Where is "here"?

So what's really going on?

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Skip
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Re: Where is "here"?

Post by Skip » Fri Sep 04, 2015 12:15 am

Virtual dribble is so much better than the physical kinds: we don't need to wipe it up.

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Greta
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Re: Where is "here"?

Post by Greta » Mon Sep 07, 2015 8:50 am

Being directionally challenged, this is a question I have asked myself more times than I care to remember. I am even capable of getting lost using a GPS. There is something wrong with my brain :)

Be that as it may, Leo, I need to take up the (fluffy padded) cudgels with you again about space.

When I am lost while driving Sydney's labyrinthine streets I know what "the relative now" is - the time - but I'll have no clue was to where "here" might be. The space between my most recent "lost place" and home is real, not an observer effect. If I don't bridge that space I don't get to sleep in my bed. As a Flatlander wandering around the earth's surface, the space between various destinations in this 2D surface is painfully real to me.

"Here" in cosmic terms is another matter, given that our absolute location in space is meaningless. "Here" is then an entirely relative term. Yet if I drive the ten kilometres from the place in which I'm currently lost to home, in real terms the Milky Way has travelled some insane distance through the cosmos. For all we know, the entire universe could be dropping like a stone or hurtling in any direction in space (or doing loop-de-loops) and it would mean nothing.

However, space remains real to us Flatlanders, and certainly to the RFSA and NASA.

Obvious Leo
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Re: Where is "here"?

Post by Obvious Leo » Mon Sep 07, 2015 9:09 am

Greta wrote:The space between my most recent "lost place" and home is real,
Relatively real, Greta. Your spaces are real relative to each other and relative only to the observer's perception of them. The spaces you observe on the streets of Sydney will look quite different to my mate on Betelgeuse V with his gee-whiz telescope. To him these spaces will have a different "curvature", if I can allow myself such a confusing metaphor and such an abominably un-philosophical turn of phrase.

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Greta
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Re: Where is "here"?

Post by Greta » Mon Sep 07, 2015 9:21 am

Obvious Leo wrote:
Greta wrote:The space between my most recent "lost place" and home is real,
Relatively real, Greta. Your spaces are real relative to each other and relative only to the observer's perception of them. The spaces you observe on the streets of Sydney will look quite different to my mate on Betelgeuse V with his gee-whiz telescope. To him these spaces will have a different "curvature", if I can allow myself such a confusing metaphor and such an abominably un-philosophical turn of phrase.
Leo, as you know, I'm perfectly comfortable with abominably un-philosophical turns of phrase. Zaphod's mum would need to be existing sometime after 2600 to see me getting lost in the present, by which time the buildings erected on the dead daisies I'd long been pushing up would have made way for a safe, sealed environment for Rupert Murdoch's distant descendants while the middle class's descendants pointlessly throw spears at the impregnable hyper-plastic, hoping to get to the food supplies ...

But surely she would still see more or less the same space?? I might need help with the curvature idea. Assuming the telescope has onboard gear that prevents distortions through gravitational lensing, as she panned in and out, why wouldn't she see more or less the same as a relatively nearby observer (say, the Moon) with a quality telescope?

Obvious Leo
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Re: Where is "here"?

Post by Obvious Leo » Mon Sep 07, 2015 11:10 am

Greta wrote:why wouldn't she see more or less the same as a relatively nearby observer
More or less? Since when has philosophy concerned itself with statements which are more or less true? Indeed what you say is more or less true but when it comes to explanations a miss is as good as a mile.

You must make due allowance for my gratuitous use of hyperbole, Greta, because the differences in lensing effects between an observer on our moon and those observed by Zaphod's mum would be minuscule and require instruments of unimaginable precision to detect. Physicists are fond of using the word negligible for effects which their instrumentation can't detect because physics is a science where near enough is good enough. However we in the philosophy business are pedants of a lofty calibre who are in the explaining business rather than in the measuring business and thus we know perfectly well that negligible is not synonymous with irrelevant. A space which is even just a little bit relative to gravity is something which SR is simply not equipped to accommodate and thus SR is immediately and irrevocably stripped of any and all of its explanatory authority.

Translated into the Aussie vernacular the above statement reads thus: Hermann Minkowski was a cockhead.

Jaded Sage
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Re: Where is "here"?

Post by Jaded Sage » Mon Sep 07, 2015 12:48 pm

"Here" is where we aren't not.

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Greta
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Re: Where is "here"?

Post by Greta » Mon Sep 07, 2015 3:02 pm

Obvious Leo wrote:... the differences in lensing effects between an observer on our moon and those observed by Zaphod's mum would be minuscule and require instruments of unimaginable precision to detect.

