question4477

Is Space-Time a Physical Entity or a Mathematical Model?

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Correct me if I'm wrong but following the above logic might get us to the point where nothing can be proven real...even a nail being hit by a hammer.

Where is the flaw? How do you test for "realness"?

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Where is the flaw? How do you test for "realness"?

Simply reproducibilty? So no "one off" test can show anything is "real" .It is all a building up of certitude? A balance of probabilities.

 

Because what we call everyday reality is lifelong we confuse that with 100% certainty?

Edited by geordief

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Yes, reality, as we know it, is a macro phenomenon and radio waves are not a macro phonomenon; the ontology of them is a mathematical.one. Any thing fundamental, like photons, are made up of measurable parameters but what they are as an entity is subject to modelling, which can change with new information. What scientists know about fundamental phenomena is always an abstraction; they are outside of our physical sensibilities to detect without apparatus.

Is it adequate to conclude that essencially what you mean is "If we can't sense it with our 5 senses it's not real" ?

 

 

 

Well, the effect of the nail hitting the hammer can ultimately be described in terms of the electromagnetic forces between the outmost surface electrons in the hammer and the nail. These are quantum effects that behave in very strange and counter-intuitive ways. So I wonder if this really is a good test of "reality". :)

Im not an expert but I dont think that our current QM is "good enough" for "testing for reality" Also I think we would have to define the meaning of reality in depth first. I think that the disagreements might come from semantic differences and the differences in general perception of "reality"

 

Where is the flaw? How do you test for "realness"?

I have no idea. Stil I would lean towards considering spacetime as "real" as radio waves or any other entity which is not dirrectly graspable by our 5 senses but as geordief wrote effects of it on the world are reproducable/repetable.

Edited by koti
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Is it adequate to conclude that essencially what you mean is "If we can't sense it with our 5 senses it's not real" ?

I think so, because if we have to use instruments we are creating a 'map of the territory' and a map is not the the territory; to borrow an expression.

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I think so, because if we have to use instruments we are creating a 'map of the territory' and a map is not the the territory; to borrow an expression.

I'm not sure if I grasp properly what you ate saying. I would like to dig into this subject deeper, Im stuck at work now and I will have more time to discuss in the evening. As a teaser...I think we deal with issues non detectable by our 5 senses all the time with them being very real.

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I'm not sure if I grasp properly what you ate saying. I would like to dig into this subject deeper, Im stuck at work now and I will have more time to discuss in the evening. As a teaser...I think we deal with issues non detectable by our 5 senses all the time with them being very real.

Think of an OS map as an analogy. Although the elevation contours on a map look instinctively like hills to us, they are really abstractions of the real thing.
Are those lines real? They are not a direct impression of hills, like in a photograph, are they; it require some extra mental gymnastics and interpretation.
Truth be told, we are heading down a rabbit-hole...fast. :)
post-14463-0-73284700-1471864161_thumb.jpg
Edited by StringJunky

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"Reality" as I see it, is much more than what our 170K year old species can currently understand. I think it would be bigheaded to assume that the nature which is 13.7B years old is constructed in such a way that our mere 5 senses have to grasp it all.

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Also I think we would have to define the meaning of reality in depth first. I think that the disagreements might come from semantic differences and the differences in general perception of "reality".

 

Exactly. It is very, very hard to come up with a useful definition of "real". And everyone has their own internal model of what it means.

I think so, because if we have to use instruments we are creating a 'map of the territory' and a map is not the the territory; to borrow an expression.

 

I am not sure that using instruments is any different than using our senses. They are just instruments for observing the world.

 

If you have to wear glasses to make your observation, does that make things less real? (Are glasses "instruments"?)

 

What about a microscope? An electron microscope? An atomic-force microscope?

 

Are microwaves less real than light, because we need an instrument to detect them? And what if those microwaves started out as visible light (e.g. the CMB)? Did that light become "unreal" at some point?

 

It's tough.

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Exactly. It is very, very hard to come up with a useful definition of "real". And everyone has their own internal model of what it means.

 

I am not sure that using instruments is any different than using our senses. They are just instruments for observing the world.

 

If you have to wear glasses to make your observation, does that make things less real? (Are glasses "instruments"?)

 

What about a microscope? An electron microscope? An atomic-force microscope?

 

Are microwaves less real than light, because we need an instrument to detect them? And what if those microwaves started out as visible light (e.g. the CMB)? Did that light become "unreal" at some point?

 

It's tough.

Yeah... I can't face it. Must remember to avoid that one in future. :)

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strange : Are those lines real? They are not a direct impression of hills, like in a photograph, are they; it require some extra mental gymnastics and interpretation.

 

Exactly one reason why koti's stance is a very sound one. +1

 

 

koti

 

Is it adequate to conclude that essencially what you mean is "If we can't sense it with our 5 senses it's not real" ?

 

The problem being that our 5 (or whatever) senses can be tricked (or just plain faulty) and we need interpretation to avoid this.

 

That is we need a combination of observation and interpretation, followed by further testing (observation) and confirmatory observation

 

What, did I just describe the scientific method?

 

;)

Edited by studiot

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Exactly one reason why koti's stance is a very sound one. +1

 

 

 

That was StringJunky, not Strange, and how does this support koti's position? (which seems to be "we can't tell, so let's call it real")

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That was StringJunky, not Strange, and how does this support koti's position? (which seems to be "we can't tell, so let's call it real")

 

Sorry to both SJ and Strange, no affront intended.

