Is Space Real? The Existential Question of the Universe

[Doctordick]

Is space "real"?

Anssi asked a very good question about "space" which you all need to think about.

Yeah exactly. For instance, is it an entity on its own right, like a giant backdrop, and are there locations in it with identity (is it possible for a spaceship to go to one location in "space", and years later find that same location even though planets and stars have been shuffled away?)

Now that is a question with one and only one answer! I am curious as to what responses it might produce on this forum.

Whoops, wasn't such a quick reply after all... :P Good night!

Personally, I loved it. -- Dick

 

[russ_watters]

The simple answer is no: there is no universal reference frame.

 

[Doctordick]

The simple answer is no: there is no universal reference frame.

That wasn't the question Russ. There was no mention of "a universal reference frame"; there was only one reference frame of any interest at all, the ship's. The question is a bit more subtle than that.

Have fun -- Dick

 

[turbo]

Einstein thought that space is not a neutral backdrop, but has properties that can be conditioned by the matter embedded in it, and that these properties can have measurable gravitational effects on matter and upon the EM radiation propagating though it. This is probably approximated best in contemporary thought by the LQG folks, who modeling space as if it has a fine-scale structure that might be probed by its interaction with the EM propagating through it. (Google on "Fotini Markopoulou" and GLAST for details.

 

[sd01g]

.
Now that is a question with one and only one answer! I am curious as to what responses it might produce on this forum.

Personally, I loved it. -- Dick

Using an on-board inertial nav system, the spaceship could return to the approximate location. Since all measurements are approximations, no matter how accurate the inertial nav system, the EXACT location could never be relocated or verified.

This is probably not the 'one and only answer' that you have in mind, but you did invite responses, right?

 

[russ_watters]

That wasn't the question Russ. There was no mention of "a universal reference frame"; there was only one reference frame of any interest at all, the ship's.

No:

For instance, is it an entity on its own right, like a giant backdrop, and are there locations in it with identity

Nothing at all about a ship in the main question and the example with the ship is only trying to use the ship to find a location in space. That is what a universal reference frame is.

The reference frame of a ship is always the same and always stationary and doesn't say anything at all about the nature of the universe.

We've had people ask the question before; could I leave a buoy of some sort as a marker, stationary in space, and come back to it later? Sure - but you can't call it stationary wrt space, just wrt itself.

 

[Langbein]

Using an on-board inertial nav system, the spaceship could return to the approximate location.

But wouldn't the accelerometers of the inertial nav system need some refference for the sensing of acceleration ?

Can an acceleration be performed relative to nothing ?

 

[russ_watters]

Accelerometers can bring you back to a location that is stationary wrt the ship's original stationary-wrt-itself position and that's it. Just like my buoy.

 

[Langbein]

And accelerometers work pretty well without two masses that are accelerated rellative to each other ?

 

[out of whack]

I suggest that space is just a relationship between entities. It is meaningless without at least two entities (or two points) that can then be distinguished from each other by the fact that a distance exists between them. If you remove one of these points then space has no meaning. Since the concept requires more than a single point then it must represent a relationship.

 

[AnssiH]

Hehe, "interesting thread" :)

I suggest that space is just a relationship between entities. It is meaningless without at least two entities (or two points) that can then be distinguished from each other by the fact that a distance exists between them. If you remove one of these points then space has no meaning. Since the concept requires more than a single point then it must represent a relationship.

Yup. Keyword "concept". "Space" is one of the concepts we use to comprehend reality around us. I think the "subtle issue" Doctordick is referring to is about do we go about assuming the ontological reality of things (of space in this case).

And like you say, the concept of space is meaningless without distances between some things we have defined as things that exist (however we understand "distance"). And like Russ is saying, the idea of "locations" is meaningless unless we relate them to the locations of some "things" (that we have also defined.

I'm sure this question has been asked many times before by people wanting to know how space is defined in relativity, but this time it was actually mentioned in slightly different context. It came up during a discussion in an AI forum, about the relationship between our mental models of reality, and the ontological nature of that reality itself.

