Does the Past Still Exist?

To try out our new course (and many others on math and science), go to brilliant.org/sabine. You can get started for free, and the first 200 will get 20% off the annual premium subscription.
Albert Einstein taught us that space and time belong together to a common entity: space-time. This means that time becomes a dimension, similar to space, and has profound consequences for the nature of time. Most importantly it leads to what has been called the block universe, a universe in which all moments of time exist the same way together. The future, the present, and the past are the same, it is just our perception that suggests otherwise.
💌 Sign up for my weekly science newsletter. It's free! ➜ sabinehossenfelder.com/
👉 Support me on Patreon ➜ / sabine
📖 My new book "Existential Physics" is coming out in August ➜ existentialphysics.com/
0:00 Intro
00:58 Space-time
02:09 Space-time diagrams
03:40 Special Relativity
05:05 The Relativity of Simultaneity
10:36 The Block Universe
12:46 The if's and but's
14:50 Sponsor Message

[@Master_Therion]

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

[@brothermine2292]

It had to happen.

[@sparkyfromel]

it's all in the past now

[@FarfettilLejl]

This video had always existed, you just needed to wait for it

[@MeppyMan]

I see what you did now.

[@w3vjp568]

Dad?

[@Gliese380]

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

[@stephenpalmer-zh9dq]

it is ALWAYS THERE

[@margaretmorrissey2714]

It's not the past doesn't haunt us, it is us who haunts the past.@@stephenpalmer-zh9dq

[@stratocasterblue]

Your thoughts are not you

[@SsuperNnova]

Felt

[@stratocasterblue]

If you start exercising everyday the bad thoughts will stop but you have to everyday, its a way of telling your mind what its going to do

[@richclarke1523]

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.

[@user-tf9yy5uq9p]

@richclarke1523 Hi Rich, it was so good to read your comment! I hope you can at least find some comfort in the fact you remember your rude teenage years with regret. It means you've gained the empathy that you lacked in the past. You should feel good about that, since so many people still have not evolved from their bad behaviour. And even worse they have no self awareness, and they have no clue of how others perceive them.

[@valicourt]

I have forgiven you

[@jimihendrix4376]

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

[@bvbxiong5791]

she lost me at the intro when i didn't have enough time to read where the little hand and the big hand were pointing to.

[@jesusislord-ht1nj]

You have to be a Godless moron to think anything she said is worth more than falling asleep to.

[@SailBoatJones]

Lmao

[@christinablacken3043]

This video made me realize how often we are watching the past. All KZbin 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.

[@darith770]

Thanks Capt Obvious

[@UNIRockLIVE]

Only if its honest

[@UNIRockLIVE]

​@@darith770poor trolly mad in the comments

[@stuart23969]

History books can take me back

[@the_kombinator]

Memories too.

[@kurisutofusan]

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!

[@whitetornado603]

Same here. perfect for learning

[@sonyavincent7450]

Absolutely love videos without background music.

[@rupes96]

I agree, ton of video looking for watch time and less explanation.

[@mireazma]

Because she's not American. I'm glad there's someone else who hates the "hyperactive tone of speech" 👏

[@MakiPavlidis]

I do love her channel's videos, and this is a big reason. However... the recent hydrogen power video would have greatly benefitted from 90% less "under pressure" gags. 🤷

[@mikey1836]

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

[@ashokkumar-se5sl]

REAL LADY SPEAKING OR AI ..

[@joelhubeny7554]

Yes as Energy or the Negative charged electrons but our human life span isn't a Mini Micro Blip coppered to all of all Existence. So it still nothing. Like the amount of Electromagnetive waves that Negitive Charge releases and we only see the visible light spark. it's absolutely Nothing to the whole

[@Flylikea]

It's "now", and the information of "now".

[@joelhubeny7554]

Now is just a Micro Nano Second moment moving through Space/time. it's gone before you can count it because Negative Energy is always moving towards the Positive.@@Flylikea

[@princeofallnegros4035]

Huh. U see dead people? 😮

[@FCDHVleerstraat]

.. 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 !

[@idiot.driverspittsburgh.ed8811]

Except that psychology shows that our brains slightly change memories each time access them….

[@SuperWingram]

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.

[@mokeish]

Physicist humor =]

[@davidjoseph7142]

Does the past still exist? Depends on whether you remembered to hit save

[@miashinbrot8388]

Yes, I love Sabine's dry humour also. The first few times I watched her videos I didn't notice it, because it's subtle -- but it's worth watching for.

