Did Repulsive Gravity Jumpstart the Cosmos?

[@PurpleChevron]

Wow I've been huge fans of Guth and Linde for years for their work on inflation. What a treat to see such a competent interview with both of them by Brian Greene.

[@Smood47]

Sometimes I listen to people telling about random political issues or about random garbage drama. When I come here I think to myself why waste a second on something that isn't enlightening like listen to Dr. Greene speak?

[@TheDavidlloydjones]

Three guys on the stage, and you pick the wrong one. Some days are just like that. Roughly a third of them, since you were wondering...

[@danielpaulson8838]

Agreed. His capacity to distill complex and convey it in somewhat accessible terms is rare. He’s a gem. Same with Sean Carrol.

[@rwitmer22]

EXACTLY! You hit the nail on the head perfectly for me also.

[@mrtienphysics666]

Does this improves the lives of the common people?

[@ianmarshall9144]

@@mrtienphysics666 I think so , growing up English and having an understanding of physics has liberated me from religion , ghosts , life after death basically all supernatural nonsense , leaving me free of any childish myth and legend dreamt up by ignorant folk . Imagine a world of modern homosapiens , the world looks in a bad shape and we are still to make the leap from a bronze age mentality to a rational , educated , modern understanding of how it all works , after all knowledge is the one thing that has been slow to be fed to the masses , coupled with the fact most parents indoctrinate their children in religion you are bound to get confused individuals with a skewed view of reality , if you taught physics like religion then we would solve many of societies problems .

[@brothermine2292]

What Linde described beginning at about 12:58 -- the problem of how to explain how the Big Bang started at exactly the same moment throughout the small hot dense clump of primordial mass -- finally helps me understand why Feynman assigned a strange homework problem in a class at Caltech that I audited in the 1980s. He called it the "firing squad" problem. Suppose there are N members of the firing squad arranged in a row. Each member can communicate only locally.. only with its nearest neighbor on its right and its nearest neighbor on its left. They can communicate only at regular periodic intervals (like cellular automata). None of them know how many members are in the squad. All of them are programmed with the same communication & firing algorithm. Their goal is to all fire at exactly the same moment. Assume that at a random moment, one of them initiates the (local) communication that is to eventually lead to all of them firing at the same moment. Design the simplest algorithm that achieves the simultaneous firing goal. Feynman didn't tell us why he wanted that algorithm. But it would solve the problem Linde described, in a 1-dimensional toy primordial universe. So I'm guessing the Big Bang problem is what motivated Feynman to assign the "firing squad" homework. I submitted my solution, which seemed reasonably simple. But I don't know if it was the simplest algorithm, because Feynman didn't review any of the answers with the class.

[@michaelogden5958]

1:00:10 or so: "Anything that CAN happen WILL happen an infinite number of times". I would add: given an infinite amount of time. Another fascinating presentation of the World Science Festival featuring Dr. Brian Greene.

[@HarryNicNicholas]

well that's clearly wrong, fictional characters will always be fictional. every combination of things that exist will occur, but pink unicorns aren't going to pop up in one of these infinite universes. pink unicorns only exist in heads, things that exist in heads aren't going to manifest however long you wait.

[@VladimirNicolici]

@@HarryNicNicholas Exactly which law of physics prevents the existence of a similar animal? Flying fish or squirrels would sound fictional to a person that never seen / heard of them. And while single horned animals are a bit rare, they do exist.

[@uliwagner1927]

Of course there are, or will be pink unicorns. Give a gazillion monkeys a gazillion typewriters, and an an infinite amount of time, they will not only produce the Bible, and the Koran, but all literature ever written by humans. Difficult to accept but it's the truth.

[@LucAnderssen]

Guth and Linde, heavy weights of Cosmology 🚀🪐🛰️🔭🍺

[@SuperBlinding]

Gravitational ! !

[@linkgunther1618]

The world is extremely lucky to have Brian and the World Science Festival. I imagine if we lived in an intellectually healthy society, these videos would top the trending charts. It is unfortunate this video has only 25K views in 48 hours when one considers the kind of trash on KZbin that gets millions of views in only a few hours.

