Astrophysics/spacetime shape and fabric
Expert: Dr. Stephen O. Nelson  11/19/2013
QuestionQUESTION: Below are some questions and thoughts of a layman. If you don't mind, can you help to comment on which thoughts are violating known laws of physics?
1. “Space is like a loaf of bread?”
1. The above is description by Brian Greene in the “The Elegant Universe” with time as one dimension and the universe as we understand as a slide of the bread
2. What if the universe is a balloon? And…btw, an expanding balloon
1. Let's say the skin of the balloon represents the 3Duniverse (a 3D space membrane).
2. The radius of the balloon is the “TIME” dimension. Remember space is just the skin of the balloon.
3. The universe is “expanding” in the “TIME” dimension (in all directions). I.e. the balloon is being inflated (by the big bang)
4. BTW, the unit of “TIME” dimension is meter. Yes, just like the other 3 dimensions. And the rate of expansion is speed of light. I.e. that means that there is “Universe clock” which determines the basic “tick” of every “Actions” of every “Matter” in the universe. TIME is just a dimension that we are pushed along (at 300 KM/“tick")
2. “Does this balloon model fit with Relativity?"
1. If an object moves at a speed of “v” per “click" on the surface of the balloon relative to you, it would be perpendicular to the direction of time.
2. Given the speed limit is speed of light in this spacetime at “c”, after one click (i.e. one second), it can only travel c * sqrt((1v2/c2)) per “ lick" in the Time dimension thus fitting the Lorentz factor (i.e. the time of the travelling object is perceived to be slower…travelling only c * sqrt((1v2/c2) instead of c after one click)
3. To explain for Twins Paradox, the concept of gravitational time dilation would be borrowed to that the acceleration/deceleration (and gravitational force also) propels the objection on the time dimension. The results are:
1. that the clock on the accelerating/decelerating objects are always slower
2. the two objects, after separation, will return to the same frame (point in spacetime)
4. Notes:
1. the simultaneity plane is the tangential (or along) the surface of the 3D membrane. Not oblique depending on direction of travel per the Minkowski space…implication is that future is not yet there… not determined !!!
2. Asking for advices what generally agreed principles / phenomena in SR/GR should be considered when pondering this model.
3. “Universe is expanding… galaxy two times further away is moving double the speed and those at three times away, triple the speed. Why?”
1. Say the radius of the balloon is R (which should be 13.7 B light years given the assumed time of big bang).
2. One galaxy is at distance d from us or R sin A (where A is the angle at the centre of the balloon), Second galaxy is at distance 2d or R (2 sin A), Third galaxy is at distance 3d or R (3 sin A)
3. Suppose all of these are “motionless” relative to you (i.e. the angles remains the same) while the balloon is expanding at c per “click”. The situation of one click later is
1. D1 = (R+c) (sinA)
2. D2 = (R+c) (2sinA)
3. D3 = (R+c) (3sinA)
Thus explains the phenomenon
4. The “Balloon” is expanding leading to:
1. galaxies are moving away
2. their speed away from earth is proportional to the distance the are currently from earth
4. "Observable Universe estimated to be 46 Bil light years away”
1. 3D Universe is estimated to be a sphere with diameter of 92 Bil lightyear radius
2. 13.7 * 2 * PI = diameter of the balloon is 86.7 Bil light year…. close enough?
1. Circumference of the balloon is the diameter of the visible 3D space estimated.
5. “Universe as a hologram of the surface of the Universe?”
1. what if the surface of the Universe is really a surface…i.e. the surface of the balloon?
1. The third dimension how we human construct out of the 2 dimension information on the balloon. i.e. Speed is “v” on the surface of the balloon, but human beings somehow make the “v” travel in “3” dimensions
6. “Why would the rate of expansion of the balloon happens to be the same as speed of light…. which happens to be the same of the speed of gravity?”
1. ripples
1. Imagine the whole spacetime is a block of gelatine.
2. Gravity is generated when it is disturbed (warped) by a mass. The ripples (the impact) spread out at a speed characteristic of this gelatine block
3. Light is also a ripple when the spacetime is disturbed. Like a tap on the gelatine.
4. Big bang is the initial bang to the gelatine block. And of course the ripple travels the only speed it knows.. speed of light
5. So, the speed bump of universe is actually the determined by the characteristic of this gelatine.
2. We are back to the notion of Aether!!!
3. Questions
1. can it be combined with the dark matter/dark energy predictions?
7. “Are objects (particles) riding the wave of this big bang…i.e. surfing?"
1. May be...
2. May be all matters are “ripples” (as related to string theory). I.e. the gelatine vibrating at fixed positions. All matters and phenomena are just interaction of ripples of the gelatin. E.g. the “ interference pattern" associated the object travelling at “v” interact with the fabric (and other concurrent ripples) and result in appearing at the resulting position at the end of the period. The fabric (gelatine) has limitation on how fast the ripple carry its effect around. The resulting energy will affect others parts of the spacetime
8. “Relating to Quantum Mechanics”
1. The question becomes how do “ripples” interact.
1. Some interactions generate more stable patterns and when becomes “observable” or “detectable”, they became known as “particles” by human beings. May be it can explains “Duality” and “Uncertainly"
2. For “ripples” that does not interact with our “ripples” that constitute our perception, those do not appear to exist for us.
2. The presence of an Aether may help to explain “Entanglement”, “Uncertainty” (as Aether is disturbed in someway)
9. “Gravity is much weaker than the other 3 forces”
1. Gravity just stretches/warps the fabric (along the line of TIME and perpendicular to the 3D space membrane) and is a stable formation of the ripples but other force are exerted in the universe plane (generated by a tap on the surface of the membrane)
ANSWER: When you have thoughts, maybe you should bring them up one at a time and not all in a massive eruption of thoughts. It would be way easier and way more focused. As it is, I'm going to cook most of these down according to your original question about which of them violate the known laws of physics, with questions separated by , my descriptions beginning with a * at their start and the original starting with a #:

