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Old May 7th 2019, 03:46 PM   #21
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I have been Googling the Planck length, with frustratingly poor results!
However, from what I have been able to find, it seems to be the length at which current theories of physics cease to work.
(unresolvable infinities in the maths, spontaneous creation of black holes, etc.)

This could imply that improved theories might resolve these issues, allowing a continuum down to zero length.

However your conjecture that universes of different scales could co-exist is (in my view) sliced to shreds by Occum's razor.
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Old May 7th 2019, 04:38 PM   #22
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I'm going to mention a couple of things that came up in this thread.

I almost hesitate to mention this here but there is no evidence that the Planck length sets any smallest scale at all. (Though we do have the rather interesting sidebar that an object with the Planck mass and a radius of the Planck length is a black hole. This may or may not be an indication that these constants are significant.)

A quick comment about dark matter: We don't have any idea of what it is. It could be sub-atomic particles such as neutrinos if they have a mass, or more generally WIMPS (Weakly Interacting Massive Particles) which we haven't discovered yet, or even the effect of a cosmological constant.

There is some questionable evidence for a second "universe" to exist that was detected in the cosmic microwave background where it appears that there was a something or other way back when that could have been a universe that broke away from ours. But it might be something else. We just don't know.

Brane theory (an extension of String theory) posits that there are likely to be several universes that only have a gravitational interaction with each other. (The word "brane" is short for "membrane" and you can think of these as a bunch of parallel "planes" side by side.) There is an idea that two branes can interact gravitationally. Again no real evidence has been found.

As far as any universes existing inside our own, someone earlier in the thread correctly mentioned that by definition we can't make any real measurements on it so as far as the Scientific Method is concerned there is no way to prove that any exist. As I understand it (and I may be completely wrong) there is a possibility that in the inflation era of the universe several "pocket universes" arose because inflation didn't stop at the same time everywhere in the universe. I rather favor this idea but again we have the no evidence problem.

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Old May 7th 2019, 04:56 PM   #23
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Originally Posted by Woody View Post

However your conjecture that universes of different scales could co-exist is (in my view) sliced to shreds by Occum's razor.
I said sub-universes that are infinite solely inwardly. But that term isn’t totally right, since uni denotes one. A better term would be subverses, and an even better term than that wouldn’t surprise me.
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Old May 7th 2019, 05:25 PM   #24
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Originally Posted by topsquark View Post
I almost hesitate to mention this here but there is no evidence that the Planck length sets any smallest scale at all.

As far as any universes existing inside our own, someone earlier in the thread correctly mentioned that by definition we can't make any real measurements on it so as far as the Scientific Method is concerned there is no way to prove that any exist.

So, I had been misinformed Thanks Dan! I just found a post that explains why this Planck limit seems to be wrong.

The objection to those several Brane theory universes is, naturally, totality semantic. Uni means one, and there can only be one one. So, again, labeling them realms or something else seems more sensible.

Yeah, an infinite number of infinitely diminishing subverses must remain as solely reasoned an understanding as is our possibly infinite universe.
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Old May 7th 2019, 06:35 PM   #25
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Cool

The appearance of this thread in PHF demonstrates that the explanations in modern physics about the ultimate structure of matter, what's space (even 3D), the relationship between matter and space (at least 3D), etc, are unsatifactory and insufficient and messy.
To arrange an appropriate position for the words universe, multiverse, matter world, etc,... cosmos is not an easy affair.
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Old May 8th 2019, 03:44 AM   #26
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Originally Posted by Georgeo57 View Post
How does moving inwards from an atom not satisfy my proposition? We're exploring progressive smallness, and moving inwards seems indispensable to doing this.

It might help if you posted your definition of fractal, and directly related it to the proposition.
'Moving inwards' is phrase fraught with the difficulties of imprecision.

Moving inwards from one atom in the way you describe implies moving outwards from any other atom.
And if you pick something 'inside the atom' and move inwards again you are therefore moving away from the rest of the structure of that atom.

