The audacity to suggest that this amount of insane energy can spring out into existence from nothing is borderline stupidity. Effectively it is a version of the Boltzmann brain theory i.e. there was nothing and suddenly there was an insane amount of energy. It is absolutely clear that BB is a result of processes we know nothing about ... the whole BB could be just a jet of energy similar to the jets coming out of black holes.

Where did these science talks take place? When? I ask, because the concept of place-time is important to me.

Yes, when was it recorded?

Not sure it is polite to refer to another channel, but I'll do it anyway. Over on World Science Festival they feature some great debates going back several years. That said, if you look closer at iai (this channel), they have other talks by scientists that do not necessarily agree with each other. You could consider that a longer form of debate too.

The entire debates are posted on the IAI"s website behind a paywall.

Penrose, probably the most brilliant person there, was put last and shushed. Shameful.

@@markuswx1322 No matter how much Penrose I see, it never seems to be enough. I can highly recommend his books as well, they are extraordinarily well written.

Yes. Utterly appalling.

Funny but also sad. I would have like to hear Penrose finish his thoughts unhurried.

_One Minute to Infinity_ sounds like the title of a _Red Dwarf_ book.

He went on for eons.

I kinda agree

should have added: "to talk about time!"

They don't like to give anybody time that knows the big bang theory is incorrect. Penrose is on the right track I believe.

I deeply hope it's true... but that makes me even more deeply suspicious of it. But there's something beautifully simple about "When all you have is quantum fluctuations in an ever stretching, ever flattening universe with no sense of time, a universe is inevitable. And that's exactly what you have at the end of our universe. Maybe that's what there was right before it." It's so easy to imagine, considering the scale of things we're working with. Like zooming in on a fractal.

@@ANunes06 yep.

The point is that Penrose does go on to explain how his hypothesis is testable by looking for disturbances or ripples in the CMB which would be the evidence of a previous universe or Aeon.. Which is slightly better than using a theory that nobody really understands once we can unify it with one that we know isn't right.

@@Lamster66 Which theory isn't "right?" General Relativity? Tell that to your GPS 😂 QM cannot account for several properties of gravitation. Ed Witten: "The reason we know General Relativity is correct is because it is the only theory ever conceived that can explain why gravity obeys an inverse square law. Newton's theory of gravitation does not do that." And quantum mechanics cannot either. Peace.

@@feynmanschwingere_mc2270 Tell it to your GPS? Yes I know how that works Thanks👍 You clearly don't understand that GR works but also has a limit after which it fails. We are talking about The beginning of the universe not time dialation for satellites. ⌚⌚🌌🌌🤣🤣😂🤣😂🤣 Wrong is the wrong word. they are both incomplete . To paraphrase most astrophysicists "The reason we know GR is wrong is we get a singularity!" GR works and is extremely reliable until we get to black holes and T=0 at the Big Bang. Then it doesn't work. This is the same for Newton's classic mechanics it works perefectly well on earth but it has difficulty once you are dealing with Galactic scales. Its not wrong rather its incomplete. Which is why we still teach Newtonian mechanics alongside GR. As it simpler to understand and gives engineers the correct answers on earth. QT is both incomplete and not fully understood. We know this because we dont currently have a GUT. What Penrose points out in his Aeons hypothesis is that "inflation" is introduced to make The mathematics fit the observation of a uniform early universe. It the same fudging as Einsteins cosmological constant was. That fudging of the numbers and the anomaly it threw up lead to physicists hypothesizing Dark Matter. Which is likely real. Penrose doesn't state that he is correct only that His hypothesis doesn't require inflation to work.

Love it!

there are other videos out there where he explains his idea, if you are interested. It's a fun idea, and he proclaims that there might even be some observational experiments you could do with it, but it's really far out.

It was a bit depressing to see the other cosmologist sitting there looking so put upon, as if he could barely endure listening to Penrose, as if he were listening to blasphemy from a village idiot... and to see the moderator check his watch as a hint to Penrose that they didn't have any more time to listen to what I can only guess they consider nonsense.

