Agreed terms help sensible discussion

[Catastrophe]

I would like to propose we have a system of agreed terms so that we know what we are talking about. This is particularly urgent, in my opinion, when we stray into philosophical matters, such as those regarding the Universe, Black Holes, Singularities and similar questions. I use the word "philosophical" only to include items of cosmology which might be excluded on the basis that science rejects anything which cannot be observed and/or measured, and subject to experiment.

May I please kick off with the word Universe. I will plead my case, but please chip in if you want a plurality of universes, or alternate realities.

First I would like to quote some dictionaries and books on cosmology.

Oxford Dictionary of Astronomy Ian Ridpath OUP 2011.
"Universe Everything that exists, including space, time and matter. The study of the Universe is known as cosmology. Cosmologists distinguish between the Universe, with a capital U, meaning the cosmos and all its contents, and universe with a small u, which is usually a mathematical model derived from some physical theory. The real Universe consists mostly of apparently empty space, with matter concentrated into galaxies consisting of stars and gas. The Universe is expanding, so the space between galaxies is gradually stretching, causing a cosmological red shift in the light from distant objects. There is now strong evidence that space is filled with unseen dark matter that may have many times the mass of the visible galaxies; and even more mass may be accounted for by a still-mysterious dark energy. The most favoured concept of the origin of the Universe is the "Big Bang Theory [BBT], according to which the Universe came into being in a hot, dense fireball 13.7 billion years ago."

The Icon Critical Dictionary of The New Cosmology Ed Peter Coles Icon Books 1998.
Universe The entirety of all that exists. The Greek word cosmos, the root of cosmology, means the same; cosmology is the study of the Universe. This definition seems relatively straightforward, but there are some confusing subtleties, and linguistic confusion. For example, what do we mean by exist?
There are over two ages elaborating. I would summarise, that there is the view of science that only that which can be observed qualifies as Universe. "For some scientists what really exists is the laws of physics; our Universe is merely a consequence, or an outcome of these laws. . . . . . . . . . But do these laws exist, or did we invent them? Is mathematics an intrinsic property of the world, or is it simply a human invention that helps us to describe that world, in much the same way as a language? . . . . . . . . . If the Universe is the entirety of all that exists, then our model universe cannot be embedded in anything. What is outside the Universe must be something that does not exist. It does not therefore make any sense to think of there being anything outside the Universe."

Universe: The Definitive Visual Guide Ed. Martin Rees DK 2012
"The Universe is all of existence - all of space and time and all the matter and energy within it. . . . . . . . . . The Universe encompasses everything from the smallest atom to the largest galaxy cluster, and yet it seems that all are governed by the same basic laws.

Note: In the more specialised texts on cosmology, it is perhaps understandably more difficult to find definitions of Universe. It is taken for granted, unless stated to the contrary, that the accepted definitions, such as the above, apply. Any mentions of "other universes" will be documented.

Bang! The Complete History of the Universe. Brian May Patrick Moore Chris Lintott
Carlton Books 2006.
"Everything, space, time and matter, came into existence with a 'Big Bang' around 13.7 billion years
ago. The Universe then was a strange place - as alien as it could possibly be. . . . . . . . . . how big is the Universe? Either the Universe is of finite size or it isn't. If finite, what lies outside it? The question is meaningless - space itself exists only within the Universe, and literally there is therefore no 'outside'. On the other hand, to say the Universe is infinite is really to say that its size is not definable.