[@treborg777]

I love this lecture. It helps me understand the underpinnings of inflation that many others have either glossed over or ignored.

[@joegordon-p6x]

Brian needs to explain how he does the animations at the precise time they are needed as the guests talk about them, seems Magical, what is goin on? this defies Physics!!

[@renezirkel]

Either 1: Green screen and after effects Or 2: He knows the theme and his question agenda, has the animations prepared and a helper plays them at the right time.

[@joegordon-p6x]

@@renezirkel well he wont say how its done, he wont talk to the Peasants who watch his channel ..

[@JolAugust]

Have you shared this with Alan and Andre. Tell me if you do.🎉

[@HarryNicNicholas]

it's all done in edit i'm guessing, brian isn't sitting in front of two giant screens, he's probably in a room with the screens in front of him and the animations are edited in after the whole thing is recorded, the entire program is then edited together. i've worked special effects on movies as well as tv, these days anything appearing on a screen is edited in AFTER all the material has been put together. also news programs use "virtual sets" these days, the presenter stands in front of green screen and anything in the "studio" is a 3D model. just cut and paste "news tv studio set 10 virtual green screen background-1080.mp4" into youtube and it'll likely give you a video of what i mean.

[@joegordon-p6x]

@@HarryNicNicholas yes of course that is how it's done, i was being tongue in cheek just to get the defies physics joke in there, Thanks for all that info

[@yrebrac]

one of the best summaries of the subject well done!

[@mandeepsingh-fd7mh]

Thank you so much wish to meet Mr green one day.

[@ngkatsantonis]

What a fantastic interview. Thank you Brian, Andrei, and Alan.

[@cosalidra759]

Aaaaaaaaaaaahh. ( That's my excitement because a new WSF has dropped ) 💃💃💃💃

[@xNillowsx]

`history of the universe` also put out a video!

[@JoseLopez-w8i]

Same 😅

[@rainajackson7878]

I still can't get past what was before before. Blows my simple mind!!!!

[@mehridin]

before before before

[@tpot725]

Thank you!

[@jeffreymarchese1762]

This was a great segment. The question I was left with is: How do dark energy (DE) and dark matter (DM) factor into these theories? At some point they must be accounted for. What are the possible mechanisms for integrating such? Also (and I think [maybe] relatedly), the previous segment here on DESI indicates the employment of baryon acoustic oscillations (BAOs) as measures of the effects of DE & DM. I am not clear on what mechanism in Inflation would manifest BAOs (or if Inflation is required for BAOs to form). My first intuition is that BAOs formed after the Inflationary period (were they "locked in" during or after cooling?), and also, that they manifest across larger spatial scales. Still, given the euclidean nature of Space-Time, it would seem BAOs are dependent on Inflation. So any effects of DE and DM on BAOs should also inform the parameters for Inflation. Am I thinking about this correctly?

[@Smood47]

By the way the way hes sitting in a chair the 3d animations and dr guth and the other physicist are around him is truely amazing.

[@rolz420]

"A fantastically dense nugget...." best quote ever!!!!

[@blengi]

has it been empirically validated that a piece of stretch rubber (29:13) has repulsive gravity _"that efffect is real"(guth)_ due to negative pressure by some indirect test?

[@techteampxla2950]

DrG , your a G, thanks for this immense information and the amazing guests

[@LarsRyeJeppesen]

I frickin love these interviews.. amazing

[@rainajackson7878]

Im 60 this year and I can remember thinking about where is the end of space, when I was about 7 years old. Is there a birick wall? But what's behind that? I know you guys know heaps, but at 60 I still can't get past what was before and where does space it end? And if it never ends, what does that mean? Sorry Im so basic, however I love watching this stuff and I kind of understand upqurks down quark nutrinos etc.

[@mattorr2256]

There’s likely no end in either direction.

[@mattorr2256]

It never ends and yes this is not very intuitive for us.

[@nunomaroco583]

Hi, incredible talk, one of the best candidate to explain the mechanism of Universe.....

[@lipgloss202]

Excellent. Love these discussions. So easy to access when they explain it for non experts like me. Now I will go watch the Tsuchinshan comet.

