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More about LIGO, Higgs Bosons, and Tabby's Star

by John G. Cramer

Alternate View Column AV-183
Keywords:  LIGO rumors, 2nd Higgs, LHC, Kepler, KIC8462852, slow light-flux decrease, alien megastructures
Published in the July-August-2016 issue of Analog Science Fiction & Fact Magazine;
This column was written and submitted 01/18/2016 and is copyrighted ©2016 by John G. Cramer.
All rights reserved. No part may be reproduced in any form without
the explicit permission of the author.

In three of my previous AV columns, I have written about the discovery of the Higgs boson (AV-165, Analog December-2012), a discussion of two possible flavors of gravitational waves that might be detected by Advanced LIGO (AV-180, Analog March-2016) , and the observation of peculiar starlight flux variations in F-type star KIC846852, otherwise known as Tabby's Star (AV-181, Analog May-2016).  In this column, I want to discuss new developments in each of these areas of discovery that have appeared with the beginning of 2016.  We'll start with LIGO rumors.


Advanced LIGO (aLIGO), which is three time more sensitive than the original LIGO configuration, began taking physics data on September 18, 2015.  Within a week, rumors were flying that aLIGO had already observed gravitational waves.  In particular, on September 25, 2015 prominent theoretical physicist Lawrence Kraus of Arizona State University, author of The Physics of Star Trek, posted a Twitter message: "Rumor of a gravitational wave detection at aLIGO detector. Amazing if true. Will post details if it survives."  By mid-January, 2016, more of these rumors have appeared.  On January 13, 1016, astrophysicist Steinn Sigurdsson of Pennsylvania State University pointed out a flurry of theoretical preprints posted on arXiv.org, all calculating the specific gravitational wave signal that would be expected from the merger of two 10 solar-mass black holes.  Sigurdsson suggested that the specifity of these papers can be taken as evidence that the authors may have received leaked information about a new aLIGO observation.  Kraus also recently posted the comment that he’s now 60% sure that his detection story will pan out.  And theoretical physicist Luboš Motl posted on his blog the rumor that aLIGO has detected gravitational waves produced by two colliding black holes, each with at least 10 solar masses, and that two such events have been detected.

My own sources have not provided any additional information that might substantiate these rumors, but I predict that within a month or so of writing this column (1/18/2016), some announcement from aLIGO will be made.  Beyond the actual detection of gravitational waves, I am particularly interested in the "flavor" of the waves detected, and in particular whether they are the tensor waves predicted by Einstein's general theory of relativity or the vector waves predicted by Carver Mead's G4v theory of gravity (see AV-180, Analog March-2016).  If the latter were to be observed, nothing less than a major revolution in theoretical physics and astrophysics would follow.


As I had reported in my AV column published in the December-2012 issue of Analog, on July 4, 2012 the CMS and ATLAS collaborations at CERN, studying 8 TeV proton-proton collisions at the Large Hadronic Collider (LHC), jointly announced that they had discovered a previously unknown boson with a mass-energy of 125 GeV.  After the study of decay modes, this particle was confirmed to be the long sought-after Higgs boson, the particle that Nobel Laureate Leon Lederman had dubbed "The God Particle".  In one way the Higgs discovery was a great triumph for high energy particle physics, since the Higgs was the missing puzzle-piece that gave mass to fundamental particles and had been predicted by the standard model of particle physics and sought for many years.

But in another way, it was more of a place holder.  Before the LHC, all major high-energy physics accelerators had regularly produced new physics, unexpected particles, and unanticipated surprises.  But the LHC had thus far only delivered a discovery that had been long expected, the Higgs boson.  Other searches for new physics at the LHC had, up to that point, failed.  None of the many particles predicted by super-symmetry, no mini-black-holes, no evidence of extra dimensions, etc.  The Higgs was supposed to be there, and sure enough, it was.  But where were the surprises we had come to expect?

On February 14, 2013 the LHC shut down for two years of improvements.  On June 3, 2015 physic running resumed again with the collision energy now boosted from 8 TeV to 13 TeV.  After about six months of running at this new energy, on December 15, 2015 there was an announcement that both the CMS and ATLAS detectors had observed hints of a new particle with a mass-energy of 750 GeV (six times the Higgs mass).  It decayed into two gamma rays, it was not observed in several other decay channels, and it might be a second Higgs boson.

By high energy physics convention the true discovery of a new particle requires a statistical precision of at least 5 standard deviations (or 5 s).  The ATLAS observation was 3.6 s and the CMS observation, based on fewer events because of detector startup problems, was 2.6 s.  Thus, their results are a suggestion, not a discovery.  Nevertheless, there is only one chance in about 96 that the observation is a statistical fluke.  The new particle is probably a second Higgs boson.

The significance of this observation is that the standard model does not predict that there should be a second Higgs, so this represents new physics beyond the standard model.  There are already a flurry of new theoretical papers proposing extensions of the standard model that can accommodate the new 750 GeV Higgs boson.  It has been theoretically connected to heavier unknown quarks and has been viewed as the harbinger of extra dimensions.  It will take some time for the observation to be confirmed at the 5 s level of statistics, for other decay modes to be fully explored, and for the theoretical dust to settle.  We'll see, in six months or so.

But there seems to be a good chance that the standard model has been broken and is in need of repair.  One physicist, recalling Lederman's designation of the Higgs as the God Particle, speculated that particle physics may be entering the era of polytheism, with multiple Gods.


