# QM randomness...

Discussion in 'Physics & Math' started by Seattle, Jun 2, 2017.

1. ### GeonRegistered Member

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Yes, and don't mistake the word ''probability'' as something that has to be random. Probability is just another word for possibility. And what is possible may not be actually random.

Those so-called probability waves could easily be described by a pilot wave mechanism - or by something entirely new.

river likes this.

3. ### GeonRegistered Member

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190

All due respect, but science is built on the principle of cause and effect. It wasn't by any magic that my world is causal before the developing of a theory.

5. ### Beer w/StrawTranscendental Ignorance!Valued Senior Member

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What exactly do you mean?

7. ### GeonRegistered Member

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''Cause and effect scientific method

The scientific method is a process for experimentation that is used to explore observations and answer questions. Scientists use the scientific method to search for cause and effect relationships in nature.''

extract from internet for quick definition

8. ### iceauraValued Senior Member

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A probability is a calculated number, the calculations assume randomness.
If you discard other basic features of the physical world as long established in solid theory. As noted:
Of course one can do that. But do it with open eyes.
1) That doesn't mean the world is.

2) Not the science built on the 2nd Law of Thermodynamics. Not the science built on the Darwinian Theory of Evolution. Not the science built on the General Theory of Relativity.

However useful, cause and effect is a slippery, contingent, approximation dependent approach to explanation. In general, the more rigorous you need to be, the less of a role it plays.

9. ### Beer w/StrawTranscendental Ignorance!Valued Senior Member

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OK. I thought you were aiming for religious sentiment.

10. ### GeonRegistered Member

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Did you actually read what I said, or have you made your mind up to only a point?

I have already explained, probability does not need to imply randomness. For instance, the uncertainty principle is about the probabilities between two complimentary observables but is not a statement about randomness.

Macrocopic systems follow probability rules. Flip a coin, the probability field dictates more or less a 50-50 chance of landing a heads or tails. As is well-established now, macrosystems follow causual rules - they also follow probability rules.. from this alone, clearly probability does not imply a system has to be random.

11. ### Write4UValued Senior Member

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The inflationary epoch was the beginning of this universe. Lets just stick with what we know. We know from the background noise that this universe started as a small singularity, which almost instantly inflated in a permittive condition of nothingness. Mathematical functions did not yet exist, until the pure energetic chaos cooled enough to start forming our spacetime fabric, our universe and the mathematical functions of Geometry, QM, and Chemistry. During this forming a probabilistic random event may well have been the beginning of the universal chronology.
Bohm proposes that the Pilot Wave formed during this period and with it all other wave functions, but it is interesting to note that the background noise of the BB lacks the longest wavelengths, which mathematically indicates the size of the emitting object as small.
Well unless you are prepared to declare that there was never a beginning, it makes no difference how far back you want to go or how many universes you want to imagine.
Care to share your mathematical findings?
All that is irrelevant, unless you want to invoke infinity. You do agree with an ultimate beginning, no?

For us there is only one universe, the one we experience physically and observationally. We have a fair idea how it began and how the first particles (virtual or real) appeared and was the end of the inflationary epoch and the beginning of our spacetime. After that the universe evolved into what it is today.

There may be many more universes, but every one must have had a beginning. But we could never enter those dimensions, because we live in this universe with the dimensions and properties from which everything in this universe evolved.

So we can speculate about a multiverse, but it does not change anything about the beginning of this universe or that prior to the beginning there existed a permittive condition, which allowed for the BB.
A single mega quantum event, where everything happened all at the same instant.

My personal take on this is the inherent conflict of a timeless Nothingness being both infinite large and infinitely small. Does this virtual tensor create a potential energetic imperative?

In a timeless state of nothingness the beginning starts at the quantum moment of the BB (inflationary epoch).
What came before is beyond our observational powers and pure speculation. What is Dark Energy?

Last edited: Aug 28, 2017
12. ### iceauraValued Senior Member

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And I agreed. Probability theory - the mathematics used to calculate probabilities - assumes randomness: a "probability distribution". It can be used to model anything that behaves as if incorporating randomness: https://en.wikipedia.org/wiki/Probability_theory
That turns out to be most of the world and everything in it, especially at the most fundamental levels.
The probability rules work better for the most rigorous calculations and most generally applicable explications. In general: cause/effect analysis is based on, derived from, and answerable to, an underlying and more rigorous analysis employing probability.
The converse is not true: many phenomena are essentially impossible to analyze as a whole using cause/effect, in any but the most superficial and generalized way. (I offered the illustration of a ballon popping).