[@miashinbrot8388]

@@mokeish Not quite the same as math humour, but it's all relative. ;-)

[@lnyitrai]

I love (and respect) her, but I think all the puns are horrible, borderlining disturbing.

[@painisvergina3693]

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

[@fidacuca]

Not ugly too.

[@Juice-chan]

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.

[@hartpa]

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.

[@edwardsp1916]

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

[@deciduousrex1219]

You hadn't disappeared yet.....

[@DukeJon1969]

It's uncanny

[@struggleboy2927]

🤯🤯🤯🤯🤯🤯

[@dylanmorrow263]

This gonna blow your mind.. but when you read this you will be watching again 😱

[@linuxbeastmaster9192]

Time is irrelevant what happened already happened, what will happen will happen, understanding this will free you from the clock. If time was relevant talking about this would be a waste of time.

[@FailBucketFilms]

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.

[@phantasticmrphasma9874]

This is the problem with knowledge and research. Some people are not naturally intelligent enough to comprehend it. Some ask “if a tree falls and nobody is there to hear it, does it make a sound” This stupid ‘but how do we know’ mentality reveals those who lack intuitive intelligence. It is a self-centric viewpoint. Light exists. Light travels at particular speed. It takes a relative (i’ll use the word) duration for light to travel a set distance at that speed. Yes those two events happened, at a duration we measured to be, a million years apart. These things are true. Focusing on the ‘meaning’ of this is self-centric. Those things happened and those were the factors. But that does not mean time exists or that the past still exists. The explosion that caused the light happened and then ceased, but the light created continues. I don’t know how or what exactly causes these phenomena or if existence is finite or not or even if there IS actually a creator, but it’s the ego that drives people’s theoretical wandering, beyond the realms that we are capable of. Time does not exist. It is merely a word we used to label a duration of moments. Time travel will never be possible in any way other than a technical way (ie. Australia are ‘technically’ in the future - but they are NOT in the future, they are in the same place, just at a different distance so are subject to different factors. Some people will get what i’m saying here, and some people aren’t capable, as they can only grasp things through technical language, limited to the definition of said language without the personal means to interpret the grey area. Objects exist before the labels we give them, and the objects are the inescapable truth, but the language can be inherently flawed

[@phantasticmrphasma9874]

I hadn’t even watched the video when i wrote that. 5 minutes in: “how do you know your phone is there? You don’t” 🤦🏻‍♂️ ‘I think therefore i am’ - the ultimate self-centric expression of ego through philosophy

[@mexreax4493]

We don't even know if that is true.

[@bombomos]

​@@mexreax4493 it's true. Light has a defined and observable speed. We can only see things through light. So anything that happens a far enough distance is the after image we are observing. Take the sun for example. It takes light 8 minutes to travel to earth from the sun. That means that if something like a planet passed Infront of the sun. We would still see the planet Infront of the sun when in reality the planet at that specific time has already moved out of the way of the sun.

[@MuchCow9000]

Thar "old" light doesn't exist. What we see isn't the old, it's the new part of the old. This argument is parallel to the river argument. In philosophy, the river argument states that if you step into a river, you aren't stepping into the same river twice since its constantly changing, but yet we call it the same river. The same can be applied to this. We can label the light old since it comes from the "old star". But the light has changed many times before it got to you. Therefor the light isn't really old, it's new.

[@DrewSoucy22]

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.

[@jawwadjawwad-ys8un]

If Sabine's the CAKE & consider me, a frosting on top of it. Sabine do you love this experiment in LAB or somewhere like, you choose the place for this experimentation & let me know.

[@JamesDevine]

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

[@jamesjeffers1217]

One of the best parts of spaceballs

[@Chrisamusic1]

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.

[@nautilus1872]

Thank you for writing your message, I took more from your comment than the video. Very nice and comforting.

[@Chrisamusic1]

@@nautilus1872 Thank you.

[@Jgriffin0808081]

I got a lot from your comment aswell, thank you

[@Muirton66]

Very thought provoking and a lovely comment.....good luck to you.

[@Sashazur]

That alien would be seeing your parents exactly the way we see distant stars- something that happened a long time ago and of which we can only see an image. That is still “reality”, but it’s beyond us in a way; we cannot interact with it or influence it.