Cosmology A Very Short Introduction Peter Coles OUP 2001
"The word cosmology itself is derived from the Greek cosmos meaning the world as an ordered system or whole. The emphasis is just as much on order as on wholeness, for in Greek the opposite of cosmos is chaos. . . . . . . . . . The advent of mathematical reasoning, and the idea that one can learn about the physical world using logic and reason marked the beginning of the scientific era."
"In the modern era of cosmology . . . . . . began with a complete rewrite of the laws of Nature. (Einstein) demolished Newton's conception of space and time . . . . . . great works by Friedman, Lemaitre, and de Sitter formulated a new and complex language for the mathematical description of the Universe." Einstein's theory plays a fundamental conceptual role in modern cosmology. Hubble's observation of galaxies led to the observation that the Universe is expanding, and Penzias and Wilson discovered the cosmic microwave background (CMB) considered by many as proof that the Universe began with the Big Bang. Whilst accepted by most cosmologists "as being essentially correct, as far as it goes . . . . . . it is important to realise that the Big Bang is not complete. "For one thing, Einstein's theory itself breaks down at the very beginning of the Universe. The Big Bang is an example of what relativity theorists call a singularity, a point where the mathematics fall to pieces and measurable quantities become infinite. While we know how the Universe is expected to evolve from a given stage, the singularity makes it impossible to know from first principles what the Universe should look like in the beginning. . . . . . . . . . Most cosmologists interpret the Big Bang singularity in much the same way as the Black Hole singularity . . . i.e., as meaning that Einstein's equations break down at some point in the early Universe due to the extreme physical conditions present there. . . . . . . . . . This shortcoming is the reason why the word 'model' is probably more appropriate than 'theory' for the Big Bang."

Cat

 

[sam85geo]

A good idea that just might keep me and other similar folks who have marginal emotional control on topic where we may actually learn new things. (No promises though, but I'll try at least initially).

 

[Helio]

The idea of the multiverse and the fun in thinking about parallel universes -- the new Star Trek series milks more then the Milky Way with this one -- seems to have created views that are contrary to how science should be understood.

So, a "Universe" vs. a "universe" makes sense. I will try to follow this guideline.

I recall another who used "Geocentric" in lieu of "geocentric" to note the difference between the Earth being the absolute center of the universe to just being one use of a center (e.g. NASA). This made sense, as does your view.


The Cole quote is interesting, " If the Universe is the entirety of all that exists, then our model universe cannot be embedded in anything. What is outside the Universe must be something that does not exist. It does not therefore make any sense to think of there being anything outside the Universe."

This is a nice example of a "valid argument" used in formal logic, not that I'm any expert. But note that it's not necessarily a "sound argument" since we have no way to determine if his premise is correct. It's the ham sandwich in reverse - "If we have no ham, we can not make a ham sandwich." The problem is we can only say we might not have any ham. He is taking the unknowable (extraUniverse) and drawing a conclusion based upon the unkown. Not logical, IMO.

 

[COLGeek]

If someone starts limiting and dictating 'Cosmology' here -- that is, beyond what it already has been -- to their own Orwellian-like ever narrowing concentration camp terms and confines of language and meanings and uses, I think a lot of people will be leaving here for Texas and Florida, so to [politically analogously] speak. When I came on I did not expect this space.com forum section to be eventually owned and controlled by a fanatically mediocre minority ("Great spirits have always encountered violent opposition from mediocre minds..." -- Albert Einstein).

If someone thinks I am problematically greatly exaggerating when I see something like "agreed terms to help sensible discussion," so be it. I instantly see tyrannical-political state here and no one is going to make me think differently. With my long background of studies and interests and careers, I know what I seeing, what I'm reading, right away.

There are basic tenets of science and terminology that helps positive discourse to occur. I think that is the basis of this thread.

That being said, it is okay to disagree with others. Just attack ideas, with sources and citations. Do not attack the person.

Another thing to keep in mind is that we have an international member base. While English is the required language for the site, using it does not always the intended context. This can lead to misunderstandings and potential conflict.

Last, there is no tyrannical political(nor religious) agenda on this site, except to snip those topics in the bud when they occur.

 

[Helio]

There is indeed far too much nonsense with twisting terms for a variety of use. Since a lot of the use is non-sensical, then it's not unreasonable to help minimize the jump into metaphysics when a lot of readers are sure of what is happening.

"Universe" could prove helpful to "eschew obfuscation", and that's really what labels should do. There is no stress to do so, AFAIK, regardless.

 

[COLGeek]

Now we are crossing the bounds of making this topic personal. Time to stop. This thread is not aimed at any individual.

