Friday, January 29, 2010

IBEX slams the Electric Sun model yet again...

A few months ago, I had written on the IBEX 'ribbon' (see "Giant Ribbon Discovered at the Edge of the Solar System") and its implications for the Electric Sun (ES) claims (IBEX Results Cause Even More Problems for the Electric Sun Model).  The Thunderbolts forum had even tried to spin the IBEX result into support of the Electric Sun model, to which I responded with  “Electric Sun Verified”?? - In your dreams

Here is map of the IBEX energetic neutral atom (ENA) flux projected on the sky in an Aitoff-Hammer projection (Wikipedia: Aitoff, Wikipedia: Hammer).  The map is projected so the 'nose' of the Sun's motion through the interstellar medium, is at the center of the plot.  This map is projected as 'unwrapping' the sky around the Sun.  An animation illustrating how the sky is 'unwrapped' to create this projection is available at "IBEX First Skymap Release".  In this map, red color corresponds to maximum atom fluxes of up to 300 energetic neutral atoms per square centimeter per second per steradian (a measure of angular area on the sky) per kiloelectron volt for particles with energies between 0.9 to 1.5 kiloelectron volts.   The minimum values in blue and violet correspond to fluxes less than 100 atoms  in the same units. The maximum flux in the 'ribbon', the bright colored feature stretching across roughly the center of the map, is brighter than the background by a factor of about two or three. 

Science@NASA recently released a followup to the initial IBEX result, “Giant Ribbon at the Edge of the Solar System: Mystery Solved?” (podcast available).  There is more at Solar scientists use 'magnetic mirror effect' to reproduce IBEX observation.  These press releases are based on the paper:  J. Heerikhuisen, N. V. Pogorelov, G. P. Zank, G. B. Crew, P. C. Frisch, H. O. Funsten, P. H. Janzen, D. J. McComas, D. B. Reisenfeld, and N. A. Schwadron. Pick-Up Ions in the Outer Heliosheath: A Possible Mechanism for the Interstellar Boundary EXplorer Ribbon. Astrophysical Journal Letters, 708:L126–L130, January 2010. doi: 10.1088/2041-8205/708/2/L126.

With this press release, a mechanism has been proposed which seems to explain the IBEX ribbon feature.  As I suggested in "IBEX Results Cause Even More Problems for the Electric Sun Model", an explanation would most likely be found in more detailed consideration of the particle kinetics, and this mechanism certainly fits that description.  The mechanism provides a simple explanation why the ribbon appears where the interstellar magnetic field is perpendicular to the line-of-sight.

The graphic below is based on Figure 2 in the paper and illustrates the mechanism.  It considers the possible trajectories of two protons from the solar wind moving through the heliosphere.  One proton scatters off the interstellar magnetic field (ISMF) and continues outward, not being detected by IBEX (violet path).  The other proton scatters off the ISMF and is essentially 'reflected' back towards the inner solar system where it can be detected by IBEX (green path).  In  this graphic, various regions are labeled:

TS = termination shock (about 80 AUs from the Sun)
IHS = Inner heliosheath
OHS  = Outer heliosheath
HP = Heliopause

This process happen in multiple steps.  The red dots along the violet and green trajectories indicates points where ionization (loss of an electron, yielding a positively charged ion) or electron capture (gain of an electron by an ion resulting in a neutral atom) occurs with other particles in the region.  The dotted portion of the trajectories indicate where the atom is actually an ion:

1) The solar wind carries hydrogen ions (H+) out from the Sun and they penetrate the termination shock (TS) into the inner heliosheath (IHS).   The magnetic field carried in the solar wind does not strongly influence the trajectories of these ions.

2) In the IHS, they can charge-exchange an electron with the ambient neutral atoms, becoming an energetic neutral atom (ENA).  This interaction could result in a slight alteration of the ENAs trajectory due to energy-momentum conservation.

3) Once electrically neutral, the ENA travels in a straight line, uninfluenced by the local magnetic fields.  The ENA easily penetrates the heliopause into the outer heliosheath (OHS), where it encounters the interstellar magnetic field.

