What would constitute proof of a ghost?

[JoeTheJuggler]

Since the theory 'it was a ghost' is the simplest way of explaining the phenomenon, that would be considered true until new evidence suggested otherwise.

Says who?

Says everybody. That's how words work.

Sorry--that's a fail. Show me any support that "everybody" considers the ghost explanation to be the simplest way of explaining any phenomenon.

What if the "ghost" doesn't claim to be a ghost, but to be a human with supernatural power (as in the Indian fakir example)? Your attempts at defining the term would not distinguish between the two, so why would "it was a ghost" be the preferred explanation?

 

[Beth]

So do you consider 'sound' to be material or immaterial then? Is an electrical current material or immaterial?

See my previous answer. Sound is a wave that propagates through a medium (air).

That doesn't answer my questions. I'm still not sure whether you consider 'sound' and 'electrical current' to be material or immaterial. I would guess that you consider them to be 'material' but I'm not certain.

At any rate, it doesn't strike me as much of an objection. Knowing nothing about ghosts or what they are made of, I don't consider it any more unreasonable to claim that ghosts can pass through solid objects like walls simply because humans cannot. Ghosts may be more akin to a sound wave or an electrical current than a human being.

You misunderstand my objection. It's not that the property is something humans can't do, but that it presents a logical contradiction with other properties.

What is the contradiction? I thought is was that if they were material they shouldn't be able to pass through walls. But since material things like sound waves can, so could ghosts.

I don't think that people who claim ghosts exist and are sometimes invisible are using your definitions. I think they are using the term 'invisible' in the sense that sometimes ghosts cannot be seen. Just as water sometimes cannot be seen.

I think you're completely wrong. I think they mean ghosts are invisible by nature--that they can dematerialize. Not that they are translucent or too small to be seen with the naked eye.

Well, no one is claiming they invisible by virtue of being too small. I don't think that the difference between become translucent versus dematerializing is distinguishable by people who claim they've been in the presence of ghosts. All that is claimed is that sometimes they cannot be seen.

You can't claim they are impossible and self-contradictory when you are using different definitions of those words than were intended by the description. Yes.

Seriously, when someone says a ghost is sometimes solid they don't mean that when it's not solid it's either a liquid or a vapor. I think they mean that it is sometimes material (and all 3 states of water are material--ice, steam and water) and sometimes immaterial (which is a logical contradiction). I think you're the one equivocating with the terms invisible and solid.

I agree with Mirrorglass when s/he says: It's perfectly okay to say 'a ghost is immaterial' when what you mean is 'a ghost can pass through walls and is only visible at times'. Most people will understand what is meant from the context.

In that context, I think your definition is narrower than should be assumed.

 

[JoeTheJuggler]

What is the contradiction? I thought is was that if they were material they shouldn't be able to pass through walls.

Yes. The definition includes it having immaterial and material properties.

But since material things like sound waves can, so could ghosts.

I already explained this. A wave is not a material thing. When sound goes through a wall, no molecules are passing through the wall.

I agree with Mirrorglass when s/he says: It's perfectly okay to say 'a ghost is immaterial' when what you mean is 'a ghost can pass through walls and is only visible at times'. Most people will understand what is meant from the context.

That's fine, but immaterial things can't be seen or make sound or have a location or any of the other properties of material things that are given in the definition of ghost. There's the contradiction. It's immaterial and material at the same time.

If a thing is immaterial, what does it mean to say that it passes through a wall? How can something that is immaterial have a location at all much less change location?

Well, no one is claiming they invisible by virtue of being too small.

Under what circumstances are you talking about water being invisible, then? I assumed you meant that as a vapor water is invisible (and that's because the molecules are spread apart, and the particles are too small to be seen by the naked eye). I can think of no other way that water is invisible.

 

[Beth]

Yes. The definition includes it having immaterial and material properties. I already explained this. A wave is not a material thing. When sound goes through a wall, no molecules are passing through the wall.