Is this what you really meant?


I think you mean something like this:-

When I was younger there was a brand of liquid coffee essence that came in a bottle, rather than the dried granules we have today.

The picture on the bottle showed a waiter serving someone the coffee.
The waiter had one of those waiter trays he held up in one hand.
On that tray was a bottle of the coffee, with the picture just discernable.

I used to think of the possibility of the infinite regression of ever smaller pictures of waiters holding trays with a bottle with a picture of a waiter holding a tray..................

This property is called self similarity and is a property of fractals.
This means that at ever decreasing scales each 'picture' is the same but contains smaller and smaller versions of itself.

So perhaps you can now see that this was a serious suggestion to help you take your proposal forwards.

To properly define fractals you need to first know the meaning of two mathematical terms

Metric
Dimension.

I say mathematical because the mathematical definitions are wider than those used in Physics, and this extra width is needed.

A metric is a real valued function, d, defined on a non empty point set X (finite or infinite) with elements {x, y, z.....} that satisfies the metric axioms which are

For every pair of elements of X

(1) d(x,y) >= 0 and d=0 implies x = y

(2) d(xy) = d(y,x)

(3) d(x,y) <= d(x,z) + d(z,y)
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Old May 8th 2019, 10:02 AM   #27
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Originally Posted by studiot View Post
'Moving inwards' is phrase fraught with the difficulties of imprecision.

Moving inwards from one atom in the way you describe implies moving outwards from any other atom.
And if you pick something 'inside the atom' and move inwards again you are therefore moving away from the rest of the structure of that atom.

Is this what you really meant?

To properly define fractals you need to first know the meaning of two mathematical terms
Yes, that's what I mean, but I also mean every geographical point in space rather than only any point we identify as matter, (there's a lot more space than matter in our universe). And, yes, moving inwards absolutely means moving outwards, (or away) from every other point. Seems to me this is amply precise. That's why there would be an infinite number of these subverses.

Again, atoms are not fractals of molecules, and protons, electrons and neutrons are not fractals of atoms.

Last edited by Georgeo57; May 8th 2019 at 10:05 AM.
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Old May 8th 2019, 10:19 AM   #28
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Again, atoms are not fractals of molecules, and protons, electrons and neutrons are not fractals of atoms.
I didn't say they were.

But they are not universes either.

Yes, that's what I mean, but I also mean every geographical point in space rather than only any point we identify as matter, (there's a lot more space than matter in our universe). And, yes, moving inwards absolutely means moving outwards, (or away) from every other point. Seems to me this is amply precise. That's why there would be an infinite number of these subverses.
Remember it is your proposal so it is up to you to support it.
So it is up to you to provide a proper mathematical description of what you mean since what you seem to be describing is not possible in standard 3D space, but is possible in fractal space.

What is the metric of the space you are describing?
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Old May 8th 2019, 10:49 AM   #29
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Originally Posted by studiot View Post
I didn't say they were.

But they are not universes either.

Remember it is your proposal so it is up to you to support it.
So it is up to you to provide a proper mathematical description of what you mean since what you seem to be describing is not possible in standard 3D space, but is possible in fractal space.

What is the metric of the space you are describing?
Precision is important to this. I didn't say the were universes, I said that within each are infinite, infinitely diminishing subverses.

A space metric is not necessary. I posted in the philosophy forum because the exploration is about something more fundamental than math. For example causality is a foundation of physics, and it's not at all about math,, nor does it need it to be fully understood.
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Old May 8th 2019, 11:42 AM   #30
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Originally Posted by Georgeo57 View Post
Precision is important to this. ................. the exploration is about something more fundamental than math.
Isn't that an oxymoron?

I didn't say the were universes, I said that within each are infinite, infinitely diminishing subverses.
How can something infinite be inside something else?

You have not defined a subverse.
So what is one?
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