I think I said all I needed to say there, so;
http://tech.groups.yahoo.com/group/ai-philosophy/message/12228

Now I would curious as to what responses the whole post might produce on this forum. :)

-Anssi

 

[MeJennifer]

Anssi asked a very good question about "space" which you all need to think about.
Now that is a question with one and only one answer! I am curious as to what responses it might produce on this forum.

Personally, I loved it. -- Dick

There is no space, it's turtles all the way down.

Seriously though, even in general relativity space is an entity. If you want to remove space from the equation you need a completely relational theory (GR is not a completely relational theory). So far no one has been able to publish a realistic theory of gravitation and EM forces in a purely relational fashion. So perhaps space does exist. On the other hand, today it's bon ton to be a LQG researcher, and that's not relational either. Perhaps purely relational theories are meant for looners in shacks, who will tell?

 

[Siah]

.

It came up during a discussion in an AI forum, about the relationship between our mental models of reality, and the ontological nature of that reality itself.

When we talk about the ontological nature of something, can this not be regarded as forming a mental model? The notion/idea/concept of what reality "really is" must still be a mental construct/model. The contemplation of reality via any mental process must surely lead to a limited comprehension of that reality (a reality which must surely include all mental processes and much more besides).
Space is a word. The word signifies a shared comprehension concerning reality (another word which seems to signify something about one's ability to comprehend). Because a comprehension is shared doesn't make it valid (or invalid).
If everyone agrees that 'space is real' then it is real. This does not necessarily reflect any actuality.

 

[oldtobor]

May I suggest the following :

http://www.ilovephilosophy.com/phpbb/viewtopic.php?t=153992



I also suggest meditating about this aspect of the question:


Size has always been viewed physically but with the advent of computers and digital information the real size of things should be seen as combinational.

Why complicate something very simple ? There is no time or space or anything, just COMBINATIONS.

A very simple example: say that the universe is made of only one number (0 to 9) and there are only three time intervals in the whole lifetime of this universe. How large is it really ?

Well 10*10*10 are all the possible combinations, that is the possible sequences of this one number times the 3 time intervals. Now just extrapolate this to any large number of particles, having any large number of states times any large number of time intervals for any universe.

It would be something like Z to the X times Y, where X is the number of possible states and Y is the number of time intervals. Z is the number of particle states and/or number of particles.

Z^X*Y. This is a universe, with all time and space included. Obviously an insanely huge number, but mathematically and conceptually very simple.


Even more interesting is the space to time converter or viceversa. Conside that all the combinations Z^X*Y can be equivalent to 2^N so instead of having many particles and states you can have a universe with only one bit of information that can follow a sequence of combinations that contain all the possible combinations of a universe, like a DVD is a stream of bits that design a 2 hour movie. In this case it is a universe with ONE bit having many (huge number!) of time intervals (N).

Or you can convert it to a universe having a given huge number of BITS but that is still because it contains all the possible combinations. So in this case it is a universe with a huge number of bits (or particles if you like) but with only one time interval, hence no time.


2^N=M so a one bit universe with a number of time intervals (N) is equivalent to a universe with a number of bits (M) but only one time interval, hence no time (a frozen universe of combinations). Time can be converted into space and vice versa because they are both arbitrary concepts, only information and combinations exist.


So let's take this up to another level. Just how big is our universe then ?

Lets consider something like 10^1000 particles and call that N. Each particle can be in maybe 10^100 different states and call that S.

So S^N are all the possible combinations of all these particles through all their states and call that C. Now let's throw in time, and say that there are maybe 10^1000 time intervals and call that T. So that would be C^T all possible combinations of all particles for all of time. Of course our real universe is only a very small subset of this, but it maybe really isn't as big as we think.


S=10^100 no. of different states for each particle;

N=10^1000 no. of particles;

C=S^N no. of all possible combinations of states and particles;

T is the number of time intervals, 10^1000;


SIZE of UNIVERSE=C^T

SIZE=((10^100)^(10^1000))^(10^1000)

This number can be converted to 2^X where X is probably really big. So the universe is just a simple number, 2^X.


