Let me touch on the ultimate level first.
At the ultimate level, there is no boundary (red thread) between me and you. There is an experiment that bring to the birth of quantum physics.
The very famous experiment that bring Atom as particle (world consists of particles) to the dustbin is in this link:http://www.youtube.com/watch?v=wEzRdZGYNvA
In that experiment, if you explain 1 phenomena with particle, you cannot explain another phenomena. But if you use wave, you can explain the unexplainable phenomena, but you cannot explain the previous explainable phenomena.
So, does particle exist or wave exist? THey can't find any conclusions.
If you see the later part of that video, it explains that THINGS CAN EXIST ONLY DEPEND ON THE OBSERVER.
This is what Buddhism term called Relative Truth.
In the sky there is no North, East, West, South. But some believe it exists. They argue it exists because my compass can show me there is NSEW. But, simply because your compass show NSEW it doesn't mean there is NSEW in the sky. It is in fact on the other hand, because ONLY of compass, we can have NSEW. Outside compass, the sky doesn't have NSEW.
So it is very clear here: Things can only exist depends on your instrumentation tools, or observers.
You use different tool, you get different object.
The idea that world consist of particles has gone to the drain.
Atom or electron, or whatever they are, cannot exist.
THey can exist only depending on the observer (or our experiment tools). When thing only depend on the observer, that thing is actually simply our model to explain phenomena. We use that phenomena to explain other phenomena.
This is the problem with human. Because this model can explain other phenomena, they think it is real and exists. So, they believe it and say "THERE IS SOMETHING IN THE WORLD THAT EXISTS."
They forget that their experiment is simply at the small scale. If they do it for the big scale (for all phenomena), their theory simply falls apart and goes to the drain.
Well, let's go back to buddhism.
At the ultimate level, then it is very clear that nothing can exist like what we think. It is inexpressible. You think it is particle, OK you are correct, but only depends on your instruments. But, if we say everything is particles, Oh Sorry no way man.
Ajahn Chah mentioned in his book "A still forest pool", there is no way we can explain the taste of mango. Reality is not for us to explain and comprehend by words. We cannot get the essence of buddhism from the words in Tripitaka. The words inside Tripitaka simply to limited to explain the real meaning what Buddha wants to convey. As we know, contemplation and Vipassana meditation are the key to penetrate that words limitation.
(Sometimes, I am quite surprise as well when I see somebody use 1 quote from this sutta or other quote from other suttas, just to show their stand. Ok you are correct, but limited to this exclusive forum, outside this forum, ehmmmmmmmmm. You know what I mean)
Although we cannot explain the phenomena, it doesn't mean we get lost. We can be very stable and very clear with understanding reality (ultimate truth). Like we eat a manggo, although I cannot explain the taste by words, I can get the meaning exactly through the experience eating manggo. THat is why reality can only be experience NOW and if we are mindful without involved in concept. I like to say it that we can only understand the phenomena during Naked Awareness, nothing involved, just experience nakedly as what it is. When we eat the manggo, and if we try to conceptualize the taste, we get lost inside the thoughts, and we lost the taste of manggo. We can describe the taste of manggo, but by simply reading it, I don't know what is the taste if I don't eat it.
If we want to know reality, Reality is not for us to be explained by words, but for us to be experienced.
I like to think this world consists of in terms of "energy flux", where is can manifest in any forms depending on your instruments. Like Einstein theory E = mc2.
Is energy a mass or mass is energy? It can be both. Energy can be in the form of heat, kinematic, etc. So, when I combine them, is mass a heat or kinematic? It can be anything. You like it? You are correct. You don't like it? You are also correct.
There is no red thread that can capsule the thing at 1 single entity. The word called entity is actually also wrong because if no entity can exists, the word called entity is a fantasy and irrelevant.
Come back to the relative truth.
Since ultimate truth show that nothing exist as inherent existance, by right nothing can be communicated. Because whatever you communicate, it is wrong. There is no way what we say can refer to reality, because that reality is inexpressible.
We need to use relative truth however, just for the sake of communication. THis relative truth is true on 1 place or 1 condition (depending) on the observer. On other place or condition that relative truth is wrong.
If we use relative truth and assuming it is valid everywhere, we will get lost. Only ultimate truth (THere is nothing can exist inherently) is correct in any conditions.
Does atom exist? Relative truth: Yes and No. Ultimate truth: never.
Does wave exist? Relative truth: YEs and No. Ultimate truth: Never.
Thinking this world consists of particle? Yes, you can. But soon or later, you will get lost.
Thinking there is existance in this world? Yes, you are welcome. But soon or later, you will also get lost.
If I can answer your question in the relative term:
"Could it be that we are not separated from each other?"
Yes, we can, but only AS IF separated.
To me, answering Yes. We can separated, doesn't reflect reality. But, in daily life, everyone say that, and no wonder many of them, get lost in their own thoughts. As long as we can know, it doesn't matter we say yes, we are separated.
If I can answer your question in the utimate term:
"Could it be that we are not separated from each other?"
No, I and you are connected. THere is no red thread between you and me. If I or you get sick, we will be affected to some extend, etc.
BTW, DOn't trust me, you can think it is new age, or Upanishads, or not buddhist view or not Theravada view or not Mahayana view, or whatever, you are correct.
Because i am sleeping while I am writing.