DARK ENERGY IN A NEW LIGHT

[Strange]

52 minutes ago, CJWilli1 said:

Can you explain where I’m wrong?

The evidence shows that the universe has always been uniformly full of matter.

And it is meaningless to talk about matter “accelerating away from the universe” - there is no outside the universe for it to accelerate into. 

There is no force available to make it accelerate. 

52 minutes ago, CJWilli1 said:

can you also explain why this wouldn’t produce the effects of DE that we see?

It is up to you to show that it can. 

53 minutes ago, CJWilli1 said:

If we assign/ imagine properties to the space that existed before the BB, then we can make predictions based on those imaginary properties.

But your guesses are contradicted by evidence. And you can’t make any predictions. 

 

[Mordred]

Matter and galaxies do not expand, their binding energy is far stronger than the energy supplied by the cosmological constant.  So no this is inaccurate to describe why the universe expands.

lets try a little lesson. Pick any number of arbitrary points, as expansion occurs those points gain separation distance. However and this is the critical part, the angles between any two or more points do not change. This describes a homogeneous and isotropic expansion. So there is no flow of matter from some centre to the outer regions. Expansion occurs in all directions equally. 

If you think about this then consider the directional direction component of how forces work, then one also has to realize that no force style effect can be causing expansion. 

 Take an object such as a star, or galaxy. Apply equal amounts of force on every side and angle from other objects gravity etc. That star or galaxy will not move as the net sum of forces at any given angle is zero. This is because the mass density distribution on all sides of the star or galaxy is equal so any force they may exert is also equal on all angles. 

 In regions where there is zero to minimal binding energy expansion occurs as the extremely low energy density of the cosmological constant term roughly [latex] 7.0*10^{-10} joules/m^3 [/latex]  has no binding forces to contend with, however neither does it have a directional component. It is only in regions where there is minimal matter/mass that expansion occurs (without any inherent direction).

 Now keep the above in mind for any speculation you may have. make sure your speculation can match the above criteria and furthermore match the criteria of no net inflow or outflow of mass/energy  leaving or entering the cosmological event horizon. (limit of our Observable universe) simply we cannot get signals beyond this point as it takes time for signals to reach us. Both due to the speed of light as well as expansion rates.

 These criteria will greatly limit the options that one can speculate on that will fit the observational data. A great deal of professional models were discounted simply due to the extreme uniformity and homogeneous and isotropic distribution of matter. The second criteria can be tested by temperature measurements, so models such as Universe in a black hole/white hole has great difficulty meeting the first two criteria.

With the uniformity and non directional component of expansion, the process causing expansion must occur everywhere equally. It can be overpowered in localized regions of matter and still occur (that region will simply not expand as a result). This is the conditions you must match to have validity. The process cannot be from localized sources such as galaxies etc as it takes time for signals to reach other locations limited by the constant c. For this reason must occur at al locations in some process. (simply overpowered by other binding energies in those localized mass densities).

There is nothing wrong with speculations, however its a real time saver to know the criteria that one needs to meet and match in observational data. 

 

Edited February 19, 2019 by Mordred

[CJWilli1]

14 hours ago, Strange said:

The evidence shows that the universe has always been uniformly full of matter.

And it is meaningless to talk about matter “accelerating away from the universe” - there is no outside the universe for it to accelerate into. 

 

 

I’m not seeing how my idea contradicts the fact that the universe has always been uniformly full of matter. Also when I talk about the outside, I’m referring to the space that our universe is expanding into, or the space that existed before the BB, assuming that that space exists. The matter that existed before the BB, including the matter that made up the “singularity” of our BB, all expanded away from each other in uniform. Due to the increased distance between these pre BB particles, their contents expanded in uniform to fill that space so it would not become empty. Of course matter in our universe cannot go outside our universe or the BB.

14 hours ago, Mordred said:

Matter and galaxies do not expand, their binding energy is far stronger than the energy supplied by the cosmological constant.  So no this is inaccurate to describe why the universe expands.

lets try a little lesson. Pick any number of arbitrary points, as expansion occurs those points gain separation distance. However and this is the critical part, the angles between any two or more points do not change. This describes a homogeneous and isotropic expansion. So there is no flow of matter from some centre to the outer regions. Expansion occurs in all directions equally. 