The universe is not infinite in size but limited by the time intervals, 10^1000, and particles which are really simply numbers or bits 10^1000, and states of these items maybe 10^100. These numbers are large excess approximations, real elementary particles are probably only a few hundred or thousand, time probably can't go down to less than 10 to the minus 200 seconds, etc.
This is just an extrapolation of a universe as a series of bits just as a DVD contains 40 billion bits and can produce a 2 hour movie. This is the informational content, or measurements of the entire universe, or state space it can occupy. We are a small subset of bits of this number. The laws of physics are just a series of strong filters allowing mostly only the major combinations, but quantum physics kind of tells us that all the combinations are possible and do indeed exist.

The problem is what external space are these bits or particles or numbers occupying ? They must be floating in some other material, or item. It is this item that can create experiences, consciousness, reality and matter as parts of these combinations of bits are grouped as people and life and experiences. Very odd, but makes some sense...

 

[Siah]

Why complicate something very simple ? There is no time or space or anything, just COMBINATIONS.

Combinations of what?

 

[oldtobor]

Combinations of what?

Combination of numbers, or bits, or any item - entity that can be distinguished from another. A pure number - item in an abstract mental space. A pure measurement... everything we perceive is a sequence of measurements, numbers and comparisons between said measurements. At least according to the scientific - physics decoding of the world (and also a language with symbols mapping onto the comparisons ?)

 

[Siah]

Combination of numbers, or bits, or any item - entity that can be distinguished from another. A pure number - item in an abstract mental space. A pure measurement... everything we perceive is a sequence of measurements, numbers and comparisons between said measurements. At least according to the scientific - physics decoding of the world (and also a language with symbols mapping onto the comparisons ?)[QUOTE/]

How are the objects of "an abstract mental space" related to the objective physical universe?
Are you saying that the universe is generated by our perception of it?
Aren't you confusing the mental constructs we use to describe reality with the actuality of reality?

 

[oldtobor]

2^N=M so a one bit universe with a number of time intervals (N) is equivalent to a universe with a number of bits (M) but only one time interval, hence no time (a frozen universe of combinations). Time can be converted into space and vice versa because they are both arbitrary concepts, only information and combinations exist.


I am not getting into the language - semantics complications of it all, but just trying to show that it seems that if we just view the universe as information - mathematics the entire deal is just a combination of numbers that can eventually be mapped onto any kind of decoding and encoding of this information into any kinds of categories desired; the combinations, group of bits, can be broken up or merged in any way possible.

 

[oldtobor]

This is just an extrapolation of a universe as a series of bits just as a DVD contains 40 billion bits and can produce a 2 hour movie. This is the informational content, or measurements of the entire universe, or state space it can occupy. We are a small subset of bits of this number. The laws of physics are just a series of strong filters allowing mostly only the major combinations, but quantum physics kind of tells us that all the combinations are possible and do indeed exist.

The laws of physics seem to be simply the combinations that have the highest probability of being repeated. I think this view could be a better view of the many worlds theory of quantum physics since in a pure combinational view all the combinations exist, only that we find ourselves within a given combination. Odd but somehow related to the many worlds - infinite parallel universe theories ...

But then again if all the combinations exist, we simply find ourselves in a quirk combination that seems to follow very strict laws, but these laws don't really exist they are just a design or pattern or painting superimposed on a subset of the combination of bits.

 

[MeJennifer]

Lets consider something like 10^1000 particles and call that N. Each particle can be in maybe 10^100 different states and call that S.

So S^N are all the possible combinations of all these particles through all their states and call that C. Now let's throw in time, and say that there are maybe 10^1000 time intervals and call that T. So that would be C^T all possible combinations of all particles for all of time.

Interesting approach. However if you want to approach it from that perspective you have to take quantum mechanics into account. In QM you cannot simply add up the individual states of particles, they combine in QM! So the number is actually very much higher than you reason here.