[@hraith]

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

[@Rockhoundingcolorado]

The fact that time exists, no matter where you go in the cosmos, you can't outrun time. You can't not exist without it, or you won't exist to know that? Its all important, and may be the actual being, we call GOD. It witnesses everything at once. Isn't that God? Its every where at once.

[@Rockhoundingcolorado]

@Dankenstein not a comedian.

[@cdes68]

Suddenly @Dankenstein is interested.

[@arkeusalexander9054]

@@Rockhoundingcolorado Nop time as we know it is just a mere creation to God. He is far beyond what can ever imagine.

[@Rockhoundingcolorado]

@@arkeusalexander9054 Well you, your just talking, I hear no theory other than cult Christianity?

[@bintangdomena]

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!

[@angelita1895]

You’re so brilliant 🥰❤

[@angelita1895]

The past is a series of events that cannot be replicated

[@bintangdomena]

@angelita1895 Right!! Maybe versions of the past exist?? Then it would have to be acknowledged as something else- not the actual past!! Thank you again- you made my day!

[@edbaiza7757]

I remember taking pictures of my grandmother one Thanksgiving in 2017 and with the family something felt special at that moment it was beautiful. The following year 2018 in September she passed away. I look at those pictures today of that special time and still feel like I'm in that moment!!! My mother passed away a month and a half later and I can still feel like I'm holding her hand on her last days, I feel it like it was yesterday!!!

[@bintangdomena]

@@edbaiza7757 That's so beautiful and very powerful in many ways- my condolences on your loss and I'm so grateful for that wonderful memory captured in time; may it last forever in your heart and mind!

[@parinyachintanakarn4953]

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.

[@helensotiriadis]

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.

[@johnbockelie3899]

It's a called a liner existence. We come from the past, as the future moves into the past. It would be neat to go back and fix things.

[@SupportTheLittleGuy]

But what good is that if we can’t revisit these events

[@tayjones8552]

I always wonder what happens to today when it becomes yesterday!

[@juliai3956]

If you can remember, they're not gone. That itself is proof enough. But the thing is, the past and future have never and will never exist, yet your loved ones have. They are not bound by space and time anymore, as we won't be when we pass. I recommend Rupert Spira or Bernardo Kastrup for further, more precise information. And I'm sorry for your loss. This won't fix the pain, but it might help you accept it.

[@pedroroggla8129]

@@SupportTheLittleGuy maybe we can! With drugs? Maybe one of this nerds can help us travel back in time, i could see my dead wife and have a good coffee with her... maybe the solution is just a shot to the head, but we have options at least

[@kenmason6135]

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'.

[@BokaDeus]

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".

[@mengel419]

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.

[@dixonmooremusic]

Heh! Timequakes!

[@danovantuyl7911]

Kilgore Trout - "ting a ling"

[@syndrome1965]

Read the book, and, saw the film, both several times. I love that story...

[@rb032682]

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

[@rb032682]

Cannabis tincture helps when dealing with my past.

[@alexbauman4203]

Word

[@petey611]

​@@rb032682 ya just get high, that's the answer 🙄

[@joshdean5867]

Gay

[@vf12497439]

I feel your comment. I for one hope the timeline runs out without being recorded so that once I pass my existence and all I’ve done disappears with me. It’s not that I don’t have a good life and enjoy my life. I’ve made mistakes that bring shame. But I’m 51 and I’m getting tired. I don’t want to be an old soul. A long rest without being revisited is what I want.

[@steveg9088]

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.

[@user-nn1vk4rt8n]

Sabine good to see you back

[@nihal114]

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.

[@bustymcnutters801]

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.

[@bruzote]

Except you are wrong, because ALL events are relative to the observation. If something is in the past, it can't be now BY DEFINITION. The past can't be now or it would be the present. It is that simple.

[@monabear7287]

Both statements are partially wrong. Watch some Carlo Rovelli.

[@fritzforsthoefel8031]

Do we not live in the past because if you live in a house for instance that was built in the past and past actions are what we are living now the car you drive was built in the past being used in the present what we have already done in the past is our present the future depends on actions on actions of today the present actions of the past

[@venuae]

that's not how it works. the only event that happens to you "now" are light hitting your eye, the light reflecting events. the event that you see in your eye, isnt happening now. anything thats ever happened cant happen now.

