Is The Future Predetermined By Quantum Mechanics?

[@ilmbrk6570]

"Wubba lubba dub dub" Damn Matt, i'm so sorry to hear this, I hope you feel better in the Future. I know these are tough times but i just want you to know that we will always be here for you :)

[@yuotwob3091]

He'll feel much better if you get in his booth.

[@iAmNothingness]

I bet that's how his brain feels when speaking to stupid humans like us

[@yuotwob3091]

@@iAmNothingness Rick's a compassionate person, the dumb ass have nothing to fear from Rick, or the Universe which is the promised land of the stupid.

[@1112viggo]

I can highly recommend Squanching, that always cheers me right up when i feel the ol Wubba lubba dub dub!

[@yvesdoesnotexist]

Out of all the episodes of Space Time, this one is the one that left me feeling like a caveman the most.

[@Biogenesiss]

Time to get augmented.

[@PattyCali]

How this not complicated? Quantum mechanics is known for being complex..

[@IamMrJerrySoFU]

@Jacob Turnbaugh It's like with the cat, but in this case, something can be and not be complicated at the same time by different observers even thought the wave function already collapsed. But don't quote me on that, I found this video complicated. And by complicated I mean not being able to grasp all the information and reasoning as the video plays, not in a way that I would be able to retell it later - I would have to sit on it first and deduce what he said by myself - which is still not calculus, but is doing things, which, by what you wrote, makes it complex. Also your presumption that english somehow makes it not (less) complicated doesn't apply to non native english speakers.

[@JesusFriedChrist]

Grug throw rock. Rock break deterministic wave function. Grug no understand.

[@barrywatts8501]

Lol. You like mammoth?!

[@jasonchastain9826]

I've learned so much from this show. And yet, every time an answer spirals out from an exploded question, two more new questions also are discovered. I love it, thank you for all you do at PBS Space Time.

[@stevewhitt9109]

me too

[@brixen0623]

I love the face he makes when he reads a line that kind of breaks the brain. Like he's trying to keep his head from exploding. It's the best.

[@DeclanMBrennan]

3:21 "The wave function is real". Actually the wave function is complex. :-)

[@DeclanMBrennan]

@Astute Cingulus Way to kill a joke. :-)

[@VladislavDerbenev]

@@DeclanMBrennan dumb jokes don't deserve a life

[@DeclanMBrennan]

@@VladislavDerbenev I can just see all those poor little jokes shivering away as they are led out one by one to the Guillotine. The blade falls and the crowd roars: "Down with dumb jokes. This is a serious world for serious people".

[@KipIngram]

Heh heh... Too easy... Actually the wave function doesn't *have* to be complex - the use of complex arithmetic there is just a handy way to cram a pair of Hamilton's equations into one equation. Just equate real and imaginary parts and see what you get - it's just an instance of Hamilton's equations for a conjugate pair of variables. Use of complex math was just a "convenience."

[@Sk8OppOsiTe4life]

@@DeclanMBrennan do think Einstein had time for dumb jokes considering he his credited with the saying “only two things are infinite: the universe and human stupidity, and I’m not sure about the former”. I doubt it. Not saying he can’t admire simplistic\dumb comedy, but I doubt he spent hours revelling in it.

[@DrSlipperyFist]

I have PhD in Chemistry and absolutely love this stuff. Having taken quantum physics, as an undergrad and P. Chem as a grad student, much of this content is vaguely "familiar", and in my mind I put it together with everything else floating around in there. What blows my mind (even more than the amazing content) is the mass appeal and genuine interest from non-scientists. This is high level stuff; if I have a PhD and it's only sorta making sense. Kudos to anyone seriously interested in this without the STEM background - I imagine everyone's mind is blown in a different way, based on their background....but everyone's mind is definitely blown by what's being suggested here (and in all these videos).

[@thealifexablecreed9811]

He's basically talking about perspective of the universe from higher Dimensions right? What consciousness would be vs now in 3D. This higher consciousness pattern of selection of possibilities? I don't have PhD in anything. So you think I am close to the jist what he's talking? Looking for affirmations.

[@KipIngram]

I totally agree with you, DrSlipperyFist. I do have a STEM education (PhD in engineering), but I'm not a physicist. I loaded up on math in grad school, because I knew I'd want to learn more as the years went by, and I've hammered away at this stuff for DECADES, and like you say, it only "sort of makes sense." It is indeed heavy duty stuff and my hat is also off to non-stem folk who care enough about it to learn.

[@enigma7791]

Agreed...I am a software engineer and logic is my world. I came here looking for answers after living in a house that had a little girl in that wasn't my child. And yes at first I thought I was working too hard, until my wife and I saw her at exactly the same time. I cannot comprehend scientifically what I saw. Hence I am asking questions now!

[@Sk8OppOsiTe4life]

I don’t think people necessarily need a stem background to grasp some of these concepts though. Yes stem trains and disciplines the brain to identify and comprehend mathematical problems like an artist sees shapes/colours, however what makes someone like Einstein and his body of work so relatable and easy to conceptualise is that he used abstract perspectives and abstract patterns of thought to help provide sense in the nonsensical. In that same manner, I think non stem focused disciplines are able to draw influence or growth (giving them that mind blown feeling) from these similar abstract thoughts. Hence where I feel my understanding of this topic comes from. My own personal ability to explore abstract thoughts beyond what my senses and logical processes can inform and make me aware of.

[@ekothesilent9456]

@@enigma7791 similar experiences here my man.

[@anarchyantz1564]

Yes, this episode was pre-determined to make my head hurt.

[@crumble2000]

But it was also predetermined to not make your head hurt. You just happen to experience being the version of you that has their head hurt.

[@lordgarion514]

@@crumble2000 That would mean there's a version where the show was predetermined to not be made. I feel sorry for that version of me.

[@anarchyantz1564]

@@lordgarion514 That would truly have been a loss to the cosmos in that version. I normally put these on repeat in the background while I build settlements in Fallout 4 and eventually my brain becomes less like grey goo.

[@i.c.rivera154]

Right there with you. 😂

[@luantuan1653]

I'm in the same universe of the multiverse than you. My head has blown up!

[@sephirothjc]

I'm learning more and more about this (bit of advice, watch more than one video on the same subject and rewatch videos too) and it is honestly changing the way I understand my own existence more than anything else ever has.

[@lewisleslie2821]

“We’ll have plenty of time for time, another time, on space time.” You’ve gone too far this time!

[@nneeerrrd]

Never enough

[@jttcosmos]

Also cannot help but notice that very short, slight grin of satisfaction when he delivered the line without messing it up

[@jupitereuropa-e3w]

He has to much power!

[@dominikbeitat4450]

"Ain't nobody got time for time!"

[@mishael1339]

@@dominikbeitat4450 My time is up, goodnight ya'll

[@crumble2000]

11:46 "There are other interpretations that deserve mention, but [they don't deserve it enough to actually be mentioned]"

[@badlydrawnturtle8484]

They deserve it fine, and pilot wave theory deserved a much deeper dive than the "honorable mention" given. Matt is letting his bias on which interpretations emotionally appeal to him dictate the conversation. It's especially funny when he uses "pilot wave theory is having trouble integrating with special relativity" as the excuse for why he didn't give it more time here, since integration with general relativity is still a problem with the entirety of quantum mechanics, but that hasn't stopped it from being the topic of this video.

