Before the 20th century, the term matter included ordinary matter composed of atoms and excluded other energy phenomena such as light or sound. This concept of matter may be generalized from atoms to include any objects having mass even when at rest, but this is ill-defined because an object's mass can arise from its (possibly massless) constituents' motion and interaction energies. Thus, matter does not have a universal definition, nor is it a fundamental concept in physics today. Matter is also used loosely as a general term for the substance that makes up all observable physical objects.
In what century was the term matter defined excluding energy phenomena like light and sound?
20th

Guest judges may occasionally be introduced. In season two, guest judges such as Lionel Richie and Robin Gibb were used, and in season three Donna Summer, Quentin Tarantino and some of the mentors also joined as judges to critique the performances in the final rounds. Guest judges were used in the audition rounds for seasons four, six, nine, and fourteen such as Gene Simmons and LL Cool J in season four, Jewel and Olivia Newton-John in season six, Shania Twain in season eight, Neil Patrick Harris, Avril Lavigne and Katy Perry in season nine, and season eight runner-up, Adam Lambert, in season fourteen.
In what season was Donna Summer a guest judge on American Idol?
season three

The slave trade was engaged in by European state and non-state actors such as Great Britain, the Netherlands, Portugal and private companies, as well as various African states and non-state actors. With rising anti-slavery sentiment at home and changing economic realities, Great Britain outlawed the international slave trade in 1807. Following the Napoleonic Wars, Great Britain established the West Africa Squadron in an attempt to halt the international traffic in slaves. It stopped ships of other nations that were leaving the African coast with slaves; the seized slaves were taken to Freetown, a colony in West Africa originally established for the resettlement of freed slaves from Britain. Britain intervened in the Lagos Kingship power struggle by bombarding Lagos in 1851, deposing the slave trade friendly Oba Kosoko, helping to install the amenable Oba Akitoye, and signing the Treaty between Great Britain and Lagos on 1 January 1852. Britain annexed Lagos as a Crown Colony in August 1861 with the Lagos Treaty of Cession. British missionaries expanded their operations and travelled further inland. In 1864, Samuel Ajayi Crowther became the first African bishop of the Anglican Church.
Which Lagos king had supported the slave trade?
Oba Kosoko