If the inflationary scenario in cosmology turns out to be wrong, and the topology of the universe is both finite and relatively small—so that Earth does not have the distant duplicates that would be implied by an exponentially vast universe—then this Earth could be the only Earth that exists anywhere, a rather unnerving thought!

Then prepare to be unnerved! 'The' Universe is space (nothing) and matter (something). Space can not expand as it is nothing. Nothing can expand as it does not exist and what would space expand into, more space? AND if space is something, then it would be a large block of matter where motion would be impossible (and still we are left wondering where that block of matter 'sits'). However, space is boundless (without borders) and there is a finite amount of matter. This is logically the default position. The burden of proof for creation lies on the one proposing this and is exactly what Monsignor Georges Henri Joseph Édouard Lemaître attempted unsucessfully with his expanding universe theory. It may have satisfied the Pope, but it did not satisfy the burden of proof for creation.

But it is dangerous to focus too much on specific hypotheses that you have no specific reason to think about. This is the same root error of the Intelligent Design folk, who pick any random puzzle in modern genetics, and say, "See, God must have done it!" Why 'God', rather than a zillion other possible explanations?—which you would have thought of long before you postulated divine intervention, if not for the fact that you secretly started out already knowing the answer you wanted to find.

Yes, there is no reason to focus on the created (Big Bang) expanding universe. Not only because it is irrational to think of space expanding since it is nothing and can not expand into more nothing, but because the default position is that there is matter. That matter was created, requires the burden of proof on the creationist (if we are using the scientific method).

You shouldn't even ask, "Might there only be one world?" but instead just go ahead and do physics, and raise that particular issue only if new evidence demands it.

I wholeheartedly agree (as if that really matters). By default there is one world, and the question of many worlds is far from being 'settled' science or established fact!

Much worse, any physical scenario in which there was a single surviving world, so that any measurement had only a single outcome, would violate Special Relativity.[Linked] > When you have a pair of entangled particles, such as oppositely polarized photons, one particle seems to somehow "know" the result of distant measurements on the other article. Einstein famously called this "spukhafte Fernwirkung" or "spooky action at a distance". Einstein didn't know about decoherence, so it seemed spooky to him.

It is easy to conceive of a solution to entanglement without positing decoherence and one that satisfies Newton, SR and GR. For instance, if instead of discrete particles, there is an electromagnetic 'rope' connecting the two photons, from 'your' pov the rope can be rotating CW and from 'their' pov it will be rotating CCW. Not only will AAAD not be spooky in this instance, aether or "the fabric of space" and other worlds are unnecessary.

For a mathematicians POV on where physics went wrong, read what (Miles Mathis has to say:) [http://milesmathis.com/death.html]

ADDED: Since I am getting downvoted once again w/o explanation, I suppose it is for using pure logic and not math.

I may as well link you directly to the mathematician that refutes MWI and much more using (oh no!) MATH! He gives mechanical explanations for many of the experiments that supposedly 'prove' QM. Here are but a few. Enjoy!

(CHSH Bell Tests) [http://milesmathis.com/chsh.pdf]

(Entanglement) [http://milesmathis.com/entang.html]

(Superposition) [http://milesmathis.com/super.html]

(Mechanical explanation for Dbl Slit Experiment) [http://milesmathis.com/double.html]

(Bohm Bell & de Broglie) [http://milesmathis.com/pilot.pdf]

I would agree that if what I want to do is increase my understanding regardless of my ability to communicate effectively with other people (which isn't true of me, but might be true of others), and if communicating effectively with others doesn't itself contribute significantly to my understanding (which isn't true of me, but might be true of others), then choosing definitions for my words that maximize my internal clarity without reference to what those words mean to others is a pretty good strategy.

You started out by asking why EY doesn't do that, and I was suggesting that perhaps it's because his goals weren't the goals you're assuming here.

Reading between the lines a bit, I infer that the question was rhetorical in the first place, and your point is that maximizing individual understanding without reference to other goals, preferences, values, or communication with others should be what EY is doing... or perhaps that it is what he's doing, and he's doing a bad job of it.

If so, I apologize for misunderstanding.

Occasionally, you hear someone claiming that creationism should not be taught in schools, especially not as a competing hypothesis to evolution, because creationism is a priori and automatically excluded from scientific consideration, in that it invokes the "supernatural".

Creationism should not be taught in school because it is irrational for the same reason that Big Bang should not be taught in school. Creationism is not possible weather done by a God or done by Hawking's tiny dimpled pea.

The problem can be solved conceptually right here and now. Matter can not exist without space and space precedes matter and motion. Therefore space, matter and motion is eternal.

It would take far more time and space (pun intended) to explain this in detail, so I will link to some refutation (here:) [http://vixra.org/pdf/1103.0047v1.pdf]

and here: (Top 30 reasons) [ http://www.metaresearch.org/cosmology/BB-top-30.asp]

and just skip directly to why conceptually it is impossible for a Big Bang.

Both space and time are self-referring fallacies. Also fallacy of reifying abstracts and fallacy of confusing between a set and its members.

Check it out here: (Space) {http://redshift.vif.com/JournalFiles/Pre2001/V00NO19PDF/NR19ANT.PDF] and here: (Falacies space and time) [(http://redshift.vif.com/JournalFiles/V10NO1PDF/V10N1ANT.pdf]

If my goal is to clarify some confusing aspects of what people think about when they use the word "consciousness", then if I end up talking about something other than what people think about when they use the word "consciousness" (for example, if I come up with some precise, unambiguous, non-circular, non-contradictory definition for the term) there's a good chance that I've lost sight of my goal.

At any rate, whatever key terms that we use in our hypothesis must be precise, unambiguous, non circular, non-contradictory and used consistently throughout our presentation.

I'm personally okay with circular definition when used appropriately. For instance, there's the Haskell definition

naturalNumbers = 1 : (map (+ 1) naturalNumbers)

which tells you how to build the natural numbers in terms of the natural numbers.