[@stichpy]

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

[@lastbulletband1605]

We cannot go back in space either. Turns out we are in a massive rock travelling at thousands mph in SPACE in a corkscrew shape "forward"-ish. So basically even when you are sitting still, you are moving. You think you can go back to some place you've been before, but it's not the same place anymore, and it's not in the same absolute location. That's why space and time are connected

[@NeonVisual]

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.

[@gerogyzurkov2259]

Oh didn't know u looked at this

[@bootre9148]

Where is the start of the stream and where is the end?

[@NeonVisual]

​@@bootre9148 It began to flow into our universe at the big bang singularity, it doesn't have an end, but can flow out of our universe through black hole singularities where time effectively comes to a complete halt as the superfluid leaves spacetime.

[@themightybuzzard3088]

So if I gain mass, I'll live longer? Sounds good to me.

[@jpd8]

Or maybe it's all meaningless and isn't t special at all but useful to figure out. Maybe what really matters is that you are an observer and bring meaning to this vast messy whatchamacallit by simply living.

[@AICoffeeBreak]

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

[@vhawk1951kl]

did nobody ever suggest you that it is ugly to end sentences with prepositions flapping about pointlessly uselessly and uglily at the end of sentences

[@wiseguy8828]

@@vhawk1951kl you are missing the word “to” in your sentence, and “did nobody” is awkward phrasing, I would have gone with “has anybody”

[@vhawk1951kl]

@@wiseguy8828 Ah, if you please, so the fcuk what?

[@peanutnutter1]

@@vhawk1951kl There needs to be a comma between pointlessly and uselessly. Plus a capital letter at the start of your sentence and a full stop to close your sentence.

[@vhawk1951kl]

@@peanutnutter1 from where do you get such weird ideas? - I don't give a damn about nonsense and trivia like that.

[@grahamrich3368]

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

[@prestonbacchus4204]

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

[@tonycole3532]

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!!!

[@Mr.Robert1]

That will be $1.00 Now what that bill is worth is relative to the year you give it out.

[@michaellongstreet4876]

It's exactly 3:38 for me, theoretically, me and you have experienced something in our lives that contributed to the experience just a few minutes a part we just went through, how interesting

[@allisonharwell7591]

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

[@taichihead42]

I think you should look for a refund on the book . Anybody that would use that Albert Einstein as some kind of example in a physics sense of the word is more than CLUELESS . Einstein was. created by the J's in the same way Pop -acts are created today. !

[@blubbietweeduizend]

If I understand correctly, your book arrived at the same moment you bought the book.

[@rollinmc5427]

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

[@garytighe1822]

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

[@desmoface]

Whenever I think about the past, it just brings back all kinds of memories.

[@timmyjohnston7247]

Most of them are now classed as false.. so we are told.

[@RainmanCT]

i think of mammaries

[@fu2588]

Which are brought to the present as thoughts. But what if thinking about the future..? Still thoughts, no memories. But hope??

[@senor2930]

This isn't about memories, although many seem to be making that mistake, for some weird reason Memory is your neuron circuits reinterpretation of a previously stored data. It is not same as the object's existence. So, you may have your cat in your memory but that memory is not same as the actual cat you see when you record that memory.

[@Rockhoundingcolorado]

The fact that time exists, no matter where you go in the cosmos, you can't outrun time. You can't not exist without it, or you won't exist to know that? Its all important, and may be the actual being, we call GOD. It witnesses everything at once. Isn't that God? Its every where at once.

[@TylerSmith-sd2oc]

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

[@GP-yc2it]

except there's no film to review.

[@kushkushbabyy]

@@GP-yc2it different dimension

[@TylerSmith-sd2oc]

@@GP-yc2it its not about the review. Its about the experience.

[@kevinrice7635]

Yeah what he said 👏

[@miroslavobranovic]

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

[@Astronet2030]

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!

[@1220b]

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.

[@larrywright1589]

Time is⁸ nothing but a measurement, Ubuntu it has no matter, atoms, volume, mass. 6TH GRAVITY can slow down clock's or other mechanisms that measure time but it can not have a effect on time.