 

I don't get the impression that is what koti is saying since the extract I quoted asked for confirmation that this was another's position.

 

I think koti means that reality includes more than just what we can sense.

 

The debate is about what additional considerations we admit and I await clarification from the horse's mouth.

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The problem is that there are things that aren't real, too. How do we differentiate between real and unreal?

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The problem is that there are things that aren't real, too. How do we differentiate between real and unreal?

 

Yes I agree that there are imaginary things.

 

But look at your double use of the verb to be tying the question up in philosophical knots.

 

There are things that are not....

 

:eek:

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The problem is that there are things that aren't real, too. How do we differentiate between real and unreal?

Interesting question. Are "unreal" things "parasitic" on real things?(castles in the mind).

 

If you have a group of real things they can be mentally arranged in quickly infinite ways and the arrangements are all unreal (maps without any territories for the most part)

 

So real things differ from unreal things by virtue of being "undiluted" with too much sensory rationalization?

 

A question of degree . everything has to be initially experienced sensorily.

 

Makes no sense to talk of a anything real without someone or something to interact with it

 

Just a stab...

Edited by geordief

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Interesting question. Are "unreal" things "parasitic" on real things?(castles in the mind).

 

If you have a group of real things they can be mentally arranged in quickly infinite ways and the arrangements are all unreal -unless they happen to correspond to another group of real things perhaps.

 

So real things differ from unreal things by virtue of being "undiluted" with too much sensory rationalization?

 

A question of degree . everything has to be initially experienced sensorily.

 

Makes no sense to talk of a anything real without someone or something to interact with it

 

Just a stab...

 

 

An example of something that is not real in physics is the phonon. The quantum of vibration in some kind of lattice. The atoms undergoing vibration is the real effect here. The phonon is our way of keeping the books in a straightforward manner.

 

If you don't want to get deep into QM: dark is the absence of light. If EM radiation (light) is real, is dark real?

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An example of something that is not real in physics is the phonon. The quantum of vibration in some kind of lattice. The atoms undergoing vibration is the real effect here. The phonon is our way of keeping the books in a straightforward manner.

 

If you don't want to get deep into QM: dark is the absence of light. If EM radiation (light) is real, is dark real?

No (if I am consistent)

 

But it has (eg stumbling) effects.

 

They are the effects (at a remove) of light

 

It is the same question as to whether holes are real isn't it?

 

If reality is information then my idea comes unstuck , think ;)

Edited by geordief

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Now the philosophical discussion is beginning to motor.

 

You can say

 

There are tomatoes that are not red.

 

But can you say

 

There are bloob fruit that are not red?

 

or

 

There are bloob fruit that are not real?

 

Edit

 

 

 

If EM radiation (light) is real, is dark real?

 

I don't know about dark, but shadows exist n'est pas?

Edited by studiot

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No (if I am consistent)

 

But it has (eg stumbling) effects.

 

They are the effects (at a remove) of light

 

It is the same question as to whether holes are real isn't it?

 

If reality is information then my idea comes unstuck , think ;)

 

 

But how do we test that light is real and dark is not?

 

And let me jump ahead: once upon a time there was the chemical model of phlogiston. Phlogiston was a real substance that underwent combustion, in this model. It was real up until it was falsified and we came up with a better model. Phlogiston was never actually real. All models are vulnerable to being replaced by a better one. Which is one reason why I would caution agains ever claiming a model represents reality.

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Now the philosophical discussion is beginning to motor.

 

You can say

 

There are tomatoes that are not red.

 

But can you say

 

There are bloob fruit that are not red?

 

or

 

There are bloob fruit that are not real?

The first time you see "bloob" it is meaningless.

 

Second time around it has meanings..

 

 

But how do we test that light is real and dark is not?

Because you cannot detect dark?

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The first time you see "bloob" it is meaningless.

 

Not if you read it in " The Purple Book of Fairy tales"

 

There is no reason why a fictional story may not refer to an imaginary fruit (and some do).

Edited by studiot

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Because you cannot detect dark?

 

 

Sure I can. It's like detecting light, but the indicator goes in the other direction.

It's similar to being able to look at electron holes rather than electrons in semiconductors. We adopt the models that are easiest to use and give the right answers. But all models fail at some point, so how can they be representing reality?

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Sure I can. It's like detecting light, but the indicator goes in the other direction.

It's similar to being able to look at electron holes rather than electrons in semiconductors. We adopt the models that are easiest to use and give the right answers. But all models fail at some point, so how can they be representing reality?

So how/where does my interpretation that you are detecting(or failing to detect ) light and deducing dark fall down?

 

There is surely a hierarchy .You cannot fail to detect dark and deduce light ,can you?

Edited by geordief

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So how/where does my interpretation that you are detecting(or failing to detect ) light and deducing dark fall down?

 

There is surely a hierarchy .You cannot fail to detect darl and deduce light ,can you?

 

 

That would depend on your model, wouldn't it?

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So how/where does my interpretation that you are detecting(or failing to detect ) light and deducing dark fall down?

 

There is surely a hierarchy .You cannot fail to detect dark and deduce light ,can you?

 

This is where your intelligence and experience come in.

 

Do you have reason to think that the region your light.dark detector is probing is in the light or the dark?

 

Or has your detector simply run out of battery?

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