Gran Sasso, Solar Neutrinos, and Radioactive Decay Rates

We interrupt your normal coverage of magnetic monopole searches today to bring you something much more cool from well.. the same location! I was jazzed to find out yesterday that the next monopole project I was going to write about was done at a stunningly pretty location Gran Sasso, Italy. (picture 1)

Then, thanks to +Oliver Thewalt I found out about a very interesting study done regarding a possible time dependence of the decay rates of radioactive isotopes. So much for the pretty location I thought, but the science is incredibly interesting. Then, while reading up on the research this morning I found out that one of the studies[2] was performed at none other than the very same lab in Gran Sasso. And we're back to where we started and I get to include a pretty picture with the post! OK, OK enough with the cool coincidences and the small world of science for today.

So, here's what's going on in a nutshell. Radioactive elements decay in a random fashion, but at a very well defined rate. In other words, you never know exactly when the next individual atom of the material will decay, but you do know with great certainty how long it will take for half of the material to decay. For example, the carbon dating process is based on the certainty of the half life of carbon 14[5]. Until recently, the rate of decay was thought to be a constant. Then, a researcher at Purdue University, Ephraim Fischbach, noticed what looked like a periodic variation in the decay rate of radioactive materials over the course of months and sometimes years. Additional research revealed that there might be a correlation between this measured variation and the neutrino output from the sun. For a great summary of the research check out the Stanford backgrounder on the subject [3]. The graph shown in picture 2 is from Fischbach's paper. It shows the variation in the decay rate of radium 226 with time and correlates the decay rate variation with the variation of the distance between the Earth and the Sun, (shown as a solid line)[6][7].

Gran Sasso
You thought I forgot about Gran Sasso didn't you? They performed an experiment which they believe refutes the relationship found by Fischbach et al. Here's a quote from the conclusion of their paper[2][2a]

"...in clear contradiction with previous experimental results and their interpretation as indication of a novel ﬁeld (or particle) from the Sun..."

The experiment was done at Gran Sasso because conditions there were great. The laboratory is actually located underground, (under a lot of ground), and well protected from variations in both electromagnetic fields and temperatures (picture 3).

The results are still up in the air. The Fischbach group responded to the Gran Sasso paper[8], and Fischbach believed in the results enough to file for a patent on a solar event detector based on the results in 2008[4], (picture 4).

There will be much more on all this to follow.

Reference:
1. The latest and greatest from Jenkins, Fischbach, et al. (open access)
http://arxiv.org/abs/1211.2138

2. The Gran Sasso null result
http://dx.doi.org/10.1016%2Fj.physletb.2012.02.083
Bellotti E., Broggini C., Di Carlo G., Laubenstein M. & Menegazzo R. (2012). Search for time dependence of the 137Cs decay constant, Physics Letters B, 710 (1) 114-117. DOI: 10.1016/j.physletb.2012.02.083

2.a. The Gran Sasso paper in open access
http://arxiv.org/abs/1202.3662

3. Stanford sums it up
http://news.stanford.edu/news/2010/august/sun-082310.html

4. Fischbach's patent
http://www.google.com/patents?id=WTy_AAAAEBAJ&zoom=4&dq=decay%20%22E%20Fischbach%22&pg=PA1#v=onepage&q&f=false

5. Carbon dating on Wikipedia
http://en.wikipedia.org/wiki/Radiocarbon_dating

6. Fischbach et al.'s first paper from 2008 (open access)
http://arxiv.org/abs/0808.3283

7. The same paper in the journals
http://dx.doi.org/10.1016%2Fj.astropartphys.2009.05.004
Jenkins J.H., Fischbach E., Buncher J.B., Gruenwald J.T., Krause D.E. & Mattes J.J. (2009). Evidence of correlations between nuclear decay rates and Earth–Sun distance, Astroparticle Physics, 32 (1) 42-46. DOI: 10.1016/j.astropartphys.2009.05.004

8. Response to the Gran Sasso paper (open access)
http://arxiv.org/abs/1211.2138

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:

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 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 concept very sim

Copasetic Flow

Search This Blog