The word "universe" is indeed problematic. What it usually means in a scientific context is "everything in this timeline". So if you don't ascribe to some sort of multiverse, it's literally everything there is. If you do, there is more out there, which would require a different term.

In my opinion, the word "universe" is such an imprecise term that makes me wonder why physicists (at least the celebrity ones) keep using it. — Wheatley

What is imprecise about the word "universe"?

Consider this:

The cosmos (UK: /ˈkɒzmɒs/, US: /-moʊs/) is the Universe. Using the word cosmos rather than the word universe implies viewing the universe as a complex and orderly system or entity; the opposite of chaos.[1] The cosmos, and our understanding of the reasons for its existence and significance, are studied in cosmology (wiki)

Are you suggesting the word "universe" doesn't commit us to the existence of "a complex and orderly" system?

Precising definitions come into play when a word is vague. My question is what's vague in the definition of the word "universe"?

Okay, suppose we define the universe as “all there is”. There’s the ambiguity concerning abstract objects (such as numbers); Some say numbers exist in the universe, others don’t. And that’s only one problem. The term universe isn’t restrictive enough, anything can be considered part of the universe.

Okay, suppose we define the universe as “all there is”. There’s the ambiguity concerning abstract objects (such as numbers); Some say numbers exist in the universe, others don’t. And that’s only one problem. The term universe isn’t restrictive enough, anything can be considered part of the universe. — Wheatley

I thought scientists are, first and foremost, concerned only about the material.

Also, I meant vagueness and not ambiguity. If it's the latter then it implies a word has more than one meaning but each of them may have a "precise" definition.

I thought scientists are, first and foremost, concerned only about the material. — TheMadFool

It depends on what you mean by "material". I also don't like the word 'materialism' because most materialist include in their ontology things that ordinary people wouldn't call "material".

Also, I meant vagueness and not ambiguity. If it's the latter then it implies a word has more than one meaning but each of them may have a "precise" definition. — TheMadFool

Ambiguity is still not good for a scientific term (but that is another story). 'Universe' is a vague concept because there's so much we don't know. 95 percent of the so-called "universe" is made of dark matter and dark energy, to which scientists are clueless as to what they are. And it's no good to say that the 'universe' is merely an extension of space (bracketing all the unknown dark matter and dark energy); There's still the question of where the boundaries exist at the edge of the universe. I'm hoping that one day scientists will come up with a better word to describe what's out there.

What is imprecise about the word "universe"? — TheMadFool

EVERYTHING.

Does it mean "everything that exists"...or does it mean "the stuff humans** are able to sense or detect?"

**Humans: The currently dominant species on a nondescript rock circling a nondescript star in a nondescript galaxy among several hundreds of billions of galaxies that humans can detect.

It depends on what you mean by "material". I also don't like the word 'materialism' because most materialist include in their ontology things that ordinary people wouldn't call "material". — Wheatley

Ok. Are numbers material in any sense of that word?

Ambiguity is still not good for a scientific term (but that is another story). 'Universe' is a vague concept because there's so much we don't know. 95 percent of the so-called "universe" is made of dark matter and dark energy, to which scientists are clueless as to what they are. And it's no good to say that the 'universe' is merely an extension of space (bracketing all the unknown dark matter and dark energy); There's still the question of where the boundaries exist at the edge of the universe. I'm hoping that one day scientists will come up with a better word to describe what's out there. — Wheatley

You mean to say there's some kind of hazy border, a gray area, between what a universe is and what a universe is not? What kind of things would you say populates this no-man's land between universes and not-universes?

EVERYTHING.

Does it mean "everything that exists"...or does it mean "the stuff humans** are able to sense or detect?"

**Humans: The currently dominant species on a nondescript rock circling a nondescript star in a nondescript galaxy among several hundreds of billions of galaxies that humans can detect. — Frank Apisa

If you approach the issue from that angle, one in which you question the definition of existence as only those things that can be sensed or detected, you'll need to provide a sensible definition of "exist". How would you define "exist/existence"?

If you approach the issue from that angle, one in which you question the definition of existence as only those things that can be sensed or detected, you'll need to provide a sensible definition of "exist". How would you define "exist/existence"? — TheMadFool

Before I respond to that question...I have to ask YOU a question you may think snarky. It is not. It is essential to my response.

How do you define "define?"

I’m going to be laconic and use a uni verse: this has drove me to get in my car and apply for University to discover if the meaning of “universe” is scientific enough.

How do you define "define?" — Frank Apisa

You wouldn't be able to ask this question without knowing the defintion of "how", "do", "you", and since you did ask the question, I'd like ask the question back at you.

If you must know, defining is simply the process of taking some aspect of experience and matching it to a word.

