Does the Past Still Exist? 

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.

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

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.

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 RU-vid 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.

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

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 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.

I suppose it then goes deeper from a Catholic understanding of the Trinity. Yet it is odd that many of my fellow Catholics do not understand The Holy Trinity is our central mystery. John Wheeler once said time is nature’s way of ensuring that everything does not happen at once. And this is so strangely accurate. In some sense there is God the Father (past), God the Son (present), God the Holy Spirit (future). We have One God in Three Persons. But then the perception of time goes deeper. There is a ‘Present’ that is everywhere at once. Right now it is the Present. But if I wait a few seconds it is still the Present. And if I wait a Thousand Years, it’s still the Present. What divides the Past & Present yet retains so interconnected? Once upon a time I’ll pass on to the next For as soon as I am here I’ve left. However this is merely how you perceive. For I never really change and yet still continue to weave. I am reminded of that old poem from long ago: “Has it ever struck you that life is all memory, except for the one present moment that goes by you so quick you hardly catch it going?” -- Tennessee Williams As Jordan Baker noted, Augustine thinks that a particular concept of time-“deictic” time-metaphysically (not just epistemically) depends on minds. That term, deictic, comes from linguistics and is used to describe words that mean the same thing but refer to different things depending on their context. For example, here, now, and I are all deictic words. They each have the same meaning no matter who speaks them, but they pick out different things depending on who speaks. Deictic time is the supposedly objective now that we all experience from within our own independent contexts, and Augustine connects this idea to a certain notion of change. For Augustine, deictic time is “flowing time.” Whereas eternity “abides,” temporal deictic time passes through past, present, and future; it passes out of being. Augustine claims, then, that there is one objectively existing time, the present, and that the other “times” are just shorthand for operations the mind performs on that fleeting present. As he states... It is manifest and clear that there are neither times future nor times past . . . perhaps it might be said rightly that there are three times: a present of things past; a present of things present; and a time present of things future. For these three do coexist somehow in the soul, for otherwise I could not see them. I suppose it's how you see it because it is indeed a paradox, a cheerful shortcut through logic. Some have suggested the sky is dark because our universe is confined within a huge black-hole. But we can still shine like stars BRIGHTLY within the singularity for others to paradoxically see through the absolute darkness of a gaussian electromagnetic field which linked all the frequencies -- a liquid-light show broadcast along all spectrums at Absolute Zero -273.15 degrees Celsius showing social behavior.

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.

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

.. 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 !

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'.

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

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.

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

This is the silliest thing ever. Sabine is just one of many who are misguided by the how their own existential conflicts are driving their beliefs and behaviors.

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.

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

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

Sabine good to see you back

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

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

Germans always speak such perfect English with beautiful accents .

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

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.

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

Loving her detailed explanations.

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

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.

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

3d Representation was amazing

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

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

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

The past does exist but we cannot change it, if we somehow can it turns into a different timeline. We can’t travel into the future because it has not been written/happen. If we can that means somehow we living another like where that future is already written.

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".

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

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.

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.

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!

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.

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

Thank u for the enlightening! Greetings from Mexico

Your past will not cease to exsist, until you pass away.

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.

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

*As seen in the novel/made-for-TV-movie "The Langoliers" by Stephen King.* *"They ate up Time and it had a bad taste."*

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

All events exist now. 🤯 That is just crazy. Anything that's ever happened can be happening right now as long as you're in the right place at the right time.

I've been metal detecting for 35 years. Each time I find a roman coin or medieval buckle I'm always aware I'm the first to see this light since it was lost. A direct link between Two periods of time.

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

I changed my mind Dr hosesenfelder I love your channel

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

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

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)

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 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.)

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

With respect to human consciousness, our past still exists in our memory...

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

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!!!

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.

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 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.

Perception is key. Maybe everything is happening simultaneously but we can only perceive in a linear fashion.😊

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!

My past continues to haunt me to the brink of insanity

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

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

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.

Sabine you are fascinating

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

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

I bought your book. You are amazing.

Time is always discussed in terms of observing the light emitted from the event reaching the observer. After that, some graphics tweaking.

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.

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 am puzzled not by whether past still exists, but by how she eats without separating the upper and lower jaw

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

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

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

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

So online video games. Response time, ping, latency. Lag. What I see on my screen differs slightly from what my counter players sees on their screens. The position of my character from your perspective. The position of your character from my perspective. Many factors in play. Just thinking and overthinking. But I guess that is how us humans works. We seek answers to questions that we kind of make up ourself. And we find them in calculations.

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

Thanks for explaining this in an understandable way!

And pluck till time and times are done, the Silver Apples of the Moon, the Golden Apples of the Sun. .."The Song of Wandering Aengus." Willuam Butler.

Yes, I believe it does, as does the future, on a course, heading, and distance that we cannot reach at sub-light speeds.

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

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

I'm normally pretty skeptical but the subtle turn to the right shows it is indeed your good side

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.

Love your content. Thanks for making these for us.

Every moment exists as its own point time passing over like a film layer giving us the illusion of life

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 wish there were more people in the world who ask these questions... Instead of burying their heads in the sand or following the nightly news brainwash program.

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 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