The U-2 is one of a handful of aircraft types to have served the USAF for over 50 years. The newest models (TR-1, U-2R, U-2S) entered service in the 1980s. The current model, the U-2S, received its most recent technical upgrade in 2012. They have taken part in post-Cold War conflicts in Afghanistan and Iraq, and supported several multinational NATO operations.
In the simple case n = 1, the group U(1) corresponds to the circle group, consisting of all complex numbers with absolute value 1 under multiplication. All the unitary groups contain copies of this group.
The general unitary group (also called the group of unitary similitudes) consists of all matrices A such that A∗A is a nonzero multiple of the identity matrix, and is just the product of the unitary group with the group of all positive multiples of the identity matrix.
Properties
Since the determinant of a unitary matrix is a complex number with norm , the determinant gives a group homomorphism
SM U-2 was a GermanU-boat built for the Imperial German Navy. Only one of the type, sometimes called German Type U 2 submarine, was built. U-2 was ordered from Kaiserliche Werft of Danzig on 4 March 1906, launched on 18 June 1908, and commissioned into the Imperial German Navy on 18 July 1908. She conducted no war patrols and spent World War I as a training platform.
Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–19452. Translated by Thomas, Keith; Magowan, Rachel (London: Conway Maritime Press). ISBN0-85177-593-4.
Rössler, Eberhard (1985). U-Bootbau bis Ende des 1. Weltkriegs, Konstruktionen für das Ausland und die Jahre 1935-1945. Die deutschen U-Boote und ihre Werften (in German) I (Koblenz: Bernard & Graefe). ISBN3-7637-5213-7.
Robert C. Stern. Battle Beneath the Waves: U-boats at War, Cassell Military Paperbacks, 2002. ISBN 0-304-36228-X
In March 2020, the US Department of Defense said there was no evidence of UFOs being alien in origin but attributed sightings to more mundane explanations like balloons, spy planes, and satellites.However, there are more sensational claims.
The number is even higher when thefts not reported to the police are included ...SaferGroup, based in Port Glasgow, Inverclyde, has worked with Morrisons, Tesco and Aldi, installing ... ... My engineering career took me from RAF spy planes to Big Tech data ... .
There’s nothing unusual about China’s trying to spy on Americans or promote itself ...China once bought a Boeing 767 as its presidential plane, the equivalent of Air Force One, and discovered 27 bugs embedded inside.
RepublicanRep ... In March 2024, the Pentagon issued a report stating that it had no proof of UFOs, claiming that many suspicious sightings were actually weather balloons, spy planes, satellites, or other normal activity ... SOURCE .
P-8 Poseidon and Rivet Joint spy planes will join the Nato operation to protect undersea cabling in the Baltic Sea, while RFAProteus has also been deployed to monitor offshore infrastructure.
When launching the government’s plan to leverage artificial intelligence last week, Sir Keir Starmer said he wanted to make the UK an AI “superpower” ...Business & Money ... ANALYSIS ... My engineering career took me from RAF spy planes to Big Tech data ... .
Cuba said last week that it was releasing 553 prisoners "in the spirit of" Francis' 2025 Holy Year and had informed the pope of its decision ahead of time ... designation of the island nation as a state sponsor of terrorism ... spy planes ... .
and European security officials last year disrupted an alleged Russian plot to smuggle incendiary devices on cargo planes in an apparent trial run for later attacks targeting the United States and Canada.
, the determinant gives a 
Chatanooga Times Free Press
25 Jan 2025
Chatanooga Times Free Press
25 Jan 2025