john 8 said:
The concept of space. This thread is dedicated to the question "Is space real".
This first sentence from your statement talks of space as a concept. In this universe we deal in those things that are either real or imagined (a concept).
So far you say space is a concept.
If something can be bent in this physical universe then it has some sort of physical structure.
In your next sentence you say space can be bent, so now you are talking of space as though it is a physical thing.
Now you say space is a physical thing.
This is a great example of the total indecisiveness that people who want to describe space put forward as an answer to what space is. To sum up what you just said:
So you say space has no atomic structure in the first part of your statement, and in the rest of the statement you say that it does have a structure.
This is a classic no answer. You my friend have not answered the question "Is space real?"
It looks like you are going to have to make up your mind, pick a side. Is space a real physical thing or not? A simple Yes or No.
This "nothing" that you say is expanding, what is it expanding in? What would you call this medium that this nothing is existing and expanding in?
Wow! How profound. Someone said this. You really drove your point home with this scientific proof.
Seriously, see if you can use all of the resources available to you and come up with a definitive answer to this space question. Is space real?
I know this will hurt, but you need to change your view of "real" and "physical". Let me start by quoting Werner Heisenberg and then i'll explain my viewpoint in more detail:
"I think that modern physics has definitely decided in favor of Plato. In fact the smallest units of matter are not physical objects in the ordinary sense; they are forms, ideas which can be expressed unambiguously only in mathematical language."
Now if you are still comfortable with the idea of me killing your notion of reality, read on. The naive realists once thought matter was composed of indivisible chunks. With the birth of modern physics, it was found that elements aren't so elementary after all. In fact, it was determined, elements are actually made of smaller pieces called 'atoms.' With atoms, scientists figured out things that were mysteries before. Before atoms, no one really knew where heat came from; after, it was figured out that atoms move, and this motion releases energy - "Heat". Atoms were still 'stuff,' but they introduced a new view of stuff. Far from being solidly fixed in space, just sitting there, atoms were feisty little critters, always moving about. This is of serious concern to the naive realist, whose solid wall is no longer just standing there, but teeming, pulsating, moving. It certainly doesn't seem to be moving, and naive realists are certain that what seems to be, is.
Another cherished assumption atoms do away with is the idea of things separate from each other. When the scientist looks at the atomic level, there is no boundary, no absolute dividing line separating one thing from another. When my hand touches the wall, there is a point at which one cannot say whether a particular atom belongs to the wall, or to my hand. When my hand is not touching the wall, there is a point at which one cannot say whether a particular atom belongs to my hand, or the air around it. Atoms are continually joining and leaving. Our sense of smell, for example, is actually the detection of molecules floating through the air from what we are smelling. When we say that we smell a rose, if we mean (as the naive realist does) that we are actually smelling the rose, we are wrong; atoms from the rose are constantly streaming out into the air, and some of them land inside our nose. It is those atoms, which can no longer be said to be part of the rose, that we smell.
Zoom in a bit more and you'll be in for a surprise - there is more empty space than "stuff" there. In fact what you call matter is composed of 99.999% empty space where subatomic forces(electromagnetism + the strong nuclear force) form your perception of matter, solid objects and reality.
By this time, the idea of 'stuff'--especially solid, motionless stuff--is completely dead. Anything you look at has more empty space in it than stuff. I'm not even talking about space that has only air in it: air, too, is stuff that is mostly empty space. I'm talking space that has no stuff in it.
Now that you might be re-thinking your idea of "reality", "real" and "physical" we may sit down and discuss what space is made of and why string theorists think space is also composed of strings. But first we need to define the idea of our perceived reality in some way so we can try and discern its constituent parts.
From the moment you are born till the moment you are dead, you perceive this said "reality" via a mental picture. Anything and everything that will ever happen in your lifetime will be mental pictures inside your mind, giving you the impression that there is a reality out there independent of the mind. Couple that with the fact that all particles exist in superposition of eigenstates in multiple places all at once before they decohere, and you have a completely new picture of "real" and "reality". This view is called solipsism and is widespread among modern physicists who believe the universe is a projection of the mind. Now is a good time to address your question what the universe is expanding into. But something tells me by now you should already know the answer. Or else, you can stick to the commonly accepted notion that space isn't expanding into anything, as it's the only thing that exists. Whatever "exists" means in that theory.
And the final question:
It looks like you are going to have to make up your mind, pick a side. Is space a real physical thing or not? A simple Yes or No.
Space is as real and physical as anything else that you call real(that's a BIG SIMPLE YES).
But if you want to go deeper, you should ask "What is real? How do you define real?"
If you are talking about your senses, what you feel, taste, smell, or see, then all you're talking about is a mental picture. And the next logical question would be - "what is the nature of the existence of this mental picture?". And here you might be treading into physicist David Bohm's territory whose theory says the whole universe is a hologram and space and the separateness of matter is merely an illusion. Thus he says, the entangled particles that seem to exchange information instantaneously over distances of tens of light years away, are not separate but are one and the same particle projected by the Holographic paradigm. The holographic principle states that space and time are not fundamental and the latest renditions of String theory all point to a holographic universe. You might want to have a look at the official site of string theory:
"This is a hint that perhaps spacetime geometry is not something fundamental in string theory, but something that emerges in the theory at large distance scales or weak coupling. This is an idea with enormous philosophical implications."
http://www.superstringtheory.com/blackh/blackh4.html
From wiki:
"Since its birth as the dual resonance model which described the strongly interacting hadrons as strings, the term string theory has changed to include any of a group of related superstring theories which unite them. One shared property of all these theories is the holographic principle."
http://en.wikipedia.org/wiki/String_theory
"The holographic principle states that the entropy of ordinary mass (not just black holes) is also proportional to surface area and not volume; that volume itself is illusory and the universe is really a hologram which is isomorphic to the information "inscribed" on the surface of its boundary"
http://en.wikipedia.org/wiki/Holographic_principle
