Semantics with Spiritus Mundi

[Spiritus_Mundi]

Are we trying to set some kind of record for floging a thread after the OP has been resolved? The horse is down, folks, let the poor bugger rest in peace.

[erislover]

From Black Holes and Time Warps by a certain Kip Thorne:

Perfection of Rulers and Clocks [box 11.1]
By “perfect clocks” and “perfect rulers” I shall mean, in this book, clocks and rulers that are perfect in the sense that the world’s best clock makers and ruler makers understand: perfection is to be judged by comparison with the behaviors of atoms and molecules.

Later we find,

What is the real, genuine truth? Is spacetime really flat, as the above paragraphs suggest, or is it really curved? To a physicist like me this is an uninteresting question becuase it has no physical consequences. Both viewpoints, curved spacetime and flat, give precisely the same predictions for any measurements performed with any kind of physical apparatus whatsoever. For example, both viewpoints agree that the radial distance between the horizon and the circle in Figure 11.1, as measured by a perfect ruler, is 37 kilometers. [author’s emphasis]

My work here is complete.

[Spiritus_Mundi]

My work here is complete.

Absoltely. You have demonstrated that some physicists don’t have a perfect grasp of semantics.

(Seriously, are you sure he’s speaking in a context of relativity? When he says “both viewpoints” he is talking about two separate models for spacetime, not two separate relative frameworks.)

[erislover]

He’s speaking about what spacetime is all about, comparing the standard relativity idea of curved spacetime versus the alternative idea that gravity causes stuff to shrink. Either view gives precisely the same answer, and so, he says, it is now a matter of philosophy.

[Miller]

Jesus, the more you two talk, the dumber I feel. I’m gonna go watch TV until I recover my smug sense of superiority.

[Spiritus_Mundi]

Yes, but does he apply that usage in a relativistic context (i.e. a comparison between two reference frames).

BTW – I fogot to comment earlier but the first quot you posted seems to use “perfect” very much in the sense of “absolute zero”. It references an idealized measurement which we have yet been able to produce physically (though in the case of time we have come close).

[erislover]

For a further quote from the same Box 11.1:

The markings on perfect rulers must have uniform and standard spacing when compared to the light emitted by atoms and molecules, for example, uniform spacings relative to the “21 centimeter wavelength” light emitted by hydrogen molecules. This is equivalent tp requiring that when one holds a ruler at some fixed, standard temperature (say, zero degrees Celsius), it always contains markings in the same fixed number of atoms along its length between markings; and this, in turn, guarantees that perfect rulers measure the spatial lengths of Einstein’s curved spacetime.

[Spiritus_Mundi]

Ah – that makes it obvious that he is referencing an idealized ruler which has no physical existence. This is precisely the same connotation as “absolute zero”. He does not “have” a perfect ruler, he is hypothesizing a perfect ruler.

[erislover]

Well, possession in no way changes his intention that perfection is “as god as it gets.”

Anyway, I’m requesting this thread be closed. nothing going on here.

[kabbes]

Don’t you dare close it before I provide three character references:

1)Spiritus - man, haven’t I already provided you with enough of these on these boards? Now what was that line of mine again? Something about having a unique ability to sum of an incredibly complex argument into one understandable and enlightening paragraph. Yeah. And yo mother.

2)erl - FTR, I love the fact that this guy goes away, thinks about the argument, is willing to read any sugegsted material and then will come back and either develop his argument or simply admit that he was wrong. If only more people on the boards were like this.

3)wring, 'cos I love 'er. No particular reason for shoving a wring-character-reference in here, but she was nice to me so I’m damn well going to.

Can you feel the love?

Oh and I like you too Scylla, I suppose.

pan

[kabbes]

Addendum:

I have to side with SM and erl on the semantics thing. You can’t have a philiosophical debate without ensuring that all sides are talking about the same thing. And since language is so fluid, double checking that everyone has the same thing in mind when they use a particular word is vital.

pan

[wring]

and a hearty “back atchya” to you, too kabbes! (blushing madly)

[Spiritus_Mundi]

man, haven’t I already provided you with enough of these on these boards?

What can I say, my appetite for ego boosts is gargantuan, and nobody does it better than kabbes. I think it’s the accent.

Besides, in a week where I was called out in the PIT twice there was always a chance that you would revise your opinion to “big ol’ meanie”. :eek: