Tegmark's type I multiverse. Can there be exact copies of you or me? I think so!
Tegmark discusses four kinds of multiversa. See here, his personal home.
I want to discuss his first type (I won't give my opinion about the other three as this probably gets me in trouble...). In an infinite universe, so Tegmark conjectures, there are infinite Hubble volumes and in this infinity an infinite of exact copies of you and me exist.
This can't be true because all Hubble volumes interact with their surroundings.
Suppose there is such a copy in a Hubble volume identical to the one we live in. How can this be? Near the border of our volume, there is interaction with stuff outside of the volume, which creates a difference between our volume and the identical volume somewhere else. Which means the volumes are different, contradicting the assumption. This is always the case. The logical conclusion is that there can't exist copies of you are me.
Am I right or am I left?
Worth a poll?
Let's ignore the question of the infinity of the actual universe. I think it's finite but let's assume it's infinite in spatial extent.
I want to discuss his first type (I won't give my opinion about the other three as this probably gets me in trouble...). In an infinite universe, so Tegmark conjectures, there are infinite Hubble volumes and in this infinity an infinite of exact copies of you and me exist.
This can't be true because all Hubble volumes interact with their surroundings.
Suppose there is such a copy in a Hubble volume identical to the one we live in. How can this be? Near the border of our volume, there is interaction with stuff outside of the volume, which creates a difference between our volume and the identical volume somewhere else. Which means the volumes are different, contradicting the assumption. This is always the case. The logical conclusion is that there can't exist copies of you are me.
Am I right or am I left?
Worth a poll?
Let's ignore the question of the infinity of the actual universe. I think it's finite but let's assume it's infinite in spatial extent.
Comments (64)
Does it not come down to whether or not, what you say here is true or false?
How would we obtain evidence of such interaction?
Are the hubble volumes described in Tegmark's level 1 multiverse, 3D volumes is a 4D space?
I followed your link and read what I had the time to read but I think I would have to dive in a lot deeper to make any significant contribution to this thread.
I think I see why you write about the 4d space. I don't think you need a 4th spatial dimension to leave the observable universe.
Let's go one dimension smaller. I remember you brought up the balloon model for our universe. A 2d closed space embedded in 3d space. On this balloon you can draw small circles. These represent our observable universe (Hubble spheres are not exactly the same as the visible universe but let's assume them equal). There are a loooot of these volumes and the balloon is actually to small to draw a visible circle (so it's in good scale to the size of the balloon). That's why space seems flat.
So. There are a loooot of these Hubble volumes in the totality of space, behind the horizon. If you consider space infinite, Tegmark hypothesizes that in an infinite number of different Hubble volumes you will encounter a universeness and Cornwell1 doing exactly the same as we do now. Now, apart from the fact that I don't think the universe is infinite, but a closed 3d balloon, how can this be? It seems to me that near the edges of identical volumes there is information exchange with spheres outside, making the spheres different from each other, contradicting the assumption.
What thinks thou?
But why not? I took the term hubble volume to mean our observable/detectable Universe.
If there is another hubble volume and its contained 'beside' ours. I can't do any better than beside/above/below, then both volumes would have to be in 4D container of space, surely?
I understand your sensible move to a 2D circle within a 3D balloon, but does this not add credence for a 3D hubble volume to require a 4D spacial container?
Quoting Cornwell1
But what exists between two hubble volumes? what separates them?
When I imagine the universe as a balloon, I consider the INSIDE of the balloon as containing the universe in its entirety. Not that the surface of the balloon is the universe.
As a 3D creature, you cannot exist outside of the balloon, there is no outside.
Unless space is 4D?
I can't get past this point, never mind getting to the idea that there are other Balloons with copies of me on them and whether or not individual/independent changes on one sphere as related to another, negates the existence of all of them, except 1.
I thought the multiverse posit was partly to explain the fine-tuning problem and help answer the logic posit that every possible mathematical outcome of a process has to happen in reality somewhere.
I don't think my maths and physics are strong enough to 'conceptualise' what you and Mr Tegmark are conceptualising. My head hurts but I love it! (no masochism involved! Just the pleasure of challenging thought!