I guess there just wasn't enough time laying around in this 14 billion-year-old universe to spare five or ten more minutes to let Penrose finish his line of thinking

Penrose was wandering here. I was hoping that he would present a coherent and illuminating idea of some kind, or adding a small but perhaps significant piece to the model, but instead he seemed to be just wandering around smelling the roses. That's fine. We all do that from time to time, either as a way of taking stock of our inventory of ideas or as a preamble to developing a critique of some kind. Survey papers are a common example of both exercises, and they're valuable contributions, not because they're offering anything new, but simply toward coherence. I didn't notice that Penrose was particularly intent on offering coherence.

The metric time (what clocks measure) depends on rest mass. Energy or relativistic mass is not enough to build clocks. But without rest mass the ordering of time makes still sense (as well as things like twice as much time). But it makes no sense to say in one minute (metric time). Why mass faded away at the beginning of the universe was discussed before in the video. The Higgs mechanism "melts away" and particles loos their rest mass. At the end of the universe most of the rest mass is in black holes. They evaporate. But some rest mass is still in a few elementary particles (positrons, electrons, ...). According to Penrose they lose their rest mass because of a complicated reason he avoids in discussions with the public (rest mass is not a Casimir operator for irreducible representations in an expanding universe - discussed in his paper or the UKposts video *Brian Greene and Sir Roger Penrose: World Science U Q+A Session* ). So at the beginning and the end the universe looks has no rest mass (no metric time, hence no size, no scale). So large and small are indistinguishable. And then the beginning and the ending of the universe look identical (that they look the same after rescaling was proven in detail by a student of Penrose under Penrose supervision). So if we apply the same laws of nature to the ending of the universe, it just expands like it always did into a new aeon. The interesting thing about Penrose's idea is, that it needs no new physics. Only the physics which is known but applied to situations nobody had done it before.

@@tofu-munchingCoalition.ofChaos ya, I've been trying to fully wrap my head around CCC for many years now haha.

@@tofu-munchingCoalition.ofChaos But even if the beginning and end of the universe look identical it still doesn’t explain the big bang itself. What is the exact math that leads to that turning point and at what exact moment does it occur? Why is the critical transition between two eons, the split second we know as the big bang? Even if the end is small it still doesn`t mean that it must have a new beginning over and over again. There`s no guarantee that some quantum fluctuation will lead to a new aeon.

@@lesalabs *What exact moment?* There is no exact moment because metric time is ill-defined there. But there is an exact "moment" in conformal time. It's the time which corresponds to the current metric time infinite future. At that moment you don't need something new (quantum fluctuations, inflation,...) to start the big bang. You just apply the laws of physics to the limit state of the universe. The "big bang" is nothing special. Once you have the initial state (limit state of a past aeon) you don't need something else to trigger it. It happens because the known laws of physics give us the big bang from the initial state (=limit state of a past aeon).

😆😆😆😆😆😆😆😆😆😆😆 And they were there to see it, but they didn't invite you.

He was cut down at the right time for this audience. He was about to start with conformal theory and how "scale" without time is the same as long as all transformations are conformal, so big = small and therefore another big bang can start. This would be hardly swallowed by the audience. In a mathematical sense I can grasp what he says, however there is only one prediction that comes out of that theory (gravity could leave a mark in the next eon) and so far observations cannot confirm anything (neither astronomical nor the cosmic background radiation studies), and most likely never will - so it is in similar status as String theory: it might be onto something but cannot be neither tested positively nor disproven, it needs better and testable predictions which are more than "there could be something that we might never find". Using math as to explain phenomena that we cannot observe, confirm or disprove is the same as what religion does, not science. Science uses math, not the other way around. "We might never know" is a perfectly good answer to what was before "time itself", and if extraordinary claims are laid down, they also need extraordinary evidence.

@@marsovac I am not a scientist but I find Penrose’s theory fascinating. I read his 3 page paper on CCC, and I got his book, Cycles in Time, for Christmas. I struggle with the concept of conformal because this is not my area of expertise. I understand that he is talking about the preservation of angles but like the Escher drawing, everything is compacted at the boundaries. Is he saying that the Big Bang is the compacted state at the boundaries? Help me if you can.

