Oven gas stove included the AGA cooker invented in 1922 by Gustaf Dalén. The first electric ovens were invented in the very late 19th century, however, like many electrical inventions destined for commercial use, mass ownership of electrical ovens could not be a reality until better and more efficient use of electricity was available. More recently, ovens have become slightly more high-tech in terms of cooking strategy. The microwave as a cooking tool was discovered by Percy Spencer in 1946, and with the help from engineers, the microwave oven was patented. The microwave oven uses microwave radiation to excite the molecules
GADGET or to address star formation and its regulation by feedback processes. The first public version (GADGET-1, released in March 2000 was created as part of Volker's PhD project under the supervision of Simon White. Later, the code was continuously improved during postdocs of Volker Springel at the Harvard-Smithsonian Center for Astrophysics and the Max Planck Institute, in collaboration with Simon White and Lars Hernquist. The second public version (GADGET-2, released in May 2005 contains most of these improvements, except for the numerous physics modules developed for the code that go beyond gravity and ordinary gas-dynamics. The most important changes lie