4) With another charge exchange with ambient plasma, the ENA becomes a pick-up ion (PUI) and is influenced by the interstellar magnetic field (ISMF).

5) The PUI gyrates in the magnetic field.  The gyro-radius for the particle energies and ISMF strength has a mean value of about 12,000 kilometers.  The density is sufficiently low that the timescale for the PUI to capture an electron and be converted back into an ENA is about two years.

6) The PUI eventually captures an electron and is freed from the magnetic field, proceeding off in the direction at the time of electron capture.

The process is surprising simple.  But the really interesting part is what happens depending on the direction of the solar wind ion with respect to the ISMF direction.  The violet trajectory crosses the ISMF at an angle that gives it a large velocity component parallel to the ISMF.  But the green trajectory crosses the ISMF with a small velocity component parallel to the ISMF.  This means the PUIs on the violet trajectory can travel a long way from the heliopause before it becomes an ENA again.  Meanwhile, the PUI on the green trajectory, with its much lower speed parallel to the magnetic field, will only travel a short distance before becoming an ENA again.  Essentially, the ENAs on the green trajectory get 'stored' for a time, by gyrating in the magnetic field.  Once neutralized to an ENA, there is a probability that some of the ENAs will be thrown back from the direction they came, where they have an increased probability of being detected by IBEX.

The authors of the paper simulated this process, constructed a skymap using the same projection as the IBEX data, which demonstrates the enhancement.

Here again is an example of how real science deals with problems.  Researchers present their model of the process in a form that can be analyzed mathematically.  This makes it easier for other researchers to critique, duplicate, and extend the analysis.  Is the IBEX ribbon solved?  I don't know.  But this analysis demonstrates that the problem is not fatal to the standard stellar models as the various pseudo-scientists try to promote it to be.

I suspect the Electric Sun (ES) advocates will continue to spin the IBEX result as a victory for their claims of the Sun and stars being powered by cosmic-scale external electric currents.  They will, as always, have nothing but 'stories' and/or 'cartoons' to support their claims and nothing that matches any actual measurements or models that can be rigorously tested. 

Will we ever see something like this from the Electric Sun supporters in a form that can be objectively reproduced by other researchers?

It's not impossible, but I'm not holding my breath.

Special thanks to Jacob Heerikhuisen (University of Alabama, Huntsville) for corrections and helpful comments.

Saturday, January 23, 2010

Review of "The Young Earth" by John Morris

Dr. Jellison provides another review of a 'creation science' book, Dr. John Morris' “The Young Earth: The Real History of the Earth - Past, Present, and Future”

Dr. Jellison focuses on issues of physics where he is more familiar, particularly radioisotope dating 'discrepencies' in recent lava flows and meteorites, which creationists commonly like to exploit.  For the lava flows, he points out that the dating studies Darylmple used in 1969 were not isochron dating methodologies.  Flows dated using isochron dating are much more in line with expected results.  There is an excellent treatment of isochron dating at which illustrates how the isochron mechanism corrects for the problems like unknown initial concentrations and diffusion of parent and daughter products.

The cavalier attitude of creationists when dealing with real data is revealed in this description of Isochron Dating on CreationWiki.  In the third graph from the bottom of the page, they present an example of points far off the isochron.  CreationWiki seems to be claiming that dropping the 'bad' data points is a legitimate scientific practice (I remember some school teachers who, incorrectly, claimed it was okay to drop 'outliers' in a set of data).  It is not legitimate practice to drop a point in the result just because it is an outlier.  However, samples can be dropped from an analysis should it be demonstrated that there is some irregularity in the sampling protocol.

However, the proper scientific approach is to fit the slope of all the data.  The spread in the points of the 'isochron' generate the error bar (Wikipedia), or uncertainty, of the measurement.  In the case of the isochron, the outliers would make the uncertainty far larger than for points which cluster tight around the fitted line.  Modern practice has more consistently enforced for all researchers to report the best fit and uncertainty of the fit. 