So you consider, by the definitions you have given, that sound is immaterial? I want to be clear on that. Previously, I was under the impression you felt sound waves were material. Now, with this post it appears you feel that sound waves are immaterial.

That's fine, but immaterial things can't be seen or make sound or have a location or any of the other properties of material things that are given in the definition of ghost. There's the contradiction. It's immaterial and material at the same time.

If a thing is immaterial, what does it mean to say that it passes through a wall? How can something that is immaterial have a location at all much less change location?

If sound ways are immaterial, they are immaterial things that can have location and pass through walls. What is the contradiction you feel is inherent with ghosts that isn't equally contradictory for sound waves?

Under what circumstances are you talking about water being invisible, then? I assumed you meant that as a vapor water is invisible (and that's because the molecules are spread apart, and the particles are too small to be seen by the naked eye). I can think of no other way that water is invisible.

It's transparent. It's easy to look through it and mistakenly think that nothing is there. Kinda of like ghosts, which are sometimes claimed to be around even though we can't see them. If you don't think that water qualifies as invisible because it's transparent, that's okay. We can switch to Mirrorglass's example of the recently invented 'cloaking' material.

 

[JoeTheJuggler]

So you consider, by the definitions you have given, that sound is immaterial?

A wave is a property (or more like a function) of a material, not a thing in itself. It would be like asking if height is material or immaterial. Or if "running" is material or immaterial. A sound wave propagates through material (air or walls or whatever), but not one molecule of any thing is passing through another material.

It's transparent. It's easy to look through it and mistakenly think that nothing is there.

You're confusing transparent and translucent with invisible. Mistakenly thinking something is invisible is not the same thing as invisibility. And you can easily show that ice is not invisible by changing the lighting.

Similarly, you can't see any object in total darkness, but that doesn't mean those objects have the property of invisibility.

ETA: And again, this is not at all what people mean when they speak of a ghost being invisible. It's not that they think if you change the angle of lighting an apparently invisible ghost would become visible. In fact, according to the stories I've read, ghosts are usually said to be invisible in the best lighting and only visible in bad seeing conditions.

 

[Beth]

A wave is a property (or more like a function) of a material, not a thing in itself. It would be like asking if height is material or immaterial. Or if "running" is material or immaterial. A sound wave propagates through material (air or walls or whatever), but not one molecule of any thing is passing through another material.

Okay, so sound waves are immaterial then. Like height or running. Unless you want to claim that those things are material. I know there are hard materialists who post on this forum that do not recognize anything as 'immaterial'. I just want to be clear on your position. You feel that immaterial things exist, like sound waves, electrical currents, etc. Correct?

At any rate, my point is that we don't know what a 'ghost' is and the possibility that it is a sort of 'wave' passing through material is not a self-contradictory notion.

You're confusing transparent and translucent with invisible. Mistakenly thinking something is invisible is not the same thing as invisibility. And you can easily show that ice is not invisible by changing the lighting.

Similarly, you can't see any object in total darkness, but that doesn't mean those objects have the property of invisibility.

No, I'm not confusing the idea, I saying that in this context, the usage of 'invisible' could mean simply translucent and the observer couldn't tell the difference. I think we disagree on whether ghosts are necessary invisible by your strict definition of the term. I think that ghosts could have the property of being so translucent at times that people simply mistakenly think they are invisible.

ETA: And again, this is not at all what people mean when they speak of a ghost being invisible. It's not that they think if you change the angle of lighting an apparently invisible ghost would become visible. In fact, according to the stories I've read, ghosts are usually said to be invisible in the best lighting and only visible in bad seeing conditions.

Yes, but I still think they could be mistaken. Your point only makes me feel that it is improbable that they actually exist. Not that they are a contradiction in terms.

 

[Resume]

Okay, so sound waves are immaterial then. Like height or running. Unless you want to claim that those things are material. I know there are hard materialists who post on this forum that do not recognize anything as 'immaterial'. I just want to be clear on your position. You feel that immaterial things exist, like sound waves, electrical currents, etc. Correct?

