Think of three raisins touching each other on the table. The space between them begins to enlarge in all directions, which way would the different raisins go? Wouldn't each one of them go in a different direction?
Now that is a good analogy. Not so much as an analogy for space as for a way to explain the nature of analogy.
The hard part of analogy is to ignore the reality of the mechanism and concentrate on the instructive symbology that is the heart of the analogy.
So, you have three raisins touching each other on a table and they start moving. Yes, they will move away from each other in different directions.
Now, lose the table. No, the raisins will not fall to the floor. We are just going to ignore the table. It no longer exists for the purpose of our analogy. In reality it is still there but (Hard Part #1) put the table out of your mind. It no longer exists. We are left with the three raisins moving away from each other.
Make yourself really small tiny and stand on one of the raisins. Climb to the top of one of the raisin-mountains and look out at the space around you. What do you see? You see the other two raisins moving away from you. To your perspective you are on the privileged raisin in this limited raisin universe since the other raisins are moving away from you. You are the central raisin. The center of the universe. I make myself really small tiny and I stand on one of the other raisins. I climb to the top of one of my raisin-mountains and look out at the space around me. What do I see? I see the other two raisins moving away from me. To my perspective I am on the privileged raisin in this limited raisin universe since the other raisins are moving away from me. I am the central raisin; the center of the universe.
Relate this to the balloon analogy. The central learning feature of the balloon analogy is the surface of the balloon. Just like ignoring the table in our raisin universe above we choose (Hard Part #1) to ignore the reality of the air inside the balloon, ignore the blow hole, ignore all the reality of the balloon except for the surface. The surface is the instructive symbol that is the heart of this analogy. This is our analogy for a 2D space. Everything real about the rest of the balloon, except this surface, is ignored and is put out of the mind as non-existent. Just pretend.
Put a bunch of dots on the balloon surface. Dozens of them all over the surface. Now blow up the balloon.
Back to Hard Part #1. Ignore all the rest of the reality of the balloon. Everything about the balloon is non-existent, in this imagining, except for the surface, our symbolic, analogous 2D space.
Make yourself really small tiny and stand on one of the dots as the balloon inflates (space expands). Look out at the space around you. What do you see? You see all the other dots moving away from you. To your perspective you are on the privileged dot in this limited 2D universe since the other dots are moving away from you. You are the central dot; the center of the universe. I make myself really small tiny and I stand 22 dots over from you. I look out at the space around me. What do I see? I see all the other dots moving away from me. To my perspective I am on the privileged dot in this limited 2D universe since the other dots, including you, are moving away from me. I am the central dot, not you. My dot is the center of the universe.
Every other dot on the balloon surface sees exactly the same thing. All the other dots are moving away and so every dot is the center of its own view. Every dot is the center of the universe, so there is no center to the universe.
Hard Part #2.
If the balloon analogy makes sense to you now (if I’ve done this right I hope it does) the next big step is to try to imagine this balloon analogy extended into 3D. Not just the 2D surface of the balloon but the 3D of our actual universe.
Every galaxy is a dot on the surface of the balloon. Except the balloon surface is no long there and there are hundreds of billions of dots extending as far as we can see in every direction we look. Space is expanding everywhere at once in 3D just like the surface in our balloon analogy in 2D. Any/every galaxy sees exactly the same thing we see from our galaxy. Every other galaxy is moving away (local movement due to gravitational bonding excepted, of course) and the closer galaxies to it move slower than the ones further away. Every galaxy sees itself as the center of the universe just like my privileged dot on the surface of the balloon. Every galaxy is the center of the universe, just like ours, therefore there is no one center of the universe.
All analogies are bad analogies if you lose yourself in the reality of the mechanism instead of concentrating on the instructive symbol that is the heart of the analogy.
Regardless there would be space between the raisins. All of a sudden the space between the raisins begins to expand. The raisins on the surface would separate from the ball of raisins first as the space would expand faster at the surface than the interior of the ball.