If you think about this then consider the directional direction component of how forces work, then one also has to realize that no force style effect can be causing expansion. 

 Take an object such as a star, or galaxy. Apply equal amounts of force on every side and angle from other objects gravity etc. That star or galaxy will not move as the net sum of forces at any given angle is zero. This is because the mass density distribution on all sides of the star or galaxy is equal so any force they may exert is also equal on all angles. 

 In regions where there is zero to minimal binding energy expansion occurs as the extremely low energy density of the cosmological constant term roughly 7.0∗10−10joules/m3   has no binding forces to contend with, however neither does it have a directional component. It is only in regions where there is minimal matter/mass that expansion occurs (without any inherent direction).

 Now keep the above in mind for any speculation you may have. make sure your speculation can match the above criteria and furthermore match the criteria of no net inflow or outflow of mass/energy  leaving or entering the cosmological event horizon. (limit of our Observable universe) simply we cannot get signals beyond this point as it takes time for signals to reach us. Both due to the speed of light as well as expansion rates.

 These criteria will greatly limit the options that one can speculate on that will fit the observational data. A great deal of professional models were discounted simply due to the extreme uniformity and homogeneous and isotropic distribution of matter. The second criteria can be tested by temperature measurements, so models such as Universe in a black hole/white hole has great difficulty meeting the first two criteria.

With the uniformity and non directional component of expansion, the process causing expansion must occur everywhere equally. It can be overpowered in localized regions of matter and still occur (that region will simply not expand as a result). This is the conditions you must match to have validity. The process cannot be from localized sources such as galaxies etc as it takes time for signals to reach other locations limited by the constant c. For this reason must occur at al locations in some process. (simply overpowered by other binding energies in those localized mass densities).

There is nothing wrong with speculations, however its a real time saver to know the criteria that one needs to meet and match in observational data. 

 

I read this, but I’m not going to admit that I completely understand it just yet. I will before I make speculations in the future. 

Couldnt the pre BB particles that I speak of expand away from each other like distant galaxies do? As they expanded away from one another there wouldn’t initially be any background radiation between these particles. As they expanded the radiation that these particles uniformly released would fill space, otherwise it would become empty. If there was no background radiation between our galaxies, and the space between them was nearly empty, I wonder if the galaxies would rip apart. 

[Strange]

22 minutes ago, CJWilli1 said:

I’m not seeing how my idea contradicts the fact that the universe has always been uniformly full of matter.

Because you are talking about matter flowing into an empty (or emptier) region of space.

23 minutes ago, CJWilli1 said:

Also when I talk about the outside, I’m referring to the space that our universe is expanding into, or the space that existed before the BB, assuming that that space exists.

It doesn't exist. Any space that exists is part of our universe. It s not expanding "into" anything.

24 minutes ago, CJWilli1 said:

The matter that existed before the BB, including the matter that made up the “singularity” of our BB, all expanded away from each other in uniform. Due to the increased distance between these pre BB particles, their contents expanded in uniform to fill that space so it would not become empty.

That space was always full.

 

[Endy0816]

5 hours ago, CJWilli1 said:

I’m not seeing how my idea contradicts the fact that the universe has always been uniformly full of matter. Also when I talk about the outside, I’m referring to the space that our universe is expanding into, or the space that existed before the BB, assuming that that space exists. The matter that existed before the BB, including the matter that made up the “singularity” of our BB, all expanded away from each other in uniform. Due to the increased distance between these pre BB particles, their contents expanded in uniform to fill that space so it would not become empty. Of course matter in our universe cannot go outside our universe or the BB.

I read this, but I’m not going to admit that I completely understand it just yet. I will before I make speculations in the future. 

Couldnt the pre BB particles that I speak of expand away from each other like distant galaxies do? As they expanded away from one another there wouldn’t initially be any background radiation between these particles. As they expanded the radiation that these particles uniformly released would fill space, otherwise it would become empty. If there was no background radiation between our galaxies, and the space between them was nearly empty, I wonder if the galaxies would rip apart. 