[@spinor]

@@badlydrawnturtle8484 you know there's a huge difference between integrating it with special relativity and integrating it with general relativity right?

[@neeneko]

@@badlydrawnturtle8484 As interesting as pilot wave interperation is, it really is way behind the other system in terms of working with special relativity. This can potentially be explained by having fewer people working o it, and could potentially be rectified and catch up, but it means that for the moment it is still stuck in the past and has not been meshed with newer discoveries as the dominant frameworks have.

[@wevedonethisbefore8729]

@@badlydrawnturtle8484 Imagine thinking a hand picked, good looking host is in charge of PBS.

[@513morris]

@@badlydrawnturtle8484 - What evidence do you have that these interpretations "emotionally appeal to him"? That's a strange assertion.

[@Veramocor]

Col. Sandurz: Now. You’re looking at now, sir. Everything that happens now is happening now. Lord Dark Helmet: What happened to then? Col. Sandurz: We passed it. Lord Dark Helmet: When? Col. Sandurz: Just now. We’re in now now. Lord Dark Helmet: Go back to then! Col. Sandurz: When? Lord Dark Helmet: Now! Col. Sandurz: Now? Lord Dark Helmet: Now! Col. Sandurz: I can’t! Lord Dark Helmet: Why? Col. Sandurz: We missed it! Lord Dark Helmet: When? Col. Sandurz: Just now! Lord Dark Helmet: When will then be now? Col. Sandurz: Soon.

[@Trump-loves-the-uneducated-lol]

Goddammit, I read that in George Wyner and Rick Moranis's voice. On that note, looking at the currently low number of thumbs up, maybe we're a little old for many youtuber's to realize Mel Brook's brilliant humor.

[@nameismetatoo4591]

@@Trump-loves-the-uneducated-lol "...they've gone to plaid!"

[@TheGrunt76]

Those instant cassettes are a real breakthrough in home video!

[@timjohnson979]

@@Trump-loves-the-uneducated-lol Mel Brooks?... Just kidding. I am that old.

[@alanfoxman5291]

I remember when he was just a writer on Get Smart. (The original. Not the god awful remake).

[@equious8413]

I've always felt like this waveform collapse is a quantum "tree falling in the forest" and the uncertain fuzziness prior to observation is just another way of saying "we can't be sure, but probability states there should be a noise".

[@Stern-warning]

So it doesn’t matter what Lottery numbers I pick as long as I pick them at the right time and have enough orange cats watching me. Got it.

[@cacophony7941]

Welcome to RNG manipulation

[@coffeetalk924]

Lol

[@clemfandango5908]

It’s called The Garfield effect

[@jenniperkins4260]

Hahaha

[@jenniperkins4260]

@@clemfandango5908 haha omg you’re hilarious!!

[@MarcdeSaint]

What is predetermined is me watching this every week

[@korpen2858]

True, good one

[@ZomB1986]

Unless, like in my case, some KZbin update disabled the slider for receiving updates about subscribed channels, by itself,, and then me thinking it's just calm on YT because of corona, and then finding out the mount I have to binge watch to catch up.

[@iordanneDiogeneslucas]

The first person to ever ponder predetermination had no say in the matter

[@iJosiah]

Uhhh, English..?

[@iheartcornwall]

My two year old watched this with me and was very into all the cats, saying "another cat!" and meowing at each of them.

[@radaro.9682]

My five year old watched it with me. She nods along like "yes, I understand. Tell me more" and I just can't help but laugh.

[@dannydevito7000]

@@radaro.9682 Turns out she's actually a genius the likes of which the world has never seen One day she says "Daddy I made a working model of quantum gravity"

[@radaro.9682]

@@dannydevito7000 Would not put it past her.

[@dpreetam]

I'm glad I found this episode. Yesterday I had the thought that maybe time has always existed and time just behaves in a way that we really can't perceive like how a 2d being couldn't comprehend 3d and so forth. If all of time and space expanded from a singular point, time could be like a series of snapshots in which we can't perceive the breaks in like a picture book being flipped to make a short animation. Every possibility making up the multiverse. The big bang or great expansion being a multiversal expansion and not just our universe. I'm glad to hear others have thought up similar things.

[@blackbearstudio666]

Is it possible that I live in another branch of reality than my wife? So many times we cannot agree on our common past light cone...

[@megamanx466]

Lol. It's possible I guess, because sometimes I feel that way about my past light cone compared to others. :P

[@danieljensen2626]

No, but human memory is not as good as we think it is. It is possible to "remember" things in detail even though they never happened, or obviously to forget things that did happen.

[@encyclopath]

The future may be predetermined, but not the past, it seems

[@Theraot]

No, you and your wife are tightly coupled.

[@stardolphin2]

@@danieljensen2626 Which is why police detectives still get all the physical evidence they can, no matter *how* many witnesses there were...

[@marcovallejo3]

I find fascinating I believe I can grasp what's going on the last two episodes even though I studied philosophy and not physics. These series are probably the best content now available on KZbin. We are fortunate to live in a time where such quality content is available for "free" (not considering you still have to pay for the internet service most of the time). Thank you very much Dr. O'Dowd, you've become a science heroe for me.

[@Does_it_come_in_black]

Me: time to go to bed. I need to get up in couple hours for work Also me: Great here we go down the rabbit hole once again

[@ntactime_w3488]

Every time

[@timo4258]

Bruh I'm jealous, I'm too sleepy and super tired after just 2 hours of sleep. My work is in 5.5h

[@Does_it_come_in_black]

@@timo4258 dammm all bad dog

[@andreabelle478]

This is fun!!! Thinking about so many things at once. On one hand your got your pillow on the other your thinking prehaps what this dude is talking about and then you go dreaming pretty neat o.

[@deriansilva368]

Sometimes I think our physics is just from human perspective and at times is limiting to our overall interpretation of the world. I think an advanced enough society may look at physics outside of their own perceptions which would probably mean they’re beyond war as conflict solution.

[@GeistInTheMachine]

Yup. Precisely. I agree.

[@SteyrR]

One thing is a certainty; I am going to watch this video.

[@morkovija]

as an observer from the past - how did that go? I guess our future was determine from where i'm standing!=)

[@Science__Politics]

@@morkovija he was struck by lighting

[@Dipsomaniac]

At least one version of you will that's for sure.

[@kevin6293]

Maybe you already watched it. 😐

[@encyclopath]

You already will

[@philochristos]

"We'll have plenty of time for time next time on Spacetime." That's just brilliant writing right there.

[@iamchillydogg]

Thanks for ruining it for the rest of us.

[@Gamer-is6ew]

@@iamchillydogg Why read the comments first place then before watching the intire video throughout? It is you responsibility since you're already agreeing non-verbally to that - when you open that comment section your bound to be exposed to spoilers...

[@iamchillydogg]

@@Gamer-is6ew Your comment is the one that shows up before you open the comments section.

[@Gamer-is6ew]

@@iamchillydogg time to burn down YT's HQ for this!