At any rate, my point is that we don't know what a 'ghost' is and the possibility that it is a sort of 'wave' passing through material is not a self-contradictory notion.

No, I'm not confusing the idea, I saying that in this context, the usage of 'invisible' could mean simply translucent and the observer couldn't tell the difference. I think we disagree on whether ghosts are necessary invisible by your strict definition of the term. I think that ghosts could have the property of being so translucent at times that people simply mistakenly think they are invisible.



Yes, but I still think they could be mistaken. Your point only makes me feel that it is improbable that they actually exist. Not that they are a contradiction in terms.

Perhaps a call to TAPS is necessary; if nothing else, the nitwit plumbers could
offer some unintended jocularity to this argument.

 

[JoeTheJuggler]

Okay, so sound waves are immaterial then. Like height or running.

No. Read carefully: these things are properties of material things, but neither material nor immaterial themselves.

At any rate, my point is that we don't know what a 'ghost' is and the possibility that it is a sort of 'wave' passing through material is not a self-contradictory notion.

You're saying a ghost is a wave? First, that's not at all how the term is conventionally used, but let's ignore that for a moment. If it's a wave, it's a wave in a medium. That medium must be material, and that material cannot pass through walls. If you make a wave in a rope, for its wave to pass through a wall, the rope would have to pass through a wall.

The wall can be vibrated which creates an analogous sound wave in the air on the other side of the wall (assuming the sound wave can't go around the wall--which is what probably happens most of the time in real life), but the medium doesn't pass through the wall. You can prove this by making a wall around a hard vacuum--sound can propagate through the air to the wall and cause the wall to vibrate, but since there is no medium on the other side, there will be no sound on the vacuum side of the wall.

However, if you want to propose that a ghost is a wave as an operational definition, it's not complete. You'd need to say what it's a wave in (what is the medium) and what measure you could take that would discern it. (That is, what measure would distinguish it from other non-ghost things--so checking random temperature fluctuations or stray changes in EMF readings doesn't do it since those supposedly "anomalous" readings are exactly what you'd get even with no ghosts around.) As I've been saying, if you make an operational definition, then what proof would be required inductively is readily obvious.

No, I'm not confusing the idea, I saying that in this context, the usage of 'invisible' could mean simply translucent and the observer couldn't tell the difference. I think we disagree on whether ghosts are necessary invisible by your strict definition of the term.

Please re-read the thread. I'm not offering ANY definition of the term. I'm only pointing out that in order to answer the question in the OP, the term must be defined--either as a formal logical definition (for deductive proof) or operationally (for inductive or experimental proof). A formal logical definition is a list of all the characteristics or properties of a thing that will include what you mean and exclude what you don't mean. That's why your approach to "invisible" is wrong. These are intrinsic characteristics of the thing.

Again, in the dark, a book is invisible, but you wouldn't consider "invisible" to be a characteristic or property intrinsic of a book.

I think that ghosts could have the property of being so translucent at times that people simply mistakenly think they are invisible.

Where to start with this? First, "so translucent at times that people simply mistakenly think they are invisible" is another way of saying "not invisible", isn't it? Second, this is not at all what people mean when they talk about invisible ghosts. They mean some kind of spirit or "person" that is completely disembodied. (Think, for example, of a poltergiest.) They do not mean something that you could see if you shined the light a certain way (which is the case with any degree of translucency or transparency).

Your point only makes me feel that it is improbable that they actually exist. Not that they are a contradiction in terms.

Again, read the thread. I'm not arguing pro or con on their existence. For something that is well-defined but doesn't exist, we can answer the OP's question. (If we define Bigfoot as a hitherto unknown species of great ape indigenous to North America, it's very easy to say what would constitute proof of its existence, even though it doesn't exist.)

