It doesn’t have to be a rocketship that grabs the twin. A plane or train or rickshaw would all suffice. I mentioned GR because it deals with more complex motions and includes the notion that time is faster on the second floor than it is on the first.

I figure between the relative motion and gravitational effects, it would actually be rather odd if two people shared the exact same clock. And that should explain my earlier statement.

Actually, I don’t have a problem other than the detail about the twins is irrelevant. Not only does it not “make the point clearer” it does exactly the opposite: cause people to think there is a paradox when none exists. Its not that I don’t understand the solution, it’s that I don’t understand why people would see a paradox

They obviously don’t need to be twins. It just makes the point clearer. The twins are exactly the same age up until the time one of them takes off on an intergalactic journey and returns to Earth. When they meet up again, the stay at home twin is ten years older than the travelling twin.

And it’s not a paradox. It’s an apparent paradox. An apparent paradox always has a resolution. The twin paradox is an apparent paradox in special relativity and it has its resolution in special relativity
So…
Why is it an apparent paradox?
What is the solution?

I don’t understand the significance of the 2 individuals being twins, and how this creates an apparent ‘paradox.’ Calling the individuals ‘twins’ seems like an irrelevant detail, and is not meaningful to the senario. There doesn’t seem to be a paradox in the senario described.

I thought my previous post explained the mainstream view on the TOL pretty well. I’ve explained it, and Steven Novella has explained it. I’m not sure that there is anything left to add.
I’m not going to get on your merrygoround, sorry.

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It’s SR, not GR.
But you have stated the twins paradox correctly.
But do you know how to resolve the paradox?
And can you see how it is different from the scenario you posed about a week ago?

http://www.ncbi.nlm.nih.gov/pubmed/21457008
“the possibility remains that the TOL concept can be reformulated and remain valid as a statistical central trend in the phylogenetic “Forest of Life” (FOL). ”

From the conclusion–
Indeed, it is now well established that HGT spares virtually no genes at some stages in their history (Gogarten and Townsend, 2005) and these findings make obsolete a “strong” TOL concept under which all (or the substantial majority) of the genes would tell a consistent story of genome evolution (the species tree, or the TOL) when analyzed using appropriate data sets and methods. However, is there any hope of salvaging the TOL as a statistical central trend (Wolf et al., 2002)?

http://www.ncbi.nlm.nih.gov/pubmed/12175808 (This is Wolf et al., 2002)
“However, this tree should be reinterpreted as a prevailing trend in the evolution of genome-scale gene sets rather than as a complete picture of evolution.”

Perhaps a different phrase for the different concepts would be less confusing.

As I understand it, microRNAs might tell a different story about later evolution as well. But that is speculation- the kind I like, but the kind you seem to not like.

Have I figured that out correctly?

Anyway—
I’ve noted an interest in GR–
Here’s one you might like–

twins A and B. twin B gets whisked away in a spaceship- flies out and comes back sometime later.
When they meet twin A will be older than twin B.
One might say that twin B has lived fewer years than twin A.
How about that?

My reservations about M/string theory lie with it’s testability. It’s a challenge to science definitionally when we have a theory which cannot be falsified. And my understanding (which is quite incomplete) is that the lack of falsifiability is not simply technical, but that an infinite amount of solutions are available, so that even if technical issues could be overcome the theory still cannot be falsified.

Again, I’m no expert ehre, but these things seem to be cause for concern. That said, I don’t think it’s pseudoscience.

I don’t know if me2earth will be back to defend his claim that climate change and string theory are pseudoscience, but I suggest we get a definition of first because, by my definition, neither qualify as pseudoscience.

With climate change, there is a vast amount of reliable data, there is a consensus of ninety-seven percent of the relevant experts in climate change and there are outcomes actually worse than the predictions (which is what you would expect with a consensus which, by its nature, is likely to be conservative). There are no mavericks or cranks (who, on the other hand, do populate the climate denialist camp). There are no laws of physics being overturned, or new ones proposed.
And to suggest that there is a money and political trail is laughable. Both have always worked on the side of climate denialists and, only recently, has climate change gained a little political traction.

And string theory is a bit like multiverse theory. Both are entirely consistent with present scientific knowledge and both explain things for which there are no evidence-based alternative explanations. Both may turn out to be dead-end science, but pseudoscience they are not. Again, I suppose we need a definition.