[@AndrewDotsonvideos]

Now I want a country singer to write a song about letting quantum mechanics take the wheel.

[@jean-lucchoiniere5587]

In 100 years the Bible turns out to be a complex analogy for the function of subatomic particle interactions and Jesus is the Higgs Boson.

[@tarubewildin6931]

eat the brown part of this banana first

[@steve1978ger]

@@jean-lucchoiniere5587 - no it doesn't. It's just bronze age myths and a mixed bag of ethics.

[@TheChadPad]

"Physics, take the wheeeel!!!"

[@corwin32]

It’s already been written, you just haven’t experienced that branch yet

[@celebratedrazorworks]

This is absolutely one of the most interesting segments I have seen. In all of this I really do wonder if there isn't much more "spookiness" going on in how reality unfolds. Things like entanglement, synchronization, vortex math.. Etc. This was an outstanding and intriguing way to weave many other complex systems and theories together. I love that he simply posits on the wonderful possibilities. Well said.

[@ct-hv1uz]

Yeah how do I explain pointless dancing of endless variety I could make in evolutionary or biochemistry or physics terms alone? I feel like our world is wonderful beyond our understanding. It’s awesome! I love living. I love seeing more unfold, I love taking more actions.

[@NicholasRehm]

I watched Interstellar (again) the other day which really messed up my mind and got me thinking about the idea of a pre-determined future...

[@anarchyantz1564]

Watch it a third time sort of in the background while doing other stuff. Hurts your head less I found.

The lesson is books cause hurricanes.

[@biblebot3947]

Watch Sabine hossenfelders video in it

[@NicholasRehm]

@Deal Negrasse Bison My guess is you think you're too smart to enjoy it, right?

[@okkomp]

The illusion of free will evaporated for me in 1997

[@Iangenker2]

What is mind? Doesn't matter. What is matter? Never mind. - Homer Simpson.

[@worldshaper1723]

That's a great joke!

[@simoncollins69]

this used to get stuck in my head as i walked to school.

[@AbbeyRoadkill1]

When I saw the notification for a new Space Time video I knew I was going to have to click on it, so... yes, the future is predetermined.

[@dwighthawkins5955]

I seriously need a revitalized definition of "predetermined" as there was no way I could watch this video without toweling off first.

[@janicepedroli7403]

I just can't tell you how much this presentation has changed my life. It has even started to change personal relationships. Thank you so much.

[@savioartwork]

Janice, this is so interesting. May I ask, how did that work for you ? What changed, and how did it change ?

[@avinashreji60]

Dude don’t change anything, this doesn’t affect anything. Whether everything is deterministic doesn’t change anything about us

[@sdfsfmnsdkfsfdsfsldmfl]

Yeah me too. Now im a millionaire. Are you into crypto?

[@dominikbeitat4450]

Not gonna lie, this is the best explanation of 2020 I've come across so far. Something something collapsing future something.

[@bigchungusdriplord2301]

Nice

[@scottjohnstone6204]

Something something corrupted and bribed and blackmailed governments and institutions.

[@0xc0ffea]

That moment when a boltzmann brain is the simplest explanation.

[@WWLinkMasterX]

I mean, is any material model for consciousness distinguishable from a Boltzmann brain?

[@VanBurenOfficial]

In the extreme far future, the same process that will give rise to a boltzmann brain will create the greatest, dankest, fattest, smoothest, most dubealicious blunt the cosmos has ever seen, and I intend to be there to blaze it.

[@lordcirth]

@@WWLinkMasterX Yes. If Boltzmann brains come into existence, the vast majority of them will experience the most likely scenario: only the brain existing, and for only a short span of time. Since we see a massive, coherent universe around us that seems capable of creating us, we are either in one of the most unlikely Boltzmann brain scenarios of all - or we aren't one, which makes much more sense.

[@WWLinkMasterX]

@@lordcirth Fair, but that isn't a distinguishing argument, it's an argument from likelihood.

[@Beastman5K]

@@VanBurenOfficial MY DUDE

[@Wetefah]

"the answer depends on your favorite flavor of interpretation" - I'll interpret this as "nobody has the slightest idea"

[@MarsJenkar]

I'd say more like, "We've got a few ideas about this, but we're still trying to puzzle out which, if any, is right."

[@badlydrawnturtle8484]

It's more like "the interpretations that make more sense logically are less appealing emotionally, so we like to downplay the part where we're supposed to find the truth, here".

[@maythesciencebewithyou]

Many people desperately want to believe that the universe is not deterministic or at least that there is a version of them that lives the life they dreamed about.

[@paulperkins1615]

There is a huge range in between "the exact answer is known beyond any doubt" and "nobody has the slightest idea" and I don't think I really like anybody who is not comfortable living in that in-between range.

[@BigBoss-sm9xj]

@@badlydrawnturtle8484 might be the case or might not be the case, we can only hope that our physicists are taking the carl saigon quote to heart

[@platypuspracticus2]

Love how this kinda glosses over the fact that a conscious observer collapse would imply a very high significance of our existence given that not everything can cause that collapse. Not quite deific but not far off given a direct impact on the shape of reality itself. Also probably why a deterministic multiversal solution feels the most right: clearly we're not gods. Despite what some people may think.

[@schmetterling4477]

Some folks just can't pass a heap of bullshit without diving into it. ;-)

[@PlayedbyInstinct]

Remove 'conscious observer', insert 'frame of reference', of which some include a conscious observer. Still deterministic, just dependent on your frame of reference (you don't cause the collapse, you observe it).

[@yuvalne]

"We'll have time for time another time on spacetime." Goddamnit Matt.

[@Robert_McGarry_Poems]

The time to discuss endless time has passed, this time. But, maybe next time, on spacetime.

[@SpeedOfTheEarth]

"But - we'll have plenty of time for time some other time in spacetime." Brilliant lol

[@internet_introvert]

Time? This isn't the time to talk about time. We don't have the time!

[@Richard-bq3ni]

I am currently picking up the pieces of my brain shattered through my room after my head exploded. Why do I always feel dumb watching your videos. I have a hard time understanding but keep coming back still.

[@goldenseal50]

So glad I am not the only one with a headache.

[@philb.1658]

I agree I too find these videos hard to understand and but they are interesting and informative. My brain only feel like exploding when I watch crap on TV about ancien aliens or ghosts.

[@Richard-bq3ni]

@@philb.1658 Hi Phil. Thanks for that, I feel less stupid now 😉 And I get what you mean with these TV shows. Channels like discovery were great to watch when I was young, but have been dumbed down to please a larger audience, or whatever the owners had in mind. It is great to have KZbin and channels like this.

[@ytechnology]

"... but keep coming back still." It's disturbing that your return visits might be predetermined. 😉

[@rilist23]

Yes..right there with y’all on that thought lol

[@Turnoutburndown]

This has got to be the trippiest episode of Space Time....yet....

[@azure6743]

"Einstein's theory of special relativity combined space and time into one unified thing - spacetime" *show ends after 9 seconds*

[@chillyman1459]

What is the difference between an observer and just any old regular particle interaction? If an observer is just made of particles, and the particles the observer uses to interact are doing the observing, wouldn't that mean every particle interaction collapses the wavefunction?