No. All the space, even the space between the raisins in the center of the ball, would expand at the given rate at the same time. Lets assume that there is space between each raisin. Since every point of space is expanding at the same rate (50,000 miles per second) at the end of the first second each raisin (all of them) is now 50,000 miles from each of the raisins it was nearest to a second ago. From the perspective of a raisin on the outer edge of the ball, a raisin on the opposite edge of the ball will have appeared to inflate outward at an enormously wild rate of many multiple times the 50,000 miles per second rate. These two raisins are now separated by a large multiple of the 50,000 miles even though each of the raisins was only moved along with its space by 50,000 miles. None of the raisins moved through space but was carried along with the space it was in when that space expanded.
You assume the raisins on the outer edge move outward first. Why? The entire ball, with every raisin in it, from every point of space in it, expands at the very same rate at the very same time.
Lets say the space is expanding at the rate of 50,000 miles per second, for our thought experiment. That would mean the raisins on the surface of the ball would be 50,000 miles from the one it was touching 1 second earlier. But that raisin would have moved as the space between it and the other raisin it was touching expanded. This space could not expand at the same rate as the earlier space due to the restraints of the pressure it was under.
The only pressure is the pressure of each point in space expanding at the same rate at the same time. You're assuming the raisins themselves are exerting a pressure inward. Whether this is true or not has no effect on space. To make this analogy act as we believe the universal inflationary period progressed, every point in space, even the space between the raisins packed in the center of the ball, inflated at the same rate at the same time.
After a couple of minutes that 10 lbs of raisins would be spread over quite a large area. The space between each raisin would continue to expand driving the raisins further and further apart. After an hour or so there would be no raisins that was anywhere near the raisins they had been in contact with just 1 hour prior.
To keep your analogy on target with the universal inflationary scenario this state where no raisin is near any other raisin is achieved within the first second.
Unless there is some other mechanism to bring these raisins together there would never be any contact between any of the raisins in the future.
Very true.
Now think of each raisin as a galaxy cluster where the force of gravity is powerful enough to overcome and keep the cluster from being torn apart by the expansion of space and you have pretty much the universe we inhabit today. Each raisin, each galaxy cluster, is moving away from every other cluster. Only within the galaxy cluster (40 million light years or so) is the force of gravity strong enough to hold the galaxies together. All of space is expanding (though at a much slower pace then the initial inflationary epoch) and will (we believe) continue never bringing the raisins back together again.
But all of a sudden I look ahead and I got one mean ugly raisin that is headed toward me and we are going to collide. That tells me the space between us is not expanding but decreasing which tell me there is something wrong with my thought experiment or the real thing of expansion.
I am referring to Andromeda and its collision with the Milky Way.
If they started in the same place and the space expanded between every object the collision could not take place.
No. The Andromeda galaxy is one of the 50+ galaxies within our local galactic raisin. Within our raisin the force of gravity, given the closeness of these 50+ galaxies, is still strong enough to overcome the expansion of space and keep our local group from separating along with the expansion.
Get this one. Each point of space within your head is also expanding, albeit on such a small scale it's not by very much, but the electromagnetic force and the two nuclear forces are way stronger at these small scales than the expansion so that is why your head doesn't explode.
If the galaxies were on the exterior of the universe as the dots on the balloon they would be at the center of the surface of the exterior of the universe relative to all the other galaxies on the surface of the universe.
The problem is that the galaxies are not on the surface of the universe. They are in the universe as they are apart of the universe. They are scattered throughout the universe just as my raisins were scattered relative to the location of the ball of raisins when it started to expand.
Yea, that is Hard Part #2: Overcoming the reality of the mechanism to get to the instructive symbol. When going from the 2D analogy and trying to apply the lessons learned to 3D space you have to give up thinking about the balloon analogy's surface but still bring the idea of the expanding space and it effects on what is seen.
If the raisin next to those three raisins moved 50,000 miles in one second and all the rest moved the same distance from the raisin next to it, it would be a far piece to the one that was on the exterior of the ball when expansion began. 1,000 raisins with 50,000 miles between each. The three raisins would be 50,000 miles from where they were. Making the one that was on the surface at least 50,000,000 miles from the three raisins we started with.
All this would be accomplished in 1 second.
Is that what you are telling me?
In essence, yes. I haven't looked too closely at your math, it doesn't really matter, but the gist of what cosmologists think that first 10-33 to 10-32 of a second of our universe's existence (the inflationary epoch) looked like, is roughly represented by your analogy.
