Natural Science Forum / Physics / Research / September 2006

It is sometimes supposed that the cosmological principle determines that
Maxwell's equations hold in empty space, and hence that cosmological
redshift must be calculated using the affine connection. This argument
does not apply in empty space. In the classical correspondence the ...

New Scientist is a British-based publication where many thousands of lay
people get their information on scientific matters, and (IMHO) it does an
excellent job about 70% of the time.  But the combination of a
sensationalist bent and a lack of basic knowledge by its writers (most ...

In QED and QCD, is it correct to hold the view that the upshot of
renormalization after all the loop diagrams are calculated, cutoffs
chosen, etc., is that the interaction couplings "run," and more to the
point, that the measurable objects one observes must be specified -- not

Thanks to Charles Francis, Oz and Igor Khavkine for clarification of some of
the issues raised by the 'Ranging and Pioneer' thread.
To quote a couple of earlier contributions to the thread;

Dear friends,
The anomalous magnetic moments of the charged leptons are presently
understood in terms of perturbative corrections Lambda^u of the form
gamma^u --> Gamma ^u = gamma^u + Lambda^u introduced via the Dirac gamma

What Electric and Magnetic field have an oscillating charge??
For example Q=q0.sin(2.pi.f.t)
Or  Q = q0.Heavside(t)
(Heavside(t)=1 if t>0, 0 if t<0)

I have 2 different light rays which have different wavelengths (for
instance one is red and the other is green).
I'm sending these rays to 2 photodiodes.
Is the electric current generated by those photodiodes the same? Are

It has been put to me that instead of giving an overview of Relational
Quantum Gravity as I did in a recent post, I would be better to give the
actual calculation which illustrates that gravity can be regarded as a
perturbation to Minkowski metric resulting from a modification to ...

Given some lagrangian, when we integrate out degress of freedom either
in quantum or classical field theory, we usually obtain an effective
one. Are there cases where, upon integrating out degrees of freedom,
one no longer has a lagrangian description of the dynamics?

In article <1157753984.435268.48320@m73g2000cwd.googlegroups.com>,
"Edward Green" <spamspamspam3@netzero.com> wrote:

http://www.physorg.com/news12054.html
" Scientists funded by the European Space Agency have measured the
gravitational equivalent of a magnetic field for the first time in a
laboratory. Under certain special conditions the effect is much larger

This is a hypothetical question.
Imagine there are two objects in space above the Earth.  They are say 3
light seconds apart from each other and an approximately equal distance
away from an observer on Earth.

The major drawback of Albert Einstein's successive attempts to establish a
relativistic theory of the non-symmetric field is the failure to deduct the
equations of motion for charged mass points from the field equations using
the so called "Einstein-Infeld-Hoffman" (EIH) method.

the amu is defined to be 1/12 the mass of a carbon-12 atom, i presume
complete with 6 protons, 6 neutrons, and 6 electrons.
even if the electrons weighed nothing, each proton and neutron is more
than the amu so it must add to more than 12 amu.  how can this be??  i

Two years ago, in Dublin, Stephen Hawking announced that he had solved
the black hole information problem.  In essence, he treated a black
hole as a particle scattering experiment, as viewed from a long
distance away.  Particles go in, some sort of stuff goes on, particles