[@christian2i]

@@larrywright1589 'time is a measurement' and 'gravity slows down what the measuring devices measure' don't go well with 'gravity has no effect on time'

[@user-ys3ev5sh3w]

When coin was laying underground , time was frozen. But when you find it, time for coin began go fastest, coin began moving. Conclusion: time is energy. i've been writing program's also for 35 year's. Each time i write line " if i found coin then BEGIN ... END" i know that time for part between BEGIN .. END is frozen but not between if and BEGIN. And when found, then energy of processor touch BEGIN and time go fast between BEGIN .. END. Surely in computer time is energy of processor.

[@larrywright1589]

@@user-ys3ev5sh3w how long did the coin lie under ground???

[@user-ys3ev5sh3w]

@@larrywright1589 time was frozen, therefore have not longitude . It's link between Two periods. Answer: 0s for coin. But for other's i don't know. Time is abstract meaning of energy. Time is called always time, but energy is usually called differently for different kinds of energy.

[@kyelsavage6296]

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

[@helafed]

Do you have any literature about this theory? genuinely interested

[@kyelsavage6296]

@@helafed I had read this years ago but I don't have the source material anymore. :(

[@alpha-omega2362]

@@kyelsavage6296 or maybe you just perceive that you had read this and it was really your own intuitive senses.....

[@alpha-omega2362]

so, it's almost like your saying everything is in some ethereal form all scrambled up and we can not in our primitive minds perceive it and thus is must be laid out flat (so to speak) in linear form....with one thing happening after another but in actuality it could be happening parallel ...geez,,, I'm getting a headache......

[@ab1858]

If NOW some alien, on some planet a million light years away, fired a signal, did that event happen NOW or when the signal is perceived by earthlings?

[@tobywestfall2970]

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.

[@BostonSteve922]

My past continues to haunt me to the brink of insanity

[@63mckenzie]

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.

[@humansrants1694]

Red Dwarf Time Slides?

[@Aggiemcdee]

Bid Time Return by Richard Matheson? There was also a 1980 movie based on this book called Somewhere in Time.

[@impeachy1518]

Badass.

[@impeachy1518]

@@Aggiemcdee Christopher Reeves! He focuses on a portrait of an "actress" from the 1800s and travels back in time for some 'congress.'

[@Thorcat001]

Butterfly effect ?

[@stilltraceable6753]

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

[@user-iv6ft3jv2o]

3d Representation was amazing

[@mm-vg7dm]

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.

[@RyanMcLeanau]

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

[@Quroxify]

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.

[@BIGUS_PENUS]

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 ...

[@MadeInArt13]

Loving her detailed explanations.

[@anthonyw6488]

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

[@dharmendrasharma6070]

"Now" is a mysterious phenomenon, it is an infinitesimal small point in the time. Most of the time we are constantly moving from the past into the future and "now" is a very small connection between these two. how big is the "now"? is it a second? or millisecond, or a nanosecond or a .............? no end to it. the passed femtosecond at this moment has also become the part of "past" but our consciousness still perceives it as present. the "NOW" perceived by us is an illusion created by our limited perception, our conscious mind throws itself to a time span which includes the past and future, and perceives it as "now". it depends upon the limited speed of our neurons in the portion of our brain which senses the time as "NOW" and when a person can be in that moment of "Now" and flowing together with it, i think that is called as "Meditation".

[@anthonyw1499]

@@dharmendrasharma6070 there is no past and future. No one has ever experienced the past so it must be as illusion of sorts. The now is beyond space time and not a piece of it as you’ve stated

[@posmoo9790]

'humor'

[@dissonantchaos7724]

If there's no past how can we take a video or snapshot of it and keep it forever? If there's no future how do we progress with how we grow? How flowers grow/die? This is ridiculous to think these things don't exist

[@mayanktripathi8726]

@@dharmendrasharma6070 "now" may not have an upper limit but it sure Does have a lower one। It cannot be less than plank's time

[@thatsentertainment5602]

In a way the past does exist and we can re-live them in our memories whether they are good or band moments. The past may not exist physically but it does mentally.

[@dennisgalvin2521]

Sort of like turning an egg into an omelette the complete egg doesn't physically exist anymore as it became an omelette but we can remember it as a complete egg.

[@Rockhoundingcolorado]

The fact that time exists, no matter where you go in the cosmos, you can't outrun time. You can't not exist without it, or you won't exist to know that? Its all important, and may be the actual being, we call GOD. It witnesses everything at once. Isn't that God? Its every where at once.

[@thomasself8096]

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.

