Does the Past Still Exist?

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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.
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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

[@morganmiller7777]

Because the human brain is unbelievably flawed

[@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

[@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. 🤷

[@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.

[@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….

[@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? 😮

[@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.

[@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.

[@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.

[@gdgers]

Germans always speak such perfect English with beautiful accents .

[@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.

[@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.

[@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'.

[@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?

[@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.

[@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".

[@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!

[@painisvergina3693]

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

[@fidacuca]

Not ugly too.

[@rudolfvenema7815]

@@fidacuca Thanks because she is AI and not a real person

[@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

[@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

[@CionnFE]

One of my favourite of your videos. Fascinating and mind-blowing 😊

[@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...

[@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.

[@user-nn1vk4rt8n]

Sabine good to see you back

[@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

[@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.

[@stilltraceable6753]

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

[@stichpy]

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

[@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."*

[@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.

[@nicolasdelaforge7420]

to 114: all it means is that when something happens (the "now"), it takes time before you see it. Because it depends on the light reaching your eyes, which takes time. So, you are late seeing it. Therefore, when you do finally see it, the event or some thing may not even be there any longer. Or it's in the next "now" that you don't yet see. So we are always already in the past. This is more obvious at long distances. For beings living on a planet a biilion light years away from us, Brahms 1st Symphony has not yet been composed or heard. It's still in their future! They will hear it in some millions of years. They will observe it then. If they're as smart as Sabine, they will know that Brahms' 1st was written long ago, by those called "humans". But it's not true in this sense: they may well see my grand- parents in some millions of years but my grand- parents are no longer living their organic life, and not being conscious. The distant inhabitants will not be able to insert themselves into their lives.

[@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.

[@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 life where that future is already written.

[@clifftanton8385]

I agree it is possible to travel to other alternative time lines but as you say and I believe theoretically that it can not be changed also be careful if you or I or for that matter anyone else were in that time line keep a very low profile information however slight from annother time line could be extremely dangerous

[@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.

[@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

[@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 ?

[@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 ...

[@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.

[@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.

[@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

[@SOHOSYNERGY]

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)

[@grahamrich3368]

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

[@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.

[@JamesLaserpimpWalsh]

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

[@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.

[@Astronet2030]

My heart skipped a beat when I saw that face at <a href="#" class="seekto" data-time="215">3:35</a>. Didnt expect horror from a science video. it was terrifying. I love it!

[@7th_CAV_Trooper]

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

[@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

[@Thomas-gk42]

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

[@gregorynixon2945]

Neither your now nor my now is actually "now". The experienced now can only be a duration. The actual now cannot be observed for certain events must occur before the observed now is registered (reaction, perception, recognition, etc.) and these all take time. The "eternal now" or actual now can have no time at all, for it is sheer potential. Perhaps it's like lightspeed itself. The actual present has no time and no space and only comes to seem to have such once the observation has taken place, yet it has enormous potential energy. (Related to the observer effect that causes the collapse of the wavelength superposition of potential?)

[@henkstel7175]

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

[@tommyhawks856]

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

[@Helidon78]

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.

[@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

[@aobdesigned3881]

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

[@michaeljfigueroa]

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

[@johncurtis5367]

How is prerogative dreams possible. To have a strange dream that leaves you puzzled but 7 years later comes true in every detail. How can this be?

[@MadeInArt13]

Loving her detailed explanations.

[@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.

[@chicchi1682]

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

[@ravinderpalsingh5182]

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

[@ersia87]

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.

[@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.

[@NeedMorePlebs]

​@@bruzoteUnless you consider the observer is God. Who exists in past, present and future. Therefore everything exists " now " for God. God is the ultimate observer. All of time exists simultaneously.

[@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.

[@raffaojeda]

Thank u for the enlightening! Greetings from Mexico

[@garytighe1822]

I changed my mind Dr hosesenfelder I love your channel

[@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

[@bobwasilewski5768]

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

[@John-bq9jh]

Molecular beams have a wavelength and thus interfere with each other when passing through a slit. When the apparatus is turned 90 degrees to the direction of motion the pattern is not the same. Special relativity and its postulates of shrinking lengths provides for this as the length of the slit shrinks but the pattern increases as quantum provides for the widening of the pattern the smaller the slit. It’s a simple experiment to do.

[@brianbissett7811]

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

[@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 👏

[@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.

[@overvygn]

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.

[@BostonSteve922]

My past continues to haunt me to the brink of insanity

[@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.)

[@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.

[@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.

[@Shadow-1949]

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 ?

[@seismictom]

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

[@leahkangas2173]

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

[@ahmetgazi3896]

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

[@sabi6684]

We’re not really going forward but backward in time. Everything is coming at as we’re just working our best to dodge it. Even old age 🤷🏻‍♂️.

[@boutayebbadaoui9665]

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

[@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.

[@user-iv6ft3jv2o]

3d Representation was amazing

[@hyper-potato]

if 2 events can always happen simultaneously to an observer i don't think that means that "past/present/future" are set or exist at the same time or "now". The fact that you can always find a location to put an observer in which 2 unrelated events photons will reach his "now" at the same time, it doesn't make those events simultaneous.. Is like looking at the stars, we can see them but we know that some of them don't really exist anymore, the fact that we can observe them in our "now" doesn't mean that they actually exist "now". Basically the information/photons, etc of x,y,z events happening at different times in space can potentially always reach an observer (coordinate) at the same time because of the speed of light limit but that's basically just a "trick".. the fact that i could hear a radio wave sent from an alien planet a few light years away NOW, doesn't mean that it is happening "now", if we know how far the origin of the radio wave is, we now it was sent X amount of time from the PAST. TL;DR you are always either watching the present or the present+ information from a past event just now reaching your location.

[@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

[@petertrebilco9430]

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

[@silversurfer2703]

???? I didn't understand a thing she said 😂😂

[@anndroid8734]

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

[@robinkleinsteuber5217]

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.

[@residentfelon]

Why does she look like she wants to stab someone? Lol

[@dr.christopherjohnson1406]

👋 i hope you’re safe over there? I hope this year brings happiness prosperity love and peace ❤ 🕊🕊 all over the world 🙏🌍 I'm Doctor Christopher Johnson originally from California 🌟🌟🌟🌟 and you where are you from if I may asked?💭💭

[@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?

[@orion2250]

At least in imagery. Fly into the red shift far enough,fast enough Turn around and everything you flew past at ftl will now be approaching you..electeomagnetic spectrum wise..fly far and fast enough and you can see yourself at journeys beginning. Fly far enough and you can see the big bang

[@bluefisshh2377]

The movement of universe creates the time. If the movement is a combination of shrinking and expanding yes past may happen again after the future again and again.

[@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

[@GSPV33]

Love your content. Thanks for making these for us.

[@jamescoulthard2208]

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

[@morganmiller7777]

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.

[@MysteriousWorld.031]

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

[@rebecca_stone]

Or the view from everywhen...

[@SimVikGo]

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