[@markiv2942]

Yes, don't just tell this to anyone, it would make too much sense.

[@zeton2000]

yes

[@db7213]

In the many worlds interpretation, different observers have different wave functions for the same particle. So even all particles are observes and collapse the wave function, their interactions don't collapse the wave function for other observers (unless the observers are entangled). Example: we have particles A, B, C and D. When particle A interacts with B, A's wavefunction of B, and B's wavefunction of A collapse (and A and B become entangled which means they now share wave functions), but C and D's wave functions of A and B are unaffected. When C and D interacts with each other, their wave function collapses and they become entangled. When A or B comes in contact with either C or D, then A/B's wave function of C/D collapses and vice versa, and all particles are entangled. So as you can see, the wave function collapse becomes a chain reaction (which is what causes the many worlds).

[@badlydrawnturtle8484]

You've just intuited the fundamental problem with the Copenhagen interpterion, which despite having this obvious issue has managed to keep going for ages because even physicists get emotionally attached.

[@mertertrern]

Gotta remember the part about there necessarily being only a single observer in the entire Universe in order for the interpretation to work. I'm not landing on either side of that question, but I wanna imagine that self-aware consciousness has some privileged position in the pecking order of wave function collapsing. It's possible we're collapsing this sea of quantum possibility into the manifest reality we perceive in real-time through unconscious processes we haven't even begun to uncover yet. You never know. New ideas are usually considered wrong by a lot of respectable scholars until some new discovery comes from out of nowhere that changes the tide.

[@petersontaylor2000]

Matt asked for our help at the end of this episode! Hang on in there, my friend! Everything is gonna be fine!

[@tiantu9830]

My problem with non-deterministic idea of these "unknown" qunatum probabilities, is that it is still ultimately deterministic. Think about it, if you are reading a book series and it is unfinished. From the perspective of the characters in the books, yes, the future is unknowable, but that does not mean the characters in the book get to influence the outcome of their future. All it means is that whatever force(in this case the author) that drives the future, has not made a determination yet. But that does not make the book itself non-deterministic.

[@s.31.l50]

The book analogy is one of my go-to analogies for determinism, happy to see someone else with the same idea.

[@johanneskrv]

So you're basically smuggling god into this by assuming an author. What if there is no book at all? What if there is no all seeing point of view?

[@typhoonf6]

@@johanneskrv he said a force... It does not have to be a deity. Could be probability or some other level of physics we don't know about. You are the one that made the assumption.

[@johanneskrv]

@deepstateflatmoonlizardcultist No i didn't make any leap. The reason is the following: in all these models an all seeing point of view is assumed from which the block universe (time+space) can be examined. From this point of view of course everything in the block universe is always deterministic. But assuming the possibility of this point of view means assuming something outside the universe. Colorfully stated this means assuming god.

[@spaceminers]

What book!? Lol there is no book we have free will! It says so in the book! Lol impossible to have free will if we are following what it says in this book of yours. Time is nothing more than a measurement of the rate of a constant chain of events. The past does not exist. The present does not exist. They never can and they never will. Get used to this! The only thing we have is now. Time has no direction it doesn’t go forward or backwards or stop or go sideways. Don’t be ridiculous! Just because you can think something up doesn’t mean it will ultimately exist. Yes we invent things all the time. No we are not gods! Nowhere on this earth or anywhere else is there one shred of evidence that anything, a UFO or a quantum particle has ever traveled forward or backwards in time or is even sustained in a fixed time frame. You can freeze an atom to absolute zero and that doesn’t stop time either. You can travel through a black hole faster than the speed of light and everything around you will look as if time is changing in all kinds of weird ways depending on your reference objects and locations but it’s just an illusion of “slow light”. Everything that occurs happens now. Everything that will occur will obviously happen in the future but not 100% controlled by current time or past time. Everything that has happened is unchangeable and is forever cemented in our history. Now all of that being said, scientist can always create laboratory experiments to prove anything or disprove anything. But just because it occurs in an experiment doesn’t mean we will have time machines in the future. The closest thing we have this idea is frozen light. Scientists are able to slow light to a crawl and even freeze light in its tracks. They plan to reverse this packet of light but not in direction, rather in time. And of course if successful the packet of light will appear to travel back to its destination point. Assuming that you are traveling back in time with it! How can you see something traveling back in time when you’re traveling forward in time!? Impossible ridiculous! The moment that photon travels out of the present we will never see it again assuming it can go anywhere else, which it can’t. Outside of everything we know is a complete void of no space and no time. If you attempted to travel there all of your quantum particles will fall apart and cease to exist as there is nothing to exist in Reality. If anything you will be nothing but virtual particles in a timeless void.

[@JanKowalski-wb2fv]

If the future means watching PBS Space Time then yes, it's predetermined

[@RagaarAshnod]

For me, it was reading and replying to this comment!

[@syngyne]

Also predetermined that I will only ever understand about 2% of any one video

[@ilkoderez601]

This is a great episode! This is the stuff that keeps us coming back. I've been interpreting the multi-worlds theory all wrong and it's not my fav... Thanks PBS SpaceTime! Bravo!

[@_shadow_1]

"The only thing that is certain is uncertainty" - Probably someone in history

[@arielsproul8811]

You could say that you're *Uncertain* as to who said that quote

[@Mp57navy]

I'll go with Feynman. Any takers?

[@rmsgrey]

"With him around, even uncertainty is uncertain" - Interesting Times by Terry Pratchett, Death(?) speaking of the great "wizzard" Rincewind (luckiest(?) person alive)

[@_shadow_1]

@@arielsproul8811 yep

[@philochristos]

I wonder how certain they were of that.

[@numinous2506]

I listen to these over and over until I understand them. Thank you for expanding my mind. What a gift that could never be repaid with any crude matter, but I'll chip in some bones when I get paid. You've earned it.

[@queenofscots839]

I spoke to my future self at age 7, and answered 40 years later ... remembered exactly on time! 🤯

[@MrBruh-xc1qy]

this is legit one of the most epic comments i have ever read

[@richardkoechl9552]

@@MrBruh-xc1qy are you allowed to change your mind in the interim???LOL

[@Imachef]

What did you tell yourself?

[@queenofscots839]

@@Imachef I had a nightmare that my younger sister surprised me with skydiving gift and I’m terrified of heights, I begged my older self to say no! So when 30 years later she did just that I apologized to my younger self and went!

[@mstandenberg1421]

The universe is infinitely predetermined, which is to say finitely unknowable, thus it makes no difference unless you’re outside it in something bigger and stranger.

[@hillarysemails1615]

I was only the 7th Like and this is over a year old? Shame people. This deserved over 100!! This comment should have been in the vid. "An Infinite series of predetermined universes, means a pseudorandom experience for any given observer."

[@christiangonzalez7438]

Im taking this as an universal wisdom quote.

[@livedadyt10]

Phew... heady stuff Matt. Still struggling with “if a tree falls in the forest...”.