Probability is, then, apparently, more fundamental than cause - but far more difficult for humans to employ.

13. ### GeonRegistered Member

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I'm sorry to disappoint you but singularities are fading away where they belong.

What does it say, when its two inventors, Hawking and Penrose, no longer believe a singularity resulted in this universe? You say things like ''let's start with things we know.''

Well, actually... no we don't know the universe underwent inflation, nor do many top scientists think the universe began as a singularity any more. Science has made a lot of progress.

river likes this.
14. ### Write4UValued Senior Member

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Well, provide some evidence or proposal that can be critically examined.

15. ### GeonRegistered Member

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The problem with singularities is that we observe none in nature. Though technically-speaking we have developed methods to make patchwork of divergence problems, you cannot do this with a big bang singularity. Quantum gravitational corrections for instance, now stand as a main theory for singularity free universes. Universes which incorporate torsion, can be singularity free. These kinds of universes are much more acceptable!! Things like singularities, are places where physics does not make sense. We need to avoid such places.

16. ### GeonRegistered Member

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Penrose has adopted an eternal view of a universe, a cyclic one - whereas Hawking has worked in the realm of string theory which proposes a larger brane world and landscape of universes.

Multiverse theories, like those predicted by string theory ... and those predicted by inflation are now being heavily criticised because they are not Popper Falsifiable and so do not conspire to work within the scientific method.

17. ### GeonRegistered Member

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190
As for me... I have my own theory. I think this universe didn't just begin at a very hot state - something made it that way, so I vote our pre-big bang universe was actually very very cold and some phase change occurred in which an all-condensed liquid matter state collapsed into radiation vapor.

18. ### Write4UValued Senior Member

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Ok, but when did the cycle begin? Or the brane with its landscape of universes?
And we're back to infinity.

So if there is no singularity and no infinity, what's the third option?
The more you throw at it, the more complicated it becomes an Occam's razor problem.
IMO, the beginning of it all cannot be complicated, but fundamentally must be very simple and probabilistically possible.

Last edited: Aug 28, 2017
19. ### GeonRegistered Member

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Of course, but an investigator doesn't give up just because he thinks a lead has gone cold. He continues to investigate so long as there are clues there... and let's be honest, there is plenty we do not know about physics, to mean there are plenty of clues yet to discover still.

20. ### Write4UValued Senior Member

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Oh, I agree, and I am confident the answer will turn out to be a simple mathematical equation, as Tegmark proposes.

21. ### river

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Why ?

Why collapse into a radiation vapor ?

The liquid state makes sense to me , because all hydrogen would be in this state .

22. ### GeonRegistered Member

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Hydrogen was made in nucleosythnesis - it is a post big bang phenomenon.

No, the model I use depends on a phase of Bose/or/Fermi statistics and the pre-big bang phase was super cool, similar in that respect to Ekyprotic theory. An all-matter state would consist of some state of matter more primordial than the matter we deal with today. The result of the phase transition from a supercool, all matter liquid state is what heated the universe giving rise to a bath of radiation, mostly of which we detect as the background temperatures.

Why Bose or Fermi statistics?

The thermal de Broglie wavelength is denoted as $\lambda_{T}$. When the thermal de Broglie wavelength is smaller than the inter-particle distance, the gas can be considered to be a classical. On the other hand, when the thermal de Broglie wavelength is on the order of or larger than the inter-particle distance, quantum effects will dominate and the gas must be treated with Fermi or Bose statistics.

$\ddot{\lambda}_T \approx \frac{3}{2} \frac{\Delta T \Delta t}{p} \geq \frac{\hbar}{p}$

The phase transition obeys the following considerations:

$\frac{V}{N\lambda^3_T} \leq 1$

and

$\frac{V}{N\lambda^3_T} > \lambda_T$

The reason why it is important the pre-big bang phase was supercool (but not zero Kelvin), is because a process of lowering the temperature of a liquid or a gas (which are both fluids) beyond its freezing point - normally when a fluid reaches freezing point it becomes a solid: in this case it will freeze below this point without becoming a solid! Strangely enough, solid state physics as a phase state is considered a third phase state below liquid!

Last edited: Aug 28, 2017
23. ### GeonRegistered Member

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190
In the case the pre-big bang phase consisted of spin 1/2 particles, then the all matter liquid state may be considered equivalent to a degenerate supercool gas. A degenerate gas is also called a Fermi gas for the same statistical reasons.