If there is ultimately only one thing that exists, the whole thing, which is reduced or divided into aspects, parts, functions, multitudes, then it is the universe.

It's like Hilbert's Hotel. Whatever is has a room in the universe motel.

TheMadFool
6.2k
How do you define "define?"
— Frank Apisa

You wouldn't be able to ask this question without knowing the defintion of "how", "do", "you", and since you did ask the question, I'd like ask the question back at you.

If you must know, defining is simply the process of taking some aspect of experience and matching it to a word. — TheMadFool

[/quote]

Then I can say the same thing back at you.

Your question was...how do you define exist?

You wouldn't be able to ask that question without knowing the definition of "how" "do" "you."

So...apparently you can take some aspect of experience and match it to the word "define."

Do the same with the word "exist."

My experience tell me that anything that IS...exists...whether I personally KNOW it exists or not. I personally do not know atoms exist...but apparently they ARE. I personally do not know what kinds of planets exist in orbit around the nearest 20 starts to Sol...but apparently they ARE.
There are all sorts of things that EXIST...that I do not know about. In fact, my experience tells me that there apparently are all sorts of things that EXIST...that no humans know about.

Which brings us back to my answer to your question about "the universe"...and your response to my answer.

You asked, "What is imprecise about the word "universe"?

I responded, "EVERYTHING. Does it (the universe) mean "everything that exists"...or does it mean "the stuff humans** are able to sense or detect?"

Do the same with the word "exist." — Frank Apisa

As far as I can tell, the conventional definition of "exist/existence" does have a matching experience - we can say of things that we can sense/detect that they exist but when you say...

Does it mean "everything that exists"...or does it mean "the stuff humans** are able to sense or detect? — Frank Apisa

...you're entertaining the idea of existence that can't be sensed/detected i.e. you're tampering with the conventional, comprehensible, definition of "exist/existence" or, more accurately, you're proposing an altogther different definition. What is this new definition? That's all what I want to know.

TheMadFool
6.2k
Do the same with the word "exist."
— Frank Apisa

As far as I can tell, the conventional definition of "exist/existence" does have a matching experience - we can say of things that we can sense/detect that they exist but when you say...

Does it mean "everything that exists"...or does it mean "the stuff humans** are able to sense or detect?
— Frank Apisa

...you're entertaining the idea of existence that can't be sensed/detected i.e. you're tampering with the conventional, comprehensible, definition of "exist/existence" or, more accurately, you're proposing an altogther different definition. What is this new definition? That's all what I want to know. — TheMadFool

I am saying that exists means to exist. ANYTHING that exists...whether we can detect it or not...EXISTS.

Surely you do not think that we humans know everything that exists, right?

There may be things and dimensions of time and spaces that EXIST...that we cannot detect.

Not sure if you are playing a game for some reason, but "what exists" is...WHAT EXISTS.

It is used for different things, you're right.

The universe is usually used to describe everything that resulted from the Big Bang, even if it is outside our light cone. It often gets used synonymously with "the observable universe" which is everything in our past light cone. It also gets used in the idea of "parallel universes" synonymously with the "world" of Many Worlds Interpretation.

Finally it is used to differentiate different universes with different big bangs in multiverse theory. There is some overlap. Universes in multiverse theory are also "parallel" in the same way universes in the MWI are parallel, as well as (or rather because of) having no overlap with our universe.

The reason is that different people work in different fields. An astronomer deals with the observable universe, a cosmologist with the whole universe, a quantum theorist with parallel states, etc. Getting them to standardise is hard. Atomic physicists still use chemical nomenclature, for instance. Absolutely no reason for it, it's unnecessarily difficult.

am saying that exists means to exist. ANYTHING that exists...whether we can detect it or not...EXISTS. — Frank Apisa

Circular.

Surely you do not think that we humans know everything that exists, right?

There may be things and dimensions of time and spaces that EXIST...that we cannot detect.

Not sure if you are playing a game for some reason, but "what exists" is...WHAT EXISTS. — Frank Apisa

I'm not playing a game - I'm dead serious about this.

You've made the claim that a thing can exist "whether we can detect it or not...". An issue arises in your usage of the word "exist" because the conventional definition of "exist" has to do with detectability with the senses/instruments and since you're denying detectability - the necessary criterion for existence - you're essentially rejecting the definition of "exist/existence" as normally understood which implies that when you say "ANYTHING that exists...whether we can detect it or not...EXISTS, you're using a different definition of "exist". What is this definition? That's all I'm asking.

You've made the claim that a thing can exist "whether we can detect it or not...". An issue arises in your usage of the word "exist" because the conventional definition of "exist" has to do with detectability with the senses/instruments and since you're denying detectability - the necessary criterion for existence - you're essentially rejecting the definition of "exist/existence" as normally understood which implies that when you say "ANYTHING that exists...whether we can detect it or not...EXISTS, you're using a different definition of "exist". What is this definition? That's all I'm asking. — TheMadFool

If there are definitions of "exists" that require human confirmation...it is idiotic. And I suspect you are confusing "detectablility" with "detection."