#
Below are some questions and thoughts of a layman. If you don't mind, can you help to comment on which thoughts are violating known laws of physics?
1. “Space is like a loaf of bread?”
1. The above is description by Brian Greene in the “The Elegant Universe” with time as one dimension and the universe as we understand as a slide of the bread
2. What if the universe is a balloon? And…btw, an expanding balloon
*
Loaf of bread and balloon are just ways of describing things which are roughly spherical and expanding. Neither violate the known laws of physics, they're just models for cosmology.

#
1. Let's say the skin of the balloon represents the 3Duniverse (a 3D space membrane).
2. The radius of the balloon is the “TIME” dimension. Remember space is just the skin of the balloon.
3. The universe is “expanding” in the “TIME” dimension (in all directions). I.e. the balloon is being inflated (by the big bang)
4. BTW, the unit of “TIME” dimension is meter. Yes, just like the other 3 dimensions. And the rate of expansion is speed of light. I.e. that means that there is “Universe clock” which determines the basic “tick” of every “Actions” of every “Matter” in the universe. TIME is just a dimension that we are pushed along (at 300 KM/“tick")
*
Time is indeed a dimension. Your description of "expanding" implies motion via some other type of time entirely, a notion that many theorists play with but has no current traction that I know of among the theoretical community. I thought of it this way myself for a long time, when I used to play with theory.