Jerry also discusses the popular creationist claim of accelerated radioactive decay.  I  have some additional details on accelerated radioactive decay, including discussions of modern experiments which demonstrate methods of altering nuclear decay rates: “Claims of Accelerated Radioactive Decay”.

Friday, January 15, 2010

"In the Beginning: Compelling Evidence for Creation and the Flood (8th Edition)"

Physicist Jerry Jellison has posted a scathing review of creationist Walt Brown's book, “In the Beginning: Compelling Evidence for Creation and the Flood (8th Edition)” (Amazon).  The critique, titled "Wrong, and I can prove it", can be found towards the bottom of the page or can be directly accessed here.

Jerry talks predominantly about the geological evidence, but he does discuss Brown's bizarre claim about the heat of accelerated radioactive decay being launched into space!

As with many pseudo-scientific claims, Brown's model is justified by computations and computer programs that are not available for testing or examination by other researchers.

Thursday, January 7, 2010

215th Meeting of the American Astronomical Society. II

The meeting is now over, so here's a summary.  I ran into many old friends and acquaintances.

Some of the highlights:

I met John Hearnshaw, who authored one of my favorite astronomy history books, “The Analysis of Starlight: One Hundred and Fifty Years of Astronomical Spectroscopy“ (Barnes & Noble).  I made heavy use of this reference when writing “The Cosmos in Your Pocket“.

I shook hands with John Grunsfeld, one of the astronauts who flew in the last Hubble Servicing mission, and thank him for a job well-done.  I had actually met John many years ago when I worked with the Compton Gamma Ray Observatory.

I ran into Sandy Antunes whom I worked with back when I did scientific programming at the HEASARC.  He is now doing science writing as The Daytime Astronomer.

I found out about work to improve the timing precision of clocks used in the GPS system (Wikipedia).  This will make relativistic effects even more important, creating even more problems for the relativity deniers among the Electric Universe supporters (see “Scott Rebuttal. I: GPS & Relativity“).

I was very pleased at the reception of the ideas presented in my poster “Crank Astronomy as a Teaching Tool?“.  There were a number of interesting stories from classroom professors about dealing with students advocating creationism.  A number of them expressed interest in the approach I was advocating and provided contact info, and I hope to follow up with them over the next few weeks.  I gave my contact info to many others.  I will refrain from mentioning names on this blog unless the individuals in question wish to identify themselves in the comments.

I spoke briefly with a professor who presented on taking a group of teachers-in-training to the Creation Museum.  That was a very interesting story and I hope this professor will follow-up with me.

Only a handful of professors I spoke to had even heard of the Electric Universe, though many were familiar with its philosophical predecessor, Immanuel Velikovsky (Wikipedia).

Among the additional ideas for my resources suggested by my visitors:
  • Many of the examples I presented illustrate very fundamental principles which physicists, astronomers, and engineers need to estimate quantities.  This is a powerful tool for future scientists and citizens.
  • Some future graduate students may encounter these types of questions in their Ph.D. qualifying exams!  They are an excellent source for testing unconventional thinking!
I listened to a number of talks ranging from astronomy education effectiveness to discovering new sources of data for developing content for this project.

I also notice a backlog of comments to earlier posts which need moderating and I should be able to address this weekend.  I want to check some of the references provided before I respond.

Sunday, January 3, 2010

215th Meeting of the American Astronomical Society

This week, I'm doing a poster session at the 215th American Astronomical Society meeting in Washington DC.  The poster is titled Crank Astronomy as a Teaching Tool?" and is based on material I've presented, or plan to present, on this blog.  Hopefully I'll get some useful feedback from people dealing with some of these issues in the classroom.

If anyone following this blog is at the meeting, feel free to drop by and say hello.

Update, January 4, 2010: Several people have reported that the link to the specific presentation above does not seem to work. Alternatively, you should be able to navigate through the abstract database. The entry point is here. Go to Wednesday, January 6 link. The session is 468: New Media and the Universe Online and the entry is 468.07.
Update 2, January 4, 2010: Okay.  That doesn't seem to work either.