The universe as a dynamical system certainly contains those critical points showing SDIC that create butterfly effects. At such points, in the continuum of time, the universe splits, with one trajectory prevailing. What of the alternate trajectories? Do they exist in alternate worlds, or simply as ghost-like speculations? Memories of non-events?
Tegmark is an interesting guy, but his ideas read like science fantasy.
I don't have too much difficulty, conceptualising other dimensions of the very small.
I can appreciate the curved pipe example, viewed from above. You see a rectangle, as the third dimension is 'wrapped around.' So from this, I can conceive a 4th dimension of the very small, wrapped around every spatial point in 3D 'cubic' space. I can accept the possibility of the 10 spatial dimensions in string theory, using this concept.
I have much more difficulty conceptualising extended spatial dimensions beyond our 3.
The best I can do is 'spheres spread out equally in a box' to try to conceive 'Hubble Volumes.'
So there are a lot of Hubble volumes (they are defined as the volumes within the surface that recedes with lightspeed). If you near such a surface (or anywhere else from its center) you see different things, so there can't be two equals. This holds for all spheres that you suppose equal, so there are no equal volumes of any size.
Perhaps if you understand how the library works, you will also see how under certain conditions there can be exact copies of yourself.
There is a copy of me in the Babel Tower?
Morning Cornwell1!
Quoting Cornwell1
What? this text flew right past me! What does it mean?
Quoting Cornwell1
Yep, I get this, wherever we are positioned inside a flat 3D space or a curved 3D space or a saddle shape etc. I get that you can only observe to a horizon in any direction. I get the 'light cone' concept.
So yeah, there may be much more beyond all currently observable/detectable distance.
Quoting Cornwell1
I get this too, because the light from other objects would reach us over time, if there was no expansion and the universe was flat.
Quoting Cornwell1
What do you mean by 'observable universe diameters?' Are you taking the universe as a sphere, cutting it into circular slices and then conceptualising viewing the circumference of each circle as a single universal horizon?
Quoting Cornwell1
So are you saying the singularity still exists somewhere by 'around the singularity?'
Quoting Cornwell1
A substrate is defined as 'an underlying substance or layer,' but such must have extent or dimension, as you call it 4D so you are suggesting a 4D space. I don't see how the term 'substrate' helps much.
Quoting Cornwell1
What do you suggest for the shape of this wormhole concept you suggest?
I know that cosmology has very little idea as to what a singularity is but if we just go with a really small point at the centre of a black hole, then I can conceive that. But does the black hole not surround the singularity as a spherical extension? Can you fly all the way around a black hole in a spaceship of the imagination?
If you can, then in my head, the only way anything could exchange anything (including information) with this other 3D universe you posit would be directly through this singularity, acting as some kind of gateway.
Does Mtheory not suggest floating brane structures within multidimensional space and at every point of collision between two branes, a singularity forms and a new Universe begins.
Are you a fan of Mtheory?
Quoting Cornwell1
Which surface in the Universe is receeding?
Quoting Cornwell1
Can you exemplify this? What kind of difference might you see and why?
Sorry Cromwell1, I realise that all I have offered you is questions but perhaps this will allow you to air more details about your own hypotheses and I can be a 'useful sounding board.'
Others may be able to contribute more.
I wondered about "universeness". Doesn't this mean "without a universe"?
Quoting universeness
The imaginary surface where the redshift of receding galaxies seems infinite. All galaxies seem to accumulate on this surface. It's like the event horizon around a black hole. Seen from our perspective all matter seems to end up on that horizon. Likewise for the cosmic horizon.
I wrote "seems" to end up. If you fall through the event horizon of a BH you will just end up at Its center. For me watching you fall from far away, you will freeze at the horizon (what joy for me to see you freeze... finally a silent forum... :wink: ). For you falli7ng in it takes, say, a second to the center, while for me it seems you take infinite time. The evaporation takes the blink of an eye (Hawking radiation originates in the entangled vacuum; the vacuum around the hole is excited by the heavy gravity present) from your inside perspective, but for me you radiate freely away over a large timespan, dependent on the BH mass.
Quoting universeness
Imagine this. You find yourself 80 billion ly away from here. You can see things from there that I can't see, like you can see a part of the world where you live that I can't see. When 80 billion ly apart we can still see each other but we both can see things the other can't. Which means there can't be two identical Hubble spheres. Because if so, everything around it should also be the same, contrary to assumption. Now I can post!