You might be interested in reading "The End of Time" by Julian Barbour.

 

[Philocrat]

A super-positioned entity or event (a zero-history type) is metaphysically and epistemologically devoid of the 'Reality of Space'. All diverse senses of time and space simply everporate. Do super-positioned entities or events communicate with each other? Yes, they do, except that they do so timelessly and spacelessly!

 

[john 8]

2^N=M so a one bit universe with a number of time intervals (N) is equivalent to a universe with a number of bits (M) but only one time interval, hence no time (a frozen universe of combinations). Time can be converted into space and vice versa because they are both arbitrary concepts, only information and combinations exist.


I am not getting into the language - semantics complications of it all, but just trying to show that it seems that if we just view the universe as information - mathematics the entire deal is just a combination of numbers that can eventually be mapped onto any kind of decoding and encoding of this information into any kinds of categories desired; the combinations, group of bits, can be broken up or merged in any way possible.

It seems that you want to say reality is just a combination of numbers. Animals and plants can percieve the world around them yet they have no concept of math. So I would say that math is not needed to precieve the universe. How did man view the world before he invented math, if you think math is necessary for perception of the universe?

I think the basic question being asked on this thread is whether space is a thing that exists in the physical universe or not.

I say space is just a term used by man to describe that area of nothing between objects.

 

[WaveJumper]

It seems that you want to say reality is just a combination of numbers. Animals and plants can percieve the world around them yet they have no concept of math. So I would say that math is not needed to precieve the universe. How did man view the world before he invented math, if you think math is necessary for perception of the universe?

I think the basic question being asked on this thread is whether space is a thing that exists in the physical universe or not.

I say space is just a term used by man to describe that area of nothing between objects.

I don't think anyone currently can answer your question with great certainty but can you picture something that has no structure? Doesn't it go against human logic? There is no evidence about it but do you think empty space has no "invisible" structure? Empty space is a macroscopic entity, how could anything that engulfs physical objects be non-physical? I mean space was created at the Big Bang, it follows physical laws, it gets bent by mass, so what makes you think it's not a thing? And if it's not a physical thing, how can it be bent?

BTW are you a member at evc?

 

[WaveJumper]

I say space is just a term used by man to describe that area of nothing between objects.

Your question about the nature of space has many hidden profound implications. Just to mess up your concepts even further, consider the fact that an atom is 100% empty space, thus matter is also 100% empty space. It's all just force fields directed by the principles of electromagnetism, that interact and form your macroscopic sense of matter and reality. So if matter is space and space is something we cannot perceive as physical, then what is reality and what is physical or "thing" as you put it? You may not like the answer to that question.

 

[Landru]

Anssi asked a very good question about "space" which you all need to think about.
Now that is a question with one and only one answer! I am curious as to what responses it might produce on this forum.

Space is an entity because afaik the universe has a definite shape, and even though the shape might be constantly changing, at any given moment any given point in space has a describable orientation within the universe.

If the universe actualy has a shape then any given point in space can be described in terms of where it is within the shape with or without material points of reference. If it were a shapeless infinite plane that never ends then there would be no way to describe a given location without reference but I personaly doubt the universe is infinite.

 

[Chrisc]

First we discern, the ink from the paper, the type from the white space, the patterns from the chaos,
these become letters, the letters become words the words become sentences the sentences become ...
what you are discerning right now.
(OK light and dark pixels not ink and paper)
Now discern space...from what?
Let's discern space from itself in a quantitative sense.
Let's measure units of space/Length and reason that any subsequent measure while completely indiscernible
from the first over time, is not simultaneously the same unit as the first.
In other words, a measure of one meter is distinct from the adjacent second meter if for no other reason than
it is not simultaneously the second.
The only constant ruler we have is the speed of light. We must use the constancy of the speed of light in its
traversal of space to measure out our units of space.
Already we have a problem more perplexing than the idea that matter is space.
Our marking of time is in fact our marking of space in the periodicity of motion through space(the hands of a clock).
How can we assert a measure of space is an accurate or meaningful measure when the ruler of time we use for the task
is itself a measure of space that is no more meaningful than our measure?
It seems MeJennifer's answer "It's turtles all the way down" is more accurate than we like to admit.
As MeJennifer pointed out, the only escape from this circular definition of space, time and mass is a truly relational theory
of all three fundamental dimensions. A model where none possesses any priority of physical reality over the others,
but all three in their present discernible nature are the ink, letters and paper that we call physics.

