1) The concept of virtual reality (VR) involves creating a simulated environment that can be explored and interacted with using specialized headsets and input devices.

2) In Greek mythology, the Trojan War is a legendary conflict between the city of Troy and the Greeks, sparked by the abduction of Helen of Troy. It is immortalized in Homer's epic poems, the Iliad and the Odyssey, and features famous heroes like Achilles, Hector, and Odysseus.

3) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.

4) The Black Lives Matter movement, which gained prominence in 2013, advocates for racial justice and equality, addressing systemic racism and police violence against Black individuals.