[@raffaojeda]

Thank u for the enlightening! Greetings from Mexico

[@ASLUHLUHCE]

With this question, I think many would think of 'present' in terms of the conscious experience of 'now' rather than in terms of where physical stuff might be.

[@dreamerworld1495]

Dont eat for few days and hunger will proof to you present is real.

[@CAThompson]

I think it's both. It's also what state we and the rest of stuff are in, after events of the past have occurred. In the future what's happening now will leave its mark too.

[@MrJoosebawkz]

i dont see what that changes really. Wether you pick the “now” where you’re thinking a certain thought or experiencing a certain sensation OR you pick the “now” where some things happen to be in a certain place, all the rules are still the same. It’s still possible that some observer in the universe can observe you thinking about my comment and see it as happening at the exact same time as a supernova that happened millions of years in the “past” from your point of view.

[@pauldzim]

The conscious experience of 'now' is the result of physical processes in your brain, so they are really the same thing

[@onetwothree4148]

Nobody believes the light we see from distant supernova explosions came from an explosion now. We all intuitively use "now" to refer to the local time of the event occurring. We see it now, it happened years before. The fact that we can't definitively know now, because everything happens outside the now of our delayed brain's local time, while as uncomfortable as any other conclusion of skepticism, is not a rational reason to believe other counterfactual theories that would allow us to believe we have real knowledge.

[@josephschwartz2180]

Sabine, you are one of my intellectual heros. What we consider the present is perceived recent past. This is why is is so difficult to truly be in the moment. Our brains are always in catch-up mode.

[@kevinerose]

Wait. Can you say that again? I didn't quite catch that?

[@Franciscasieri]

The older you get the closer our brain is to actually catch ing up

[@edwardx4979]

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

[@brianbissett7811]

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

[@Theafterhourshow]

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.

[@aogwaro]

I agree. Her jokes land so weirdly funny.

[@vhawk1951kl]

If you know any, ask a grownup to explain to you why nothing can be " *very* or nearly(as is occasionionally heard) unique" - see also *very* pregnant or *very* dead. I am a little puzzled that you appear unable to understand that, but seemingly you have no idea what unique means.

[@MrZorx]

@@vhawk1951klsomeone can be very pregnant, and something can be very unique. Something can’t be very dead though.

[@vhawk1951kl]

@@MrZorx Only an imbecile would say that

[@vhawk1951kl]

@@MrZorx Ask a grownup that speaks English to help you; pregnant and unique are absolute terms like on or off and dead -thus very unique and very pregnant are no more possible than very, on very off or very dead. Whoever says to you than an object is very or nearly unique is either an imbecile or an American, but then most Americans are imbeciles and I have never met one that can speak English similiter very or nearly or quite pregnant, and anyone that tells you otherwise simply cannot speak English and is a halfwit. You will occasionally hear 'very' pregnant when used to describe a woman that is obviously pregnant, but it is simply bad English. Unique means that there is *only* one which it either is or is not which is absolute, but you will hear the lower classes and those that are simply witless say nearly unique and that *because*they are witless members of the lower classes and do not understand what unique means, nor understand anything about absolute and relative terms.

[@vinnymarchegiano]

The past existed once as now...This topic is too mind bending, and perplexing for someone like myself to comprehend. Great video 👏 You are a brilliant woman 🙏

[@williambowling8211]

Excellent treatment of that point in "Spaceballs".

[@vinnymarchegiano]

@@williambowling8211 Great minds think alike. Now? When? Just now!! But that's then?

[@LegendLength]

It's similar to calculus where you integrate each slice of a graph. With time each slice is a moment. When you 'integrate' them all together you get regular time.

[@garytighe1822]

I changed my mind Dr hosesenfelder I love your channel

[@darthtorment]

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

[@marmadukewinterbotham2599]

I've always had a strange feeling that the past is 'somewhere over there'.

[@JamesLaserpimpWalsh]

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

[@peterella1814]

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.

[@contecrayononpaper]

I'm homeless now. It's pleasant for me to imagine I'm not homeless --- but I am homeless. Now. 'Cause if I'm caught sleeping outside, I can be arrested. And mister (or miss) police officer won't buy this argument now.

[@jsmith1746]

So happy this came up in my feed. I have always been interested in math, physics, and engineering, but am nowhere near smart enough to have had any success studying it. So happy there are smart people who are able and willing to explain it to dummies like me!