 

[IG2007]

"Not on your life," as the old saying goes. On the surface it appears not that bad, But I'm not one that only surfs the surface. Let there be nonsense to the point it is already permitted and curbed by space.com. I can't speak for those who run space.com, but neither you nor Cat are going to be arbitrators of what is nonsense and what isn't or I, and probably others, will leave you an increasingly empty readership and forum. There is a tiny nugget of gold occasionally in "them there hills" of nonsense. Your maps are not my maps, and your maps will not define the territory. You may try, but you will not make your maps the boundaries of the territory here, I sincerely hope. Leave well enough alone! As someone -- a philosopher -- once said, and I'm not quoting exactly, cosmology is intrinsic to philosophy, and philosophy is intrinsic to cosmology. Maybe it was "physics" rather than "cosmology" (including "metaphysics" to a certain degree) but it really makes no difference. I will use words in whatever way I think appropriate to describe what "Cosmos" or "cosmos" I'm trying to describe. I won't use terms like "Oh-my-God particle" for description, but neither you nor Cat will dictate usage to me. And you can quote dictionaries and physicists and others from now until doomsday and you will be wasting your breath and fingers typing.

#1 is not a rule, it is a suggestion. And it is a good one.

 

[Catastrophe]

I agree with Helio, stating in post #3: " recall another who used "Geocentric" in lieu of "geocentric" to note the difference between the Earth being the absolute center of the universe to just being one use of a center . . ."
Of course the suggestion that everywhere is the centre of the Universe means relative to the observer at that point. At least that is my view. The idea ties in with what I was posting about the observable universe changing with position of the observer, It is therefore more correct to state that every point is the centre of the observable universe for an observer located at that point. Of course there is no absolute Centre, because there is no absolute observer. This should even suit believers in any 'supreme being' since they seem to suggest afaik that their such entity is everywhere and not at some mythical "centre". Is this not (overall) basic Einstein? Cat

 

[Catastrophe]

How about Big Bang (BB) as the next topic?

Cosmology A Very Short Introduction Peter Coles OUP 2001
. . . . . . . . . "For one thing, Einstein's theory itself breaks down at the very beginning of the Universe. The Big Bang is an example of what relativity theorists call a singularity, a point where the mathematics fall to pieces and measurable quantities become infinite. While we know how the Universe is expected to evolve from a given stage, the singularity makes it impossible to know from first principles what the Universe should look like in the beginning. . . . . . . . . . Most cosmologists interpret the Big Bang singularity in much the same way as the Black Hole singularity . . . i.e., as meaning that Einstein's equations break down at some point in the early Universe due to the extreme physical conditions present there. . . . . . . . . . This shortcoming is the reason why the word 'model' is probably more appropriate than 'theory' for the Big Bang."

I only begin with this reference because, for a very long time, I assumed that terms like Big Bang and singularity and Universe represented "absolute truth". They may well, depending on the subject, represent the best idea that science has come up with, and should be treated as such, but anything which cannot be observed, measured, and experimented with is not science, but philosophy. We all know, I believe, that science progresses and refines its terminology and ideas according to its gains in knowledge. This, in turn, keeps a check on Philosophy.

Oxford Dictionary of Astronomy Ian Ridpath OUP 2011.
"Big Bang Theory (BBT) The most widely accepted theory of the origin and evolution of the Universe. According to the Big Bang Theory, the Universe originated from an initial state of high temperature and density and has been expanding ever since. The best current measurements place the occurrence of the Big Bang at 13.73 billion years ago +/- 0.1 billion years. In other words, this is the age of the Universe."
"The theory of general relativity predicts the existence of a 'singularity' at the very beginning, where the temperature and density were infinite. Most cosmologists interpret this singularity as meaning that general relativity breaks down at the Planck era under the extreme physical conditions of the very early Universe, and that the very beginning must be addressed using a theory of quantum cosmology. With our present knowledge of high energy particle physics, we can run the clock back through the lepton era and hadron era to about a millionth of a second after the Big Bang, when the temperature was 10^13 K. Using more speculative theory, cosmologists have tried to push the model to within 10^-35 seconds of the singularity, when the temperature was 10^28 K."