However, the conventional usage of the term ghost is logically inconsistent. (It's usually considered to be a person who is discorporate, immaterial, or disembodied but that exhibits material characteristics--can be seen, can make sound, etc.)

The best anyone can do is what you and Mirrorglass are doing which is to offer an operational definition of "ghost" that is far removed from conventional usage. As I've said, it would be akin to saying that we operationally define "intelligence" as something that can be discerned by measuring height. You could do that, but anytime you said anything about "intelligence" you'd have to explain that you're using it as a construct radically different from any conventional usage, otherwise people would misunderstand.

So you could re-define "ghost" (contrary to conventional usage) as being something material, or a wave in some specified material medium. In that case, it would be easy to say what would constitute proof. The specifics of the definition would point to the measurement we'd need to get to prove its existence. Then, if someone gets hold of a ghost and performs the specified measure, you'd have proof of its existence.

Similarly, if you define Bigfoot as I have, all you'd need is a tissue sample with good DNA to have prove of its existence.

 

[Dmarie]

Perhaps a call to TAPS is necessary; if nothing else, the nitwit plumbers could
offer some unintended jocularity to this argument.

If you look at the "Articles" section of the main TAPS website, they catagorize ghosts as: Demonic, Poltergeist, Intelligent, and Residual.

I guess that ends the debate, eh?

 

[P.J. Denyer]

Because there are so many ghost stories and so many of them contridict each other in the details I don't think it's possible to make one comprehensive definition of ghost that will cover every possible ghost story, particually if you want to catigorize poltigeists and dopplegangers etc as ghosts. That in itself doesn't necesasrilly rule them out as it could be a term which covers a number of phenomina. I would even suggest that a ghost isn't a thing so much as an event.

My attempt-:"A ghost is an event in which a previously living entity who is, or may be reasonably assumed to be, deceased spontaniously interacts with the current environment in a detectable manner for a limited period in the absence of, or in addition to, their known physical presence".

 

[Kahalachan]

A ghost has to demonstrate human intelligence before I come anywhere near considering it a once dead human.

 

[P.J. Denyer]

A ghost has to demonstrate human intelligence before I come anywhere near considering it a once dead human.

I think that would be an unusual criteria, most of the 'real' ghost stories I've heard concern apparitions that repeat the same actions over and over again, day after day, night after night, year after year. Hardly a sign of intelligence (looks around office... ummmmmmm.... )

 

[Resume]

If you look at the "Articles" section of the main TAPS website, they catagorize ghosts as: Demonic, Poltergeist, Intelligent, and Residual.

I guess that ends the debate, eh?

The plumbers seem to think so.

 

[JoeTheJuggler]

My attempt-:"A ghost is an event in which a previously living entity who is, or may be reasonably assumed to be, deceased spontaniously interacts with the current environment in a detectable manner for a limited period in the absence of, or in addition to, their known physical presence".

Again, this is at odds with most conventional usages of the term, but would be a decent start for an operational definition.

If you specify how it's detectable and distinguishable from non-ghost causes of the same measures, then you'd have an operational definition, and it would be abundantly clear what would constitute proof. But that's a huge "if"! If you only say it's detectable by producing measurements that are the same as we'd expect in the absence of a "ghost", you haven't provided an adequate operational definition.

[ETA: This is what most ghost-hunters do. They say random fluctuations in measures of temperature or EMF or whatever is a measure that detects a ghost. But since this is indistinguishable from measures we'd expect without a ghost, it is not an adequate operational definition.]

And your separating out the "entity" and the "event" doesn't do anything at all, does it? In fact, you're just using "ghost" as a synonym for "haunting" or something like that, contrary to conventional usage where a ghost is the entity and the event is a haunting.

FWIW, you'd also have to specify that it's a deceased person, because I am a previously (and currently) living being who fits all the other characteristics, yet I am definitely not a ghost. And this is why such definitions fail instantly in terms of logic. You'd be saying it has the property of being dead and the property of being alive. This is a logical contradiction. That's partly why most people who believe in ghosts say that it is immaterial (a soul or spirit or some non-physical thing) because they can't get around the fact that there's no part of the body that survives death. And they run headlong into the primary logical contradiction I've been talking about that something can't be both immaterial and material.