 

The Universe can add space internally, so for Galaxy Cluster A and Galaxy Cluster B, they can be increasingly separated though neither one is accelerating away from the other.

ie.

A is 5 meters from B

A is 11 meters from B

A is 34 meters from B

More properly research the 'metric expansion of space-time' but that's the gist of things.

[Mordred]

10 hours ago, CJWilli1 said:

 

I read this, but I’m not going to admit that I completely understand it just yet. I will before I make speculations in the future. 

No worries very few layman grasp all the ramifications until they spend time studying on something I describe in the above manner. Here is a little hint though what I described is a homogeneous and isotropic scalar field. This is precisely the type of field that the cosmological constant matches in observational evidence and is modelled as such.

Here is some handy study material specific to the cosmological constant.

http://arxiv.org/abs/1002.3966 "why the prejudice against a constant"
http://arxiv.org/abs/gr-qc/0508052 "In an expanding universe, what doesn't expand? Richard H. Price, Joseph D. Romano

 

Here is a handy analogy to understand how local mass ie a galaxy doesn't expand due to the cosmological constant.

First ask yourself a question, why does the moon orbit the Earth and not the Sun whose mass far exceeds Earths mass? Well the simple answer is that local to the Earth (where the moon orbits, the gravitational field of the Earth is stronger than the Suns gravity.

 A similar thing occurs with galaxies, local to the mass of a galaxy, the gravitational force is stronger than the cosmological constant. The only areas that expand are in the voids between large scale structures. This is where gravity is too weak to counter it far far away from mass sources. 

Edited February 20, 2019 by Mordred

[CJWilli1]

On 2/19/2019 at 10:54 AM, Strange said:

Because you are talking about matter flowing into an empty (or emptier) region of space.

It doesn't exist. Any space that exists is part of our universe. It s not expanding "into" anything.

That space was always full.

 

I’m not talking about a flow of matter from a less empty region to a more empty region. I know that is what I was describing earlier, but I’m trying to get away from that idea now. 

 

What I am imagining is this. Before the BB there were many particles, or “singularities”, that were clustered together. These particles accelerated away from one another in a uniform expansion. At the same as time that occurred, the matter within those particles expanded in uniform so that there was no empty or more empty space. 

 

These expanding particles would all be a part of the same universe. What we consider “our universe” is the matter that expanded from our singularity. What I’m suggesting is that we are not the only uniformly expanding particle in the universe. 

 

The space always remains full. The contents from the “singularities” expand in uniform so that the added space remains consistently full. 

 

Pure speculation

Sorry about the font size it was an accident 

[swansont]

22 minutes ago, CJWilli1 said:

I’m not talking about a flow of matter from a less empty region to a more empty region. I know that is what I was describing earlier, but I’m trying to get away from that idea now. 

 

What I am imagining is this. Before the BB there were many particles, or “singularities”, that were clustered together. These particles accelerated away from one another in a uniform expansion. At the same as time that occurred, the matter within those particles expanded in uniform so that there was no empty or more empty space. 

 

These expanding particles would all be a part of the same universe. What we consider “our universe” is the matter that expanded from our singularity. What I’m suggesting is that we are not the only uniformly expanding particle in the universe. 

 

The space always remains full. The contents from the “singularities” expand in uniform so that the added space remains consistently full. 

 

Pure speculation

Sorry about the font size it was an accident 

You can’t have our universe stemming from one expansion, and also include others.

[Strange]

32 minutes ago, CJWilli1 said:

What I am imagining is this. Before the BB there were many particles, or “singularities”, that were clustered together. These particles accelerated away from one another in a uniform expansion. At the same as time that occurred, the matter within those particles expanded in uniform so that there was no empty or more empty space.

Singularities are not "things"; they are failures in the mathematics. There is a singularity at time 0 in the Big Bang if you extrapolate the theory back to where it is no longer valid.

Also, the Big Bang was not an event so talking about "before the Big Bang" doesn't really make sense.

Apart from that, it is not clear what you are saying. In the standard Big Bang model, space was full of particles (a quark gluon plasma at the earliest time we have theories for). Space then expanded and cooled allowing other particles and then matter to form. How is this different from what you are saying? 

