From “A BGO scintillating bolometer as dark matter detector prototype.” By N. Coron, E. García, J. Gironnet, J. Leblanc, P. de Marcillac, M. Martínez, Y. Ortigoza, A. Ortiz de Solórzano, C. Pobes, J. Puimedón, T. Redon, M.L. Sarsa, L. Torres and J.A. Villar. Optical Materials, Vol. 31 Issue 10, August 2009.
Even though dark matter has never been directly detected, that does not bother most physicists. Dark matter is matter that does not interact with barionic matter via the electromagnetic force; it does however, interact gravitationally. Dark matter is a particle (or set thereof) beyond the Standard Model of Physics, so detection would be a great discovery, and powerful purview of science.
Even without understanding exactly what dark matter is, we can still use General Relativity, Newtonian equations of motion, and celestial mechanics to determine projected properties of the dark matter. Dark matter is currently best examined by the behavior of faraway galaxies; which move in ways that can only be explained by a gravitational pull caused by more mass than can be detected using light.
Particle cosmologists state that only around five percent of matter in the universe can presently be detected. They estimate dark matter represents around 20 percent of the universe, with the other 75 percent made up of dark energy, a repulsive force that is causing the universe to expand at an ever-quickening pace.
Coron et al, created a detector called a scintillating bolometer, a crystal so pure it can nearly perfectly conduct the energy generated when a particle of dark matter strikes the nucleus of one of its atoms. (There is some quantum 1/f noise generated, along with phonon radiation.)
prevent interference by cosmic rays, the scintillation bolometer is sheathed in lead and kept underground, under over a kilometer of rock. It’s also chilled to near-absolute zero, the temperature at which all motion stops, and quantum zero energy effects become greatly measurable. Millionths of degrees above absolute zero, it is possible to measure expected changes of a few millionths of a degree Fahrenheit.
As described in a paper published in the August Optical Materials and released online Friday, the bolometer is currently able to distinguish between the vibrations produced by the vibrations of nuclei and spinning electrons. While this is too much quantum noise to detect dark matter, it is orders of magnitude greater in sensitivity then current liquid Xenon detectors, which operate at temperatures of -100ish C.
In order for the bolometer to work reliably, it needs to become even more sensitive, and maintain that sensitivity as it’s scaled up from the 46-gram prototype to a half-ton full scale working experiment.
While this seems insurmountable, I expect that it will be achieved within five to ten years. I, for one, cannot wait for the results from the experiment to be made public, as a positive result will greatly enhance our knowledge of physics beyond the standard model, and a negative result will leave us with more questions to answer.
frame, very far from the origin (that is, (0,0,0), let there be a source of electrodynamic waves, which at the origin of the K frame may be represented by:
, and 
for 
(that is 
,
,
).
are the amplitudes of the electric and magnetic fields, and 
, the normalized direction-cosines of the wave-normals. We will now transform these equations into the moving frame 
. Remember, 
.
, 
, 
,
,
,
, and
.
it follows that if an observer is moving with velocity 
, in such a way that
, the frequency 
of the light perceived by the observer is given by:
the equation assumes the more commonly seen form 
.
.
, the equation for 
.
, the equation becomes simply
or 
respectively, we obtain
if 
. (Prove this fact.)
, we have to regard 
, by the 
, if the volume of a light complex were the same, measured in bot 
, is
).
be a perfectly reflecting surface, at which the plane waves considered above are reflected. We must find the pressure of light exerted on the reflecting surface, and the direction, frequency, and intensity of the light after it is reflected.
. Viewed from 
. The energy leaving the same is 
. The difference between these two expressions is the work done by the pressure of light in the unit of time. If we denote this work as the product Pv, where P is the pressure of light, we obtain
, we can perform a Taylor approximation to the first order, and we get 
, which is in agreement with experiment.
times the density of electricity, and 
the velocity-vector of the charge. Since the electric charges are such things as ions, electrons, and protons, these equations are the electromagnetic basis of the Lorentzian electrodynamics and optics of moving bodies.
, 
,
is nothing else than the velocity of the electric charge, measured in the 
and 
and 
), they also hold in frame 
; that is to say that the vectors of the electric and the magnetic force 
, satisfy the following equations in 
given in 
, 
,
,
,