Penrose says there was no 'time' before the universe. But there was 'eon' . Eon is time. How flip floping could he be?

@@junacebedo888 (space) time only exists within a (or our) universe. You can not say "before there was time". However penrose thinks our big bang is the same as a big rip in a different universe. A different eon as he calls it, which had its own (space)time.

@@vertigo2893 God is eternal therefore timeless. Universe is a creation. God is the creator. That universe of Penrose which has no evidence that it exist; will also be a creation

It's all fantasy... hopefully I live long enough to see this theory get completely discarded

@@aaronmarchand999 why is it fantasy?

Because none of it is true, it only exists in the human imagination

@@aaronmarchand999 how do you know?

.......... so anticipatedly contradictory

And all so wide of the mark!

Are you asking "where has all the truth gone, is that the ultimate question"?

The audacity to suggest that this amount of insane energy can spring out into existence from nothing is borderline stupidity. Effectively it is a version of the Boltzmann brain theory i.e. there was nothing and suddenly there was an insane amount of energy.

@@reasonerenlightened2456 I don't think that's what the Boltzmann brain theory is about. You should check out the PBS Spacetime video on Boltzmann brains. It's a really good explanation.

Not exactly. If I explode a firecracker or an atom bomb, matter and energy move outward from the explosion into more or less empty space, less if it's on earth since we do have an atmosphere. The Big Bang Model isn't matter and energy moving out into empty space from somewhere but space itself expanding and carrying matter and energy with it. This isn't based on guesses but on observations that can be verified. As far as springing out of nothing, we don't know and maybe can't know how it originally sprung since we can't see back beyond that 1*10^-28 seconds.

Baby universe or fetus universe look like a 'period' at the end of a sentence. But much more tiny!!!. AND THEN it expanded so infinitely fast. Did they observed that event? NO!!. As Sabine said " we are just speculating. We have so many assumptions"

​@@junacebedo888"Did they observe the event" is literally the dumbest argument one can make when it comes to astrophysics 😂

> Wanted more Bjorn E. Yeah, no; Bjorn Ekeberg is a philosophy guy, he has no understanding of big bang cosmology and he has no clue what he's talking about. He speaks with some aura of authority on the subject, where he's completely ignorant on the actual mathematics and physics behind it. Don't listen to that guy at all. He's a typical Dunning Kruger effect 'victim'.

What he describes is called "Conformal cyclic cosmology". I think he wrote a book about it called "Cycles of Time".

A few hundred years ago: "You're not allowed on this stage unless you agree the Earth is the center of the Universe".

@@fins59 Always politics

@@TheFith67 If not politics, it is at the very least dogma, and no theory should be treated as dogma. Skepticism is supposed to be central to good science.

@@NondescriptMammal Yes exactly. Only beliefs cower from it. They seem to be scientists of great faith. I'd even say a bit fascist too.

@@TheFith67 Yeah it was pretty pompous and presumptuous for him to say that, as if he is the self-appointed authority on who gets to participate in a debate on the subject. Especially in cosmology, where they try to surmise what happened billions of years ago, from a very limited and tenuous set of data. Any cosmological theory necessarily requires a number of assumptions. And it's not the kind of science where you can do repeatable experiments to prove a theory, you're almost entirely stuck with whatever data can be gleaned from EM radiation received from distant celestial objects.

Buy a mirror

Awesome

Sean brings it to another level, all is information. Roger's more intuitive.

