donaggie03 writes: An official statement explaining the unusual GPS timing anomaly that occurred a few days ago has just been release. The root cause was a software bug at the ground station. As some have suggested, the bug was triggered by the removal of SVN 23 from the satellite constellation. The full press release is as follows:
Subject: CGSIC: FW: Official Press Release — GPS Ground System Anomaly
Air Force Official Press Release — GPS Ground System Anomaly
On 26 January at 12:49 a.m. MST, the 2nd Space Operations Squadron at the 50th Space Wing, Schriever Air Force Base, Colo., verified users were experiencing GPS timing issues. Further investigation revealed an issue in the Global Positioning System ground software which only affected the time on legacy L-band signals. This change occurred when the oldest vehicle, SVN 23, was removed from the constellation. While the core navigation systems were working normally, the coordinated universal time timing signal was off by 13 microseconds which exceeded the design specifications. The issue was resolved at 6:10 a.m. MST, however global users may have experienced GPS timing issues for several hours. U.S. Strategic Command's Commercial Integration Cell, operating out of the Joint Space Operations Center, effectively served as the portal to determine the scope of commercial user impacts. Additionally, the Joint Space Operations Center at Vandenberg AFB has not received any reports of issues with GPS-aided munitions, and has determined that the timing error is not attributable to any type of outside interference such as jamming or spoofing. Operator procedures were modified to preclude a repeat of this issue until the ground system software is corrected, and the 50th Space Wing will conduct an Operational Review Board to review procedures and impacts on users. Commercial and Civil users who experienced impacts can contact the U.S. Coast Guard Navigation Center at
CGSIC Executive Secretariat
GPS Information Analysis Team Lead
U.S. Coast Guard Navigation Center
donaggie03 writes: "Well, my fellow mathematicians, it's that time again. Agostino Prástaro, from the Univeristy of Rome, claims to have proven Goldbach's Conjecture. The 14 page paper, THE GOLDBACH’S CONJECTURE PROVED (link to pdf) is pre-published on Arxiv. Prástaro claims to have proven the conjecture through commutative algebra and algebraic topology: Abstract. We give a direct proof of the Goldbach’s conjecture in number theory, formulated in the Euler’s form. The proof is also constructive, since it gives a criterion to find two prime numbers 1, such that their sum gives a fixed even number 2. (A prime number is an integer that can be divided only for itself other than for 1. In this paper we consider 1 as a prime num-ber.) The proof is obtained by recasting the problem in the framework of the Commutative Algebra and Algebraic Topology. So is this a valid proof? Are there any glaring errors or has this conjecture finally been proven?"
donaggie03 writes: "The Air Force's X-51A Waverider crashed into the Pacific Ocean after being dropped from the wing of a B-52 bomber. 16 seconds into the test flight, a faulty control fin caused the Waverider lost control.
The Air Force had hoped the craft would be able to reach speeds of up to 4,600 mph. The service said it will release details of the failed test in a few weeks, after researchers are able to analyze the data from the flight."