[@itcamefromthedeep]

I can clear up "if a tree falls in the forest...” if you'd like. We use the same word for two concepts, in this case one of those concepts is vibrations in the air, while the other is the subjective qualia of mental experience. The falling tree definitely makes sound in the first sense, and definitely not in the second. The confusion lies in the ambiguity of the word, not the concepts it points at. If you were to try it in some other languages it probably wouldn't work unless they shared the same homonym.

[@johndoe-sh8in]

If a tree falls in the forest and nobody is able to hear it... then my illegal logging business is a success.

[@Willdras]

@@itcamefromthedeep Exactly right! Funny how people don't examine this and think it is profound :D

[@ultratot]

@@itcamefromthedeep Yeah... but... if you ascribe any level of consciousness to animals, squirrels and deer and such, then the subjective mental experience, that qualia (maybe my new favorite word since the last exurb1a video?) definitely is there. So in both definitions, objective vibrations and subjective experience, the answer is an unambiguous YES. So now that that's cleared up, onto determinism and the hard problem of consciousness...

[@Pheonix1328]

I'd say it doesn't make a sound, at least in any meaningful way. Observers are needed to allow things to exist, for if there were none, then it would be like it didn't exist at all.

[@0ptimal]

This one of the best videos y'all have made.

[@omaewamoshindeiru3657]

You just made me questions my existence and reality

[@Matty94]

Try to watch Pursuit of wonder

[@TheChadPad]

Great way to start the day

[@ankysid8022]

What do you think Physicist do ?

[@kaseyboles30]

Always question and seek answers.

[@playnite2188]

You exist so I can reply your comment.

[@kena7007]

I love listening to this show, I memorize a few quotes and say them at dinner and people think I’m a genius.

[@dadk5470]

Lol

[@elaranlovesyou8220]

Juan.

[@didact777]

lel

[@TheTuttle99]

@The Unblinking Eye is he really? I was actually pretty taken aback by his appearance. He looks sick man :(

[@timothyletwin5911]

What's with the judgment ? Looks like a normal man too me. He's trying to teach you something.

[@TheTuttle99]

@@timothyletwin5911 what judgement? Or were you referring to the now edited top comment? I'm a little concerned to be honest. Matt looks like he's lost a TON of weight :/

[@aguasanta]

@@TheTuttle99 Well, to be honest, this year have been hard for everyone

[@XIIchiron78]

Doesn't the speed of light + relativity of simultaneity "fix" the 2nd example? Observers in your "present" can't gain any information that isn't within their light cone and therefore can't collapse your future wave function by learning about it from an observer in your future path. Or do I misunderstand?

[@loturzelrestaurant]

I have the (silly) hobby to ask people if they'd like some recommendations; especially science-channel and such. Yeah, its random and i'm often called Robot for it, but who cares? I live for those few who say 'Yes thanks' (though No thanks is also nicer than calling me non-alive...) and i wont stop asking around. I wanna spread Education, so i recommend edu-channel, duh!

[@RussellCatchpole]

The wave function probably collapsed, just in time, for Matt to deliver his final line, in a rhyme, before the final chime, of this episode of, PBS Spacetime.

[@_tnk_]

Love the focus on metaphysics and philosophy these past 2 episodes. These are really difficult concepts to understand, and I appreciate seeing your perspective as a physicist. Question: What do you think about the “moving spotlight theory” of time as an explanation for the experience of the present?

[@MichiganUSASingaporeSEAsia]

I see the point of the spot light theory

[@shamashmindful]

You've literally put him on the spot

[@erikzetterberg3887]

Thanks to Matt and the PBS space time team for making these great videos! This time, however I find the argument at 6:50 unconvincing. The claim that the event at the bird would collapse the future of the event at the human does not seem to me to be supported within SR. Just because the human sees the cat event as simultaneous and the cat sees the bird event as simultaneous does not imply that any of the observers see the human event and the bird event as simultanous. Actually, the human, the cat and the bird would all agree that the bird event happens after the human event, and because of this the bird event could not collapse the human's light cone. In fact, there could be no observer moving at the speed of light or slower that would see the bird event as simultaneous with the human event, since these events are time like separated. The human's event and the human's future would remain uncollapsed from any observers view. At least as far as I understand SR. Please comment if there is anything wrong with my line of reasoning, so that I could understand the argument in the video,

[@nyrdybyrd1702]

My first watch of this episode (years ago) went swimmingly but I've been around since the days of Gabe (seen erry episode, most several times). I sympathize/know the feeling though; the most difficult concept/topic covered here for me was (without doubt) time crystals (pretty much baffled to this day 🤷‍♂️).

[@protercool8474]

I understood this whole video, was just digesting it all when suddenly "we don't have time for time this time, maybe next time on space time" and it's like the whole episode never happened. All I can think is next time

[@juliusc.2088]

Sounds like the Future is in a superposition of being predetermined and undetermined.

[@Galv140577]

How was it predetermined at the start when it spontaneously began ?

[@technomage6736]

@@Galv140577 It never began, unless it turns out that something (energy) spontaneously appeared out of literal pure nothingness. I suspect it's more likely that the cosmos is eternal, and time and probably space wraps back in on itself, or is perhaps cyclical.

[@Tonatsi]

@@Galv140577 it can’t be predetermined if the future doesn’t yet exist as a concept, so it is both predetermined and undetermined, as neither is true, yet both can be defined as an opposite of the other

[@joshuacornelius25]

@@Tonatsi all possible future, and the threads of causality are predetermined if you plot a path of continuity from start to the conclusion. The problem is that consciousness is a quantum process and "we" are in superposition as well and have no idea which future we will arrive at. The continuity of consciousness is an illusion because we have access to memory, current sensory input, and predictions for the future (past, present, future)....but consciousness is actually a series of neural electro-chemical oscillations (quantum process) stitched together over time to give us the experience of continuity.

[@oscarrodriguez3754]

@@joshuacornelius25... wow.. this better not be copy and pasted

[@Jayarbuck]

(Warning for photosensitive viewers: this video contains a lot of flashing and repetitive imagery at various points) Such a fascinating topic! I do find the many worlds interpretation to be the most interesting, and the most satisfying to my personal sense of elegance.

[@Volamek]

The first 30 seconds of this video just 100% light bulbed the entire previous episode. I'm hooked.

[@Trekfolie]

I'm happy for the countless other me-s who lives in world where 2020 is a nice year

[@zhangalex734]

We could be wiped out by quantum Darwinism :(

[@megamanx466]

@@zhangalex734 Or a quasar shining our way... OR... OR... :P

[@WaveOfDestiny]

There's also one where 2020 is even worse wich is scary

[@megamanx466]

Or where neither of us exist. :P

[@adrismith3134]

This is slicing through the layers of my brain.. I need to listen to more so I can figure out how I managed to time travel to my own past and give myself advice.. I know I've done it in the future from meeting myself in my past.. But this time is the time to give myself the answer to Save myself time.. So now that I've found this maybe I'll figure it all out in time... Thank you for your time and this....

[@dynasticlight8706]

Isn't it ,the older We get life is seen or understood more clearly .We seem to live backwards w/ more understanding .Maybe ,not being able to use it now as We could have then.

[@andreabelle478]

Wow you have a very interesting matter of thinking and reading this helps make sense of all this. Thank you.

