Dirk Van de moortel wrote:
"Mike" wrote in message oups.com...

Sam Wormley wrote:
Testing Special Relativity and Newtonian Gravity
http://www.aip.org/pnu/2006/split/775-1.html


Lorentz invariance says that the laws of physics are the same for an
observer at rest on the Earth or one who is rotated through some
angle or traveling at a constant speed relative to the observer at
rest. Looking for a crack in the universe in the form of a very faint
field pervading the Cosmos, one that exerts a force on electron spin,
would mean the end of Lorentz invariance.

An important ingredient in Einstein's theory of special relativity,
Lorentz invariance has been borne out in numerous experiments. A new
experiment conducted at the University of Washington, in Seattle, has
sought such an anomalous field and not found it even at an energy
scale of 10^-21 electron volt. This is the most stringent search yet --
by a factor of 100 -- for Lorentz-invariance-violating effects
involving electrons.

The Washington work, described at this week's American Physical
Society's (APS) April Meeting in Dallas by Claire Cramer, is part of
an ongoing battery of tests carried out with a flexible and
sophisticated torsion-balance apparatus. In this case, a pendulum is
made of blocks whose magnetism arises from both the orbital motion of
an electron around its nucleus and from the intrinsic spin of the
electron itself. Carefully choosing and arranging the blocks, one can
create an assembly that has zero magnetization and yet still have an
overall nonzero electron spin. Cramer refers to this condition as a
"spin dipole," analogous to the case of an electric dipole, an object
with zero net charge but which, because of a displaced arrangement of
positive and negative charge, possesses a net electric field.

The existence of a preferred-direction, Lorentz-violating
spin-related force would have shown up as a subtle mode in the
rotation of the pendulum. The conclusion: any such quasi-magnetic
field would have to be weaker than about a femtogauss, or 10^-15
gauss.

At the APS meeting, Eric Adelberger, leader of the Washington group,
summarized some of the other efforts underway in his lab such as the
search for evidence of extra dimensions in the form of departures
from Newtonian gravity -- for instance, the inverse-square dependence
-- at a size scale of tens of microns. In fact, he said that
something strange was happening at a measurement scale of about 70
microns; the most likely explanation of this, he conceded, was an
experimental artifact.


Obviously, the trivial type of experiment they perform does not
facilitate he emergence of condtions that will lead to Lorentz
violation.

How would you know about Lorentz violation?
http://users.telenet.be/vdmoortel/di...Androcles.html


Essentially, they observe approximate symmetry which leads to Lorentz
invariance. They cannot observe neithr spontaneous breaking of symmetry
nor anomalous effects before they are counteracted by radiative
effects.

How would you know what they essentially observer?
http://users.telenet.be/vdmoortel/di...s/Learned.html


As I have said many times, affirming the consequent is one of the most
serious formal logical fallacies one can make.

How would you know the link between science and logic?
http://users.telenet.be/vdmoortel/di...rainHoles.html

Dirk Vdm

How would you know the difference between a joke and unethical
behavior:

http://groups.google.com/group/alt.j...ead/d88c93cc65...



You have been warned.


Mike