[@mistahtom]

31:01 the energy needed to get over that little bump are the quantum mechanical limits of your instruments that are in an inertial reference frame. You need a copy of all necessary experimental equipment in a kinematic reference frame to complete the scalar value that gets you over that bump.

[@isatousarr7044]

Inflationary cosmology suggests that the universe experienced a rapid expansion in the first moments after the Big Bang, smoothing out its initial conditions and leading to the large-scale structure we see today. This theory addresses key problems like the flatness and horizon issues, and supports observations such as the uniformity of the cosmic microwave background.

[@LarsRyeJeppesen]

Why do you write this?

[@markoszouganelis5755]

All particles in the universe are entangled, since the big bang? Thank you for your comments! The purpose of my question was: "It is GOOD to think about a beginning of our existence as the Big Bang Theory"🌈

[@TheDavidlloydjones]

Yes.

[@jameshoey303]

price it

[@jameshoey303]

prove it

[@danielpaulson8838]

The universe is made from an expanding quantum energy field. Matter emerges from there too. Particles are tiny waves, not solid mass. They are all connected, as are we, in and of that expanding quantum field. Particles are tiny waves within cosmic sized waves.

[@JoseLopez-w8i]

​@@danielpaulson8838Mic 🎤 drop

[@cubfendi8714]

what triggered the initial expansion? what behaves this way ?

[@framethis]

Imagine our universe was like a tiny microscopic bubble presurized in a sealed bottle of champagne then something removed the cap and all the bubbles within rushed out and expanded i think we are one of those bubbles foerever expanding .

[@johnnuaxon3]

Imagine if there is just one observer. He is lonely and bored. And he wants to create someone else. He just split in two and made others. Then others split in two and so on. So everything starts from just one who became many. "THE POWER OF ONE THE POWER OF TWO THE POWER OF MAAAANYYY."

[@EricDMMiller]

Prior to inflation, the universe was within an order of magnitude of the Planck length. The early universe was very flat. Entropy increases to further flatten any variance. The forward flow of time is just a return to nothing.

[@simesaid]

So far as we know (according to the Lambda-CDM model of cosmology) the universe began from a random quantum fluctuation. It may not be entirely satisfying, but that's where we are. It's either that or a cyclic universe model like Penrose's Conformal Cyclic Cosmology, in which the universe constantly expands and then contracts again, forever. But even in this model there _had_ to be a beginning at some point in the past... Have a great day!

[@cubfendi8714]

@simesaid This makes sense. A cyclic universe would explain a lot I think. Thank you.

[@mistahtom]

29:12 the negative “pressure” is calculating time that is derived from the energy and mass equations, as they relate to c^2 where time is = -√seconds and you get this holographically represented by calculating the eigenvector (x) right past the “theoretical event horizon” at the moment of singularity

[@pauldirac6243]

@18:57 HAHAHA.😂 I love it. What about the double box around the statement, "miraculous breakthrough!"

[@DavidFMartin]

You don’t need expansion if everything is still connected via a dimension of zero length and size. Or effectively a singularity. At the start of the universe everything was at a singularity point, there were no dimensions and everything was connected at the same non point place. After the universe began expanding maybe this single point dimension remained and all matter and energy has become entanglement within this point and still is. This would also explain why entangled particles in our 3D (4D if you accept time as another dimension) universes can affect partner particles across huge distances instantaneously. Basically the conditions where everything was compressed into a singularity are still in place and we are all connected to a point via higher dimensions to (or lower dimensions) via this original start point.

[@DomenG33K]

There is to much stuff to produce a singularity. If we condense all the matter we know of it can't fit into a single point since we reach plank density before that point.

[@LarsRyeJeppesen]

Vídeos like this always brings out the arm chair physicists.

[@truebones]

love this

[@mistahtom]

34:43 M-Theory describes 11 dimensions because it takes into account observer bias when it comes to String theory because the researching observer is in a deterministic state, philosophically because they’re constantly having to publish which itself can collapse some sort of quantum mechanical waveform.