[@embyrr922]

Ever since I got a basic understanding of relativity, I’ve sort of assumed that time is an emergent property of fundamental physics in the same way that the mind is an emergent property of the brain. It just seems... squishy.

[@nostalgia63]

Nice video. Philochrony is the theory that describes the nature of time and demonstrates its existence. Time is magnitive: objective, Imperceptible (intervals) and measurable.

[@theonetruemorty4078]

It's me, I'm the one collapsing the wave function. I know I've made mistakes, especially as of late, but if you cancel me you do so at your own risk. Cheers!

[@cezarcatalin1406]

Yeah it’s big brain time.

[@nunyobidniz]

I squanch it😎

[@chrisfinley]

Does it have to be one person or can a solar system bound species be the one collapsing the wave function? That would explain the Fermi Paradox and probably means we are a simulation. ;)

[@big_changus4905]

Does your momma know you do this, aren't you a little young to do this

[@discreet_boson]

If I had to choose only 1 yt channel to watch for the rest of my life, it would be this one

[@eventhisidistaken]

This would get boring if watched for the rest of your life. Nyan cat is where it's at for a life long commitment.

[@CanisSubwoofus]

I thoroughly enjoy the fact they went through the trouble of adding "meows" to the cats.

[@linux1800]

Hahaha

[@matthewabln6989]

The subtle touches.

[@marcelolibermandeloreto5252]

LMAO

[@jfjkdkjfj]

Cats come with meows automaticly. Its the most certain thing in the universe.

[@gbail9566]

Congratulations on the wonderful graphics on the Copenhagen and Many Worlds theories.

[@Alverant]

I liked it when we see the "third" guy laugh at the cat doing something cute.

[@Mandanara]

Last time I was this early the universe was still in a hot, dense state.

[@Galv140577]

If it began spontaneously then how is it predetermined at all?

[@matthew944]

I look into the past every night we have clear skies.

[@freelancer42]

I look into the past every time I open my eyes

[@gregoryfenn1462]

By that logic, you look into the past whenever you look at anything...

[@john-or9cf]

...which isn’t very often in Ohio...

[@Galv140577]

The Moon is 2.5 seconds into the past, but your comment is now 1 hour ago.

[@jorgepeterbarton]

@@gregoryfenn1462 especially youtube comments as digital discrete information?

[@winstonsmith8240]

Glad we've cleared that up.

[@nUrnxvmhTEuU]

You forgot to mention Carlo Rovelli's relational QM interpretation! My favourite interpretation, where even the very collapse of a wavefunction is relative to the observer. I feel like it would be relevant here.

[@valkyrie321]

Now that offers some intriguing questions of its own. If that’s true, than I take it that every observation is only relative to the observer itself... And thus it’s a flavor of the many worlds interpretation? So as I’m cutting my way through space-time, the collapse of the waveform is unique to me only... Oof.

[@diribigal]

Yeah! I like it more than the interpretations mentioned in this video, and it seems like it might mesh with relatively more easily, as you said.

[@nUrnxvmhTEuU]

@Jaggyroad Yes, you are right, technically it is a flavour of Many-worlds, but it doesn't need the concept of a "global wave function". But philosophically it is quite different, and I would argue that it gives the same results using fewer assumptions.

[@thedeemon]

@@nUrnxvmhTEuU I wonder how an interpretation can have fewer assumptions than MWI. MWI just says "take wavefunction and its evolution equations literally", no more assumptions, no collapse, no special role of observer, no classic-quantum distinction etc. Gotta read about the relational one, I'm not familiar with it.

[@StrongButAwkward]

I'd really like to know the PBS Space Time Team's feelings about the show DEVS since I thought it was one of the better sci-fi shows of the past several years and is centered around a lot of what this episode is about.

[@ASLUHLUHC3]

0:53 "For every observer, It's possible to imagine another observer who lives in their definition of the present, but for whom your future is the past" - I still don't think this implies eternalism/determinism. Imagine seeing another observer waving at you from far away. It may indeed be the case that from their present, they're in fact waving at an old man (or perhaps a fetus). But as far as I understand, this does not mean that your past and future are equally in existence. Rather, isn't this all just a dramatisation of the relativity of simultaneity? Whilst what you see of each other indeed depends on your velocities (due to the way light from you reaches them and vice versa), the two of you will only ever see things *that have already happened to each other* - just as Einstein's train thought experiment so evidently points out.

[@riddick165]

Thank you, I'm stuck on same thing. By moving in different directions I can choose to see distant observer's past 20 years ago or his past from 10 years ago but never his present or his future. How does this suggest eternalism?

[@ASLUHLUHC3]

Welp, this comment wasn't mentioned in their next video. I might just have commented too late

[@riddick165]

@@ASLUHLUHC3 Yeah, too bad. But I'm thinking maybe we are taking this too literally and the only point of this thought is to show that present is relative and if two people can have different presents then this must mean there is block universe. Or do you have some other idea?

[@daviddelaney2407]

@@riddick165, what it means is that if there IS such a thing as a consistent "present" for each observer, of whatever velocity, THEN you can assemble those "present"s into the block, predetermined universe. GR says you're only ever gonna see pasts, using light that has travelled null geodesics to get to your eyes, so only your past light cone's stuff is visible to you - there isn't actually "a present" for you YET. Anywhere you're thinking of as simultaneous to you - in "your present slice" - is out in Elsewhere, outside your past (and future) light cone, and can get moved as close to your past OR FUTURE light cone as you like by changing velocity of the frame you're in... so an observer at a different velocity to you will NEVER see the same 'present slice' as you. This strongly implies that the "slice of present" concept isn't meaningful, and only seems to be because we're used to velocities much smaller than light's, so that light seems to take no time to get to us. It's trying to make it into a meaningful concept that gives you the determined block universe ... which is another sign pointing to 'DON'T DO THAT'. As time passes, stuff further away from you at previous times gets added to your past light cone, making it look like there WAS a consistent "time T" slice in your frame ... but you don't ever see stuff from "T+t", just the sphere far enough back for light to have gotten to you from it. Your "current present" isn't known to you, says GR... and any observer in your past light cone CAN'T have anything in your future light cone in their past light cone, only stuff you can already see in your past light cone. And any observer in Elsewhere can be arbitrarily close to ANY point on the boundary of your future light cone, by changing frames via changing velocity ... so, again, trying to make a "consistent present" runs you head-on into 'DON'T DO THAT'. --Dave, here's our Sign

[@ASLUHLUHC3]

​@@riddick165 Actually, now after re-watching this video, I realised that I didn't take Matt literally enough. When Matt said "For every observer it's possible to imagine another observer who lives in their definition of the present but for whom your future is the past", he wasn't talking about - say - a waving observer in our past light cone. Rather, it seems he's saying an observer that exists at this very moment (like the cat at 6:34) may find their very moment of existence paradoxically coinciding with our future self (like the chicken at 6:46). And thus, this apparent paradox implies eternalism (the equal existence of our past, present, and future). But are such claims about relative 'now-slices' valid? Why would your 'now slice' be affected by your velocity? Is Matt conflating this idea of 'now slices' with the relativity of simultaneity?