My AV column published in the May-2016 issue of Analog reported the discovery in data from NASA's Kepler exo-planet-finding satellite mission of unexpected intensity fluctuations in the starlight from KIC8462852, a yellow-white main sequence F3 V star of about 1.43 solar masses that is about 1,481 light years from the Earth.  The star has been informally given the name "Tabby's Star" after astronomer Tabitha Boyajian of Yale University , the leader of the reporting group.  Their investigation showed bizarre starlight intensity fluctuations including deep dips of 15% and 22% lasting about a day each at two separate times during the Kepler observation.  The scenario that the Boyajian group favored for explaining the fluctuations was that the dips were a coincidence that happened to be produced by an infalling comet swarm. The hypothesis is that the comet swarm intercepted light flux from the star at just the time period when Kepler was making its observations.  A distant-binary companion of Tabby's Star had been found, and it was suggested that orbit perturbations by this companion may have produced the swarm of comets.  Such an occultation by comets, however, would probably be a rare and fairly brief event, and so the group urged additional observations.

Another group of astronomers led by Jason T. Wright of Pennsylvania State University suggested the alternative that the light flux variations might indicate the presence of a large Dyson-type swarm of orbital mega-structures around Tabby's Star, presumably placed there by a high-technological-level extraterrestrial civilization.  Assuming that a swarm of eight or more such mega-structures were in orbit, they found that this scenario could fit and explain the observed occultation, and they recommended an SETI search for unusual radio emissions from the system.  Radio astronomers have subsequently studied Tabby's Star, but so far they have found no tell-tale radio emissions.

Now, however, there is an observation of a new peculiarity associated with Tabby's Star.  Astronomer Bradley Schaefer of Louisiana State University used the Harvard Observatory's archival collection of astronomical photographic plates spanning the time interval from1890 to 1989 to look for variations in the average light flux from Tabby's Star.  He found that the star has been becoming progressively dimmer over the century that is spanned by the plates.  Fitting a set of intensity points representing averages over 5-year periods, he found a systematic decrease in astronomical magnitude of 0.165±0.013 per century, corresponding to a drop in light intensity of about 0.164% per year (or 16.4% per century).  As a check, he used the same techniques to measure the light flux of nearby stars and showed that they exhibited no similar decreases.

Thus, Tabby's star shows at least two peculiarities, fast drops in flux of 16-20% over a period of about a day and slow progressive drops in flux of about 16.4% over a century.  The latter observation makes the comet scenario favored by the Boyajian group seem rather unlikely.  Schaefer estimates that it would require a steady flow over the century of 648,000 comets with diameters of 200 km each to produce the observed decrease.

Does this make the alien super-civilization hypothesis more plausible?  In a way, it does.  One can imagine that once the high technology and motivation for building mega-structures in space exists, more and more of them will be built as time goes on, blocking more and more starlight.   However, Schaefer argues that it seems unlikely that even an advanced civilization could build enough structures to block 1/6 of a star's light in only a century.

Further, there is a question of where the star's light-energy is going.  Freeman Dyson had used thermodynamic arguments to predict that mega-structures that absorbed energy from visible starlight would have to re-radiate a sizable fraction of that energy in the infrared.  Studies of Tabby's Star in the infrared have shown no enhanced emission in expected region, and radio astronomers have found no suggestive radio emissions.

This leaves us with the question of just what is going on with Tabby's Star.  There seem to be no plausible scenarios that fit all of the available observations.  As Alice might say, Tabby's Star is getting curiouser and curiouser.


References:

Carver Mead, "Gravitational Waves in G4v", ArXiV preprint 1503.04866 [gr-qc] (2015).

Maximiliano Isi,  Alan J. Weinstein,  Carver Mead, and Matthew Pitkin, "Detecting Beyond-Einstein Polarizations of Continuous Gravitational Waves", Phys. Rev. D 91, 082002 (2015); ArXiV preprint 1502.00333 [gr-qc].

T. S. Boyajian, D. M. LaCourse, et al., "Planet Hunters X.  KIC 8462852 - Where's the flux?", Monthly Notes of the Royal Astronomical Society (submitted); arXiv: 1509.03622v1 [astro-ph.SR].

J. T. Wright, K. M. S. Cartier, M. Zhao, D. Jontof-Hunter, and E. B. Ford, "The G Search for Extraterrestrial Civilizations with Large Energy Supplies: The Signatures and Information Content of Transiting Megastructures", Astrophysics Journal (submitted) ; arXiv preprint: 1510.04606v1 [astro-ph.EP].

Bradley E. Schaefer, "KIC8462862 Faded at an Average Rate of 0.165±0.013 Magnitudes per Century from 1890 to 1989"); arXiv preprint: 1601.03256v1 [astro-ph.SR].


John Cramer's new book:  a non-fiction work describing his Transactional Interpretation of quantum mechanics, The Quantum Handshake - Entanglement, Nonlocality, and Transactions, (Springer, January-2016) is available for purchase online as a printed or eBook at: http://www.springer.com/gp/book/9783319246406

SF Novels by John Cramer:  my two hard SF novels, Twistor and Einstein's Bridge, are newly released as eBooks by Book View Cafe and are available at : http://bookviewcafe.com/bookstore/?s=Cramer .

AV Columns Online: Electronic reprints of about 180 "The Alternate View" columns by John G. Cramer, previously published in Analog , are available online at: http://www.npl.washington.edu/av.


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