[@OpenWorldRichard]

I don’t buy the idea of repulsive gravity. The hypothetical matter doesn’t exist. This concept seems completely contrary to all observations of the behaviour of matter. There is no such thing as negative mass. Richard

[@danielpaulson8838]

What if our universe is occurring within a much older and larger universe? Thinking. Thinking. Thinking.

[@cirusMEDIA]

good provocative thought!

[@jimgraham6722]

A Kuhn Level 8 nothing

[@johnnuaxon3]

*much older and larger multiverse

[@nefertitib4313]

When I got tired of all the “noise” that the news these days talk about, as if I am forced to care about all the issues that I cannot solve or do anything to change the outcome, I just like to listen to World Science Festival. It makes me feel like there’s a bigger more powerful force out there that we cannot comprehend, and I love listening to these smart people talk for a change.

[@mehridin]

eternal inflation sounds like the zimbabwean economic model

[@thomasjorennielsen]

“Success in science means finding one theory that matches what we observe to a high degree of accuracy”

[@-LightningRod-]

oh this is gonna be gooood,.....

[@rainajackson7878]

So what was space before space?

[@trebell885]

Inflationary is a fullfilling density?

[@Khashayarissi-ob4yj]

With luck and more power to you.

[@mistahtom]

26:10 Special relativity describes that flatness and general relativity describes the players in that 1Dimensional reference frame of Time in spacetime

[@street_struggle7]

These guys are literally wizards

[@thomasjorennielsen]

Please do a video on negative pressure and repulsive gravity

[@MF_Loomy]

I thought this was a jujutsu Kaisen video before I finished reading the title

[@crazieeez]

If all particles are entangled since the Big Bang, the concept of soul and afterlife are very much alive and relevant. Sometimes at night, a ghost or some soul talk to me that I will do great things.

[@hahtos]

I find Neil Turok's mirror universe theory much more compelling

[@zelmoziggy]

Is that like the mirror universe in the Star Trek episode “Mirror, Mirror?”

[@jimgraham6722]

I don't believe Turok's ideas are fundamentally incompatible.

[@kundakaps]

Turok doesn't believe in that anymore.

[@TIMEPHYSICS]

yes below the Schwartz radius, the gravity is repulsive at larger distances. This is why the universe is still expanding. It will keep expanding for another 9 billion light years and start contracting when it reaches its Schwartz radius of 22 billion light years.

[@ChristopherWentling]

So is the reality of the entire universe and not just the visible universe most likely closed at a massive scale? If it wasn’t flat before inflation can it somehow transition to flat? This doesn’t seem possible.

[@Kbrutha]

The cbcc model could explain beautifully the cmb discordance, Hubble constant, horizon problem, flatness problem, helium problem…

[@mistahtom]

1:26:12 That’s my hope that good AI learning can help with solving the problems of physics on other worlds

[@ValidatingUsername]

“Repulsive gravity” is a convergent vector for light and matter from a previous place to a Minkowski singularity from a past light cone to a future light cone. It’s now an ongoing process for every “observable universe” that an “observer”, that is anything that obeys geodesics of electromagnetic fields, since the universe “came into existence”

[@luminousfractal420]

visible universe not whole universe. vastly different things.

[@vitr1916]

In my opinion, we may see boundaries of the inflation when a system is changing seriously. For example, Earth may be changed if many keys of earth elements (including livings…) are making critical changes; The solar system may be changed if one or two planets are destroyed; our galaxy may be different if one or more solar systems are changing their shapes. If things from a system are adapting changes quickly from the inflation, then the system is going back originally state faster, and we may not see its effects.

[@captainzappbrannagan]

The measurement problem exists. The community is it now 70% on board with inflation or competing/antithetical points have brought it lower?

[@rnedmondson]

The background 'music' is horrible. Surely, we can listen to people talk without having an incessant background noise? Personally, I couldn't concentrate because of the (loud) background noise.

[@Designer-Alan]

Apparently you dropped your comment under the wrong video.

[@rnedmondson]

@@Designer-Alan Nope. Introduction by Brian Greene was very off-putting. Others might like it but I prefer to concentrate on the words.