[@nhannhan4406]

I need CC english subtitle in this video, really like all your video. I've learnt so much about our universe in your channel. Thank you.

[@monochr0mat]

I was thinking about this a couple of days ago. If you consider the universe as a graph with nodes being Quantum states. You are a DFS algorithm through this graph looking for your death 🤯

[@big_changus4905]

My computer friend

[@kingreinhold9905]

Can you please explain this a bit more?

[@ConnoisseurOfExistence]

I'm a special algorithm, looking how to avoid death and survive forever.

[@ethanconnelly8794]

Maybe our qualitative experience (qualia) exists in the momentary entanglement of ourselves and the world. This would mean any other conscious entity who wants to see the colours of our soul would have to entangle with our wavefunction or collapse it and just see quantitative data. With pansychism this means that everything that is still in it's quantum state would experience it's own qualia and only under a non-zero like cooperation would it be able to join another conscious entity and create higher orders of autopoiesis. The sharing of electrons is simply the sharing of consciousness. Higher complexity leads to higher states of consciousness and therefore the most complex systems (our brains) are experiencing the highest levels of qualia.

[@kallianpublico7517]

An algorithm is a sequence. Is my sequence the same as yours? Not if my definitions are distinct, unrelated, to yours. If I have words, thoughts, which are "more advanced" than yours then the set of rules that leads from proposition to conclusion, from if to then, will be different in number and in "meaning". Is meaning the source of the quantum enigma?

[@Starryknight2011]

I think a great T shirt for this episode could say, "I'm just here to collapse the wave function"

[@paulperkins1615]

Ah, but you can't, because the wave function never collapses. Or at least, there is no logical reason it ever has to collapse and all the explanations of why it would collapse look suspiciously like hand-waving. That's Everett's great insight that got him kicked out of the Quantum Physics club.

[@cherubin7th]

What if we do the same but instead of "now" to slice the block universe, we use the path light cone as reality and as soon as they leave the cone they don't exist anymore or they exists but at an undefined time (but all observers are still equally valid)?

[@ride14fun]

this is the BEST, I think, MOST accurate description of reality. FURTHER evidence is that it supports the axiom of choice from Zermelo Frankel set theory which is critical to generate modern mathematics.

[@ZZ-vl5nd]

Yes. My comment was pre-determined.

[@Mr.Muscaria]

As well as this reply

[@zac3758]

As was mine. Tee hee lulz 69 comments currently, now 70.

[@0ADVISOR0]

Mine wasn't

[@LuisSierra42]

Mine is the result of an uncollapsed wave function

[@hdbgdz]

I want a tee shirt that says "The wave function is real"

[@nathanielhunter1280]

Or "I just collapsed your wave function"

[@waffles3987]

Bump

[@paulperkins1615]

@@nathanielhunter1280 I like "We just entangled parts of our wave functions with each other" even better. But "The Wave function is real" fits on a tee shirt better and captures the essence of what is usually called the many-worlds interpretation.

[@thedeemon]

"...but unobservable"

[@pierreabbat6157]

Is it real or complex?

[@twokidsmovies]

Would love to see a video or series on how to survive through the far future of the universe. Like how some intelligence could make through the black hole era, proton decay, like I find it so fascinating as much as it is a hypothetical. Exploring the possibilities of "humans" making it to the next big bang

[@alextaunton3099]

life won't survive past the black hole era, guaranteed. No energy sources=no life. Esp with proton decay, proton decay only happens because statistically it has to happen eventually; that is, if protons are decaying at an appreciable rate, that means matter as a whole has broken down into a sparse medium of elementary particles, as things like scale and time start to lose meaning. Matter density would have long since been far too sparse to even permit microbial life.

[@twokidsmovies]

@@alextaunton3099 Isaac Arthur has a video series on how to survive till the next eternity, it is theoretically possible as if yoh live to the black hole era youre technology would be so great that you might find loopholes around conversation of energy

[@jetison333]

@@alextaunton3099 you can fairly easily (fairly easy being from the perspective of a society that managed to live to the black hole era) get energy out of spinning black holes, and thats an energy source that could potentially last for trillions of years. But your probably right about proton decay, unless said society could figure out a way to reliably produce new protons to replace the ones that are decaying.

[@lucapaolini2765]

Check Isaac Arthur's channel. There are various episodes. I think one that talked about that is called: civilizations at the end of time

[@twokidsmovies]

@@lucapaolini2765 yes that's it

[@elliotnicklinmusic]

The intersection of the conscious experience of a single branch with these interpretations is so alluring, as is the romantic notion of altered states of consciousness (like dreams) being an experience of these other possibilities.

[@exp9r]

I'm sure you probably have planned this already, but could you do an episode explaining the exact theoretical work that earned Penrose the Nobel?

[@simpsosh7648]

Matt, hearing you say "Wubba lubba dub dub" just about salvaged my 2020, thank you!

[@jf3130]

😅

[@jf3130]

I'm in pain, help me

[@Mr.Nichan]

My viewpoint is that the "now slice" in relativity does not correspond to the traditional notion of the present. The traditional notion of present basically refers to everything on the SURFACE of both light cones and all the "elsewhere" zone in between the past and future, including but not limited to, the "now slice". In normal situations, this is all approximately one slice for things we care about, because we experience amounts of time that are much larger than the amounts of space we experence. Imagine a person at a particular moment in their life: The Earth for all the years of their life before the present is in their past light-cone, and the Earth for all the years of their future is in their future light-cone. Only a fraction of a second exists between the two for any point on Earth. Viewed from this perspective of how it relates to life on Earth, Special Relativity revealed that the "present" was not just one thing, but had a finer structure. Something similar can show that our traditional view of the "present" for distant stars and galaxies corresponds mostly to the past light cone. Currently, we can do nothing to affect these things in a way we can notice in our lifetimes, and until recently that was true of other solar system objects. Thus, the only way in which part of their existence seems like the "present" is the way that there is always some point in their timeline which is the state we are OBSERVING them in now. People without knowledge of relativity tend to assume that this is also the point in their timeline whose arbitrarily soon future we can affect, i.e. that the point in it's timeline on the surface of the past light cone is the same as the one on the surface of the future light cone, because that's what experience on Earth seems to show. Special Relativity revealed that these are actually two totally different types of present, which can be separated by large amounts of time for distant objects.

[@Wulable]

"We'll have plenty of time for time another time on space time." Haha great.

[@HaveYouTriedGuillotines]

What if the "many worlds" interpretation is right, but "worlds" as we know them aren't... Well, fully real, at least not on the quantum level, and certainly not in the future. In the sense that they exist in potential, but not physically and collective reality doesn't fully exist until observation, despite still existing in a sort of fuzz of potential. Meaning that only the quantum world exists in the future, but the macroscopic universe actually _doesn't._ The collapse of the waveform actually _creates_ the macroscopic universe. Quantum "reality" and macroscopic "reality" are two different halfs of the single reality we know, and their rules are different. Which may actually be part of what creates time as we know it. To put this another way: Reality is an emergent phenomenon, the future *is* deterministic, but not down to a singular outcome. Basically, the pre-determined future is the full set of quantum possibilities, which exist in a very real sense on the quantum level, but not macroscopicly. The upswing to this is that, if we assume that the macroscopic universe is a divergent phenomenon, and consciousness is an exclusively macroscopic phenomenon, we get a picture where neither the Neumann-Wigner interpretation or the non-conscious interaction are wrong. Conscious observation can only experience the present and remember the past, because it legitimately has no access to the future. Non-conscious interaction, on the other hand, doesn't really matter in the past (which is already stable and knowable, decided that is), but can be mapped out in the future, even if not perfectly.