36 minutes ago, CJWilli1 said:

These expanding particles would all be a part of the same universe. What we consider “our universe” is the matter that expanded from our singularity. What I’m suggesting is that we are not the only uniformly expanding particle in the universe.

There are many "multiverse" theories. This sounds a bit like eternal inflation: https://en.wikipedia.org/wiki/Eternal_inflation

37 minutes ago, CJWilli1 said:

Pure speculation

But why? What is the point of making stuff up that is not based on any science nor supported by any evidence?

[CJWilli1]

44 minutes ago, Strange said:

Singularities are not "things"; they are failures in the mathematics. There is a singularity at time 0 in the Big Bang if you extrapolate the theory back to where it is no longer valid.

Also, the Big Bang was not an event so talking about "before the Big Bang" doesn't really make sense.

Apart from that, it is not clear what you are saying. In the standard Big Bang model, space was full of particles (a quark gluon plasma at the earliest time we have theories for). Space then expanded and cooled allowing other particles and then matter to form. How is this different from what you are saying? 

There are many "multiverse" theories. This sounds a bit like eternal inflation: https://en.wikipedia.org/wiki/Eternal_inflation

But why? What is the point of making stuff up that is not based on any science nor supported by any evidence?

I’m thinking that the particles expanding and accelerating away from each other are a continuation of the Big Bang, this doesn’t happen before it. Perhaps time 0 doesn’t exist. The BB is a continuous process, and perhaps if you keep going back in time you will never reach time 0. 

I don’t think it is different from what you’re saying. 

I wasn’t originally going for a multiverse theory. But that’s what my idea developed into resulted in unfortunately. 

I recognize this idea fails to fully explain what ultimately drives dark energy. I’ll share some more ideas later after I think them through. 

 If we want to consider the posibilty of things effecting our universe that we cannot observe then we are forced to speculate. The first step would be to discuss the speculation on a conceptual level. If the speculation cannot be disproven on a conceptual level, then the next step would be to make a mathamatical model that accurately describes that speculation. If that mathematical model can predict what we can observe, then we can address that there is a possibility that the speculation is true. It’s a messy approach, but it might be the only one we can take if we want to understand what we cannot see. Even if my speculation is completely false, I don’t believe that the approach I’m suggesting is wrong. 

 

[StringJunky]

8 minutes ago, CJWilli1 said:

I’m thinking that the particles expanding and accelerating away from each other are a continuation of the Big Bang, this doesn’t happen before it. Perhaps time 0 doesn’t exist. The BB is a continuous process, and perhaps if you keep going back in time you will never reach time 0. 

Time - as we know it - may have emerged at that point, but it doesn't automatically follow that the universe started at that point just because time (as we know it) did. It could have been in some other state

Edited February 20, 2019 by StringJunky

[CJWilli1]

5 hours ago, swansont said:

You can’t have our universe stemming from one expansion, and also include others.

The others and our own “universe” would be apart of the same universe. They all would be stemming from one expansion. Would that make any sense? 

[beecee]

36 minutes ago, CJWilli1 said:

The others and our own “universe” would be apart of the same universe. They all would be stemming from one expansion. Would that make any sense? 

Different universes,  would be different spacetimes, or different fluctuations in the quantum foam by definition, I think.....All arising separately from different fluctuations in the nothingness of quantum foam, speaking speculatively of course.

Some interesting ideas here.....

https://www.forbes.com/sites/startswithabang/2018/07/17/what-is-and-isnt-scientific-about-the-multiverse/#2c4bcec925c4

 

Here's another, re quantum entanglement and multiverses.....

file:///C:/Users/BARRY/Downloads/universe-03-00028.pdf

Quantum Entanglement in the Multiverse

Abstract:

In this report, we consider cosmological implications of quantum entanglement between two causally disconnected universes in the multiverse. Supposing that our universe was initially entangled with a causally separated universe, we compute the spectrum of vacuum fluctuations of our universe. To clearly see the effect of entanglement, we compare it with the spectrum of an initially non-entangled state. It is found that, due to quantum interference, scale-dependent modulations may enter the spectrum for the case of an initially non-entangled state. We discuss that the existence of causally disconnected universes may be experimentally tested by analyzing correlators in detail.