Hubble bubble, toil and trouble! :grin:
Nah! that would be UniverseLESS, universeness means something OF the universe.... :halo:
Quoting Cornwell1
But is this not expansion of an entire 3D volume in all directions, rather than any kind of surface expansion? Some galaxies are blue-shifted, such as andromeda as it is moving toward us. We would also be red-shifted, if observed from most other galaxies, so we are part of the expansion. All galaxies are moving away (receding) from each other, including the milky way. Every part of the volume of space
expands at the same increasing rate. At that scale, the cosmological principle suggests a homogeneous and isotropic space so why use 'an imaginary surface model?'
I get the time issues and the 'freeze at the event horizon' of a black hole from the point of an observer stuff.
I get the spaghettification idea of what would happen to you if you fall into a black hole
I get the hawking radiation and black hole evaporation.
But why would all matter end up at the event horizon of black holes?
In the 'big rip' and 'heat death,' the expansion continues until we can't see any other galaxies and then everything just ultimately disassembles and fade's away. Why would everything end up at black hole's?
Quoting Cornwell1
But if we live on opposite sides of a really big spherical universe then we don't need two 'hubble volumes', we could just be on opposite hemispheres of the same big Universe.
Double Hubble --->
No more rubble
but nubble gubble
and pubble
in the inflated dubble
That's what the universe is. God blowing a bubble in his chewing gum.
Dunning-Kruger meets Method-Feynman.
Now that I took extra time to think about the point made in the OP about the interaction between Hubble volumes, I think I came to a conclusion. It was a fun exercise thinking about this, and I'm sure you will be able to figure this out, and you'll enjoy the experience. I have two metaphors for this.
Let's say the Universe is an infinite sheet of cookie dough. It was super dense 14 billion years ago, but since then it has risen just enough for us to start making cookies. It so happened that exactly 14 billion years ago we drew a small circle on that dough, and this circle has been expanding with the dough this entire time. Besides that, there is a second circle that initially was equal to the first circle, but its expansion was at the speed of light. We know that dough expands slower than the speed of light, so the second circle ended up being larger than the first one. Within the inner circle is out cookie (Hubble volume). Within the outer circle is all the dough that has ever interacted with the cookie (Particle horizon). Outside of the outer circle is the rest of the dough. We cut our cookie out of the dough, dispose of its surrounding dough, and then we repeat this process again in a new location on our infinite sheet. We end up with an infinite number of cookies that have never interacted with each other in 14 billion years. Moreover, no two cookies have ever interacted with the same piece of dough. The cookies are so far apart that they could have came from different Universes. If we assume that within a finite area of the dough there can only exist a finite number of arrangements of particles that make up the dough, then some cookies will have multiple copies inside an infinite jar. It can also happen that the cookie that we live in is unique, or that an infinite number of possible cookies can exist within a finite area of the dough, which would mean that no two cookies are unique.
My second metaphor is the following. Let's say that you're standing in a line of people that are one light year apart from each other (socially distancing). When you're looking at the person next to you, you see them 1 year younger than they actually are. This is because the light from them had to travel one year to reach you. In this example, all people in the line have the same age, because they were all borne at the time of Big Bang. Then, you look at the person next to your neighbour. This person is now 2 years younger than you. You keep looking farther and farther, and you keep noticing people getting younger, until you reach a 1 year old baby, and there is no one beyond the baby. It's not that this is the end of the line, but this is the horizon of your vision. You know that there are more people out there, but you just haven't got a chance receive any light from them. Now, here is something interesting. The one-year-old baby that you're seeing is actually a full grown woman. You just don't know it yet. At the same moment that you're looking at the baby version of her, she is looking far ahead and seeing many more people in the line. The baby version of her hasn't registered any people at all, so you have no way to learn about other people in the line beyond her. You never know. There may be someone in the line far away that is an exact copy of you. It can even be that the baby that you're looking at is a copy of yourself.
Ah! Of course! Like universality...?
Quoting universeness
I think I see how you envision it. If we are on opposite sides of the universe we are not on opposite sides of a 3d sphere.