Dictionary of Geophysics, Astrophysics and Astronomy Ed R A Matzner CRC Press 2001
Big Bang The initial explosion that gave birth to the Universe, and a standard model of the Universe in which all matter space and time expand from an initial state of enormous density and pressure. All models of the Universe constructed in the classical relativity theory (General Relativity) must take into account that at present the Universe is expanding. . . . . . . . . . This moment of infinite compression is called the Big Bang. It is a formal mathematical conclusion that only implies that every region of the Universe must have been much denser and hotter in the past than it is now. . . . . . . . . . The Robertson Walker models imply that the Big Bang occurred simultaneously for all matter in the Universe, but more general models exist in which there is a nonsimultaneous Big Bang.

The Icon Critical Dictionary of The New Cosmology Ed Peter Coles Icon Books 1998.
Big Bang Theory "The standard theoretical framework within which most cosmologists interpret observations and construct new theoretical ideas. . . . . . . The existence of the cosmic microwave background radiation is extremely strong evidence that the Universe must have been hot in the past. It is also not entirely correct to call it a theory and many prefer to use the word model. The difference between theory and model is subtle, but a useful definition is that a theory is usually expected to be completely self-contained (it can have no adjustable parameters, and all mathematical quantities are defined a priori), whereas a model is not complete in the same way. Owing to uncertain aspects of the Big Bang model, it is quite difficult to make cast-iron predictions from it, and it is consequently not easy to falsify (falsifiability being regarded in many quarters as an essential quality of a scientific theory)."
"In the Big Bang model, the Universe originated from an initial state of high temperature and density (the primordial fireball) and has been expanding ever since. The dynamics of the Big Bang are described by cosmological models, which are obtained by solving the Einstein Equations in the theory of General Relativity. The particular models that form the basis of the standard Big Bang Theory are the Friedmann models, which describe a universe which is both homogeneous and isotropic. These models all predict the existence of a singularity at the very beginning, at which the temperature and density are infinite. . . . . . . . . . Most cosmologists interpret the singularity as meaning that the Einstein Equations break down at the Planck time under the extreme physical conditions of the very early Universe and that the very beginning must be addressed using a theory of quantum cosmology. This incompleteness is the reason why the word model is probably more appropriate."
. . . . . . . . . . . . . . .
"There is another important gap in the Big Bang theory, apart from the problem of initial conditions and the breakdown of known laws of physics at the initial singularity. The Big Bang model describes the properties of the Universe only in an average sense, because it is built into the theory that the Universe is the same in every place and looks the same in every direction.

The Natural History of the Universe Colin A Ronan Marshall Edition 1991
"Mathematics and reality. The theory of the Big Bang has much observational evidence to support it. Yet there is another side to the study of the Universe. Mathematics often enables cosmologists, like other scientists, to work out in theory what Nature should be like before experimentalists and observers have confirmed that such is the case."
"Mathematical reasoning is the only way to grasp the fundamentals that lie behind what we observe. This is so because mathematics is a language in which ideas can be formulated in a precise way and which allows the mind to work out logical sequences at profound depths, where mere words would present quite unsurmountable obstacles. Time and again, mathematical reasoning has provided insights available in no other way."

Cosmic Dispatches - Reports on Astronomy and Cosmology Ed John N Wilford Norton 2002
"Astronomers detect explosion second only to Big Bang. Astronomers have detected a titanic explosion in the outer reaches of the cosmos - one so violent and bright that for about 40 seconds it apparently outshone all the rest of the Universe. Except for the Big Bang that is generally believed to have created the Universe, no other cosmic explosion of such magnitude has ever been discovered."
Dr Stephen Hawking and Dr James Hartle "pictured a finite, closed Universe in the shape of a sphere, only in four dimensions. It starts with a Big Bang, expands to a maximum point like the spherical Earth's equator, and then contracts toward an eventual collapse in what is sometimes called the Big Crunch. Like Earth's surface, this has no edges and would seem to require a closed universe."

more follows

 

[IG2007]

How about Big Bang (BB) as the next topic?