[@Designer-Alan]

@@rnedmondson I get it, but it's such a kvetch, like eating a Michelin 5-star meal and complaining that the color of the plates clashed with the hors d'oeuvres.

[@danielpaulson8838]

I would just leave then and never come back. Anyone who is that hurt needs to protect themselves.

[@Flailfist_Jr]

i hope those extremely annoying and distracting ads aren't the new WSF policy

[@JonathanLangdale]

What is the critical mass density of a singularity?

[@TheMaddmann]

cool

[@Bcraw428]

A mirror verse would explain why we see everything moving away in all directions. It’s like a quantum copy verse

[@NoRiceNoRice-wx2sb]

As if to commentarily represent your colleague & 1 other pioneer proponent of Inflation, Alex Vilenkin, the problem of the physically unknown "beginning"' or the beginning 'singularity' in the original BigBang turned out to be unavoidable even in the Inflation Theory.

[@NewMessage]

So.. my expanding waistline isn't such a big deal after all. Told you, DEBORAH!

[@The.world.has.gone.crazy...]

😂

[@jameshoey303]

yeah… but your cardiologist has a different viewpoint

[@jameslacey5654]

Wake up baby, new wsf just dropped!

[@lastchance8142]

One must remember that inflation was proposed to explain the unresonable flatness and homogeneity of the observed universe. The other option of course, is that the initial conditions were so perfect that perturbations were so minimal as to have little effect until the era of recombination. Proposing such perfect initial conditions is problematic for a materialistic origin of the universe.

[@alexturner5658]

Doesn't the dreaded anthropic principle take care of some of the need for our universe type to be the most likely product of inflation? Ours could be the rarest of rare universes (although still one of an infinite number) and we see it only because it produced us and no other kind of universe could do that. Hasn't there been some discussion of that re the anomalous value for vacuum energy, for instance, considered unlikely per string theory? I suppose we'd still want measures of likelihood at some broader level, setting the range of possible values for a given parameter for instance. Not to mention the implications if false vacuums could be produced artificially, as a paper by Guth from the '90s seems to assert.

[@jameshoey303]

We are uplifted by listening to these debates grateful and thankful for the gift of contact with serious people of caliber....then you listen to Trump/ Biden /Debate… and despair returns… as John Mc Enroe said long ago " you cannot be serious" ..really that's the best we got to chose from… do we not take our future seriously ? Come on USA stop the joke now,

[@ZZ-ev2ed]

"How many types of cheese in Safeway?" 😂❤

[@street_struggle7]

These are guys you just give money to and leave them alone and ask them to try to write down their thoughts

[@SolaceEasy]

It's all a dream we dreamed one afternoon, long ago.

[@monkerud2108]

Dude. Andres opener woth the dog, was amazing, i laughed.

[@YuTv1408]

So how useful is to current technology?

[@tebi1kurieudidon172]

Lol

[@FrankBarnwell-xi8my]

The way the universe is might be

[@SolaceEasy]

Not as much as Drake.

[@tebi1kurieudidon172]

@@SolaceEasy Sorry, I prefer Kendrick.

[@m.sarvon]

but what is the nature of the inflaton field and the mechanism that triggered inflation? Time to stop all the ad hoc theorizing & paradigm stretching... a new cosmological model is on the way. aside from the flatness and horizon problems, there're just too many challenges for the Big Bang model.

[@stevenrussell1114]

Fun fact, repulsive gravity is also what brings MAGA together

[@mistahtom]

01:55 The equations describe a universe that recycles itself

[@cirusMEDIA]

Did i miss something? When was the Big Bang Theory proved as factual? Tunnel vision is a hell of a drug.

[@andrecoleman1856]

I feel like scientists are terrible about describing how the univ is flat. Makes no sense to me...