Physicists are fond of using the word negligible for effects which their instrumentation can't detect because physics is a science where near enough is good enough. However we in the philosophy business are pedants of a lofty calibre who are in the explaining business rather than in the measuring business and thus we know perfectly well that negligible is not synonymous with irrelevant. A space which is even just a little bit relative to gravity is something which SR is simply not equipped to accommodate and thus SR is immediately and irrevocably stripped of any and all of its explanatory authority.
It would be weird if there was zero difference since there what lies between us and other stars/planets is not "nothing" or "space" but the quantum foam, which you'd expect to have at least some small effect.

Obvious Leo
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Re: Where is "here"?

Post by Obvious Leo » Mon Sep 07, 2015 8:29 pm

Now there's a blast from the past, Greta, and spoken like a true flower child and refugee from the sixties. It's been a long while since the old "quantum foam" has been trotted out as a metaphor for the luminiferous aether. How thin can foam stretch before it vanishes into froth and bubble?

Obvious Leo
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Re: Where is "here"?

Post by Obvious Leo » Mon Sep 07, 2015 8:42 pm

Greta. It remains the case in physics that SR is regarded as a special case of GR in the "flat space". Regrettably for SR it also remains the case in the physical universe that there is no such region as a "flat space" because a "flat space" is one where gravity is absent i.e. a mathematical abstraction.

This has serious consequences for QM, which is entirely predicated on the "flat space" of SR, because if there's no such region as a flat space then QM is also merely a mathematical abstraction. Naturally this last is not breaking news to anybody.

surreptitious57
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Re: Where is "here"?

Post by surreptitious57 » Mon Sep 07, 2015 8:52 pm

Skip wrote:
Virtual dribble is so much better than the physical kinds : we do not need to wipe it up
Yes but whereas the physical can be erased it cannot so remains in cyber space for ever

Skip
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Re: Where is "here"?

Post by Skip » Mon Sep 07, 2015 9:04 pm

Aaaawwwk!
In that light, I'd be relieved if Dubious had meant 'drivel', because a little more of that wouldn't be noticed.

Dubious
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Re: Where is "here"?

Post by Dubious » Tue Sep 08, 2015 12:05 am

Skip wrote:Aaaawwwk!
In that light, I'd be relieved if Dubious had meant 'drivel', because a little more of that wouldn't be noticed.
My exceptional sense of logic leads me to this conclusion ... that drivel is what we mostly dribble on philosophy forums and with all the dribbling going on, you'd need a full time janitor to clean it up!

Skip
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Re: Where is "here"?

Post by Skip » Tue Sep 08, 2015 1:32 am

Here, then, is a messy place. Here, people lose their inhibitions, manners and syntax. Here, they wear avatars which allow them to appear clever, handsome or brave; to win every argument, to leap tall buildings, levy flat taxes and explore their dark side. When they leave here, they shed all that, leave it lying around on the floor.... and nobody wants the role of janitor.

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Greta
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Re: Where is "here"?

Post by Greta » Tue Sep 08, 2015 1:56 am

Obvious Leo wrote:Now there's a blast from the past, Greta, and spoken like a true flower child and refugee from the sixties. It's been a long while since the old "quantum foam" has been trotted out as a metaphor for the luminiferous aether. How thin can foam stretch before it vanishes into froth and bubble?
I don't find anything cosmic about quantum foam. The fact is that space is not empty but full of quantum particles. Quantum foam seems like a good name for it.

As for Dubious and others talking about "drivel", isn't it fun and easy to criticise from the sidelines without adding content? You might want to try Facebook, YouTube and Twitter. It's pretentious behaviour - people trying to create the illusion that they have more substantial content that they withholding until worthy conversationalists arrive. Uh huh. Berne would have called it the "Ain't It Awful?" game.

Obvious Leo
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Re: Where is "here"?

Post by Obvious Leo » Tue Sep 08, 2015 2:18 am

Greta wrote: The fact is that space is not empty but full of quantum particles.
This is not a physical statement but a mathematical one, Greta, because you left a critically important adjective out of your statement. Space is full of VIRTUAL quantum particles and the meaning of "virtual" in physics is exactly the same as the meaning of "virtual" in the common usage. "Virtual" means NOT REAL. Your quantum foam is a mathematical metaphor and nowadays a much unloved one. Even Feynman had the decency to shudder at such a usage and clever Dick was a logical positivist in a class of his own.

Nowadays if you wish to appear up with all the latest in hip pseudo-scientific jargon the fashionable rhetoric is to speak of the "vacuum energy of empty space". This is the energy of nothingness contained within nothing and it is a construct central to quantum field theory, a bizarre mish-mash of crackpot notions also sometimes referred to as the "ontology of the equations". It has a small but dedicated following amongst a few of the more metaphysically challenged members of the geek priesthood.

It's hardly any wonder that the physicists decided to kick the philosophers out of their playpen. Back in the good old days of ancient Greece the whole fucking lot of them would have been sold into slavery.

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