Cosmology A Very Short Introduction Peter Coles OUP 2001
. . . . . . . . . "For one thing, Einstein's theory itself breaks down at the very beginning of the Universe. The Big Bang is an example of what relativity theorists call a singularity, a point where the mathematics fall to pieces and measurable quantities become infinite. While we know how the Universe is expected to evolve from a given stage, the singularity makes it impossible to know from first principles what the Universe should look like in the beginning. . . . . . . . . . Most cosmologists interpret the Big Bang singularity in much the same way as the Black Hole singularity . . . i.e., as meaning that Einstein's equations break down at some point in the early Universe due to the extreme physical conditions present there. . . . . . . . . . This shortcoming is the reason why the word 'model' is probably more appropriate than 'theory' for the Big Bang."

I only begin with this reference because, for a very long time, I assumed that terms like Big Bang and singularity and Universe represented

I have no problem with that. I agree to changing the word "BBT" to "BBM."

 

[Helio]

... It is therefore more correct to state that every point is the centre of the observable universe for an observer located at that point.

Right, this is a geocentric model that NASA uses for NEOs because local gravity dominates, and it is fully supported by GR.

But, given this thread's topic, the Geocentric model, interestingly enough, is worthy of discussion simply because of the above. IOW, GR doesn't rule-out that the Earth isn't the center of the Universe. [Some double negatives make a point. The contortions, however, one must go through with the addition of fictious forces to make a modified Tychonic model (Geocentric) work is too absurd to take seriously.]

[It's similar to Einstein demonstrating that no aether is required to exist, in lieu of arguing that no aether exists. To him the concept of the aether was superfluous, and unworthy of consideration. Yet, given the "foam" of virtual particles, perhaps it shouldn't be completely dismissed.]

 

[David-J-Franks]

How about Big Bang (BB) as the next topic?

Cosmology A Very Short Introduction Peter Coles OUP 2001
. . . . . . . . . "For one thing, Einstein's theory itself breaks down at the very beginning of the Universe. The Big Bang is an example of what relativity theorists call a singularity, a point where the mathematics fall to pieces and measurable quantities become infinite. While we know how the Universe is expected to evolve from a given stage, the singularity makes it impossible to know from first principles what the Universe should look like in the beginning. . . . . . . . . . Most cosmologists interpret the Big Bang singularity in much the same way as the Black Hole singularity . . . i.e., as meaning that Einstein's equations break down at some point in the early Universe due to the extreme physical conditions present there. . . . . . . . . . This shortcoming is the reason why the word 'model' is probably more appropriate than 'theory' for the Big Bang."

I only begin with this reference because, for a very long time, I assumed that terms like Big Bang and singularity and Universe represented "absolute truth". They may well, depending on the subject, represent the best idea that science has come up with, and should be treated as such, but anything which cannot be observed, measured, and experimented with is not science, but philosophy. We all know, I believe, that science progresses and refines its terminology and ideas according to its gains in knowledge. This, in turn, keeps a check on Philosophy.

Oxford Dictionary of Astronomy Ian Ridpath OUP 2011.
"Big Bang Theory (BBT) The most widely accepted theory of the origin and evolution of the Universe. According to the Big Bang Theory, the Universe originated from an initial state of high temperature and density and has been expanding ever since. The best current measurements place the occurrence of the Big Bang at 13.73 billion years ago +/- 0.1 billion years. In other words, this is the age of the Universe."
"The theory of general relativity predicts the existence of a 'singularity' at the very beginning, where the temperature and density were infinite. Most cosmologists interpret this singularity as meaning that general relativity breaks down at the Planck era under the extreme physical conditions of the very early Universe, and that the very beginning must be addressed using a theory of quantum cosmology. With our present knowledge of high energy particle physics, we can run the clock back through the lepton era and hadron era to about a millionth of a second after the Big Bang, when the temperature was 10^13 K. Using more speculative theory, cosmologists have tried to push the model to within 10^-35 seconds of the singularity, when the temperature was 10^28 K."