 

[Beth]

Okay, so sound waves are immaterial then. Like height or running.

No. Read carefully: these things are properties of material things, but neither material nor immaterial themselves.

Excuse me, but are you now claiming there are three classes of things: Material, immaterial and neither? And you classify things like ‘waves’ as neither material nor immaterial? How do you know that ghosts could not be like waves that are neither material nor immaterial?

At any rate, my point is that we don't know what a 'ghost' is and the possibility that it is a sort of 'wave' passing through material is not a self-contradictory notion.

You're saying a ghost is a wave?

No, I’m saying that we don’t know what a ghost is and a wave is one possibility. And that possibility removes the contradiction that you have been claiming exists with the description. Even if not a wave, a ghost is could be some other thing that is neither material nor immaterial according to your definitions.

I think that ghosts could have the property of being so translucent at times that people simply mistakenly think they are invisible.

Where to start with this? First, "so translucent at times that people simply mistakenly think they are invisible" is another way of saying "not invisible", isn't it? Second, this is not at all what people mean when they talk about invisible ghosts. They mean some kind of spirit or "person" that is completely disembodied. (Think, for example, of a poltergiest.) They do not mean something that you could see if you shined the light a certain way (which is the case with any degree of translucency or transparency).

I disagree. I think they simply mean that they can’t see it. Whether it is invisible by your definition or invisible by the more common “I can’t see it”, the meaning should not be assumed since it is ambiguous. Therefore, I don’t think it’s logical to conclude ghosts are inherently contradictory. You only get that contradiction by assuming a meaning of invisible that may not be correct.
Look, I’m starting to feel that we’re simply repeating ourselves. I feel I understand what you are saying, I simply disagree with your insistence on certain narrow definitions of terms like ‘invisibility’.


I rather like the idea of categorizing a wave as being neither material nor immaterial, but it’s a rather unusual classification system. Most people insist that everything must be either material or immaterial. At any rate, thanks for sharing your point of view and thoughts on the matter.

 

[P.J. Denyer]

I did specify it was deceased Joe!

I think that the distinction between entity and event is significant as there are claimed ghosts which are only observable by their actions and are not themselves seen but rather implied. But I could have phrased it differently.

The method of detection would depend on the claimed charateristics of the ghost, but yes they would have to be different to what you would see if there was not a ghost present, if they weren't I don't think the word 'detectable' would apply. In asking for the method of detection to be specified I think you are moving into the area of test protocol rather than working definition after all we could define telepathy without reference to whether we were going to try and send words, pictures or the death screams of baby rabbits couldn't we?

I think specifying that the interaction is by a dead entity in the absence of or in addition to their known physical presence pretty much covers the bases of non ghost causes, the details of how you establish this is protocol. Once you establish any other cause (draught, thermal expansion, fraud, next doors radio etc) the ghost is falsified. But again it would depend on the attributes of that claimed ghost.

 

[JoeTheJuggler]

Excuse me, but are you now claiming there are three classes of things: Material, immaterial and neither?

No. I said that a wave is not a thing but a characteristic or function of a thing. Please re-read my post if you're still confused.

Height is also neither material nor immaterial but rather a property of a thing.

How do you know that ghosts could not be like waves that are neither material nor immaterial?

This is more repetition. I've already answered this question.

If a ghost is a wave (or some other property of a thing), the the existence question is about the thing and not the property. But calling a ghost a property of a thing (or a wave in some medium) is contrary to conventional usage. Also, that medium would not be able to pass through a wall.

No, I’m saying that we don’t know what a ghost is and a wave is one possibility.

Please re-read the thread. The main point I have been making is that if you can't define the term ghost, then we can't answer the question asked in the OP. Do you disagree?