[CJWilli1]

3 minutes ago, beecee said:

Different universes,  would be different spacetimes, or different fluctuations in the quantum foam by definition, I think.....All arising separately from different fluctuations in the nothingness of quantum foam, speaking speculatively of course.

I’m not talking about separate universes. It would all be the same universe. The spacetime would be shared. 

I like what you said In the second half of your paragraph. I had planned to bring up that same possibility. I also think that I may have evidence that shows a similarity between quantum flux and the observations of our universe. This evidence is still rather weak in my opinion. I’ll discuss my thoughts on this idea and others tomorrow. 

[Mordred]

One can discuss the concept of different universes in the context of different causally connected regions of the overall universe. The term universe gets rather ambiguous in this application. For example in the chaotic eternal inflation model one can have different bubble universes that are causally disconnected from one another. However none of this defines how these universes evolve per se in accordance to the cosmological constant problem, only that different expansion rates can apply in each of these causal disconnected universes or each can have the same expansion rate but they remain causally disconnected depending on the local where the fluctuation first occurred in the initial spacetime.

Please note the application of causally disconnected (extremely important in this application)

the last link by Beecee is a descriptive of the bubble universe  model under chaotic eternal inflation. It actually arose as a solution to the runaway inflation problem that plagued earlier inflationary models. Once inflation starts one needs a mechanism to stop inflation. The slow roll parameters largely handle this in current inflationary models such as Higg's inflation. 

Here is a study of 74 different inflationary models that looks for the best matches to observational evidence, this article is continuously updated periodically or used to be at one time. The latest Planck data tends to favor single scalar field models with a low kinetic term

https://arxiv.org/abs/1303.3787

This article usd to use chaotic eternal inflation as the benchmark best fit but lately its been a certain SM Higgs inflation (non supersymmetric)

53 minutes ago, beecee said:

 

Here's another, re quantum entanglement and multiverses.....

 

One needs to be careful here in order for two currently causal disconnected universes to be entangled they must have been in causal connection in the past prior to their inflationary rates causally disconnect the two bubble universes. One needs to be able to establish the correlation functions between the two

Edited February 21, 2019 by Mordred

[CJWilli1]

3 hours ago, Mordred said:

One can discuss the concept of different universes in the context of different causally connected regions of the overall universe. The term universe gets rather ambiguous in this application. For example in the chaotic eternal inflation model one can have different bubble universes that are causally disconnected from one another. However none of this defines how these universes evolve per se in accordance to the cosmological constant problem, only that different expansion rates can apply in each of these causal disconnected universes or each can have the same expansion rate but they remain causally disconnected depending on the local where the fluctuation first occurred in the initial spacetime.

Please note the application of causally disconnected (extremely important in this application)

the last link by Beecee is a descriptive of the bubble universe  model under chaotic eternal inflation. It actually arose as a solution to the runaway inflation problem that plagued earlier inflationary models. Once inflation starts one needs a mechanism to stop inflation. The slow roll parameters largely handle this in current inflationary models such as Higg's inflation. 

Here is a study of 74 different inflationary models that looks for the best matches to observational evidence, this article is continuously updated periodically or used to be at one time. The latest Planck data tends to favor single scalar field models with a low kinetic term

https://arxiv.org/abs/1303.3787

This article usd to use chaotic eternal inflation as the benchmark best fit but lately its been a certain SM Higgs inflation (non supersymmetric)

One needs to be careful here in order for two currently causal disconnected universes to be entangled they must have been in causal connection in the past prior to their inflationary rates causally disconnect the two bubble universes. One needs to be able to establish the correlation functions between the two

Thanks for all the info guys. I’m going to research inflationary models in the days to come, but my current understanding of them isn’t great. Is there any evidence against inflationary models? Is the evidence for them that strong? Is the accuracy of their predictions considered to be strong evidence?

 Just because they could support my spec doesn’t mean I should just assume they are true. But I would certainly like to think of an inflationary model as being true if one could lay down a foundation for my spec. Maybe I could tie my model, an inflationary model, and observational data all together.  Easier said than done. Of course I still have to consider the possibility of inflation models being wrong. 