​@@TheEmergingPattern Well Sean Carroll continued the introduction of course then talked very briefly about emergent approximate reality and then about 'times arrow' (as seen by 'us') as stemming from a 'symmetric' larger universe that parallels ours (which certainly isn't 'set in stone' lol). I think that at this stage of his great career Roger Penrose has more than earned the right to do whatever he wants with his time, but though I always love hearing Penrose, I most enjoy Sabine Hossenfelder's arguments in general (she was in the video directly after). In her own brief moment she mentioned dark matter and dark energy, and it's because she feels that more time and energy should be spent honing the core models that people base their speculative theories on. Hossenfelder isn't against theoretical physics at this level (and she's a Penrose admirer and theoretical physicist herself), she just has a very practical approach, and she talks a lot about the now really-long stagnation in any major advancements in physics, and what she's come to see as a misuse of scientific funds in continuing to advance particle colliders (building bigger etc largely in the hope of bumping into new things) and in maintaining such a strong focus on trying to develop theories that haven't gone anywhere for decades now, like string theory.

@@mattlewis5095 oh yes, can imagine proving dark matter is an earning model. Ruling out the theories that can do without it.... Perhaps, I'm not an expert

​@@TheEmergingPattern I did wonder about theories that could replace the need for dark matter etc, but my point is that most of if not all of these kind of theories either progress or depart from Newton and Einstein and the standard model.. and to some degree they probably have to, to be taken seriously. I'm probably not explaining this well (I'm certainly no expert either), but there could be a few paradoxes in there. I think there is money to be earnt (private and public) in all areas of science - and people like me (who don't think science will 'save us' in my case) will like to keep half an eye, when we can, on where it is in general going. Hossenfelder's argument, which seem to be to focus more on the core of what we actually use, makes a lot of sense to me.

@@mattlewis5095 yes, I believe this new core you mention is also part of a new theories from "Erik verlinde" or "Wolfram" . The rules of relativity and Newton are within the boundaries of it and agree with observations so far. However, being an amature I can not say more about this dark stuff and probably better to focus on relevant and praktical things. Time is precious, but we get sucked into these media bubbles once in a while. It's interesting but also a waste of time

In this context, it's really no more complicated than when you turn your head around and see a roller coaster whizzing down an incline at 60 mi/hr, and you look at the ups & downs of the track it's on, and you can figure out from that, just where it was at any time in the past, back to the endpoint of its initial launch. You didn't need to actually see it before you turned your head. Fred

Break

_*Breakthroughs_

Don't hold your breath, there is no good reason to expect that better answers are imminent, just more and more speculation. Even JWST and further improvements on observational abilities do not hold the promise that they are often said to.

Another word for metaphysics is 'imagination'

@@junacebedo888 no, it isn't

@@bobbabai ....bad thoughts?

True.

The big bang appears to affect the observable universe but we can only speculate about the unobservable universe.

His superpower is that he doesn't die

I agree. I have been trying to understand it, and while I think I have a vague idea of what he's saying, I'm not entirely confident I've got it right. But what I think he's saying is that he DEFINE's time as the direction of increasing entropy. He believes that for the universe to have had a low entropy at the beginning, it had to have reached that low entropy by decreasing entropy prior to the beginning of the Big Bang. Since entropy was decreasing prior to the Big Bang, and since time is defined as the direction of increasing entropy, it follows that time was running backward prior to the Big Bang. But this, it seems to me, is just semantics. Time wasn't REALLY going backward prior to the Big Bang. He's just DEFINED his terms in such a way as to say time was going backward. But what was REALLY going on is that time was moving forward, but it just happened to be the case that entropy was decreasing. This is possible if you take the statistical approach to entropy. Entropy tends to increase because statistically it's much more probable that it would increase than that it would decrease since there are vastly more random configurations that particles can take than there are ordered configurations that particles can take. So the decrease in entropy prior to the beginning of the universe was just a rare statistically anomaly. That's my take on it, anyway. Like I said, I may have Carroll all wrong.

@@philochristosWhat really troubles me is his claim about the multiverse that in some universe, their our past is their future and their past is out future.....I don't believe that could be true with any plausible physics...