What is even more mind blowing is that we estimate that during each tiny fraction of that already very small time period (the inflationary epoch) the size of the universe doubled. So starting at the age of 10-33 seconds, a tiny fraction of a second later (10-35 seconds later) the universe had doubled. Then by 10-35 seconds after that the universe had doubled again, and yet again and again until the inflationary epoch ended when the universe reached the ripe old age of 10-32 seconds and was now 10300 times it's initial size.
Though the exponential doubling at such a high rate has ceased we still live in a universe where space itself appears to be expanding in much that same way. Every point in space everywhere is expanding at a rate of about 68 km per second per 3,261,563 light years. If I haven't messed my sums up that's about .00000000687 millimeters per year at the tip of your nose.
I'm thinking we are getting confused between the fast exponential inflationary epoch of the early universe and the slower expansion of space we are experiencing today. My fault.
If we start first with the early universe (10-34 seconds) there were no neutrons, protons, electrons, anti-electrons, photons and neutrinos as well as no electromagnetic or nuclear forces. The hyper inflationary period of space expansion lasted from about 10-34 seconds to about 10-32 seconds after which the universe has experienced some varying degree of the space expansion we see continuing today (sorta more or less).
But that is not what I was trying to show.
Each raisin represents the neutrons, protons, electrons, anti-electrons, photons and neutrinos, that existed 1 second after the BB.
At this point, 1 second old, the universe is huge due to the ravages of the inflationary epoch and, yes there are now neutrons, protons, electrons, anti-electrons, photons and neutrinos, etc, but there is also the full suite of fundamental forces we know today.
But if the space had expanded between each element in and after the big bang each of those electrons would have been a long ways apart with no way of touching each other.
Why? The hyper inflationary epoch has ended and the (more or less) usual expansion of space like we see today is in play.
Just like today, the fundamental forces between particles can more than overcome the expansion of space if the particles are close enough, and at 1 second of age the universe is chuck full of elementary particles in a mega-hot plasma all crashing into each other, splitting apart, recombining and going round and round all while every point in space is lazily expanding like a slow summer stroll.
According to cavediver the universe existed as well as everything in it and was about the size of a pin point. It was very dense and very hot billions upon billions of degrees K.
According to Son Goku the universe existed as well as everything in it and was about the size of a pea. It was very dense and very hot billions upon billions of degrees K.
This is correct, except that the "everything" at this T=10-35 seconds is something we don't know. We can conjecture that this "everything" was (I hate to use this...but) pure energy in a super concentrated form. We do not yet have a working theory of Quantum Gravity nor a working Theory of Everything and since Quantum Field Theory and General Relativity do not work together well in this extreme state we have no way of knowing what this stuff was.
Therefore, you cannot say everything we see today was somehow squeezed into this pinpoint. The giant oak tree was not squeezed into an acorn. Instead, we can say this "stuff" was the initial condition of the universe from which "everything" ended up manifesting, evolving, growing out of.
Your raisin is the singularity. Other dots, raisins, stars, whatever...appear to move away from you only when you speak them into existence or imagine them. (which I suppose means that You Create through imagination)..One could argue that you are indeed standing on the privileged dot as your dot is, in fact, the initial singularity. Does that make any sense? Shall I attempt to run with it and pretend further or shall I throw the analogy away and begin again?
My advice would be the latter, but, it's your boat and you can float it anywhere you like.
Instead, we can say this "stuff" was the initial condition of the universe from which "everything" ended up manifesting, evolving, growing out of.
I prefer to say everything we can see in the universe and all that we cannot see existed at the beginning, just not in the form we see it today.
Then we are saying the same thing.
That is the reason I believe the universe is very old. Much older than any numbers given at the present for the age of the universe.
And you may be right. At present our best theories and best evidence indicate a universe just under 14 billion years of age. That may change as theory and technology advance. But until then 14 billion is the best we can realistically say without appealing to tea leaves, charlatans and superstition.
If it is not eternal where did the energy come from to create it out of.
We don't know, yet.
Laws don't change and energy cannot be created ...
As far as we can tell, in this universe, that is true. However, if there was a "before," then we cannot say that. We have no idea what physics may have been operating prior to this universe or (maybe) in some other universe from which ours was born.
Reality is that the universe does not have an outside. Therefore trying to use the outside of the balloon's surface to represent the universe is useless.
