Recent content by jgraber

More on extreme energy gamma rays If you look at log plots of spectra from HESS, there are points at 30 TeV for the Crab and for MGRO J1908+6. This implies they’ve seen more than one photon at or near that energy. As gamma rays get more and more energetic, it gets harder and harder to tell...

http://www.mpi-hd.mpg.de/hfm/HESS/pages/about/telescopes/ Here is a link to their home page. Hess has four telescopes about the same size as MAGIC. HESS is in southern Africa in Namibia. Jim Graber

Highest secure claim I am aware of is 20 Tev, detected by HESS from LS5039 reported in Astro-ph/0607192. LS5039 is a High Mass X-Ray Binary. Jim Graber

Below is a link to a recent paper about globular clusters discussing evidence favorable to MOND: http://arxiv.org/ftp/arxiv/papers/0707/0707.2459.pdf

If CarlB (or anyone else) wants to compare his recent results to the relativistic orbits used to make predictions for black hole inspirals by the people who work on LIGO, LISA, VIRGO, TAMA, GEO etc., they are readily available on the web at Living Reviews in Relativity...

Hi everyone, Sorry I can only post on coffee breaks when I am near the APS temporary hotspot. As I understand the "glimpses" each ellipse is a one sigma radius, and GR is very near the center of the earliest, crudest glimpse, and about two radii (i.e. approx two sigma) from the smallest...

The fractional data is due to two things: 1 They are not yet done analyzing it. 2. The spacecraft shut down briefly nine times during the eleven months of science data taking. they are working on "stitching it together." Best. Jim Graber

henryco, the other axis is the geodetic effect. The center of the largest ellipse is close to the expected GR value. Jim Graber

Preliminary Frame Dragging "Glimpse" I am posting from the APS meeting in Jacksonville. You can see the preliminary result that was presented here, with lots and lots of caveats, by going to the GPb Homepage, http://einstein.stanford.edu/index.html and clicking on poster L1.00028...

Lagrange's calculation is based on very general (but also very specialized) mathematics, in particular the Newtonian two body problem. So yes, there should be the same old 5 lagrangian points for the Milky Way and the Andromeda galaxy, since they are a reasonably good approximation to a two...

Jacquesl, Go to the interactive chart of nuclides at http://www.nndc.bnl.gov/chart/ for answers to your questions. Its true you need a basic education. But do it yourself is fun, too. good luck! By the way, 8B->4He + 4He. 5Li -> 4He + 1H. It really is like simple arithmetic. Other...

See comments at Lubos Motl's blog for more on this story. I'm far from an expert, but here's my take: Bumps like this two sigma thing come and go all the time and mean nothing. Most of the experts seem to expect a light Higgs, but a heavy Higgs, eg near 175 Gev, is predicted by split...

recently I found a link which reminded me that it is split supersymmetry which has a preference for a Higgs mass near 170 GeV. look at slides 6 and 7 in this reference. http://james.physik.uni-freiburg.de/Graduiertenkolleg/talks/TPlehnFreiburg.pdf So now I am puzzled why this option has...

This is not possible unless the first nucleus is initially in an excited state. (See also nuclear isomer). In this case it could be theoretically possible, but I am not aware of any such case which is actually known to occur. Jim Graber

Whatever happened to the old GUTS? Since you're a big believer in GUTS, I will ask you a question I was thinking of making into a thread of its own: Whatever happened to the old GUTS like SO(10), SU(4)xSU(4) and Flipped SU(5)xU(1)? As I remember it, these were the three leading...