#
2. “Does this balloon model fit with Relativity?"
1. If an object moves at a speed of “v” per “click" on the surface of the balloon relative to you, it would be perpendicular to the direction of time.
2. Given the speed limit is speed of light in this spacetime at “c”, after one click (i.e. one second), it can only travel c * sqrt((1v2/c2)) per “ lick" in the Time dimension thus fitting the Lorentz factor (i.e. the time of the travelling object is perceived to be slower…travelling only c * sqrt((1v2/c2) instead of c after one click)
3. To explain for Twins Paradox, the concept of gravitational time dilation would be borrowed to that the acceleration/deceleration (and gravitational force also) propels the objection on the time dimension. The results are:
1. that the clock on the accelerating/decelerating objects are always slower
2. the two objects, after separation, will return to the same frame (point in spacetime)
4. Notes:
1. the simultaneity plane is the tangential (or along) the surface of the 3D membrane. Not oblique depending on direction of travel per the Minkowski space…implication is that future is not yet there… not determined !!!
2. Asking for advices what generally agreed principles / phenomena in SR/GR should be considered when pondering this model.
*
There's nothing extra to consider in relativity for this conceptual tool (it's not really even a model). The conceptual tools you're talking about (not so much models as just tools to visualize the overarching models) are indeed consistent with relativity.

#
3. “Universe is expanding… galaxy two times further away is moving double the speed and those at three times away, triple the speed. Why?”
1. Say the radius of the balloon is R (which should be 13.7 B light years given the assumed time of big bang).
2. One galaxy is at distance d from us or R sin A (where A is the angle at the centre of the balloon), Second galaxy is at distance 2d or R (2 sin A), Third galaxy is at distance 3d or R (3 sin A)
3. Suppose all of these are “motionless” relative to you (i.e. the angles remains the same) while the balloon is expanding at c per “click”. The situation of one click later is
1. D1 = (R+c) (sinA)
2. D2 = (R+c) (2sinA)
3. D3 = (R+c) (3sinA)
Thus explains the phenomenon
4. The “Balloon” is expanding leading to:
1. galaxies are moving away
2. their speed away from earth is proportional to the distance the are currently from earth
*
I'm not sure I'm seeing the problem with any of this. You do realize that the models involving bread rising or an inflating balloon still ignore some of the actual dimensions, right? But essentially this does not have anything too fundamentally wrong with it.

#
4. "Observable Universe estimated to be 46 Bil light years away”
1. 3D Universe is estimated to be a sphere with diameter of 92 Bil lightyear radius
2. 13.7 * 2 * PI = diameter of the balloon is 86.7 Bil light year…. close enough?
1. Circumference of the balloon is the diameter of the visible 3D space estimated.
*
This isn't quite so simple. It's hard to put a semiclassical definition on something you can't observe (the edge of the universe). And your subpart 1) here is definitely too much in the notions we get from oldfashioned understandings that are outdated. 2) Makes no sense at all, trying to define a circumference of something that's expanding and that you can't see around and is not static...no. Try again. That's like trying to define the circumference of a balloon while you're still inflating it and using something that travels around the edge really slowly.

#
5. “Universe as a hologram of the surface of the Universe?”
1. what if the surface of the Universe is really a surface…i.e. the surface of the balloon?
1. The third dimension how we human construct out of the 2 dimension information on the balloon. i.e. Speed is “v” on the surface of the balloon, but human beings somehow make the “v” travel in “3” dimensions
*
No, it's not like that. These tools of visualization are incomplete because we can't picture four dimensional spacetime. You're mixing dimensions. The holographic thing is different entirely, so avoid that for now.

#
6. “Why would the rate of expansion of the balloon happens to be the same as speed of light…. which happens to be the same of the speed of gravity?”
1. ripples
1. Imagine the whole spacetime is a block of gelatine.
2. Gravity is generated when it is disturbed (warped) by a mass. The ripples (the impact) spread out at a speed characteristic of this gelatine block
3. Light is also a ripple when the spacetime is disturbed. Like a tap on the gelatine.
4. Big bang is the initial bang to the gelatine block. And of course the ripple travels the only speed it knows.. speed of light
5. So, the speed bump of universe is actually the determined by the characteristic of this gelatine.
2. We are back to the notion of Aether!!!
3. Questions
1. can it be combined with the dark matter/dark energy predictions?
*
No. Just...what the heck are you talking about?