 

[WaveJumper]

As MeJennifer pointed out, the only escape from this circular definition of space, time and mass is a truly relational theory
of all three fundamental dimensions. A model where none possesses any priority of physical reality over the others,
but all three in their present discernible nature are the ink, letters and paper that we call physics.

It doesn't seem like anything has really changed quantum mechanically since very shortly after the Big Bang. It's the same energy that was available between T=0 and T=10^-43sec., but now it's in a different configuration that allows tiny specs of energy to acquire an ability to observe itself and get fooled into believing there is a physical reality out there independent of the conscious existence that recognises and deciphers the ink on the paper as information. Behind this veil that forms our perception of reality shines the work of a creatinve Mind as Paul Davies put it.

 

[Landru]

I like the idea that the universe is information that we only perceive has having substance as a result of our own configurations in the way that a CD player passes along binary data as music, but I don't like attributing it to a creative mind of some sort. It uses a known formation as an analog of the unformed.

 

[john 8]

I don't think anyone currently can answer your question with great certainty but can you picture something that has no structure? Doesn't it go against human logic?

If no one can currently answer my question with certainty, than what are you trying to convince me of? This belief that space is a physical thing is just that, a belief. Without any physical evidence it is just fantasy.
This is a science forum, show me some science to back up your claims. Space is not a something so it does not have a structure, so the knowledge that space is nothing does not go against human logic.

What goes against human logic is the idea that space is a physical thing despite any physical evidence and when no one can describe space with any certainty. I say space is nothing and the proof is that this space thing has never been perceived, observed, or codified. There is no proof that space is a thing, believing so is against logic.

Right. A something has a structure. If you want to say that space is a something, then tell me what this something is made of and what would you call that area or location that this space structure is existing in? the area between objects that contain no thing is just that...nothing. Are you going to suggest that there is a structure between you and the computer monitor that you are reading?

There is no evidence about it

Exactly! There is no evidence, so all your talk about this mystery structure is pure fanasy.

but do you think empty space has no "invisible" structure? Empty space is a macroscopic entity, how could anything that engulfs physical objects be non-physical?

The area between things is no thing. Entity made of what? Take a glass jar, put a marble in it, and remove the air out of the jar. Are you saying that there is some invisible entity that is still "engulfing" the marble?

I mean space was created at the Big Bang, it follows physical laws, it gets bent by mass, so what makes you think it's not a thing?

Created from what? Ever seen this bending? Is there any documented scientific observation confirming this bending of this invisible structure?

I know space is not a thing because there is no scientific evidence to confirm this. If space were a thing it would be made of something and yet science has not stated that space is a physical thing. Look at any scientific reference book. You want to prove me wrong then just give some scientific evidence that space is an invisible structure. If this space thing is invisible, what are the physical perceptions that make it known to you?

And if it's not a physical thing, how can it be bent?

If it is a physical thing then just show me evidence of the type of physical thing this space thing is.

Gas?
Solid?
Liquid?
Energy?

This space thing that you believe to exist, does it have an atomic structure?

BTW are you a member at evc?

Yes.

 

[john 8]

Your question about the nature of space has many hidden profound implications. Just to mess up your concepts even further, consider the fact that an atom is 100% empty space, thus matter is also 100% empty space. It's all just force fields directed by the principles of electromagnetism, that interact and form your macroscopic sense of matter and reality. So if matter is space and space is something we cannot perceive as physical, then what is reality and what is physical or "thing" as you put it? You may not like the answer to that question.

There is no scientific evidence to back up what you just said here, but just say what you mean. What are you saying this space thing is made of?