[lightarrow (OP)]

From NewScientists 23 june 2007 "RealityCheck":

[...]

<<What they found(*) is that Leggett's formula is violated as well: even if you allow for instantaneous influences, quantum measurements do not fit with the idea of an objective reality. This is surprising because you might expect that, once any spooky "non-local" action is allowed, you could account for almost any relationship between two particles, and there would be no reason to ditch our concepts of reality. "This is not the case", says Aspelmeyer.

Although some loopholes remain - not all non-local models have been ruled out - we now have to face the possibility that there is nothing inherently real about the properties of an object that we measure.
In other words, measuring those properties is what brings them into existence. "Rather than passively observing it, we in fact create reality", says quantum researcher Vlatko Vedral of the university of Leeds, UK.>>


(*) It refers to an experiment performed by Markus Aspelmeyer e Anton Zeilinger (Nature, vol 446, p 871) to test Leggett's formula (a variant of Bell's inequality, with the additional hypothesis that instantaneous influences are allowed).

[paul.fr]

This is something that has often ruined my day. I have always thought that nothing exists until we give it a name, measure it or physically see it. On the other hand, i know the moon was there before i saw it and may day is a mess and my mind scrambled.

[Bored chemist]

The tides still work during cloudy days.

[lyner]

I can't see YOU! Do you exist?

[lightarrow (OP)]

I can't see YOU! Do you exist?

I have to assume none of you know that when someone asks: "Does Moon exist if you don't look at it?" intends to refer, in allegoric sense, to the argument of objective reality and measurement in physics or philosophy?

[another_someone]

A solipsist would have argued all along that we can only believe something to exist, we cannot know it exists - so maybe nothing exists at all.  Maybe nobody and nothing exists, except as my imagination, and thus if I do not imagine it, then it does not even exist there?

[lightarrow (OP)]

I can't see YOU! Do you exist?

Yes, because it's YOU that don't really exist!  []

[paul.fr]

The tides still work during cloudy days.

Is this supposed to help or hinder me? I can make a fair assumption that the moon exists because of the tides, but if i had never seen the moon would i "know" for sure that it did exist?

I can't see YOU! Do you exist?

Yes, because it's YOU that don't really exist!  []

Do i exist, to you me or others? To you and others i may not exist, afterall i could just be a programme that is running with a very poor spell and grammer checker [] .Do i exist to myself, another one that keeps you/me awake at night. Do i exist am i conscious of my own existence and that of those around me. am i alone in a world that i have subconsciously created for my own amusement, interaction or pleasure...

A solipsist would have argued all along that we can only believe something to exist, we cannot know it exists - so maybe nothing exists at all.  Maybe nobody and nothing exists, except as my imagination, and thus if I do not imagine it, then it does not even exist there?

Spot on George, this is what i will take to my bed. Hopfully i will get some sleep because this subject does disturb both my sleeping and wakened thoughts.

[lightarrow (OP)]

A solipsist would have argued all along that we can only believe something to exist, we cannot know it exists - so maybe nothing exists at all.  Maybe nobody and nothing exists, except as my imagination, and thus if I do not imagine it, then it does not even exist there?

Yes. (I assume I have become a solipsist with this statement?)
I create reality in the exact instant I perceive it.

[Soul Surfer]

You are getting hung up on this prersonification of the "observation" that creates reality.  The fact that water is moving on the surface of the earth is in the quantum sense as much an "observation" of the existence of the moon as a gravitiating object as two lovers going gaga in the moonlight ie the "observers" do not need to be a sentient lifeform.

[another_someone]

You are getting hung up on this prersonification of the "observation" that creates reality.  The fact that water is moving on the surface of the earth is in the quantum sense as much an "observation" of the existence of the moon as a gravitiating object as two lovers going gaga in the moonlight ie the "observers" do not need to be a sentient lifeform.

But what does it mean to suggest that the observers do not need to be sentient?

Yes, you can say that the tides are an observer of the moon, but would the tides themselves actually exist if no human observes them?  If, because no human observes the tides, so we cannot show the tides exist, then how can we say that the tides observe the moon? It is quite reasonable to say that a human need not directly observe something; but if a human plays no part (even an indirect part) in the observation, then does not the whole chain of observation fall down?

Ultimately, the observation is not even something that must be human (for there is no difference in principle between another human being or a cat), but ultimately it must be our own personal observation that must be the ultimate terminal point in the series of observations.

