A finite universe

[Strange]

 

Why you gotta be like this Strange?

 

 

Because you are making false claims. You started off saying that there are scientific theories that are wrong because they are incomprehensible.

 

Then when it was pointed out that that was no way to judge a theory you said that there are theories that are self-contradictory or inconsistent.

 

When asked for examples, you produced some "paradoxes" (counter-intuitive results) from pure mathematics.

 

So, again, are there any scientific theories that are internally contradictory or not?

 

 

 

Your assurance that all scientific theories are obviously self-consistent is contradicted by Godel's second incompleteness theorem at least, isn't it?

 

Of course not.

[substitutematerials]

I can virtually guarantee you that there is a scientific theory, accepted presently, that will be shown to self-contradictory at some future point. If I knew which theory this was, I would not be lurking in science forums. Furthermore, mathematics and logic are the foundations of the physical sciences, so the things you can say about them necessarily also apply to science, although not necessarily the other way around. My example of Euclidean mathematics discovering internal contradictions most definitely has relevance to scientific models. A historical example from the physical sciences of self-contradiction could be Phlogiston theory, which ended up suggesting that phlogiston had both positive and negative mass- an internal contradiction that helped undo the theory.

[Strange]

I can virtually guarantee you that there is a scientific theory, accepted presently, that will be shown to self-contradictory at some future point.

 

 

In which case it will no longer be a theory.

 

 

 

A historical example from the physical sciences of self-contradiction could be Phlogiston theory

 

Which is no longer a theory.

 

So lets see where we are now. You have gone from:

 

"There are scientific theories that are wrong because they are incomprehensible"

 

(Incomprehensible to who?)

 

"No. I mean there are scientific theories that are wrong because they are inconsistent"

 

(Name one)

 

"No. I mean there are scientific theories that might be found to be inconsistent in future"

 

(Duh)

 

Well, I guess you should be congratulated for eventually getting to a rational position. (Although I think it is far more likely that a theory will be falsified by contradictory evidence.)

 

Note that examples like phlogiston where a theory is shown to be completely wrong, and is abandoned, are incredibly rare. I can only think of one other (the steady state universe).

 

It is far more common for a theory to be replaced by a more accurate one, but to continue to be used in some cases. The obvious example is Newtonian gravity, which was shown to be "wrong" by Einstein, but is still the standard theory of gravity used in most cases.

 

 

My example of Euclidean mathematics discovering internal contradictions most definitely has relevance to scientific models.

 

Sure. Because that led to the development of non-Euclidean geometry, and eventually the development of pseudo-Riemannian manifolds which were then used by Einstein to create his model of gravity.

[substitutematerials]

Alright, I'll take it. And your point that scientific theories are rarely abandoned completely is valid.

 

Note that examples like phlogiston where a theory is shown to be completely wrong, and is abandoned, are incredibly rare. I can only think of one other (the steady state universe).

 

It is far more common for a theory to be replaced by a more accurate one, but to continue to be used in some cases. The obvious example is Newtonian gravity, which was shown to be "wrong" by Einstein, but is still the standard theory of gravity used in most cases.

 

I can think of a host of abandoned theories that are prescientific or were only ever quasi-scientific, but it depends in part on where you draw the line for Science right? We've tossed out the four humors in medicine, geocentrism in astronomy, the four elements and alchemy in chemistry, phrenology in biology, homeopathy in medicine... But like you said, most of these were probably abandoned more due to contradictory evidence than internal contradiction.

 

Can we close by returning to this narrower question: In the case of a finite universe (bounded or unbounded), could we define the aggregate rate of spatial expansion by

 

[math]d*H_o[/math]

 

Imagine that we obtain a really fantastic measurement of curvature, and the universe is curved right at the threshold of what we can't observe right now- so implying a diameter of 14 trillion light years or 4292419 megaparsecs as per the article mentioned. Why couldn't I multiply that diameter by the present rate of spatial expansion, 72 km/s/megaparsecs, and state that the diameter of the universe is increasing by 309,054,168 km/s?

 

This rate might have no use whatsoever, but wouldn't it be logically implied, when we assume a scaling factor and finite diameter?

Edited February 23, 2017 by substitutematerials

[Strange]

Imagine that we obtain a really fantastic measurement of curvature, and the universe is curved right at the threshold of what we can't observe right now- so implying a diameter of 14 trillion light years or 4292419 megaparsecs as per the article mentioned. Why couldn't I multiply that diameter by the present rate of spatial expansion, 72 km/s/megaparsecs, and state that the diameter of the universe is increasing by 309,054,168 km/s?

 

This rate might have no use whatsoever, but wouldn't it be logically implied, when we assume a scaling factor and finite diameter?

 

 

That assumes the universe has a "diameter". Which, depending on the topology, may or may not be true.

 

But you could certainly use that to calculate the rate at which the most distant point is receding.

[michel123456]

. (no comment)

Edited February 24, 2017 by michel123456