sleep. Just watched this video and at long last I understand Einsteins Relativity theory. It's like a mist had cleared. After decades of uncertainty over it you have now explained it! Thank you so much!!!

Thank you very, very much for your light-hearted, nicely informative videos AND your collaboration with the brilliant group! I have tried out brilliant, like it, and have recommended it to others.

Is this correct? If you travel at light speed for a week, when you stop relative to where you started could be a (?amount) yrs? So for the travel it is a week but when returning to point of origin a million yrs went by?

past somehow exists I think - but in subtle way - until it interacts with rest of universe it still in the past - but this can be broken by entanglement - so we dont need interaction in now to obtain information about what is going in far region of universe - if we measure quantum properties of entanglement particles - we may be sure they also observe same experimantal quantity (same spin etc.), but here appears practical aspect - the more far second entanglement particle is placed the less confident we can be if it is not interacted with its surrounding already - so we dont know spacetime of its decoherence event... interesting - so if we want to deal with this problem - what is probability of decoherence if particle interacts with virtual particles in vaccum itself ?

I have watched many videos about physics trying to understand all this. Without doubt, this one is the best explanation in simple terms that I have come across

In the block universe - you've just now explained this 🙂 And I appreciate the humor in the examples. Brilliant!

At 3:35, that flash of the creepy monster was a nice touch! 😁

Yes, it is like recording (but multi dimension), like tv show (2 dimension). I think we can watch it over but we cant interact.

I could listen to Sabine talk about this topic, time and time again.

Time is a fluid, like a stream flowing in one direction. Anything with mass creates drag, causing time to bend around it like a big rock in the stream. Only things without mass can move freely in the stream at the same speed as the stream itself, and thus it doesn't experience time at all.

If we changed our measurements of time we should ask, to what extent would it influence our experience of it and furthermore we need more square clockface designs

Interesting perspective along with the killer comedy. Futurama is my favorite show. Haha.

I just discovered you and OMG you are awesome! Love your explanations with just a bit of dry humor tossed in here and there :).

I love how you pepper this serious discussion with humor bombs! Thanks for making such complex ideas more understandable!

At what point of the word “now” does “now” start? Moment before pre-beginning, beginning, middle or end? I’ve always thought the word “now” is too long to say, we need another abrupt sound to be more precise 👍

I had some conversations along side with whom who never rests and keep blogging.Humanity is best form to reciprocate in gentle behavior

I truly enjoyed this, the dry humor, the information, and the speech. It’s very unique. I would gladly take a masters class with her as the teacher.

I'm so glad I've discovered this channel. This is amazing content.

It depends on interpretation??? My interpretation is ,depends where one is, ie space or on earth ,on earth =different energy systems than space ,space time depends what energies are in the area one is in ????,due to common denominator of any time is energies interactions acting on an item be it human race or an other biological system, time will work differently, due to the ways energies are used ?? = why time is a degenerative system

In general, nothing is explained about the time, it all boils down to the delay of information from the moment of the event

Spot on Sabine. A joy to follow your thought exploration 🙌🙏

Thanks for explaining this in an understandable way!

I'm living the same time all my life and millions of different events. But I am still here at the same time. The same place everything is changing with me.

Germans always speak such perfect English with beautiful accents .

Definitely going to get a copy of the new book when it comes out. I found your channel after reading your first book and I'm so glad to follow your work. Keep helping all of us stop taking things for granted and actually getting informed.

I remember reading a sci-fi story where scientists used old photographs to go back in time. Something about the photos capturing the space/time co-ordinates.

I might greatly misunderstand this video. But it satisfies me greatly. I have, as I'm sure have many others, previously thought of the experience of a lower dimensional being in contact with a higher dimension. the conclusion has been that a lower dimensional being sees a "slice" of the higher dimension. So my conclusion of how a four dimensional "ball" would look like "passing through" our perception would be a three dimensional ball growing in size and then shrinking out of existence. I'm not sure if my realization is correct now, but I've been wrong to think of an object passing through our perception. The whole world does. Each moment that passes we see a new slice of the fourth dimension. A completely new part of the threedimensional space.

IT is quite Simple thanks for explanation.

Beautiful Video! Very sharp thinking, and very well explained in a gentle and pleasant way

I've watched many videos on this topic. This is the first one that explained it in a way that I understood.