Dictionary of Geophysics, Astrophysics and Astronomy Ed R A Matzner CRC Press 2001
Big Bang The initial explosion that gave birth to the Universe, and a standard model of the Universe in which all matter space and time expand from an initial state of enormous density and pressure. All models of the Universe constructed in the classical relativity theory (General Relativity) must take into account that at present the Universe is expanding. . . . . . . . . . This moment of infinite compression is called the Big Bang. It is a formal mathematical conclusion that only implies that every region of the Universe must have been much denser and hotter in the past than it is now. . . . . . . . . . The Robertson Walker models imply that the Big Bang occurred simultaneously for all matter in the Universe, but more general models exist in which there is a nonsimultaneous Big Bang.

The Icon Critical Dictionary of The New Cosmology Ed Peter Coles Icon Books 1998.
Big Bang Theory "The standard theoretical framework within which most cosmologists interpret observations and construct new theoretical ideas. . . . . . . The existence of the cosmic microwave background radiation is extremely strong evidence that the Universe must have been hot in the past. It is also not entirely correct to call it a theory and many prefer to use the word model. The difference between theory and model is subtle, but a useful definition is that a theory is usually expected to be completely self-contained (it can have no adjustable parameters, and all mathematical quantities are defined a priori), whereas a model is not complete in the same way. Owing to uncertain aspects of the Big Bang model, it is quite difficult to make cast-iron predictions from it, and it is consequently not easy to falsify (falsifiability being regarded in many quarters as an essential quality of a scientific theory)."
"In the Big Bang model, the Universe originated from an initial state of high temperature and density (the primordial fireball) and has been expanding ever since. The dynamics of the Big Bang are described by cosmological models, which are obtained by solving the Einstein Equations in the theory of General Relativity. The particular models that form the basis of the standard Big Bang Theory are the Friedmann models, which describe a universe which is both homogeneous and isotropic. These models all predict the existence of a singularity at the very beginning, at which the temperature and density are infinite. . . . . . . . . . Most cosmologists interpret the singularity as meaning that the Einstein Equations break down at the Planck time under the extreme physical conditions of the very early Universe and that the very beginning must be addressed using a theory of quantum cosmology. This incompleteness is the reason why the word model is probably more appropriate."
. . . . . . . . . . . . . . .
"There is another important gap in the Big Bang theory, apart from the problem of initial conditions and the breakdown of known laws of physics at the initial singularity. The Big Bang model describes the properties of the Universe only in an average sense, because it is built into the theory that the Universe is the same in every place and looks the same in every direction.

The Natural History of the Universe Colin A Ronan Marshall Edition 1991
"Mathematics and reality. The theory of the Big Bang has much observational evidence to support it. Yet there is another side to the study of the Universe. Mathematics often enables cosmologists, like other scientists, to work out in theory what Nature should be like before experimentalists and observers have confirmed that such is the case."
"Mathematical reasoning is the only way to grasp the fundamentals that lie behind what we observe. This is so because mathematics is a language in which ideas can be formulated in a precise way and which allows the mind to work out logical sequences at profound depths, where mere words would present quite unsurmountable obstacles. Time and again, mathematical reasoning has provided insights available in no other way."

Cosmic Dispatches - Reports on Astronomy and Cosmology Ed John N Wilford Norton 2002
"Astronomers detect explosion second only to Big Bang. Astronomers have detected a titanic explosion in the outer reaches of the cosmos - one so violent and bright that for about 40 seconds it apparently outshone all the rest of the Universe. Except for the Big Bang that is generally believed to have created the Universe, no other cosmic explosion of such magnitude has ever been discovered."
Dr Stephen Hawking and Dr James Hartle "pictured a finite, closed Universe in the shape of a sphere, only in four dimensions. It starts with a Big Bang, expands to a maximum point like the spherical Earth's equator, and then contracts toward an eventual collapse in what is sometimes called the Big Crunch. Like Earth's surface, this has no edges and would seem to require a closed universe."

more follows

more follows

I hope so so, most of your quotes are around 20 years old , with the exception of one in 2011.