So hard to buy into anything ever said or done at any time by Mr. Carroll

The Big Bang:- Contraction to a point or singularity implies null homotopy (topology). Non null homotopic implies a second point/singularity = duality. The big bang is a Janus hole/point (two faces = duality) or non null homotopic -- Julian Barbour, physicist. Topological holes cannot be shrunk down to zero. Homotopic equivalence = duality. The future is dual to the past -- time duality. We remember the past and predict (syntropy) the future. Space is dual to time -- Einstein. Continuous (topology) is dual to discrete (quantum). Duality is the bare minimum for any metaphysic of reality! "Keep your ideas as simple as possible but no simpler" -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. "Always two there are" -- Yoda.

We do not "measure" time because there is no time to measure. We create the illusion of time from the mechanical movement of matter in space such as the pendulum of a clock, the vibration of a quartz crystal, or the oscillation of a Cesium atom. Einstein alluded to that when he said the following: "We say a train is on time when it arrives at the station when the hands of a mechanical clock are in a particular position." Thus there is no absolute time and therefore we cannot either go forward in time nor backward in time. We can only live in the present. It is not time that controls the motions of the planets, rather, the motions of the planets define what we call time, and thus, all motion is relative to some other motion in space.

probably why half the people got here to begin with... and left 5 seconds later :D

And even galaxy clusters collide...

Galaxies within our Local Cluster aren't moving away from us by expansion. They are gravitationally bound to us and Andromeda happens to be moving toward us. More correctly, it should be most of the galaxies in other clusters are moving away from us and the further they are away, the faster they are moving.

It sounds like handwaving to me. The way I heard him explain it one time, if there's no space, then there's no difference between things being close together or far apart, so no matter how spread out things are, they might as well create another Big Bang from a point. This strikes me as being pure philosophical speculation.

@@philochristos In the reference frame of the photon what he said is true. It's not handwaving at all. Mass has a clock so it observes and measures space time. It is hard to grasp but if all of the mass in the universe decays into photons, there is no space time.

@@philochristos It's a simple fact that in the absence of matter an extremely dense collection of high-energy photons is indistinguishable from an extremely sparse collection of low-energy photons. Having said that, we don't really know with any certainty that the universe began with nothing but photons. We only know that that's how it will probably end.

Haaaa ha ha ha! They will run like mice when the cat finds their hide out!

My interpretation The model depicts the start of time, as in a timeline. We always use timelines, and no such things as timespheres.

Every place is the center of the universe.

I think it’s like a tree of evolution diagram.

No, it isn't directional. The x axis in that diagram is time (from left to right). Each 'slice' along the y axis is a two-dimensional representation of the observable universe at any given moment (although we can actually observe the CMB of the early universe from here and now).

@@ck58npj72 Even that schematic diagram has a center point all along its time path... if you took one slice of any part of it, it would be a circle for which a center could be found

In QM the term "observation" doesn't actually imply a conscious, intelligent observer. A wavefunction can collapse due to interaction with a particle, in which case the particle is the 'observer'.

@@nagualdesign Upon interaction with a particle a state goes into one of infinite states, until you measure, when the state collapses.

@@sonarbangla8711 All of our measurement apparatus are made of particles, even when we're not looking. Wave functions collapse due to interaction with the external world, regardless of human intelligence or consciousness.

@@nagualdesign Evolution of the whole universe is a quantum phenomenon, it is all waves and quantum fields.

Not all believe 'infinity' is a reality

One difference is that an explosion is a rapid expansion IN space, while the Big bang is a rapid expansion OF space.

@@oj5218 But it doesn't matter though wether it's the space or in a space because in each case you'd still have a big bang. That's not to say they are similar or the same but the effect exercised upon both is still an explosion.

Thats just silly. First of all, there is no way you or anyone knew we wouldnt find dark matter. Yet. There is no way anyone knows it doesnt exist, there are still plenty of candidates that havent been ruled out, sterile neutrino's, simps, axions, even primordial black holes. We call it dark matter because if our theories are correct, then there has to be something, whatever that may be made off. That doesnt mean no one is looking for alternative theories. Plenty of attempts at modifying gravity. Nothing so far comes close, but if anyone comes up with a theory that explains observations better than our existing theories and dark matter, we will just drop the word and accept it doesnt exist. Until then, our current theory of gravity is the best we have, and dark matter is a perfectly good word.