Only if one gets trapped into thinking the analogy is there as a reality. The analogy is there only to present an idea. The idea that space is inflating and that is why it appears the other galactic clusters are moving away from ours with the farthest ones moving away the fastest. Just like the dots all move away from each other on the balloon with the farthest ones moving away the fastest.
Simple. Ignore the balloon. Ignore the surface. Learn the idea of spatial inflation, the expansion of space which explains what we see happening with the other galactic clusters around us.
I know many who claim nature is that god but I can't find anything nature ever created.
Look in the mirror.
I don't know of any law that exists that created itself.
Physics is our set of human estimates, written in mathematical symbology, of the operations of the things we see around us. The ones that seem most consistent, within the error bars of our technology, we call "laws". And they work very very well. But they are still estimates at best always subject to change in changing environments.
Why these things around us seem to operate in this specific manner and not some other is yet to be determined. Again, without appealing to tea leaves, charlatans and superstition, we do not know why and neither do you.
Really? Then you go and quote the idea the analogy was giving?
Intellectual disagreement is one thing, but this level of deliberate ignorance is dishonest, ICANT. You already knew exactly what idea was being demonstrated.
Why you do that?
There is nothing on the outside of the universe.
The lesson has nothing to say or do with any "outside of the universe".
But all those dots are moving in a arc as they are on the surface of a balloon being expanded with air.
Ignore the balloon. Ignore its surface.
If expansion is true certain things would happen.
Yes. Things like all the other galactic clusters moving away from us with the farther ones moving faster than the closer ones. Just like the analogy demonstrates.
You understand the analogy already. Why the obfuscation?
Ok now I got 2000 raisins squeezed into as small a space as I can get with the pressures of my hands. I am going to make an assumption that I can get the ball of raisins down to a 3" diameter ball.
The space between each raisin begins to expand at the speed of light
No you don't and no it isn't.
At the time of the inflationary epoch, ICANT, there were no raisins (which in one message you equated to protons, electrons, quarks, etc.) There was nothing but a smooth uniform mixture of time, space and energy in the universe, so there were no particles to experience this hyper inflation. But, due to this hyper inflationary expansion the smooth uniformity of the plasma developed denser and thinner areas of the energy.
After this inflationary epoch stopped then the particles and forces began to condense out of the plasma with areas of denser and lighter concentrations. Since then the universe has continued to inflate but at a much slower rate. Much slower then this speed of light conjecture as you seem so enamored.
All of this distance was covered in 1 second.
Do you think this scenario is as preposterous as I do?
Yes. Preposterous because no one, except you, is pushing this absurd idea.
Yet that is what we are supposed to think is reality.
No. Think in the terms I have given above, about the differences in the inflationary epoch and after. And, please, ICANT, don't insult me again by deliberately ignoring it and going on like the idea never existed.
ABE: I can deal with the raisin ball analogy but I don't want to repeat the error of confusing which inflation we are talking about. There are two: the inflationary epoch at the beginning of the universe and the expansion of space we are experiencing today. They are two separate distinct items with separate details and different effects.
You tell me which one you want to talk about first and I will do my best to relate the raisin analogy to that period.
... but don't some physicists propose the possibility that the universe itself is infinite in size.
Yes. Caution, they (outside the charlatans and the crazies) do not propose that the universe IS infinite but that there may be the possibility that our universe may be infinite in extent. What some of them study is how one would go about finding evidence either way.
Right now our best evidence is that the universe is flat which could (but not necessarily) mean our universe may be infinite. Problem is the error bars on these more and more precise measurements still leaves open the realistic possibility that this universe is ever so slightly curved by trillions upon trillions times trillions of mega-parsecs in extend leading to a universe that may be finite after all, just ... big.
The problem with infinities in cosmology is that in working with General Relativity's tensor analysis the equations force a divide-by-zero at the extremes. An infinity and the absurdity of the singularity are the results.
And the singularity is acknowledged to be absurd thus cannot be real. Infinite mass/energy/gravity (meaning all the mass/energy/gravity of an infinite number of universes) squeezed into an area of infinitely small size (meaning it isn't there). Something is very wrong with GR at these extremes.
Maybe a bit aggressive but here is a video of a simplified example of the differences in math vs physics infinities.
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