 

[JoeTheJuggler]

I did specify it was deceased Joe!

No, you didn't. You said "previously living". I am something that was previously living (and in fact still living). I know, it's just a minor quibble over the wording, but if you're attempting to make a formal logical definition or an operational definition, you do have to be very careful.

I think that the distinction between entity and event is significant as there are claimed ghosts which are only observable by their actions and are not themselves seen but rather implied. But I could have phrased it differently.

Again, though, even if you can only see the actions of the thing, the thing is not equivalent to the actions.

The method of detection would depend on the claimed charateristics of the ghost,

And that's exactly the point I've been making for this entire thread. The OP asked, "What would constitute proof of a ghost?" My response was that you have to define the term ghost (and I specified that it means a list of the characteristics or properties such that in includes what you mean and excludes what you don't, or an operational definition that specifies the measurements).

but yes they would have to be different to what you would see if there was not a ghost present, if they weren't I don't think the word 'detectable' would apply.

Yes, that's what I said. So what are these measurements? Most ghost hunters miss this point and claim that temperature fluctuations or other readings are the same as detecting a ghost even though the measurements are no different than we'd expect in the absence of a ghost.

In asking for the method of detection to be specified I think you are moving into the area of test protocol rather than working definition after all we could define telepathy without reference to whether we were going to try and send words, pictures or the death screams of baby rabbits couldn't we?

I noted in this thread that the OP's question has a bit of ambiguity--"proof" can refer to a deductive logical proof or inductive, experimental proof. If the former is meant, then the definition provided must be a formal logical definition; if the latter, then we need an operational definition which specifies the measurements that need to be taken.

I've said this several times now. It seems that any attempts at a logical definition of the term ghost based on conventional usage of the term fail since they include logical contradictions and the OP's question is the same as asking, "What would constitute proof of a 4-sided triangle?"

It seems that what people are trying to offer instead are various kinds of operational definitions, but no one has gotten specific enough in their definition for us to answer the OP's question. And I've been noting that these operational definitions are using a version of "ghost" that is not at all like conventional usage of the term.

The issue of a dead person somehow having characteristics of a living person is more like a logical definition than an operational one (again, any measure of something that is a characteristic of a living person wouldn't then distinguish this sort of "ghost" from a living person). And of course it's logically flawed. A thing can't have the characteristics dead and not-dead. Same as with material/immaterial, visible/invisible, etc.

 

[P.J. Denyer]

No, you didn't. You said "previously living". I am something that was previously living (and in fact still living). I know, it's just a minor quibble over the wording, but if you're attempting to make a formal logical definition or an operational definition, you do have to be very careful.

I actually used the word 'deceased in the definition, mate! I included the 'reasonably assummed' to cover situations where the claimed entity can't be resolved to an individual or where the individual has to be assummed to be dead, eg: an un-named roman soldier or someone who went down with the Titanic and whose body was never recovered.

Again, though, even if you can only see the actions of the thing, the thing is not equivalent to the actions.

How about waves or echos? Some people claim ghosts are analogous to one or other of these things. Dropping a rock into a pond creates a wave that can be recorded, verified and measured but the wave is not the rock.

Incidentally, you said previously that I was substituing 'haunted' for 'ghost', this felt wrong but it took me a bit of thought to clarify why in my own head. I would draw a distinction between the two on the basis that a location where 'ghostly events' occur is said to be haunted outside of the specific times when said events are occuring.

And that's exactly the point I've been making for this entire thread. The OP asked, "What would constitute proof of a ghost?" My response was that you have to define the term ghost (and I specified that it means a list of the characteristics or properties such that in includes what you mean and excludes what you don't, or an operational definition that specifies the measurements).

The actual characteristic to be measured would depend on the ghost that someone claimed existed at the site being investigated, unambiguous video/audio recordings, confirmed movement of objects under genuinely controlled conditions would be a good start.