Given that you want to call it a model. Model is an ongoing thing, so, interesting as it is, can we have some modern definitions of Big Bang please. Something that comes to mind is slow roll inflation, I don't know much about it, but I think it is the accepted current version. I personally think it's absurd, it's the model were bubble universes keep appearing indefinitely, sorry for use of that word, and as the universe expands indefinitely, new bubble universes keep forming, a Multiverse Theory (another bad word). Looks like a Something for Nothing Theory.

Also some models go right back before particle formation right to quantum fields, something about that might be interesting as well, rather than just saying GR breaks down.

 

[Helio]

Given that you want to call it a model. Model is an ongoing thing, so, interesting as it is, can we have some modern definitions of Big Bang please. Something that comes to mind is slow roll inflation, I don't know much about it, but I think it is the accepted current version. I personally think it's absurd, it's the model were bubble universes keep appearing indefinitely, sorry for use of that word, and as the universe expands indefinitely, new bubble universes keep forming, a Multiverse Theory (another bad word). Looks like a Something for Nothing Theory.

Also some models go right back before particle formation right to quantum fields, something about that might be interesting as well, rather than just saying GR breaks down.

Yes, all that argues for your point about a better definition, or label, for Big Bang. Big Bang shouldn't be seen from nothing or a singularity or whatever to get us to Now. It should be taken as a theory from Now to as far back as physics remains competent. There are multiple stages of this. From now to the CMBR is the most competent level of Big Bang. To proton/neutron/electron formation the next level, perhaps. Then comes quarks. After that things get shaky.

 

[IG2007]

After that things get shaky.

For example, how did the Big Bang happen? A quantum fluctuation? (I don't really know what a quantum fluctuation is) Or a burst from nowhere? Or "The Hand of God"?

 

[Catastrophe]

Helio, your reply to my post:
Catastrophe said:
"... It is therefore more correct to state that every point is the centre of the observable universe for an observer located at that point."

I really cannot see anything wrong with this, except that it should be self-evident.

Cat

 

[Catastrophe]

David-J-Franks Your post #14.
1. As you point out, it is not yet finished. If there is to be a yet.
2. It is not a monologue, and was never intended to be.

To be honest, I am considering "cutting it adrift" as I think I have done my bit.
I have no intention of posting indefinitely on every conceivable term.
Thank you for contributing - such was the point of the exercise, that there should be a consensus, a general discussion and agreement on the meaning of terms.

Cat

An addition re: your post #15:

"more follows"

"I hope so so, most of your quotes are around 20 years old , with the exception of one in 2011."

Strangely, I did not start with search quotes. Anyone could have done that. I have a large library of those "old fashioned" books, and therefore thought it would be useful, without antiquated examples, to have the historical perspective books can supply.

Anyway, if anyone or many want(s) to take it over, I am done.

Cat

 

[sam85geo]

Thanks Cat; good apropos commentary for a good and logical concept.

 

[Catastrophe]

The idea of the multiverse and the fun in thinking about parallel universes -- the new Star Trek series milks more then the Milky Way with this one -- seems to have created views that are contrary to how science should be understood.

So, a "Universe" vs. a "universe" makes sense. I will try to follow this guideline.

I recall another who used "Geocentric" in lieu of "geocentric" to note the difference between the Earth being the absolute center of the universe to just being one use of a center (e.g. NASA). This made sense, as does your view.


The Cole quote is interesting, " If the Universe is the entirety of all that exists, then our model universe cannot be embedded in anything. What is outside the Universe must be something that does not exist. It does not therefore make any sense to think of there being anything outside the Universe."