If there is life on any planet in a distant galaxy ...it EXISTS regardless of the fact that we can detect it or not. If there are other dimensions of existence that we cannot detect...it exists whether we can detect it or not. The fact that we have not detected something does not mean it does not exist...nor that it cannot be detected.

Other galaxies exist...even though it was less than one hundred years ago that we discovered they did.

You said you were not playing a game.

I suspect you might be...even though you seem unable to detect that you are.

If there are definitions of "exists" that require human confirmation...it is idiotic. And I suspect you are confusing "detectablility" with "detection."

If there is life on any planet in a distant galaxy ...it EXISTS regardless of the fact that we can detect it or not. If there are other dimensions of existence that we cannot detect...it exists whether we can detect it or not. The fact that we have not detected something does not mean it does not exist...nor that it cannot be detected.

Other galaxies exist...even though it was less than one hundred years ago that we discovered they did.

You said you were not playing a game.

I suspect you might be...even though you seem unable to detect that you are. — Frank Apisa

Firstly, you raise a good point. What's the difference between detectability and detection and how is it relevant to our discussion?

The conventional definition of existence is based on detectability but knowledge of existence is tied to detection. If I posit the existence of a thing, say, x then, that x has to be detectable but for me to go from ignorance of the existence of x to knowledge of the existence of x, detection of x is paramount.

You said a thing can exist whether it can be detected or not i.e. you reject the feature of existence that has to do with detectability; in other words you're claiming something doesn't have to be detectable for it to exist and if so, if you were to claim something, say z, exists, you're not committed to z being detectable and that means your definition of "exists" is not the usual one we're familiar with, no? All I'm asking then is what's this other definition of "exists" you're using?

Firstly, you raise a good point. What's the difference between detectability and detection and how is it relevant to our discussion?

The conventional definition of existence is based on detectability but knowledge of existence is tied to detection. If I posit the existence of a thing, say, x then, that x has to be detectable but for me to go from ignorance of the existence of x to knowledge of the existence of x, detection of x is paramount. — TheMadFool

You can posit things that CANNOT be detected...and may not even be detectable.

You can posit things like the Red Queen in Alice in Wonderland.

I can actually posit things that are POSSIBLE...that cannot be detected.**

**Detected meaning perceived or reasonably inferred by human senses.

You said a thing can exist whether it can be detected or not i.e. you reject the feature of existence that has to do with detectability; — TheMadFool

I certainly am saying it is POSSIBLE. I am the consummate agnostic, so I am not saying "it is" but I am saying "it is possible." Are you saying it is impossible for things to exist that are not detectable by humans?

If so, please explain why you are saying that.

in other words you're claiming something doesn't have to be detectable for it to exist and if so, if you were to claim something, say z, exists, you're not committed to z being detectable and that means your definition of "exists" is not the usual one we're familiar with, no? All I'm asking then is what's this other definition of "exists" you're using? — TheMadFool

Let's be careful about our wording. I have tried to use "detectable by humans." If I have led you to suppose I mean "not detectable at all"...I apologize. I have NO IDEA if there are things that exist that are totally undetectable at all. If, for instance, a GOD who refuses to be detectable to anyone or anything other than itself...IT WOULD EXIST even though it cannot be detected (except by itself.)

I really wish you would make one thing clear, TMF.

Are you asserting that the only things that can exist are things that humans can detect?

So I ask: Can the word "universe" have a scientific definition? — Wheatley

What exactly do you mean by a "scientific definition"? It's certainly a word that scientists use in the course of their profession, so on that account it's a scientific term. Although as far as I know it doesn't have the same kind of formal definition within some mathematical model that something like an electron does within the Standard Model.

What exactly do you mean by a "scientific definition"? It's certainly a word that scientists use in the course of their profession, so on that account it's a scientific term. Although as far as I know it doesn't have the same kind of formal definition within some mathematical model that something like an electron does within the Standard Model. — Michael

I mean a rigorous definition. I bet 'universe' is used much less in scientific communities than it is used to communicate with the public. Take Cosmic Background Radiation for instance. It sounds much more rigorous than 'Background radiation from the universe'.

Ok. Are numbers material in any sense of that word? — TheMadFool

I haven't seen any philosophical position that states that numbers can be material.

You mean to say there's some kind of hazy border, a gray area, between what a universe is and what a universe is not? What kind of things would you say populates this no-man's land between universes and not-universes? — TheMadFool

Between the universe and the emptiness/void. I know it's a little speculative (so bear with me).