The balloon (2D). Draw, on a huge balloon of say Earth size, a circle on it. Diametrically opposed points on this circle are you and I on opposite sides of the visible universe (which you can see from the center).
In reality the balloon is much bigger. If you draw a circle of one meter radius on the balloon, then the circumference of the balloon is about 10exp11 meter... About a hundred million kilometers. There's more behind the horizon!
Quoting universeness
The matter seems to end up on the horizon because there time seems to stop. If you fall in as a particle you get radiated away in a wink. All matter ends in black holes which seem to last long. Evaporation to photons takes a wink though for the matter inside them. Information of this matter resides in the virtual particles, the closed one particle propagators in Feynman diagrams. A negative energy solution is sent inside, so the mass of the hole reduces bit by bit. Positive energy solutions, particle-antiparticle pairs, annihilate to send information outside (some photons can go back in the hole too, but slowly the information about the inside particles gets out). So if you throw in a bike you can still see the bike in the Hawking photons. Somewhat fucked up, but still...
Two good thought scenario's:
Quoting pfirefry
This suggests that only one Universe exists and what you are about to describe are possible limitations for any lifeform living within it, yes?
Quoting pfirefry
So we could call this state the singularity, yes?
Quoting pfirefry
So our current observable/detectable 'section' of this one Universe you posit.
Quoting pfirefry
So we now have a section of the Universe that expands faster than our section.
Quoting pfirefry
So the Universe has a section that expands faster than the rest of the surface.
In my head, this would be the same idea as one of my organs moving faster than the rest of my body was running. Ouch! OR your cookie image indicates that during the initial expansion, something happened to break up the expanding dough into 'cookie' sections. What happened? where did the cookie cutter come from? etc. I can conceive the fundamentals of what's going on in your scenario but I cant see why this is a multiverse. It suggests we started off with a universe of dough that became a multiverse of cookie's, instead of a multiverse of dough's.
Quoting pfirefry
So what did this cookie expand into? would it not crunch against its surrounding slower moving dough?
Does each cookie create a new layer to the Universe depending on its expansion rate?
Ok, yes, I understand what you have typed but what is the inside of the volume of the balloon you are describing in relation to the Universal structure you suggest?
I am still very far away from getting this one.
Is this theory based on the idea that the black hole at the centre of a galaxy will eventually expand/grow so that it will consume all of the matter in that galaxy?
Reminds me of the 18 000 000 trees where I live. If every tree has 100 000 leaves, how many trees at least must have an equal number of leaves?
I'll contemplate later. State is calling me... i don't have a job now and they want me to order the flora in town... Djeeeezus!
Quoting universeness
And there it's exactly where it gets interesting! I'll explain later. Right now I gotta an appointment at 3. I'm invited by state. To discuss my working possibilities...
It's the theory of black holes. If you look at a collapsing sphere of dust from a distance, the sphere seems to slow down in collapsing. When the sphere has a radius equal to the Schwarzschild radius it seems to have frozen and starts to emit Hawking radiation over a long time. On the inside the process takes a small time, about the time it takes light to travel over the Schwarzschild radius (so for the Sun about 1/100 000 seconds as the SR is about 3km.
To spare unnecessary anxiety - or perhaps to spoil the surprise - Tegmark's answer is clear and unambiguous:
I understand the material on the death of large stars and all of the 'types of supernovae, hypernovae) involved. involved.
I understand collapse to the size of a white dwarf, a neutron star (or pulsar) and the final possibility based on the mass of the original star, a black hole. I understand the basics of the forces involved and the subsequent events. Still doesn't suggest that all matter in the Universe is destined to fall into black holes.
Yeah, I'm talking about the single infinite 3D universe introduced in the OP: "In an infinite universe <...>". I think you contributed with the idea of a 4D space with many 3D universes, but for the purpose of the OP I'm assuming a single infinite 3D universe. I'm also assuming that the universe has a finite age and it's expanding similar to our universe. The finite age allows us to consider the regions of the infinite universe so far removed from each other that there is there no way for them to interact with one another. If they sent beams of light towards each other at the moment of the Big Bang, the light wouldn't have reached the destination by today. I'm just trying to play by the Tegmark's rules. Personally, I don't find the idea of infinity very realistic. I'm also subscribed to the idea of isolated pockets of the universe, most of which I know from this video. This sets the ground for a multiverse within a 3D universe.