@@vertigo2893 Actually the term "dark matter" is problematic, as it is strictly a place holder term for a hypothetical substance, for which the ONLY evidence we have is that certain celestial observations do not conform to our expectations and cannot be explained by our current knowledge of physics in light of the visible matter we can see. It is a term that presupposes the existence of an entity that we do not know exists. And recent data has actually weighed in favor of modified gravity which doesn't require any "dark matter". Sabine H. has worked on the dark matter problem for years, and was strongly inclined to believe it was most probably due to an undiscovered particle, but recently she has publicly said that she is now more inclined toward the MOND theories and is no longer so confident in dark matter's existence.

i think so, it would explain a lot

It's called 'foresee' and you can in limited small time scales and for limited parameters. That's why you can't foresee the weather for example, too many parameters.

If a person overthinks, his metaphysical thoughts are actually hallucinations

@@junacebedo888 this itself is a metaphysical thought...

@@supersmart671The Illogical is also metaphysical. Schizophrenia and other mental insanity are also metaphysical. Multi-verse or string theory, I think, is just pure and plain craziness

@@junacebedo888 Is your own statement Metaphysical?

@@supersmart671 My statements are utterances

Carl Sagan is idiotic in saying that statement. "Extraordinary or ordinary claims only require sufficient evidence" is the correct rule

@@junacebedo888 Sufficient evidence would need to be extraordinary for extraordinary claims.

@@bballen3097 Nope. Adequate proof would suffice. Hiroshima was extraordinarily destroyed by an atomic bomb. Einstein's 'E=mc (square) is enough proof it happened

@@junacebedo888 What a terrible example. There is nothing extraordinary about the claim that Hiroshima occurred. It was seen by innumerable witnesses as it happened. We are talking about extraordinary claims, not extraordinary events. If you claim to know with certainty what exactly happened billions of years ago, based on relatively scanty evidence, with a number of built in assumptions baked into it, and your claim also doesn't satisfactorily answer fundamental questions inherent in it... that is an extraordinary claim.

@@NondescriptMammal I disagree on the age of the universe based on the speed of light

His idea that if clocks are absent the scale of spacetime is undetermined is attractive because then a new quantum fluctuation could occur which form a next big bang with a new scale of spacetime and a new low entropy value. Resetting the scale of spacetime seems logically possible, but this should also be demonstrated for entropy.

@@morrienb hmm yes. The interfeterence of electrically encabulated fields carries dire implications for the bourgeosie.

@@BlastinRope I actually thought you were one of those electromagnetism conspiracy theorist dudes for a split second

@Stinky Piece of Cheese I couldn’t disagree more. Einstein believed all of space and all of time (past present and future) were created at the moment Of the Big Bang. Besides a lot of theory is belief and intuition until it’s falsified

"... his just rings true somehow" So did the Steady State Theory of Hoyle, Gold, & Bondi (which Penrose alludes to), until the CMBR was found. "Nothing in life is quite so tragic as the murder of a beautiful theory by a brutal gang of facts." Ultimately, we are compelled to listen to what the universe tells us, by way of observations, regardless what we would like to be true. If we're lucky, observations will support our "favorite" theories. If we're not, we'll have to adopt a new "favorite." Still, I share your desire for a theory that "rings true." Fred

Lol

Stick to colouring books dude, this is way too intelligent for you

@@waynedarronwalls6468 True, and thanks for your deep analysis of my failings as a human being. I'll just stick to my low IQ derived simulations of generalized abiogenesis and their axiomatic cosmogenic information theoretic analogues, entropically evolving emergent group structure physics from first principles ex nihilo lol....

Where does the energy go ? Up your arse? Secondly, Even if that was true there are still two observational facts (1) Redshift is GREATER the further the source of astronomical EM radiation is (2) the above happens in absolutely every direction EM radiation is measured from anywhere on Earth There is simply no way to avoid the proven fact of Universal Expansion. New space is coming into existence as we speak. If you went into deep space far away enough from any powerful gravitational fields , and drew an an imaginary of 1m^3 There wouldn’t be 1m^3 in that volume for long. You’d get MORE volume and more space due to Universal Expansion

Light doesn't lose energy as it travels through space, it only becomes more dispersed. The individual photon does not lose energy. It cannot lose energy except by collision with particles. The incidence of that happening through intergalactic space has already been calculated and found to be too negligible to account for red shift. in any case, light that has experienced collisions will be dispersed and not observable as an image that can be analyzed in respect to red shift.