As to what the edge of universe looks like: that's way beyond my conceptual abilities at the moment.

Are you saying it is impossible for things to exist that are not detectable by humans? — Frank Apisa

I'm only asking for the definition of "exist" as you've used in the question above.

Below is the philosophical definition:

Exist: Existence is the ability of an entity to interact (detectable) with physical or mental reality. In philosophy, it refers to the ontological property of being.

Since detectability isn't part of your definition of "exist" it means your definition is different. I only ask you to state your definition of "exist".

I'm only asking for the definition of "exist" as you've used in the question above.

Below is the philosophical definition:

Exist: Existence is the ability of an entity to interact (detectable) with physical or mental reality. In philosophy, it refers to the ontological property of being.

Since detectability isn't part of your definition of "exist" it means your definition is different. I only ask you to state your definition of "exist". — TheMadFool

First of all...that "definition" you offered is something taken from Wikipedia...and has the following disclaimer included:
This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)
This article's lead section may not adequately summarize its contents. (March 2012)
This article needs additional citations for verification. (April 2009)

I could not agree more with that disclaimer. The "definition" is an absurdity.

Secondly, I HAVE offered my definition.

Exist...is EVERYTHING THAT IS...regardless of whether it can interact (detectable) with physical or mental reality.

If a thing exists...IT EXISTS.

Are there things that exist that humans cannot detect?

I do not KNOW, but I would bet huge sums that there are.

We humans are the currently dominant life-form on a nondescript hunk of rock circling a nondescript star in a nondescript galaxy among hundred of billions of galaxies in what we humans call "the universe" but which may be just a nondescript hunk of matter in a gazillion other universes.

So I ask my question again, TMF. Are you saying it is impossible for things to exist that are not detectable by humans?

If you are not, we are in agreement that when we say a thing exists...it means that it IS...without regard to whether we humans can detect it or interact with it.

@TheMadFool

Not sure if there can be any resolution to your back & forth regarding definitions. You can take any word and define it - but that definition is composed of words - and those words must have definitions - etc etc etc. So all definitions are in some sense circular.

I don't have any clear way to get out of this loop. But ultimately you have to get away from your computer or smartphone and get something to eat, go to the bathroom, etc. And all the time you are doing these things you are breathing in & out, your heart is beating, etc.

So unless you believe that you are in some sort of Matrix world - or any of the numerous philosophical variants - you must act 'as if' there is something out there. What word do you use to refer to what is outside of you? Reality, the universe, existence, all that is the case, the totality of facts, etc?

In other words, perhaps the way out of the definitional loop is somehow to point to reality, the universe, existence, all that is the case, the totality of facts, etc?

Yes, there are numerous holes in this line of reasoning. . . .

Thanks, Eric. I do not disagree with you...or with TMF for that matter.

I live life as it is for me...whether it is an persistent illusion (as Einstein suggested) or if it farce...which considering all the shit I've seen, it may well be.

I don't say ghosts or spirits or multi-dimensional beings exist...

...but I say they might. Gods may exist...which is one way of saying, "There may be no gods."

The REALITY of "all this" may be so much more complicated and astounding than any of us are able to suppose...even Philip Dick or Kurt Vonnegut.

Just talking and musing about what "might be" is fun...at least, for me, it is.

So all definitions are in some sense circular. — EricH

I tend to agree but would like a demonstration if you don't mind. As far as I can tell, the purported circularity of [all] definitions doesn't hold water for the simple reason that (I feel) the foundation of semantics is ostensive definitions i.e. all definitions can be traced back to a set of objects or a set phenomena that can be perceived directly. There is no way that any definition that ultimately tracks back to an ostensive definition can be circular and that includes all definitions because ostensive definitions don't require knowing any other word at all. No requirement of knowing words beforehand, no circularity possible.

First of all...that "definition" you offered is something taken from Wikipedia...and has the following disclaimer included:
This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)
This article's lead section may not adequately summarize its contents. (March 2012)
This article needs additional citations for verification. (April 2009) — Frank Apisa

:up: But is it just a coincidence that the author of the article had the same thoughts regarding existence as me?

Exist...is EVERYTHING THAT IS...regardless of whether it can interact (detectable) with physical or mental reality. — Frank Apisa

Now I think you're playing with me. Anyway, below is an excerpt from a more reputable philosophy resource:

To be red (or even to be an apple) it must already exist, as only existing things instantiate properties. (This principle—that existence is conceptually prior to predication—is rejected by Meinongians.) — Stanford Encyclopedia of Philosiphy (SEP)

As only existing things instantiate properties translates as:

1. If properties are instantiated then something exists that instantiates those properties

What does "properties are instantiated" entail other than detectability through senses/instruments?

In other words, existence is based off of detectability. No detectability, no existence.