Quoting universeness
Exactly. I'm assuming that singularity was uniform. When the universe started expanding, the areas of space appeared everywhere at the same time, so that space was already infinitely large the moment it appeared.
Quoting universeness
Not exactly. I'm trying to outline the observer here. We can observe the universe from a single point in space, but it's hard to fit a person or a copy of a person into one point. It's also hard to reason whether two points can be exact copies of each other, since a point doesn't have volume. Instead, I'm allocating a chunk of space in which an observer will exist. This area of space can be the size of our observer, or our planet, or our galaxy. Arbitrarily, I chose the size of a Hubble volume to connect with the OP. I will introduce the second circle to outline the observable/detectable 'section' of the universe, where the first circle acts as the observer.
Quoting universeness
Yeah, that's when my metaphor starts breaking down. I stared with one circle in mind, but I then realised that I needed two. The first circle represents spacial boundaries, but things can move within space at the speed of light. So the second circle is the horizon of information that travels through space. Coming back to our dough metaphor, let's say that yeast bacteria is living inside the dough. It can travel through the dough over time, regardless of its expansion. The second circle represents how far the bacteria could have gotten in 14 billion of years while traveling through the expanding dough
Quoting universeness
The first circle is the boundary of your heart. But the second circle represents a wave produced by a heart beat, travelling outside of your body and expanding over time. If someone in another galaxy sent an impulse to impact your heart, the moment your heat beat reaches them is the moment their impulse reaches you. The wave produced by your first heartbeat outlines the area of the universe that can impact your heart, assuming that nothing existed before the heartbeat happened.
Sorry, I'm not sure my explanation holds together well at this point. I have a very specific idea of what happened at the time of the Big Bang, but I'm not sure that I can articulate it, or that anyone can grasp it just from my description.
Quoting universeness
It just expands because new space appears for it to expand into. New bubbles of space are forming in the dough, while no new dough is being created. We don't know where the space is coming from, but we know that it just appears and it causes the expansion of dough. It's not important where the space is coming from for the purpose of the OP.
I think the idea of layers is the result of attempting to look at the Universe from the 4D point of view. I don't want to disregard this view. I think it's interesting, and I'd like to give it a go. But as far as my analogy goes, I'm not concerned about what the "outside" of the universe looks like, or how the universe is arranged in a higher-dimensional space. I think that's consistent with Tegmark.
But consider now two volumes incredibly far apart. No information could have traveled between them. Assume the volumes have identical configurations of particles. Now imagine yourself not far from the border. What do you see? You should see different things from both. The surroundings of both are different. But if you see different things on the outside from the inside, then both volumes can't be identical, as you assumed.
But how can there be two different volumes then? With two copies of you?
But that's exactly my point. How can they be identical?
Imagine a spot near the edge of each bubble. The same spot in both (as you assumed both identical). From these identical spots you can look to the space outside the volumes. You will see different things, as the outsides diverge. Then how can the insides be identical?
But you can see the one living near the edge.
This is by far, my favorite stuff to discuss. I am on a few 'cosmology' sites, with a wide range of folks who discuss this stuff. I also enjoy TPF as I am also interested in the philosophical aspect of all issues. I watch Sam Harris, Dan Dennet, Steve Pinker, Jordan Peterson etc on YouTube for the more Scientific side of Philosophy and I watch recorded lectures on the classical philosophers and on those who became historically well known for philosophy since. On TPF I see how their musings are debated by many contributers from Garret Travers through to Agent Smith et al. I do like the cosmological threads the best however.
If you think that the Universe has a finite age (and I agree) then how do you arrive at 'infinite?'
If at an earlier time it was smaller then it expanded then an infinity of time would have to have passed for space to be infinite due to the spacetime concept. We still move towards a future, every second so has enough time passed for space to be infinite? is it possible for space to be infinite, given the constraints I am suggesting? I think that this suggests at least a 4th extended spatial dimension. You confirm your own doubts about 'infinite space' with:
Quoting pfirefry
Quoting pfirefry
Yep, I agree but only if 'information travel' and movement from A to B at light speed is the only way one part of 'existence' can 'affect' another. The only way I can conceive this is that I can touch two parts of an object at the exact same moment in time, using two fingers as I can stand above it. If there is a 4th extended dimension then I wonder if any two parts of its 3D components can be affected instantly due to the existence of the 4th D. I can touch any two parts on a 2D shape, within the extent of my arms.