[lightarrow (OP)]

You are getting hung up on this prersonification of the "observation" that creates reality.  The fact that water is moving on the surface of the earth is in the quantum sense as much an "observation" of the existence of the moon as a gravitiating object as two lovers going gaga in the moonlight ie the "observers" do not need to be a sentient lifeform.

But what does it mean to suggest that the observers do not need to be sentient?

Yes, you can say that the tides are an observer of the moon, but would the tides themselves actually exist if no human observes them?  If, because no human observes the tides, so we cannot show the tides exist, then how can we say that the tides observe the moon? It is quite reasonable to say that a human need not directly observe something; but if a human plays no part (even an indirect part) in the observation, then does not the whole chain of observation fall down?

Ultimately, the observation is not even something that must be human (for there is no difference in principle between another human being or a cat), but ultimately it must be our own personal observation that must be the ultimate terminal point in the series of observations.

I agree with you.

[Soul Surfer]

The fossil record shows that tides existed long before there were human or even animal "observers" on this planet.

[lightarrow (OP)]

The fossil record shows that tides existed long before there were human or even animal "observers" on this planet.

Does a low energy photon exist before you detect it?

[another_someone]

The fossil record shows that tides existed long before there were human or even animal "observers" on this planet.

Yes, but this is only so because we can read the fossil records.

If there were no records for us to read, of any kind, then can the events be said to have taken place?

[Soul Surfer]

The fossil records would still be there whether or not we or anything else read them.

The universe is a causal place where things happen and this affects how other things happen so almost everything that happens leaves some sort of record however faint.  Ok the record is often ovewritten by further things happening.

I find it very difficult to imagine any event that leaves no trace of it actually happening.

[lightarrow (OP)]

The fossil records would still be there whether or not we or anything else read them.

The universe is a causal place where things happen and this affects how other things happen so almost everything that happens leaves some sort of record however faint.  Ok the record is often ovewritten by further things happening.

I find it very difficult to imagine any event that leaves no trace of it actually happening.

But what you call "record" is just exactly a "measurement", or, said in a less precise but more intuitive way, an "observation" (this was the meaning of my initial question); so, the question is: does reality exist when it's not measured (from us or something/someone else)?

Now we have moved further and we are discussing if such "measures" have to be recorded from a sentient being or not. My opinion is that someone/something must be aware. Without "awareness", unspecified, there couldn't be any proof of such a "measure".

[another_someone]

The fossil records would still be there whether or not we or anything else read them.

That is an assumption, not a known.  You can only know what you see, and if you cannot see it (or some consequence of it), then it becomes arbitrary to assume it is there.

The universe is a causal place

Is it?  Can we be sure?

Science is about creating a causal model of the universe, but is this really about how the universe works, or how our mind works, and trying to find a way to explain the universe to the human mind?

In fact, there are many aspects of quantum physics that seem to stretch the notion of causality to almost breaking point.

The double slit experiment assumes that a particle can know where it is to travel before it has travelled down the path.  Although there is nominal causality, insofar as we can create a rule that explains the macroscopic features of the experiment, but the rule seems to assume that information travels backwards in time at a quantum level, and so temporarily violates causality.

The EPR paradox assumes that events can happen simultaneously, despite being causally linked, and thus implying that cause and effect need not be separated by time (although this is not as bad as causality happening in reverse time).

Then there is the problem that even under general relativity, two observers in different accelerating fields of reference can observe the same pair of events happening in different sequence.  How then can either observer claim to deduce an absolute notion of causality (assuming that cause must precede effect)?  If there is no absolute notion of causality, then causality can only be a manifestation of the observers reference.

[Soul Surfer]

The truth is that the particle wave duality and entanglement means that ALL particles ALL waves occupy ALL the universe for ALL the time its just that it is extremely improbable that you will find any of them a long way away from where they "are" in space and time.   Bearing this in mind the fact that the particle that goes through one slit is "aware of the existence" of the other slit that is quite close to it is not really a surprise.

Once you have accepted the total connectedness of the whole universe it does not seem so peculiar.

[another_someone]

That only makes sense if you remove the notion of space.

That a particle can exist both here and a million miles away does not alter the requirement for something to be effected a million miles away by something happening here then information has to traverse the million miles between.  That the information is contained within the same particle that spans that distance still does not remove the distance.

The only way of removing that distance is to remove the notion of space (i.e. to assume that space has contracted within that particle, and so information passing from one part of the particle to the other does not actually need to span the distance at all).