#
7. “Are objects (particles) riding the wave of this big bang…i.e. surfing?"
1. May be...
2. May be all matters are “ripples” (as related to string theory). I.e. the gelatine vibrating at fixed positions. All matters and phenomena are just interaction of ripples of the gelatin. E.g. the “ interference pattern" associated the object travelling at “v” interact with the fabric (and other concurrent ripples) and result in appearing at the resulting position at the end of the period. The fabric (gelatine) has limitation on how fast the ripple carry its effect around. The resulting energy will affect others parts of the spacetime
*
Again...what? No. Go ask a cosmologist.

#
8. “Relating to Quantum Mechanics”
1. The question becomes how do “ripples” interact.
1. Some interactions generate more stable patterns and when becomes “observable” or “detectable”, they became known as “particles” by human beings. May be it can explains “Duality” and “Uncertainly"
2. For “ripples” that does not interact with our “ripples” that constitute our perception, those do not appear to exist for us.
2. The presence of an Aether may help to explain “Entanglement”, “Uncertainty” (as Aether is disturbed in someway)
*
No Ether! We're past that. These questions are getting really out there with no substance, I can't make sense of them.

#
9. “Gravity is much weaker than the other 3 forces”
1. Gravity just stretches/warps the fabric (along the line of TIME and perpendicular to the 3D space membrane) and is a stable formation of the ripples but other force are exerted in the universe plane (generated by a tap on the surface of the membrane)
*
Gravity is a force, and it is fundamentally very very weak compared to the other fundamental forces. This is measureable fact and not just something people say. You measure the forces on particles relative to their basic fundamental units and you get a really tiny force in gravitation. Stop talking about ripples and stuff that you don't really define. If you look at spacetime in the presence of gravitation, you do indeed get curved spacetime and the gravitational force as a consequence...but the mathematical definition of curvature involves tensor math and you're nowhere near it by trying to wave your hands and define it without the math. It's not really curvature the way you're trying to understand it in a traditional sense.
 FOLLOWUP 
QUESTION: This is not an follow up question, just an thank for your patience and time expended. With no training of physics and the related maths, I am just trying to "align" the information from wiki and TV :) to make them feel logical for myself. Thanks very much for responding in the first place.
I think there are fundamentally two questions when I set off:
(1) In the expanding balloon concept tool, the circumference of the balloon happens to be numerically close to the estimated diameter of the Universe (per Wiki) triggers me to think if we are really constructing three dimensions out of two dimension "reality". I.e. distance and "speed" is the same as measured but somehow we interpret it as 3D instead of 2D with some extra bits of information on the 2D plane. BTW, there are suggestion that the universe is of 11(?) dimensions per string theory and also other suggestion that the universe is just one dimension...so seems the verdict is still out there? :)
(2) I know Aether was dismissed one hundreds years ago, just that the recent emergences of dark matter/dark energy seems suggest that there are something out there that is required to explain that total mass/energy of the Universe and the accelerated separation of galaxies. So, there seems to be required of "something" out there in space which we cannot see and measure at the moment?
AnswerFor 1) these theories are fantastically untestable, and the definitions involving diameter and circumference at "any one point in time" are wildly loose. I myself think there's probably a way to tighten the definition up in concept, but not in any physically meaningful way right now. It's also not my area of research, so I don't spend a lot of time thinking about it.
2) Dark matter and energy in no way imply the existence of an ether. There is required to be something to explain the motion and rotation of galaxies, as well as the unexplained acceleration of the universe. We use dark matter to explain the extra local gravitation at medium distances. We use dark energy to explain the longrange acceleration of the universe. Alternate explanations (like gravity "leaking" into other dimensions over long distances) abound to explain both, so far neither has experimental evidence. A hot area of research for this right now is even in the field of "dark photons" (which would have mass but not interact electromagnetically) to explain the extra positrons from deep space recently observed by different experiments. The jury is out on which explanation will hold weight in the future, or if we need new ones, but an ether that fills space is currently not one of them.