Quoting pfirefry
Yep, If we define a single universe in accordance with light speed since 'our singularity' and reject Mtheory and the brane idea with many singularities starting many universes.
Quoting pfirefry
I don't understand this one? Already infinite space? so why to we need inflation and expnsion?
Quoting pfirefry
Yeah I get this, the observer can't get any information from anything moving away at faster than light speed, even if the observer was traveling at light speed, light would still move away from the observer at light speed. This is a really difficult concept. Especially when trying to think about light source.
Quoting pfirefry
Yep, I understand but does the yeast bacteria move through in a 'ghost like' way. Some quantum effects seem to do this OR does it compress/warp the space around it to 'move through it'. Perhaps I warp surrounding space in some way to allow me to move or be dynamic in anyway. To be animated is an old meaning for 'spiritual' interestingly.
Quoting pfirefry
I digress but, this should be a line in a song :lol:
Quoting pfirefry
Yeah, I share your feelings of frustration at this point. We just don't have all the answers yet so conjecture or projecting possibilities based on what the current evidence gives us, is all that Max Tegmark is doing and I for one, label him a 'Truth Seeker' for that. You are doing similar thinking in your own head. Another truth seeker! Keep going! Someone will make progress eventually. I have FAITH in that, but I would never insult it with the God label.
I don't understand your last comment.
Suppose we look at a galaxy near the edge. Far away in spacetime. My copy does the same. The galaxies are different because of interaction with stuff outside the two volumes. But if I see a different galaxy than you, we are not the same anymore.
If you start with two identical regions in infinite space, same particle configuration in phasespace, then... indeed there could be two or more copies of you and me if the diverging surroundings find themselves at distances greater than the time it takes light to travel from there to you and me typing. If not, I could look through my 80 meter telescope and see a different thing, far away.
Enter entanglement...
That's the problem with dark energy. It generates new space, apparently. How can that be? Dark energy doesn't have a related particle. The inflaton? Maybe. What if our (finite) universe is a 3D structure immersed in a 4D structure. Say all matter is confined to this 3D structure. And that the vacuum energy (closed propagators in Feynman diagrams) give this 4D substrate space negative curvature (repulsive gravity). Then the particles in the (two) universes will accelerate away from each other. I imagine the hole of a torus. There is negative curvature there. On the Planck-sized mouth of a 4D torus two 3D universes might be ejected, two big bangs, like two 1D circles can be ejected from the mouth of a 2d torus. If the torus is open on the outside, the circles (universes) can accelerate to infinity and a new bang can start at the mouth.
I don't conceive the same depth of problem with this general issue of a replicant.
In general, replication is fundamental in our own local. DNA does it all the time.
Cloning claims that its possible to replicate humans in the future. It's already been done with sheep etc.
Surely the idea of 'multiverse replication,' is to deal with the mathematical posit that every member of a set must be an outcome. Every possibility that can happen must happen. But the point of replication would be the only point where 'identical' is true. Divergence will occur one instant after the state 'identical.'
Maybe it does or perhaps we will never find the graviton either and dark energy like gravity may be a 'consequence of the structure of the Universe' rather than a force. Perhaps gravity and dark energy are both different aspects of the same affect.
Well, in fact there could be two identical parts in the universe. Imagine the space that banged into existence. It had a diameter already of 10exp11 times the diameter of the observable universe. If this universe comprised two identical halves then the centers of these halves are surely still the same, so J realize now, thanks to pfirefry (nice name, but WTF does it mean?). I almost started a chapter to attack Tegmark, but I have to find new ways now. Maybe entanglement, which is non-local, will do. But copies on both sides of the 4D mouth I have in mind (I'm
a bigmouth!) will always stay the same, even if made of antimatter.
Dark energy has no related particle. It must be a particle that can curve space negatively. Virtual particles can have negative energy or mass, so.