Science said Time space and the Universe began. (Before) that, time did not exist

I wonder if 'dark energy' is information. As more information is generated, the area of the boundary of the Universe has to expand to accommodate it.

They truly have no solid idea of what dark energy is.

Things below the event horizon can't escape. Above that boundary, the escape velocity is less than c (the speed of light). Things escape from above the horizon all the time, it just requires higher and higher energies for mass particles to do so the closer they get to the horizon. These extremely high energy plasma jets black holes eject from their poles are how they were first detected. As the escape velocity approaches c, only massless particles such as light can escape. As for evaporation: the short answer is that due to quantum randomness, photons can be generated just above the event horizon and escape, taking bits of energy from it. This is called "Hawking Radiation". At the moment, the universe is putting more energy into it than what comes out in these photons. What Penrose was saying is that eventually the universe will become so defuse and cold that the energy balance will flip, more will leak out of the black hole and eventually evaporate. Don't worry though, that's an unfathomably long time from now.

@@rpgspree Pairs of photons are created, and 1 is captured by the BH. So the BH gets the same energy he puts into the escaped photon... ?

@@laurenth7187 It still loses the energy of the escaped photon.

it started everywhere in space, but one point in time. everywhere was smaller back then.

The usual answer is because "space and time did not exist" before the event from which the Big Bang evolved, and that all of time and space were contained in that "singularity"... I find this answer completely unsatisfactory, and have looked for better explanations, but have never found a coherent explanation. If they say the universe is expanding, and that it started from a smaller extent than the vast universe we have now, it seems geometrically impossible that there is not a location in our current universe that would correspond with the location of that event. Even if we accept the metaphysical explanation that "space itself is expanding", there would still be a geometric location that would correspond, you would think.

The paradox of something from nothing is always glossed over, and I have never seen a serious attempt to explain it scientifically, or to even explain how it is conceivably possible.

Yeah, Penrose's cyclic cosmology has time being infinite in the past, and presumably into the future. There is no problem with that mathematically or otherwise. Theologists just don't like it because it does away with any need for their creator god.

They didn't, as general relativity didn't. That's what I remember from a video

In a universe consisting only of photons you can't measure their relative position because they can't change direction (since there is nothing to interact with). It follows that you can't measure time in such a universe (i.e. you can't make a light clock). Understanding these points is key to truly understanding special relativity. Sir Roger's theory may well be wrong, but his book on it has counter arguments to your points.

@@KitAdams this is not true. They don't change direction but they change position because they are not static. Therefore there is a meaningful way you can speak of event 1, event 2, as a modification of any distance between photons a and b. If you base your theory only on the clock paradox of special relativity, that applies not only to photons but to anything else. And we have time. Penrose is wrongheaded on this one.

@@atmanbrahman1872 Try to imagine how you would construct an apparatus to measure distance (e.g. a radar) where the only building materials available are photons that can never change direction. Also remember you are inside this universe, not looking down on it, and therefore you are also made of photons that never change direction.

@@KitAdams There is no need of apparatus - for time to be spoken of in a meaningful way. All you need is change, any change, any movement, and you get a before and an after. Secondly, even if no change would happen, at the end of the universe and everything would decay to nothingness so to speak, time is still spoken if meaningfully because that state of affairs is posterior to the current state. All this photons don't experience time is jibber jabber. Nothing lacking consciousness does.

@@atmanbrahman1872 You forget that time is relative. To measure motion you need a constant, and time as we know it is relative to a constant. (Plancks constant) In a universe of only photos you will have no constant to measure their entirely random motion by. Thus time cannot exist, and neither can your universe.