[@zhavlan1258]

Здравствуйте. Эйнштейн создал, теорию относительности но сам не ссылался на проделанный опыт Майкельсона Морли для подтверждения своей теории. Но при этом у него, мечта была, чтобы такой же опыт проделать в поезде или самолёте. Просьба. Помощь найти, кто захочет стать автором изобретения. В Китае на предприятии по выпуску Волоконно-оптических гироскопов, возможно договориться. Производить устройство ГИБРИД гироскопы. Эти устройства будут использоваться в качестве ❤учебного пособия в школах❤, высших учебных заведениях. Также ВОЗМОЖНО будет с помощью «гибрид гироскопа» сделать научные открытия; в астрономии, астрофизики, космологии, высшей теоретической физики, …

[@Govstuff137]

Dear Mr Green . Isn't inflation of the universe creating it's own gravity. Like a rocketship accelerating faster and faster increases gravity pushing the astronaut down to the bottom of the spaceship. The increased rate of inflation is increasing gravity throughout the universe. And I don't mean dark matter. 🎉

[@dirtbird7415]

Seems that inflation is not nessesary if there wasn't a Singularity. I/E the universe was never that small. To date no one I think has ever gave a satisfactory reason as to why it ever had to be that small before it expanded.

[@MrDogonjon]

Hyper luminal inflation serves poor portions of mass/ energy gradient. there is no causality.

[@kx4532]

Space would have to expand or everything would just be a black hole? 🕳️

[@gorankurir9270]

Its allways inlitening to listen to dr Green speak but in this case,for somebody who hasn t study fizics the video is realy to tehnical and that is something that is not the case in the other videos.But i think doctor Green thinks in this case it was necesery

[@mistahtom]

14:58 yeah that’s what was erroneous about fixing Boltzmann’s constant to be exactly 1.380649×10−23 J⋅K−1 You claim to have this expanding universe, so you fix a naturally fluctuating fundamental cosmological constant, and ignore the entropy tensor instead favoring this T_munu business without having unified quantum mechanics, gravity or magnetism.

[@FrankBarnwell-xi8my]

Pocket universe? We're a drop of water in the waterfall?

[@jasonwilliams8730]

👍

[@군주-b9v]

Thomas Daniel Moore Gary Martinez Eric

[@wintervenom123]

16:20

[@monty3854]

I think they had the same barber.

[@jasonmills8592]

I see how the little guy is kept down.

[@rpoorbaugh]

8:38

[@krisjupp]

TURN OFF THE MUSIC !!!!

[@santisageorge4154]

????

[@The.world.has.gone.crazy...]

In my humble opinion, there must be something before the big bang but what was it? And if space is expanding it must be expanding in to something. Also in my opinion everything has a limit. For example if you poor water with a hose in a swimming pool after a while the pool is full and the water would spill over. So if space is expanding like the water, what is it expanding in and when will it spill over and in to what?

[@TheDavidlloydjones]

The word you're looking for is "pour," but we got it anyway: it's going to be a while before you join the conversation.

[@mikesradiorepair]

Outside the universe is nothing, there is no "space" outside the universe. The expansion of the universe is the creation of new space.

[@jimgraham6722]

Kun level 8 nothing

[@SolaceEasy]

There is no before time starts.

[@willmpet]

If The World Science Festival would stop taking funds from The Templeton Foundation, I would listen to their content, but until that time I will continue to not listen to anything that they produce.

[@georgemwanza6339]

Y

[@petetap4255]

How many times could an event in all of its aspects and outcomes take place until it is not actually the same event but becomes a form of mutation of the original event, nature loves to mutate...😂👍

[@SolaceEasy]

And just as staged.

[@hyperhybrid7230]

The current scientific theory is big bang, yet science waits for nobody and the understanding of creation. Likewise a religion such as Islam, the koran mentions the expanding universe for those scholars and intellectuals pursuing this path, this the 'Sign of the Times' hence who knows what new theory is evolving.

[@OpenWorldRichard]

nozamA morf 1 koob dlrow nepo esrevinU eht fo noitulovE eht eeS. Richard

[@jacekpiterow900]

Strange that Andrei and Putin are risen in the same country...

[@danielpaulson8838]

Brain types. Every country produces good and bad.

[@jinstinky501]

You know these guys have hit a brick wall when they start talking about tiny dudes sending signals to each other in order to regulate the temperature of the CMB. Ouch! Kind of embarrassing for the human race.

[@Designer-Alan]

Listen to that part again because you missed the point and/or you don't understand what metaphor is.