Im not exactly sure if the model that I am speculating would be classified as causally disconnected universe. The acceleration of the particles in a uniform expansion CAUSES a simultaneous uniform expansion of the contents of those particles. So the distance between the “universes” techinaclly effects their contents. So they effect each other so that their expansion, and most likely their cosmological constant, remains uniform. I don’t think these “universes” would be any different for the most part. Perhaps slight differences could arise from the Heisenberg uncertainty principle, or quantum flux. Is there a model of inflation that could fit with my spec?

If the exact conditions of the BB were recreated elsewhere, would the results at our current point in time be exactly the same? Observe the present, Mentally rewind the Big Bang, and then allowed it to expand back to the same present moment. Would both of those “present moments” be the same? 

I know my wording is bad. I’m very tired, goodnight.

Edited February 21, 2019 by CJWilli1
Accidental premature upload

[Dagl1]

I don't have time to fully read the entire thread, but I did some searching of Hawking radiation across the three different pages. 
From what I have read, most people here seem to misunderstand Hawking radiation by the commonly used (but wrong) analogy of virtual particles appearing on the edge of the horizon, then having the negative matter particle fall in, thereby reducing the overall mass of the black hole. I am not a physicist of any sort and I wouldn't be able to properly explain the mechanism but this analogy is, as far as I am aware false. It doesn't make much sense, why do only the negative particles fall in, and not also the other way around. Thus see the video linked below.

I am sorry if this was addressed already but I thought it is important to properly understand physical phenomena before coming up with new theories (or give explanations which may or may not be true).

-Dagl
 

 

[Mordred]

1 hour ago, CJWilli1 said:

 The acceleration of the particles in a uniform expansion CAUSES a simultaneous uniform expansion of the contents of those particles. 

Let me ask you a question, If you have an expansion force strong enough to cause matter to expand (as I think your implying here)

How can stars ,galaxies and planets form ?

Yes there is strong evidence that inflation occurred, however there is also some models that argue against inflation.

Edited February 21, 2019 by Mordred

[beecee]

37 minutes ago, Dagl1 said:

I don't have time to fully read the entire thread, but I did some searching of Hawking radiation across the three different pages. 
From what I have read, most people here seem to misunderstand Hawking radiation by the commonly used (but wrong) analogy of virtual particles appearing on the edge of the horizon, then having the negative matter particle fall in, thereby reducing the overall mass of the black hole. I am not a physicist of any sort and I wouldn't be able to properly explain the mechanism but this analogy is, as far as I am aware false. It doesn't make much sense, why do only the negative particles fall in, and not also the other way around. Thus see the video linked below.

I am sorry if this was addressed already but I thought it is important to properly understand physical phenomena before coming up with new theories (or give explanations which may or may not be true).-

You raise a fair point......................

http://newt.phys.unsw.edu.au/~jkw/phys3550/Hawking_radiation/How_does_Hawking_radiation_work.pdf

 

Hawking radiation There are a number of ways of describing the mechanism responsible for Hawking radiation. Here's one: The vacuum in quantum field theory is not really empty; it's filled with "virtual pairs" of particles and antiparticles that pop in and out of existence, with lifetimes determined by the Heisenberg uncertainty principle. When such pairs forms near the event horizon of a black hole, though, they are pulled apart by the tidal forces of gravity. Sometimes one member of a pair crosses the horizon, and can no longer recombine with its partner. The partner can then escape to infinity, and since it carries off positive energy, the energy (and thus the mass) of the black hole must decrease. There is something a bit mysterious about this explanation: it requires that the particle that falls into the black hole have negative energy. Here's one way to understand what's going on. (This argument is based roughly on section 11.4 of Schutz's book, A first course in general relativity.)

To start, since we're talking about quantum field theory, let's understand what "energy" means in this context. The basic answer is that energy is determined by Planck's relation, E=hf, where f is frequency. Of course, a classical configuration of a field typically does not have a single frequency, but it can be Fourier decomposed into modes with fixed frequencies. In quantum field theory, modes with positive frequencies correspond to particles, and those with negative frequencies correspond to antiparticles.

