Dark Matter and Spacecraft Flyby Anomalies

A number of sources[2][3] today reported on the possible detection of dark matter particles or WIMPs from the CDMS II experiment. This is pretty slick for a number of reasons. First, one of the research teams on the CDMS II experiment is located right here at Texas A&M. Second, the other dark matter experiment that's mentioned in the nature blog, LUX, also has a team of researchers working here at A&M. I was sitting in a professor's office discussing using liquid helium as a scintillator for the h-ray experiment a few days ago and he mentioned their use of liquid xenon as a scintillator on LUX, and now this! For those interested, liquid xenon makes a better scintillator than liquid helium for a few reasons. The most interesting of these to me is that helium is small enough to penetrate into a photomultiplier tube and ruin it's vacuum over time. Basically, it's very hard to keep helium from penetrating containers.

What about the spacecraft flyby anomalies?
Finally, there's the association between dark matter and the spacecraft flyby anomalies I mentioned in my previous post[4]. I mentioned a paper[1] by Adler that studied whether or not spacecraft flyby anomalies might the result of interactions with dark matter. The predictions for dark matter mass from Adler's paper do not match the mass measured in the data reported from CDMS II experiment today. Adler's paper calls for a dark matter particle with a mass below 1 GeV, (look for the white asterisk in picture 1). The CDMS II data implies a particle mass of roughly 8.6 GeV. So, for now, no confirmation of any spacecraft interacting with dark matter halos.

References:

1. Adler on flyby anomalies and dark matter mass
http://dx.doi.org/10.1103%2FPhysRevD.79.023505
Adler S. (2009). Can the flyby anomaly be attributed to earth-bound dark matter?, Physical Review D, 79 (2) DOI: 10.1103/PhysRevD.79.023505

2. Nature blog on the WIMP data
http://blogs.nature.com/news/2013/04/another-dark-matter-sign-from-a-minnesota-mine.html

3. CMDS II paper
http://cdms.berkeley.edu/CDMSII_Si_DM_Results.pdf

4. Flyby anomalies and dark matter post
http://copaseticflow.blogspot.com/2013/04/spacecraft-flyby-anomolies.html

Comments

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain ...

The Alcubierre Warp Drive Tophat Function and Open Science with Sage

I transferred yesterday's Mathematica file with the Alcubierre warp drive[2] line element and space curvature calculations to the +Sage Mathematical Software System today, (the files been added to the public repository [3]). If you haven't used Sage before, it's a Python based software package that's similar in functionality to Mathematica. Oh, and it' free. I also worked a little more on understanding the theory, but frankly, I made far more progress with the software than the theory. What follows will be a little more of the Alcubierre theory, plus, a cool Sage interactive demo of one of the Alcubierre functions[1], as well as a bit about my first experience with using Sage. Theory The theory is fun, but it's moving slowly. Here's the chalk board from this morning's discussion Alcubierre setup the derivation using something called the 3+1 formalism which means we consider space to be flat, (in this case), slices that are labelled ...

The Valentine's Day Magnetic Monopole

There's an assymetry to the form of the two Maxwell's equations shown in picture 1. While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero. This is typically explained in the following way. While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare. That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2]. Cabrera was utilizing a loop type of magnetic monopole detector. Its operation is in...

Copasetic Flow

Search This Blog