Yes, that's what I said. So what are these measurements? Most ghost hunters miss this point and claim that temperature fluctuations or other readings are the same as detecting a ghost even though the measurements are no different than we'd expect in the absence of a ghost.

I agree 100%, I think most of them could do with a bit more time reading the manual for that EMF reader they're waving around and less time watching 'Ghostbusters'!

I don't think anyone will ever prove the existance of ghosts as an independant phenomina, because I don't think that they exist.




Sorry, I'm a bit short of time otherwise I'd go through the rest of your post point by point.

Believers in ghost believe that it is a real world phenomina that contridicts 'scientific dogma' (yes I know....), saying that something is impossible therefore becomes pointless because the 'as far as we know' excuse comes into play.

Incidentally, your point about something being dead but having characteristics of being alive being impossible is wrong, a simple example is the old 'frogs legs and an electrical current' example. Newly dead but definately dead and showing charateristis of life, it wouldn't contitute a ghost of course!

I don't believe you can logically define ghosts out of existance anymore than you can define gods out of existance (beyond the 99.9%rec) because that whole 'you can't prove a universal negative' thing keeps coming back to bite us on the ass. Hence I've tried to come up with a usable definition that excludes anything that isn't a ghost. So far as I know no-one claims to know the precise physical charaterists of a ghost, rather they claim it is a genuine phenomina that cannot be currently explained, this isn't unknown by science, many things have been discovered or infered from their effects before they themselves were known and things have been accepted as existing long before they were understood or measured.

I think my definition excludes anything that would not generally be classified a ghost, but if you can think of something that would fit the definition that you wouldn't consider a ghost, I'd be interested in hearing it so I could try and close the 'gap'.

As with our old friend the 'God of the Gaps' it's an unending struggle, they keep puttin' them up, we keep knocking them down!

 

[JoeTheJuggler]

I actually used the word 'deceased in the definition, mate!

Fair enough, but it wasn't in part of the definition of the object, but rather about the belief of observers. You didn't specify that the thing is deceased. You said it was previously living and it may be reasonably assumed to be deceased.

How about waves or echos? Some people claim ghosts are analogous to one or other of these things. Dropping a rock into a pond creates a wave that can be recorded, verified and measured but the wave is not the rock.

Exactly. Please see my posts to Beth regarding the idea of a wave traveling through something. A wave is not a separate thing from the medium. In your pond analogy, the wave is merely a parameter or characteristic of water, which is a thing.
[ETA: So you might say the wave in a pond travels from the point where the rock hit the water to the edge of the pond, but in fact there is no molecule of water that makes that journey. The water molecules only go up and down in a wave pattern. When a "wave" cheer travels around the stadium, the spectators don't travel around the stadium; they stay at their seats.]

Incidentally, you said previously that I was substituing 'haunted' for 'ghost', this felt wrong but it took me a bit of thought to clarify why in my own head. I would draw a distinction between the two on the basis that a location where 'ghostly events' occur is said to be haunted outside of the specific times when said events are occuring.

I have no idea what you're talking about. You said you thought a ghost was an event and not a thing. When you tried to elaborate you said it's because sometimes the only observable phenomena are the actions of the ghost. That doesn't mean a ghost is an event. In a way, you could say the same about anything. When you see a book, light from a source reflects off the book and is sensed by light-sensitive cells in your retina that send a neural signal to the brain. You could say you're only seeing the characteristic of the book (its ability to reflect light) rather than the book. This doesn't make a book an "event".

Similarly, we only detect a number of subatomic particles by the traces they leave. Yet we consider particles to be things and not events.

The actual characteristic to be measured would depend on the ghost that someone claimed existed at the site being investigated, unambiguous video/audio recordings, confirmed movement of objects under genuinely controlled conditions would be a good start.

So you're saying you can't define a ghost until you have one. Without defining ghost, how do you know you have one?

You don't know what a ghost is until you detect one, yet you can't say what measure or detection can let you know a ghost is there without defining what a ghost is so you know what measures will tell you that you have one.