[@edtheduck6219]

I find the whole subject fascinating, especially as most of our human experiences ill prepare us for the underlying concept of spacetime. I’m not sure that there is a difference between quantum and macroscopic reality, just that as you get more and more wave functions interfering, the result starts to look “normal” to us but it is really all still quantum. I consist of ~10^29 elementary particles all interacting though QFT so I have some sort of certainty that I’ll still be here in the morning but there is a chance I might not be...

[@AnoopKulkarniACK]

If dark energy is creating new space through expansion, is it creating new time as well?

[@Frog89mad]

i have read that some theory says the expansion of the universe is what causes time go forward instead of backwards

[@ThatCrazyKid0007]

Well, I imagine the answer is pretty much yes.

[@Lozza9000]

Perhaps it's the new time blocks (and associated information) that creates the illusion of dark energy.

[@itcamefromthedeep]

There are a bunch of clear answers, depending on your paradigm. Mostly no.

[@jamesross160]

@@Frog89mad if you wanted to go back in time one second, you would have to contract the universe 1 second back to where every bit of matter was before, so in a sense yes. But if you imagined a universe with no mass and just photons all moving at c, then there is nothing to relativitity to measure time with, so in a sense no. But you could also argue these photons if not moving, with no mass and c, then e would equal 0 and they wouldn't exist, so your back to yes.

[@Aleph_Null_Audio]

10:30 So the universe is like a "choose your own adventure" book. It's already written, but we can still pick our own story from the set of possible stories.

[@thekingofmojacar5333]

Interesting very advanced topic, thank you very much PBS! In Buddhism there is a convincing statement: Karma is the tool of our lives, if it is positive karma, a positive future develops, if we deal with negative energy, negative karma develops with negative experiences... To put it in a European or North American denominator: the future can develop either way, but it always depends on the moment and its fate (or karma)! ⛩

[@SoleaGalilei]

I tend to take a "Pascal's Wager"-ish approach to this. If the future is predetermined, there's nothing I can do to change it so it doesn't matter what I do or what I believe. But if the future is not predetermined, then my beliefs and choices matter very much. Might as well take the latter view, just in case.

[@internet_introvert]

The perfect illusion of free will is just as good as the real thing, since we can't tell the difference.

[@pelorix4969]

Your choice technically only "matters" if Determinism is true, because if it is, then what you do or believe is part of a chain of events that make up reality itself. If Free Will is true, then your choices are random and tied to nothing but the inside of your own head; and that is truly meaningless. Pascal's Wager is not a great stance for anything, really.

[@Luca48882]

@@pelorix4969 It's the best solution but simply doesn't account for the fact it's not an isolted choice but a lifestyle and you cannot choose those unless you artificially deviate what leads to it. It doesn't have to be black or white, can we stop with the determinism vs free will already? There is no such thing as free, will man or particle, it's completely contextual and you build glass castles on flawed notions.

[@missvikkianne2011]

Déjà vu says it all

[@pelorix4969]

@@Luca48882 I don't recall building any castles of the sort! Deep peace to you.

[@AdamAlbilya1]

16:10 I feel you brother, this year was harsh indeed for everyone. How can I help?

[@maythesciencebewithyou]

send cookies

[@AdamAlbilya1]

@@maythesciencebewithyou Some Eyeholes snacks might be better perhaps

[@ericjorgensen6425]

Why is the possibility of a single observer dismissed so readily when in fact this is the simplest of all the explanations? Occam's razor suggests that we give more than passing credence to the idea that there is just one conscious observer in the entire universe.

[@jwb52z9]

Hardcore scientists and science enthusiasts don't want "observer" to include "conscious living human being". That's why.

[@poncho4638]

If a single observer is what breaks down the wave function, then how do you explain the entire universe outside of the observer's light cone moving through time? Is time separate from the individual observer, does it just "tick" on its own, and the observer observing is the only function that produces a measurement?

[@ericjorgensen6425]

@@poncho4638 One explanation for this is the simulation hypothesis. In a simulation, the universe outside the light cone might not exist at all. Heck, the universe outside of your head might not exist. Or put another way, the only collapse that you, as the soul observer in the universe, can verify is the collapse you observe.

[@josephrittenhouse5839]

A single observer of the universe is still a thing observing within a thing observed. That cannot be denied. The reality of both could actually be defined by this state. If you are the observer, and you observe things, then there must be a thing to observe. Whether or not this observation is actually reality is not as important as there being a thing that is observed, and therefore real. Once you have this, even if you question the understanding of your observations, there really isnt much question to the correlation between what is observed, and the observation itself. We witness causality, change, regularity, repetition, divergence, dissipation...and all of these are in ways things which can be described, comprehended, probed and questioned. With such a state at hand, and a part of our shared experience, one must add new things to the description of the observed to account for a single observer, in the face of many observations (people) who report that they too, are observing. Occams Razor doesnt apply here, as things need to be added into the description including a real, observed universe where your observations display intelligence and curiosity...but are only figments of your imagination...within a universe that is otherwise real.

[@Daymjo]

@@ericjorgensen6425 if you subscribe to the simulation hypothesis, well there's your answer. You don't need the CPH or many-worlds or single observer theories anymore. the universe obeys the rules of the simulation. Not saying the theory is wrong, just saying that you can't assume it to be right, there's simply no point. If you're curious, try to youtube 'isaac arthur simulation hypothesis' , he makes it much clearer than me. guarantee you'll enjoy the video.

[@OuroborosVengeance]

I have re-seen this several times now. Its so interesting, every time i see it again i go to different places in my mind

[@wizardofki]

As always, this kind of blows my mind. It's kind of spooky too to think of whether things are deterministic or not, or whether or not I have a "choice". So, was my writing this sentence at this "time" predetermined since the big bang? And, if so, then it was predetermined for part of the universe ("me") to observe and think about the rest of the universe and its origins. Weird.

[@Jagar_Tharn]

Yes. Causes cause effects. It's that simple.

[@PromethorYT]

Random thought: so if entangled particules are separated one at rest and the other moving near the speed of light and we measure the particule that is at rest, it does it means we affect the state of the moving particule in the past?

[@tellmemoreplease9231]

To me, that sounds like a very good question.....

[@flumbz5266]

You mean like the double slit experiment?

[@callum8322]

If say, earth is the only observer in the universe, then what is outside our light cone. If we break down that wave function, does an entire planet or galaxy reveal itself into existence? I'm going to need to re-watch this episode i think.

[@markl3763]

Hi Dr. O'Dowd. 2 questions: wave function collapse seems to require observation, which to me seems to require life, so what if life never evolved? and if time causes gravity, and time is money, does money cause gravity?