Quoting universeness
:grin:
The bloody bull at the center
Hit by my poisoned arrow
But why would two identical parts, remain identical over time. Why would every event in each remain identical? Under which scientific imperative?
Quoting Cornwell1
Are you referring to the singularity here?
But this is just your opinion, there is no accepted proof of this.
Well, if two halves on a 2d sphere contain particles that have identical relative positions and velocities , then they will develop identically. From the circle where they meet the two halves will diverge until both halves will be different.
I assume the singularity to be the Planck-sized mouth on the 4d torus on which two 3d universe inflate from Planck diameter into 10exp11 times the size of the observed universe (about 90 billion ly).
Dark energy, the negative curvature of space, can be caused by the virtual particles in QFT. Real particles yield positive curvature.
Title: Tegmarks Lover
Verse I
The first circle is the boundary of your heart
The bloody bull at the center
Hit by my poisoned arrow
Will the sound replicate baby?
Can ya hear me now?
Chorus:
We cant talk no more baby
There are too many stars
The distance between us
Is just too far
Do you think we can finish this song before we finish with this thread?
All titles and words are fully open to review and editing by anyone.
No copyright is claimed!
Life has to be as fun as we can make it!
Hey! maybe that line should be in the song!
I assume you mean 3D sphere. You cant get a 2D sphere. But two such particles can still have some different attributes? You are talking about aspects such as spin, charge, mass, wavelength etc but there could be other attributes that we have not yet identified which are different in each one.
So does the singularity still exist as the nexus between your two universes?
I know you cant graph a 4D torus but what shape do you posit for the two universes?
Flat? But what is flat in 3D? a cube or cuboid?
Is this 4D torus what you suggest is the inside volume of the ballon?
Sorry, earlier you said your universe was curved, so curved in what way? curved and closed?
I think you said before that you think the universe is closed. If so do you mean closed in the form of your 4D torus and if so, what shape would that cause in our 3D universe?
Yes, say two halves on the sphere of the balloon. I think that they live parallel, separate, simultaneous lives makes both non-identical. How can a parallel copy of you and me be the same as us?
Yes. Behind us, in the fourth spatial dimension. Imagine the 2d case of the torus (the outside is not closed though). From the small mouth, two 1d circles (two universes) can spring into being. They contain all matter and the circles get larger when diverting from the center away. Space seems to appear in both of them. Expansion. At the same time, the both influence the curvature around the mouth. When they have accelerated into infinity, a new bang can inflate two new universes into being (two circles). The center of a torus has negative curvature (repulsive gravity).
Yes, two closed 3d universes moving on the 4d torus. The outside of the torus is open though and extends to infinity. Two 4d spaces connected by a 4d wormhole, the singularity, fountain of life.
Probably like most people, I read each word/label you or anyone else types, access its traditional meaning and try to garnish an overall understanding of the idea/opinion being expressed. But I am 'tripped' by combinations such as '1D circle,' 'space seems to appear,' 'accelerated into infinity,' etc.
I cast no blame for this as I have the same struggles.
So far, I am unable to conceive your 'big picture' of the structure of the Universe but I would ask the following.
Do you think there has only ever been one singularity in existence and if so, what's at the center of every super-massive black hole?
Quoting Cornwell1
By parallel, do you mean 'can never meet?'
"You and me be the same as us?"
In the literal sense, I think these are synonymous aren't they?
If I was standing next to you then I could use the reference 'You and me'
If I was talking about you and me to a third party then I might use the label 'we' or 'us'
So you must be talking about 'how a third observer' would view identical copies of you or me, in which case I would use 'them.'
If they could observe both the copy and the original. I think they would see them act differently(diverge), but are you sure Tegmark is suggesting they would be tied to a kind of 'Simon says' duality of action and that every event that happened to one copy would happen to the other in the exact same order? I don't think he is claiming that but I say that not having read everything he has written about his Level 1 multiverse.
The center of a BH is no singularity as the one at the center of the 4d torus. In a bh all matter is compressed to a planck volume. With point particles a true singularity would have formed. I don't think particles are point-like though. But neither strings. You can think of them like Planck-sized circles on a long closed cilinder. But the circles replaced by small 3d torus shapes, a 6d space of which 3 dimensions are curled up into circles, ie, an S1xS1xS1 torus. Like this they fit around the Planck-sized mouth of the open 4d torus. They are tied to a closed 3d space, a sphere, that is wrapped around the 4d mouth like a 1d closed line, a circle, is wrapped around the mouth of a 2d torus.