So how would you answer the OP's question? "It depends"? If so, I agree with you. As I've been saying all along, it depends on how you define ghost. You seem to think that there is a different definition of ghost for each instance of a ghost, which isn't how language (or logic or science) works.

I don't think anyone will ever prove the existance [sic] of ghosts as an independant phenomina [sic], because I don't think that they exist.

I've addressed this point several times before as well. Bigfoot doesn't exist, yet if you gave a valid definition, I could still answer the question, "What would constitute proof of a Bigfoot?"

Believers in ghost believe that it is a real world phenomina[sic] that contridicts [sic] 'scientific dogma' (yes I know....), saying that something is impossible therefore becomes pointless because the 'as far as we know' excuse comes into play.

"Scientific dogma"? At any rate, now you seem to be agreeing with what I've been saying: that most conventional definitions of ghost include a logical contradiction. If a thing doesn't obey the rules of causality, then there is no way you can say what would constitute proof of its existence.

Incidentally, your point about something being dead but having characteristics of being alive being impossible is wrong, a simple example is the old 'frogs legs and an electrical current' example.

Nope. You're just committing the composition or division fallacy (depending on which way you look at it. Basically the whole doesn't have to have the characteristics of all its parts and vice versa. Because a frog is dead doesn't mean all its tissues are dead.

Newly dead but definately [sic] dead and showing charateristis [sic] of life, it wouldn't contitute [sic] a ghost of course!

Yes. So this talk about a dead organism with living tissue isn't relevant to ghosts anyway. When people talk about ghosts as disembodied and so on, they don't mean anything like the resurrection or reanimation of the body. (That's usually covered by the term zombi.)

This is very similar to the point I keep making that when people talk about a ghost as being sometimes invisible, they don't mean it's a material object that is so translucent that it appears invisible unless you change the angle and degree of the light.

I don't believe you can logically define ghosts out of existance [sic] anymore than you can define gods out of existance [sic] (beyond the 99.9%rec) because that whole 'you can't prove a universal negative' thing keeps coming back to bite us on the ass.

If the definition of a term contains a logical contradiction (as in a 4-sided triangle), then by definition the thing can't exist.

I'm not sure what you mean about "you can't prove a universal negative", but I assure you that it is completely logical to prove a negative. Here's a simple example:

If P then not Q.
P.
Therefore not Q.

I think what you mean is that you can't inductively prove that something doesn't exist by the failure to find an example of one. (A single example of a black swan can prove that the statement, "There are no black swans" is false, but you can't prove that there are no black swans inductively by not finding one since it's impossible to search every place in the universe quick enough to rule out a black swan.)

Here's a decent essay on this issue: http://skepticwiki.org/index.php/"You_Can't_Prove_a_Negative"

Basically, "you can't prove a negative" is only valid for inductive/experimental reasoning and not deductive logic. We can indeed prove that 4 sided triangles are impossible.

That's why I limit the issue of logical contradiction in the definition to matters of deductive (not inductive) proof. I don't think it so much as proves the non-existence of something as it merely notes the contradiction. How else could you answer the question, "What would constitute proof of a 4 sided triangle?"

I can indeed show the same sort of logical contradiction in many (most) conventional definitions of the term God and in the definition of ghost based on conventional usage.

Hence I've tried to come up with a usable definition that excludes anything that isn't a ghost. So far as I know no-one claims to know the precise physical charaterists [sic] of a ghost, rather they claim it is a genuine phenomina [sic] that cannot be currently explained, this isn't unknown by science, many things have been discovered or infered from their effects before they themselves were known and things have been accepted as existing long before they were understood or measured.

This is an argument from ignorance. The fact that a phenomenon can't be explained doesn't prove that any particular explanation (as in "it's a ghost") is true.

As with our old friend the 'God of the Gaps' it's an unending struggle, they keep puttin' them up, we keep knocking them down!

Funny you mention this. God of the Gaps is another example of an argument from ignorance.