Now, here's the key observation: frequency depends on time, and in particular on the choice of a time coordinate. We know this from special relativity, of course -- two observers in relative motion will see different frequencies for the same source. In special relativity, though, while Lorentz transformations can change the magnitude of frequency, they can't change the sign, so observers moving relative to each other with constant velocities will at least agree on the difference between particles and antiparticles.

53 minutes ago, Dagl1 said:

 I am not a physicist of any sort and I wouldn't be able to properly explain the mechanism but this analogy is, as far as I am aware false. It

 

Nice video, but it doesn't say Hawking Radiation is false, or anything like that...around the 8 minute mark it does say..."that it is fair to interpret this mixing as the promotion of virtual particles into real particles" and then follows on in more detail with regards to quantum entanglement. 

Edited February 21, 2019 by beecee

[Strange]

6 hours ago, CJWilli1 said:

The others and our own “universe” would be apart of the same universe. They all would be stemming from one expansion. Would that make any sense? 

No. You either have one universe or you have multiple (independent) universes. What does it mean for multiple universes to be part of the same universe?

2 hours ago, CJWilli1 said:

Is there any evidence against inflationary models? Is the evidence for them that strong? Is the accuracy of their predictions considered to be strong evidence?

There is absolutely no evidence for inflation (but no evidence against it).

[Dagl1]

@beecee

I did not mean to say that Hawking Radiation was false (I reread my original statement and I don't feel like that is the way one would interpret it, but my bad if I was being unclear).
I meant to say that, when speculating about new models for natural phenomena, it may be a good idea that everyone understands what they are talking about, and is not just using an analogy they have heard somewhere (which does not make sense when thought about it in more depth). 

It is fair to say that virtual particles are becoming real particles (in some ways) but it is not fair to say that this is due to the anti-matter particle of a virtual particle pair falling into the black hole. 

Again though, I am definitely not someone who should be lecturing physics (although I "know"  a lot of random facts, my understanding is quite poor:( ), so I accept that it is possible this video also gives a wrong explanation (although PBS spacetime seems pretty nice in general).

-Dagl

[Strange]

1 hour ago, Dagl1 said:

From what I have read, most people here seem to misunderstand Hawking radiation by the commonly used (but wrong) analogy of virtual particles appearing on the edge of the horizon, then having the negative matter particle fall in, thereby reducing the overall mass of the black hole. I am not a physicist of any sort and I wouldn't be able to properly explain the mechanism but this analogy is, as far as I am aware false. It doesn't make much sense, why do only the negative particles fall in, and not also the other way around. Thus see the video linked below.

I don’t think this analogy (which came from Hawking himself) is any more false than most other analogies. 

But as with all analogies, it is not a good idea to try and base new theories on them. 

7 minutes ago, Dagl1 said:

It is fair to say that virtual particles are becoming real particles (in some ways) but it is not fair to say that this is due to the anti-matter particle of a virtual particle pair falling into the black hole. 

That is a common misunderstanding of the analogy. Either particle could fall in. But the one that falls in has an effective negative mass (this may be what your video says, I don’t know).

[Dagl1]

5 minutes ago, Strange said:

I don’t think this analogy (which came from Hawking himself) is any more false than most other analogies. 

But as with all analogies, it is not a good idea to try and base new theories on them. 

He did? Hmm I am probably wrong but I seem to remember hearing that Hawking himself thought it was a bad analogy (but maybe he was criticizing his own analogy, or my memory is just bad and I seem to remember something that hasn't happened, a google search did not help me find where it came from (granted searching for 2 min isn't a real "search")).

Edit: Interestingly to note, while asking Mr. Googly, I came across the explanation that it is not an matter-antimatter particle pair, but negative_mass-positive_mass pair, this of course would mean that negative_mass exists, which I don't think has been proven to be the case.

 

Edited February 21, 2019 by Dagl1

[Strange]

1 minute ago, Dagl1 said:

He did?

Apparently. I was surprised as well!

[Mordred]

5 hours ago, Strange said:

 

There is absolutely no evidence for inflation (but no evidence against it).

There is evidence for inflationary processes contained in the CMB its one of the fundamental reasons its primarily used to determine which inflationary model is more accurate. Granted it is based on indirect evidence as opposed to direct but it is still evidence.