[@11dsw]

If you’re interested in this, in any way, you’re not a dummy😀

[@leejohnston2003]

Don't put yourself down

[@victoriamassey9830]

Same

[@mimidec]

I was always too scared to pursue science for higher studies tbh. Most people are. None of us are dumb, since we're all humans lol. You just have low self esteem, you're not dumb ♡

[@usernameinsane3]

the dummies are those with no desire to learn at all. you’re smarter than most without even knowing

[@tommyhawks856]

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

[@ravinderpalsingh5182]

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

[@gundarsmiks4889]

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.

[@chicchi1682]

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

[@7th_CAV_Trooper]

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

[@rialgobarnard1592]

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

[@gdgers]

Germans always speak such perfect English with beautiful accents .

[@henkstel7175]

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

[@adrianamatlack532]

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.

[@jsl151850b]

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

[@ez8308]

The Langoliers make sure that the past doesn't exist.

[@jakubkrcma]

There is a huge difference between something actually happening and an observer perceiving it. All observers perceive nonsense that isn't there anymore. Just distorted footprints of the past.

[@violenceisfun991]

come off it barney we all know you went to tennis camp last summer

[@gazzaaussie1000]

Summed up much easily ‘Time passes because we age’ Thank you!

[@shawnstatzer95]

I bought your book. You are amazing.

[@Ambone84]

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

[@edreusser4741]

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!

[@mala24890]

556666666666

[@mewlipaws8947]

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.)

[@user-mv9mg1pn4j]

I know this is a challenging view of the world and there's not enough philosophy on it. But I think this is ultimately something that helps us love the world and its inhabitants more, and despair less, not more.

[@Stand_By_For_Mind_Control]

I wonder if gravity and time are hard to pin down because they exist independent of the universe's existence, whereas other concepts in physics sort of needed to bake in the oven that is universal expansion. Like the universe is a bubble inside a void where not all physics like particles and waves exist, but time and gravity do.

[@sergifernandezmiranda1311]

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

[@glyndaley5844]

Watch DR WHO lol 😆

[@tricisport8259]

Better look forward.

[@bobwasilewski5768]

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

[@PaulWarren-dt1ms]

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

[@bon6461]

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.

[@michaeljfigueroa]

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

[@JC-yy8iv]

Such a cool coincidence that I found this video today! Just yesterday I was thinking to myself that the past is no more real than fantasy. Specifically I was thinking about my city, the version of it that existed 20 years ago, and how that place may exist in my mind and the minds of others, but so do Oz and Wonderland, and none of these is a place one can go. I’m glad to be challenged and informed on this at the same time!

[@charlessands6933]

I can understand how you would proceed if the past is fantasy but you can't take it too far because there's one key difference. That difference is things that happened in the past actually did happen and they have an influence on the present and since things that were done or bills or said in the past can still be a witness today that that means the past is never truly gone.

[@Mr.Robert1]

@@charlessands6933 The past played a big part in what's going on today and why.

[@studas2011]

Which city are you referring to?

[@benjaminroe311ify]

Ah. Yes... If only the past was really gone... but alas the past is now and the past is the future. It is all ONE. Peace my friend.

[@johnowens22]

The only caution I would add is...the past does, in fact, exist now for some place/time, but this is not necessarily compatible with saying that it exists in our minds. Our minds do not contain the past. They contain perceptions or conclusions only. They are mere interpretations and can be and likely are ALWAYS "wrong." Example: Newton was wrong when he came up with his equations and laws. He thought he was right. Many thought he was right. He was, indeed, possibly partially right, but he definitely was not correct. Nor is ANY perception that we have actually the "real" correct perception. It is both incomplete AND wrong, due to our lack of knowledge and our incorrect assumptions that some things are one way, when they aren't.

[@dalelerette206]

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.

[@charlesflint9048]

Apart from the physics, consciousness is a key part of this; it is instantaneous, always connected.

[@barbkrienke8400]

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

[@mtlicq]

Yup! She thinks her left side isn't as beautiful as her right side

[@yourlogicalnightmare1014]

You mean like pronouncing it 'eyen shhtienn'

[@yourlogicalnightmare1014]

There's an alternate universe where this female is physically attractive

[@mtlicq]

@@yourlogicalnightmare1014 She is beautiful

[@sekovittol3124]

@@mtlicq Yes, I noticed that. She'd be great to go take a 'trip' with. She'd blow my mind.