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In 1974, the unmanned AstroFlight Sunrise plane made the first solar flight. On 29 April 1979, the Solar Riser made the first flight in a solar-powered, fully controlled, man carrying flying machine, reaching an altitude of 40 feet (12 m). In 1980, the Gossamer Penguin made the first piloted flights powered solely by photovoltaics. This was quickly followed by the Solar Challenger which crossed the English Channel in July 1981. In 1990 Eric Scott Raymond in 21 hops flew from California to North Carolina using solar power. Developments then turned back to unmanned aerial vehicles (UAV) with the Pathfinder (1997) and subsequent designs, culminating in the Helios which set the altitude record for a non-rocket-propelled aircraft at 29,524 metres (96,864 ft) in 2001. The Zephyr, developed by BAE Systems, is the latest in a line of record-breaking solar aircraft, making a 54-hour flight in 2007, and month-long flights were envisioned by 2010. As of 2015, Solar Impulse, an electric aircraft, is currently circumnavigating the globe. It is a single-seat plane powered by solar cells and capable of taking off under its own power. The designed allows the aircraft to remain airborne for 36 hours.
When was the first unmanned flight by a solar powered plane made?
A: 1974

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On 15 July 1974, the Greek military junta under Dimitrios Ioannides carried out a coup d'etat in Cyprus, to unite the island with Greece. The coup ousted president Makarios III and replaced him with pro-enosis nationalist Nikos Sampson. In response to the coup, five days later, on 20 July 1974, the Turkish army invaded the island, citing a right to intervene to restore the constitutional order from the 1960 Treaty of Guarantee. This justification has been rejected by the United Nations and the international community.
What did the Turkish army to do respond to the coup d'etat?
A: invaded the island

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God's consequent nature, on the other hand, is anything but unchanging it is God's reception of the world's activity. As Whitehead puts it, "[God] saves the world as it passes into the immediacy of his own life. It is the judgment of a tenderness which loses nothing that can be saved." In other words, God saves and cherishes all experiences forever, and those experiences go on to change the way God interacts with the world. In this way, God is really changed by what happens in the world and the wider universe, lending the actions of finite creatures an eternal significance.
What effect does Whitehead claim that experiences have on God?
A: those experiences go on to change the way God interacts with the world

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Due to the tree structure of the filter bank, pre-echo problems are made worse, as the combined impulse response of the two filter banks does not, and cannot, provide an optimum solution in time/frequency resolution. Additionally, the combining of the two filter banks' outputs creates aliasing problems that must be handled partially by the "aliasing compensation" stage; however, that creates excess energy to be coded in the frequency domain, thereby decreasing coding efficiency.[citation needed]
Combining two filter banks' outputs creates what kind of problem?
A:
aliasing