'Edge' of the Universe

Understanding is not the same as believing. I understand Special Relativity and I understand Lorentzian Relativity. Both of them work in the math and logic senses. And both of them give the same predictions as far as the experiments we are able to do can tell.

(They do differ, however, in their predictions of FTL phenomena. SR says "no way", while LR says "no problem".)

I do not 'believe' Special Relativity is the 'correct' model of the relativity of motion. But I understand it.

LB

[kcody] "As Dr. Tom van Flandern postulates in his book, it seems like the fundamental laws of physics should apply equally throughout. I take that to mean the laws of causality and thermodynamics as well as the laws of motion."

Our understanding of what is and what is not fundamental is likely to change as we grow.

Causality is a good candidate (IMO) for a truely fundamental natural 'law'. But not thermodynamics. Take entropy for example. Electromagnetic force is entropic in its behavior. But gravitational force exhibits anti-entropic behavior.

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In an infinite universe entropy would (logically) be conserved. Observation seems to support this notion.

[tvf] "But no existing cosmology hypothesizes an edge to the universe."

[kcody] "Understood, but this one does imply intrinsic limits to where we can physically go, however enormous."

This is an interesting speculation. To the extent that the matter we are made of *depends* on being immersed in the elysium ocean in order to exist as it does, it makes sense. But if ordinary matter maintains its characteristics even outside of the elysium we are free to explore.

Or, perhaps we will be able to build vehicles that have an elysium filled cabin to keep us safe and an external shield of ... mumble-ite ... that keeps the vehicle safe.

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[kcody] "Since our personal existences depend on relatively stable local elysium, we probably shouldn't be going too near to quasars or any other suspected elysium boundary either."

It's never too early to speculate about things like this, but we have so little data to guide us at this point that speculating really is all we can do.

LB

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
Individual real things are finite. Individual conceptual things (including the concept of 'the sum total of all real and conceptual things', AKA the universe) can be infinite.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Rebuttal:

1.) That reads like "infinity plus constant equals infinity", where "concepts = infinity" and "substance = constant". This is an example of treating the undefined value ("infinity") like an algebraic variable. See my comment above.

2.) If all individual real things are finite, so is their sum total; following both common sense (finite plus finite = larger finite) and your quote above that the finite cannot become infinite.

- Kevin

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
This is an interesting speculation.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Well, I'd rate it one step above speculation, 'conjecture', on the basis that it came from deductive, not inductive, reasoning.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">But if ordinary matter maintains its characteristics even outside of the elysium we are free to explore.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Unlikely IMO; molecular bonds depend on electron behaviors, which in turn would seem to depend on elysium.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Or, perhaps we will be able to build vehicles that have an elysium filled cabin to keep us safe and an external shield of ... mumble-ite ... that keeps the vehicle safe.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I agree. Such a shell would have to trap elysium without being dependent on elysium to remain trapped, if the conjecture is correct that elysium is a liquid-like substance under pressure from C-Gravitons. Superdense matter might be a first guess.

It'd be like a submarine - you're fine until the hull cracks, and then once the air is out you're irrevocably screwed.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">[kcody] "Since our personal existences depend on relatively stable local elysium, we probably shouldn't be going too near to quasars or any other suspected elysium boundary either."

It's never too early to speculate about things like this, but we have so little data to guide us at this point that speculating really is all we can do.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Agreed. Speculating is fun, though.

- Kevin

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Larry Burford</i>
Our understanding of what is and what is not fundamental is likely to change as we grow. ... Causality is a good candidate (IMO) for a truely fundamental natural 'law'. But not thermodynamics.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Point taken. Thermodynamics needs more study across scales before calling it a fundamental law. IMO the causality argument is enough to debunk the idea that the universe's contents are infinite.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Take entropy for example. Electromagnetic force is entropic in its behavior. But gravitational force exhibits anti-entropic behavior.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

What we see as gravitational force is anti-entropic. What about the consequence to the CG medium that provided that force? Should it not become more disorganized when some of its particles smash into larger matter ingredients at high relative speeds?

This looks to me like an example of entropy being transferred from a particle-large scale to a particle-small one.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">In an infinite universe entropy would (logically) be conserved. Observation seems to support this notion.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

We can't see enough of the universe to call that a hard data point, and "seeing" has little to do with the distances we're discussing. I'd be interested to hear which observations you have in mind, though.

IMO an isotropic universe, that cycles entropy between scales, makes the same intuitive sense without implying acausality.