This is a nice example of a "valid argument" used in formal logic, not that I'm any expert. But note that it's not necessarily a "sound argument" since we have no way to determine if his premise is correct. It's the ham sandwich in reverse - "If we have no ham, we can not make a ham sandwich." The problem is we can only say we might not have any ham. He is taking the unknowable (extraUniverse) and drawing a conclusion based upon the unkown. Not logical, IMO.

This should not be a premise - it is a definition. vide "If the Universe is the entirety of all that exists"

 

[IG2007]

This should not be a premise - it is a definition. vide "If the Universe is the entirety of all that exists"

Indeed, but it depends on how you define it, you may call the Universe as something that is the entirety of all that exists. Or you might also call the Universe as the totality of reality. Though that might sound the same, it does not mean the same.

 

[Catastrophe]

IG, you are correct as far as you go, but . . . . . . . . .

The definition of Universe is all that exists.

or, you can define "the totality of reality" as the observable universe. As you say, not the same.
N.B. The observable universe varies with the location of the observer.

Only one can be the totality, and it is the one defined as the totality viz. Universe.

We cannot observe the entire Universe, and never will be able to. The part we can observe, the only part which can be real to science, is the observable universe, which merits only a small 'u'.

Cat

 

[Atlan0001]

I wonder which of two forum members is going to reach 10,000, or even a 100,000, thumbs up first, they are giving each other thumbs up so fast and furious in even worthless "nothing" posts? They make it completely meaningless.

Other than that, no one but me seems to realize what different and paralleling universes can mean. The original Star Trek series gave one example of parallel universe with the characters being military members of a Nazi-like totalitarian gestapo state. An infinity of paralleling finite universes (u) being within an infinite Universe (U) have such possible universes (no information, including no conflicting information, or information branching(s) to infinity, is ever lost or gained). Other possible universes are from different branching decisions made by every living being that ever lived. How often has a member of the forum wished they had made a different decision than they made sometime in their lives? In an infinity of universes, they did make that different decision and there was an existing universe in which it happened (in quantum mechanics a particle, all particles in fact, will take all possible paths to a destination, there is a universe (u) for each possible path of all possible paths). In an infinity of universe(s) (u), all time(s) exist at once as well. In the infinite Universe (U) ('1') (at once Multiverse) of an infinity of universes (u), at once multiverses, no time(s) is ever lost or gained either (no information, no matter and energy or matters and energies, is ever lost or gained).

Also. there was an author whose sci-fi books I read as a pre-teen and young teen whom my teachers would not allow me make book reports on because they said no one else of my peers would understand the gist of the books. A. E. Van Vogt -- (in particular) 'The World of Null-A' and 'The Players of Null-A' as they were titled at the time and from that particular publisher.

 

[COLGeek]

I wonder which of two forum members is going to reach 10,000, or even a 100,000, thumbs up first, they are giving each other thumbs up so fast and furious in even worthless "nothing" posts? They make it completely meaningless.

If you concerned about such things, then please ignore them. The "thumbs up" is just a way for others to agree with (like) another's post. Otherwise, you used to see lots of wasted "+1" posts with older forum software/sites.

Other sites have more elaborate badging mechanisms for technical recognition of expertise. We really haven't implemented to a large extent here. To see one such example, take a look at the system at https://forums.tomshardware.com/members/ .

 

[IG2007]

IG, you are correct as far as you go, but . . . . . . . . .

The definition of Universe is all that exists.

or, you can define "the totality of reality" as the observable universe. As you say, not the same.
N.B. The observable universe varies with the location of the observer.

Only one can be the totality, and it is the one defined as the totality viz. Universe.

We cannot observe the entire Universe, and never will be able to. The part we can observe, the only part which can be real to science, is the observable universe, which merits only a small 'u'.

Cat

I completely agree with you.

PS: (But who knows if someone really manages to do an Alcubierre Drive some day? )

 

[Catastrophe]

"(But who knows if someone really manages to do an Alcubierre Drive some day?"

A bit vague for you IG

Cat

 

[IG2007]

A bit vague for you IG

Cat

I do really think that Alcubierre Drive is possible.