Natural Science Forum / Physics / Research / December 2007

Neutron-neutron fusion is an example of nuclear fusion because neutrons
are nucleons. Is it possible to solve the energy crisis using
neutron-neutron fusion? Can this fusion be used to generated sufficient
amounts of power? One advantage to neutron-neutron fusion over H-H

If Moderator allows it for the festive season, you might be amused by
this link, from the Boing Boing blog 25/12/07, apparently concerning
an ether-drift-detecting machine from 1932 (sic).
http://blog.modernmechanix.com/2007/12/24/queer-machine-checks-up-on-ether-drift/

Have multi-particle state of full Hamiltonian and one-particle state
of free Hamiltonian a non-zero scalar product? Intuitively one can say
that scalar product of such states should be zero because each of
these states mentioned above belongs to different (orthogonal)

I'm beginning a research on the different approaches to QG (or also
calssical QM) where the attempt to introduce the notion of spacetime
as an emergent concept is made. I would like to find for introductory
material which describes in one (or few) papers these different

I flipped through two papers (gr-qc/0005126, gr-qc/9710007) and found
out that they calculated the black hole entropy by counting the number
of states of which the area lie between A-l_p^2 and A+l_p^2 where l_p
is the planck length. I wonder why this is not between A-l_p^2/2 and A

I am reading John Baez's writing on energy-time uncertainty and have a
question about his claim of the non-existance of any observable
varaible T satisfying relations [H,T] = i hbar. In fact, for a
classical harmonic oscillator, H=P if we use action-angle variables P

From QM follows that the position of a photon can not be determined
better than L (de Broglie wavelength).
Suppose one creates a wave in the meter range - say L=2m. Could the
photons in this wave go through a tube of radius 1 cm?

In cloud chambers (or bubble/spark/crystal detectors,) do MeV photons
leave trajectory-tracks like particles do?
I've been arguing with myself about the details of laser
amplification, and it doesn't make sense to me that stimulated

This is an expansion of the reply issued back in April or May in
sci.math.research to:
This Week's Finds: Week 250
2007 April 26

In PF, Marcus notes:
"I see that the whole contents of EPL from July thru December 1986 is
free to download until the end of the year. If you (or anyone else)
sees any other paper that might be of special historical interest,

Hallo to all,
I have been reading a paper regarding electric pulse attenuation and
the values are quoted in dB. The conversion to dB was done by
multiplying the value with (20log10e) where "e" is the base of the

I ask this question only of believers in Everett's many worlds
interpretation of quantum mechanics.
How small an event will be accompanied by a splitting into (two?,
many?) worlds?  Is there a world where some protozoan flicks its

Is there a formal proof that the 2-body problem in GR cannot be solved
exactly?
If so can someone point me to it?
Thanks

http://arxiv.org/abs/0711.2274
The cosmological constant is claimed to be tamed and computable.
Curious...
"The Poincare' group generalizes the Galilei group for high-velocity

In a different thread (http://groups.google.com.au/group/
sci.physics.research/browse_frm/thread/836f60ae8caec5a8/
cd0d72b214648c59?hl=en#cd0d72b214648c59), as somewhat as an aside,
Igor Khavkine posed the following problem: