Archive for February, 2011

Feb 22 2011

LHC Motto

In an earlier entry it was lamented how some physicists seem to make a transition from special to general relativity as though the two are somehow linked.  I don’t know if the Wikipedia article on Albert Einstein was written by a physicist, however it goes one step further and gets relativity completely mixed up.  It calls Einstein “a German born theoretical physicist who discovered the theory of general relativity effecting a revolution in physics.” [1]

For young people studying math and science, please note that it was special relativity that advanced physics by a giant leap, not general relativity.  In a recent article on CERN’s startup of the Large Hadron Collider after a 10-week shutdown, Robert Evans of Reuters, and the Toronto Sun, got it right when it was said:

“New Physics, the motto of the LHC, refers to knowledge that will take research beyond the “Standard Model” of how the universe works that emerged from the work of Albert Einstein and his 1905 Theory of Special Relativity.” [2]




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Feb 10 2011

Steady Sources

Published by under Astrophysics

The “Fermi Sky Blog” can be reached from the Fermi main web page [1], though I guess it doesn’t hurt to note the direct link here [2].

In the “Fermi LAT weekly report N. 138 … 2011.January.24 – 2011.January.30”, we find the following:  “3C 454.3 fairly bright for all the week, with daily flux between 2.5e-6 and 6.4e-6.”  This type of report has been a fairly common format in the Fermi Sky Blog, with flux levels often being very low, from sources so far away that it leaves one quite impressed with the technology and analysis methods whatever they may be.

Noteworthy is that “Fluxes are in the unit of photons/cm2/s above 100 MeV. All errors are statistical only.”  Gravity is at 313 MeV and, as has been said many times before, the LAT seems designed to measure gravity as one of its main purposes.  The designers would not have had to know how gravity works; they would only have had to know the typical frequency range of sources from past data and experience.

Steady sources said to be “fairly bright for all the week” are encouraging to see, because gravity at a given relative location and time period is normally a steady field.  Most sources above 100 MeV are indeed steady, and let us be reminded that even the closest celestial body to the earth, the moon, is “an object with an absolutely known gamma-ray output” [3], and a stunning image [4].






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