Total agreement is a bad thing.

I like it when people disagree. Stops me becoming complacent, and too fixed in my own ideas. The whole issue of the nature of spirits is open: we have really no idea what it's like for them, nor what's in store for us, but our brains are designed to categorize. So we work out a theory and, if nobody disagrees, it becomes entrenched. Sometimes the categories we form need a damn good shakeup.

So it's good to see Southern Writer contesting the points I made in the last post:

I'm thinking there must be more than one kind of ghost, because I don't always find this to be the case (and was glad to see you said, "it's very common," which does not mean it's an absolute, right?)

No, it's not an absolute. The cold part is not universally reported, it's just frequently reported. As I said, it's all conjecture. Nobody has persuaded a ghost to subject themselves to tests. I wouldn't let myself be used as a lab rat, so why should they? It's not even as if we can offer any reward for their services.

It's certainly possible that different ghosts have found individual energy sources they can tap into. One that can make use of emotional energy might well thrive on fear, and would do things to scare people to get their 'fix'. One that could use sexual energy might be labelled 'succubus'. I don't think they're supposed to take energy from the living, but some seem to have worked out how to do that. It's never good when they do.

There's also the possibility that some might visit from that theoretical place where they have all the energy they need. In that case, there would be no chilling of the room. They are, in effect, well-fed.

Let's say for instance, you're out hunting and find a ghost in an old empty house, and it's dressed in something from a hundred years ago. What has that ghost been existing on? Which reminds me of something else I've been meaning to ask you: why are ghosts always dressed? Do you think they still have the same code of decency and shame that the living have? And are they dressed in their burial clothes, or something they particularly liked when they were living?

Lots of questions, to which I have only theoretical answers :)

Even empty houses contain energy; if the ghost can use heat, they might get enough to keep going from the heat absorbed by the stones of the house during the day and released at night. That's a possibility. Plus, if a place is known to be haunted, you can bet it gets visited a lot by the living. We're naturally curious creatures, and we don't like cold, so we'd bring heaters. And a good dose of emotion.

Why are they dressed? Well, let's assume ghosts have some control over their appearance. Most will try to recreate their living appearance. Now, would you appear in front of strangers naked? Remember, the apparition isn't the spirit, no more than a footprint is a shoe. It's a projection produced by the spirit. It can be wearing whatever they choose to think they're wearing. So far, it appears that any individual ghost always appears in the same clothes (think 'lady in grey/white/red type of haunting). Maybe that's their favourite outfit, maybe it's harder to think up a new outfit than to stick with the one they've already devised. Until one of them tells us, we won't know for sure. It's interesting to note that, as far as I'm aware, no investigation has ever questioned a ghost's choice of fashion. Perhaps that should be added to the list of stock questions.

Here's another thing that worries me. Ghosts seem to remain the same age they were when they died. So if I had any plans to get jiggy with an old boyfriend who died when he was 24, and I don't die until I'm 60 or 80, I'll pretty much be s.o.l., won't I?

They're projections, probably from the spirit's memory (my opinion, remember). Their most recent memory of themselves is just before they died, so it's the easiest one to reproduce. Some can project images of themselves when they were younger. I think it depends on individual skill. If they're exceptionally skilled, they might even be able to appear as something other than human.
Don't worry about the ex-boyfriend; unless you plan on taking the succubus route, getting jiggy won't be an issue ;)

I'm not sure I fully accept that ghosts must live by the same laws of physics that we do,

Quite right. You shouldn't accept any 'definitive' view on the subject, because there isn't one. My feeling is that they are subject to some kinds of physical laws, but I can't say for sure what they are. I think they should be subject to the law of conservation of energy but that's based on what my senses tell me. When I'm dead, I might have a completely different range of senses.

They have the ability to walk through walls and yet, wasn't it interesting in that video of the little girl at the top of the stairs walked through a doorway, like the rest of us (which was the most convincing ghost footage I've ever seen, but why are all his other ones so obviously bad imitations?). Anyway, I'm not sure they have to adhere to the laws of gravity, magnetism, centrifugal force, etc. like we do.

I think they walk through walls that weren't there when they were alive, but are (in most cases) restricted by walls that were there in their lives. Again, it might come down to individual skill. Once you go beyond three dimensions, passing through a wall is no problem, as long as the individual ghost knows how to do it. Some of those that float in the air are walking on floors that existed once, but don't now. Some, I think, are entirely free of our three-dimensional limitations. These are the ones who can bring apports, objects transported over long distances in an instant. Theoretically possible, if you have more than three dimensions to play with.

Thinking about multiple dimensions can make your head hurt. I recommend this little book as a place to start. It explains the concept without frying your brain. The link is Amazon UK: you might get it more quickly from a local supplier.

It is entirely possible that everything we think we know about ghosts is wrong. We work with what our senses let us perceive, and it's likely that the dead have different senses. So argue with me. Every new idea is a good one, until we find some way to set down definitive facts. Every passing thought should be considered.

You never know where those thoughts might have originated.