I ain’t ‘fraid of no ghost…

I actually have a theory. It might be shit – and not funny - and just as difficult to prove as ghosts themselves…but here we go.

Although I don’t believe in ghosts, I believe that people have seen things they can’t explain – even images of people and things from the past.

Here’s how I think it might work…

The definition of an ‘echo’ is:

‘ the repetition of a sound resulting from reflection of the sound waves, a reflected television or radio or radar beam, an imitation or repetition.’

Now we know and can measure such echoes concerning sound…but what about light? What if there are certain hitherto unknown atmospheric conditions that can record, reflect and ‘beam back’ light images into a recognisable form? Due to the vast speed difference between light and sound, this could have a adverse affect on the timescale of the ‘echo’?

This could also possibly explain the ‘repetitions’, the 'see-through' appearance of 'ghosts', and due to environmental and structural changes, suggest why the ‘ghosts’ can sometimes appear to ‘walk through walls’; why they do not acknowledge or communicate, and usually appear to be doing relatively mundane activities like just standing there or walking along, like they may have been doing 50 years ago when the ‘echo’ was snapshot?

/discuss

*prepares for flaming*

*goes back to puns and mimsy-related posts*
( Pooflake braces for an onslaught..., Thu 3 Jul 2008, 12:30, 14 replies)

...
Not sure about this: after all, sound waves are pressure, and light waves are electro-magnetic. So the behaviour of one won't tell us about the behaviour of the other. Moreover, even if light could "echo" in the way you suggest, the signal would diminish in a tiny amount of time - imagine sitting in a dark room with a torch when you switch it off: the light doesn't fade as it bounces about the room. It's just too quick.

You're right, though, to suppose that there is a straightforward explanation for all this stuff - even if it's one on which we never stumble. "I don't understand what I saw therefore it was a ghost" boils down to "I don't understand what I saw therefore I do" - which is, clearly, incoherent.

EDIT: I guess Dr K6 and Dr Forgot her Password - and maybe Dr Crow - are your people here. They're, like, proper scientists.
( Enzyme is powered by sunlight, Thu 3 Jul 2008, 12:40, closed)

Spooky..
When I saw 1 reply, I just *knew* it would be from Enzyme....
( Madam Marlboro wonders if you've found her yet, Thu 3 Jul 2008, 12:55, closed)

that just won't work in so many ways
e.g. light is faster, so the timescale would be shorter.

To get a year delay you'd need an optical path a (heh) light year long. For six years, it'd have to (in effect) travel to Alpha Centauri and back.

Unless you want to posit a nearby group of atom-trapping physicists with some kind of slow-light holographic storage system and a tunable recurrence time. Has anybody seen such a thing near their ghost sightings? Should be easy to spot ... especially by the impressive blizzard of publications in PRL and Nature Physics appearing shortly thereafter.

Alternatively, I could nip downstairs to the Centre for Cold Matter's labs and try to see if there's an unexplained spectral presence.
(haberman is singing in the changes, Thu 3 Jul 2008, 12:56, closed)

@MM
Awww... thanks.

*hugs*
*kidnaps*
( Enzyme is powered by sunlight, Thu 3 Jul 2008, 12:58, closed)

Although it's been covered already
I'll give it a shot. The reason that doesn't work is that your "light echo" is, in fact, a reflection. You experience that ever time you look into a mirror.

We can experience an echo because sound travels fairly slowly. Light travels at approx. 186,000 miles per second- far too fast for there to be an appreciable delay between transmission and perception of the reflection. (It can be detected, of course- but only by electronics that are far more sensitive than our own senses.)

Sorry, the theory doesn't work.
( The Resident Loon Not a demographic. Do not measure., Thu 3 Jul 2008, 13:10, closed)

I was going to explain why this can't be
but everyone else has done it already.

I blame dark matter myself...
( K2k6 has a proper job these days, Thu 3 Jul 2008, 13:29, closed)

Ah, my learned friends...

Of course the theory is incorrect using what we can currently prove about physics etc.

This is why I used such phrases as 'hitherto unknown'...

A wise man knows that he knows nothing...a fool is the one who doesn't question etc etc.

Douglas Admas said that there is a theory which states that if anybody ever discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.

Hawking's Unified theory of everything on multiple universes and dimensions can't be conclusively proved...yet.

So who's saying that they're any smarter than me?

eh?....eh?...

oh
( Pooflake braces for an onslaught..., Thu 3 Jul 2008, 13:57, closed)

hey!
*reminds Enzyme that Dr CHCB is a proper scientist too, thank you very much*
( crackhouseceilidhband Fuck off back to Mumsnet, Thu 3 Jul 2008, 13:59, closed)

@CHCB
Indeed. But by "Proper" scientist I meant one who lives in a lab with test-tubes 'n' shizzle.
( Enzyme is powered by sunlight, Thu 3 Jul 2008, 14:01, closed)

hmph!
I got to do psychophysics experiments on people for my PhD. I think that counts.
( crackhouseceilidhband Fuck off back to Mumsnet, Thu 3 Jul 2008, 14:46, closed)

@ CHCB
psychophysics

psychosexual


;)
( chickenlady b3ta's very own Elizabeth Taylor, Thu 3 Jul 2008, 14:56, closed)

@chickenlady
psychosexual
(Bazongaloid, Thu 3 Jul 2008, 15:45, closed)

@ Al
We know exactly what type of scientist CHCB is!
( chickenlady b3ta's very own Elizabeth Taylor, Thu 3 Jul 2008, 16:01, closed)

"Dr Crow" would just like to point out...
...that it'll be a couple more years before he can actually call himself "Dr." But thank you.

I will say, however, that there isn't much of a basis for your theory. It's a nice idea - very Dr Who, in fact - but the main problem is that the only reason we see an object is because light is being reflected from it. Take the photons reflected from a woman's skin 50 years ago as she walked down a corridor - they will have been scattered in all directions, and probably absorbed eventually. The chances of a similar combination of photons coming together and making for someone's retina are so small as to be virtually non-existent.

This is not to say I believe in ghosts. Personally I suspect they're just hallucinations, and perhaps the associations of certain places result in people seeing similar things.

EDIT: Should have read the other replies more closely, as everyone else has come to more or less the same conclusions I have. Oh, well.
(LongJohnBaldry, Sun 6 Jul 2008, 0:03, closed)