🚀 go-pugleaf

No doublethink in France: the greater youthfulness of the travelling
twin is due to acceleration and that's it:

http://www.techno-science.net/?onglet=articles&article=39&page=4
"La théorie de la relativité nous dit que les phénomènes sont
identiques dans tous les référentiels, or, pour Fred, celui-ci est au
repos, mais c'est Franck qui voyage, donc le temps doit s'écouler plus
lentement dans le référentiel de Franck vu par Fred. Franck fait
exactement le même raisonnement et en déduit la même chose. Comme
d'après la relativité, tous les référentiels sont identiques, ils
devraient avoir le même âge, or ce n'est pas du tout le cas, comment
est-ce possible ? Tout simplement parce que la relativité restreinte
s'applique aux référentiels non accélérés, et que Fred, par le fait
d'aller et revenir doit obligatoirement accélérer, c'est ce qui est à
l'origine de la dissymétrie."

Pentcho Valev wrote:

Advanced triplethink in Einsteiniana: Lie 3 one leap ahead of Lie 2
and two leaps ahead of Lie 1:

http://www.physorg.com/news163738003.html
Lie 3: "Just when you thought you were beginning to understand the
twin paradox (maybe), scientists have found something new to ponder.
In the original version of the famous thought experiment on time
dilation, one twin stays on Earth while the other twin takes a rocket
at nearly light speed into space, and returns to find that he is
younger than his twin on Earth. But a new version of the story now
shows that the twin who experiences an acceleration can be older than
the twin who doesnt accelerate, under slightly different conditions."

http://www.liferesearchuniversal.com/1984-17.html#seventeen
George Orwell: "Doublethink means the power of holding two
contradictory beliefs in one's mind simultaneously, and accepting both
of them. The Party intellectual knows in which direction his memories
must be altered; he therefore knows that he is playing tricks with
reality; but by the exercise of doublethink he also satisfies himself
that reality is not violated. The process has to be conscious, or it
would not be carried out with sufficient precision, but it also has to
be unconscious, or it would bring with it a feeling of falsity and
hence of guilt. Doublethink lies at the very heart of Ingsoc, since
the essential act of the Party is to use conscious deception while
retaining the firmness of purpose that goes with complete honesty. To
tell deliberate lies while genuinely believing in them, to forget any
fact that has become inconvenient, and then, when it becomes necessary
again, to draw it back from oblivion for just so long as it is needed,
to deny the existence of objective reality and all the while to take
account of the reality which one denies - all this is indispensably
necessary. Even in using the word doublethink it is necessary to
exercise doublethink. For by using the word one admits that one is
tampering with reality; by a fresh act of doublethink one erases this
knowledge ; and so on indefinitely, with the lie always one leap ahead
of the truth."

Sometimes "the lie one leap ahead of the truth" degenerates (or
progresses) into "the lie one leap ahead of another lie". When
Einsteinians explain the absurdity called the twin paradox, they
oscillate between the following Lie 1 and Lie 2:

Lie 1: The greater youthfulness of the travelling twin is due to
acceleration (Einstein's 1918 explanation):

http://plus.maths.org/issue36/features/aiden/index.html
"This is the story of twins Peter and Paul. Paul makes a round trip in
a high-speed spaceship and leaves his brother Peter on Earth. With the
help of his telescope, Peter watches Paul whizzing through space. As a
result of time dilation, Peter sees that Paul is aging more slowly
than he. But, just as Alice and Bob both thought that the other was
experiencing time more slowly than themselves, shouldn't Paul observe
Peter aging more slowly than he? This would mean that each twin
thought the other one was aging more slowly. In fact, the situation is
not symmetrical: only the twin who stays at home is in an inertial
frame. Paul experiences acceleration (that is, changes in velocity) as
his rocket leaves Earth, turns around and comes back. In general,
accelerated clocks (or clocks in gravitational fields) will go slow
relative to unaccelerated clocks (or clocks feeling no gravitational
fields). So the twin that feels the accelerations will age more slowly
than the one who doesn't."

Lie 2: The greater youthfulness of the travelling twin is not due to
acceleration:

http://www.people.fas.harvard.edu/~djmorin/chap11.pdf
p. 44: "11.19. Modified twin paradox. Consider the following variation
of the twin paradox. A, B, and C each have a clock. In A's reference
frame, B flies past A with speed v to the right. When B passes A, they
both set their clocks to zero. Also, in A's reference frame, C starts
far to the right and moves to the left with speed v. When B and C pass
each other, C sets his clock to read the same as B's. Finally, when C
passes A, they compare the readings on their clocks..."

In the previous version of David Morin's textbook there was the
following additional text:

"This form of the twin paradox loses a bit of the punch of the usual
statement of the problem, since we don't compare the ages of the same
two people before and after the journey. But on the other hand, THIS
VERSION OF THE PROBLEM DOES NOT INVOLVE ACCELERATION."

Pentcho Valev
pvalev@yahoo.com