Ok, well thanks for trying to make your hypothesis clearer to me.
Tegmark litterally says that there exist collections of particles and surroundings that are identical. A twin that cts, thinks, and feels like you or me. So the other me is typing this words too, at the same you. But two copies can't be identical.
Is this as close to pornography as physics gets? :gasp:
Incoming message:
"The father of modern-day bouldering is kindly requested to go hang on one arm on a branch of the closest tree in the neighborhood."
Mr. Gill! 84 and these thoughts? Shame on you! :grin:
Well if that is what he suggests then I would require irrefutable evidence, that he is correct.
If that is not available then I would put this idea of duplication of events to the levels of the entire history of the Earth or even an individual life, as nonsense.
You should have visited the last year college at university here... :mask:
Multiverses..,total speculation. When there is even one piece of observational evidence,
I will take it seriously. Right now it seems to be an atheist's delusion, nothing more.
As far as I can see it, the pornography of Tegmark is a perversion. There cannot be copies of you and me because the universe is finite. The closed propagators before inflation contained elementary particles that were in a superposition of all energies and 3-momenta up to the Planck energy, not on mass shell (that's what virtual means). Just like closed photon or electron propagators can be turned into real particles by real electron-positron pairs (pair annihilation), resp. by photon pairs (positron-electron creation), the virtual gauge bubbles and fermion bubbles can get realized by inflation, somewhat reminiscent to the realization of particles in the production of Hawking radiation (though there are negative energies excited to reduce the mass inside of the hole, and these negative energies are not involved here). Cornwell1 seems a fair pornography director.
MWI is unrelated to a level-1 multiverse. The argument that there are infinite copies of yourself seems to presume counterfactuals, which MWI does not, so right there Tegmark's stated preferences precludes the existence of an identical copy of yourself out there. So I will proceed under the premise of 1) a universe of infinite spatial extent, and 2) a quantum interpretation that supports counterfactuals, such as Bohmian mechanics.
Quoting Cornwell1Funny that it's worded that way. Hubble volumes have nothing to do with it. We can see objects that are currently outside our Hubble volume, so clearly those objects have a causal influence on us.
Fallicious reasoning. A given state (say current state of Earth) has a finite set of events in its past light cone, which was (as measured in proper distance) was merely the size of a grapefruit at the end of the inflation epoch, grew to a maximum proper size of nearly 6 billion light years around 7 billion years ago, and is today the size of Earth. By definition (and assuming cause and effect cannot happen faster than light), no event inside that past light cone can interact with an event inside that light cone.
So all we need for an identical Earth is for some finite volume of space (a similar light cone) out there with identical state. There are only a finite number of possible states for this finite volume, which Tegmark computes, hence there must be infinite copies given an infinite number of rolls of this finite sided die.
Yes, which is why Hubble volume is useless. It affect the thing at the edge of the Hubble volume, but it doesn't effect you, so it matters not. Use past light cone instead of Hubble volume, and the logic works.
Tegmark's argument does not proceed along these my lines at all, and nor the one you describe. He does use a Hubble volume (like that matters. Only Earth matters). He computes that any finite volume can, at any given time, be only in some finite number of states. It's causal past is not considered. Since it is a current state, influence from the outside of the arbitrary volume is similarly moot. Infinite volumes divided by finite states makes for a vanishingly small probability of each state not appearing elsewhere.
No it doesn't. It might mean that the identical (arbitrary) volume evolves subsequently differently, but that has no effect on the existence of the copy of you already at the center.
Polls get you opinions. The above is logic, not opinion.
Extra credit: Tegmark's argument (finite state possibilities of a given volume) is stronger than mine (worded from a causality standpoint). Can you point out why?
Personally (opinion here) I don't think there's an exact copy of me out there, but only because I don't accept all the premises I list above, not because the logic is faulty. I do accept the infinite spatial extent premise, without which the argument is meaningless. If it's finite at all, it's probably smaller than the insane large number that Tegmark computed for the nearest copy.