MatterIn classical physics and general chemistry, matter is any substance with mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic particles, and in everyday as well as scientific usage, matter generally includes atoms and anything made up of them, and any particles (or combination of particles) that act as if they have both rest mass and volume. However it does not include massless particles such as photons, or other energy phenomena or waves such as light or heat.
VeliaVelia was the Roman name of an ancient city of Magna Graecia on the coast of the Tyrrhenian Sea. It was founded by Greeks from Phocaea as Hyele (Ὑέλη) around 538–535 BC. The name later changed to Ele and then Elea (ˈɛliə; Ἐλέα) before it became known by its current Latin and Italian name during the Roman era. Its ruins are located in the Cilento region near the modern village Velia, which was named after the ancient city. The village is a frazione of the comune Ascea in the Province of Salerno, Campania, Italy.
VacuumA vacuum (: vacuums or vacua) is a space devoid of matter. The word is derived from the Latin adjective vacuus for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space.
TheophrastusTheophrastus (ˌθiː.əˈfræstəs; ; 371 - 287 BC) was a Greek philosopher and the successor to Aristotle in the Peripatetic school. He was a native of Eresos in Lesbos. His given name was Τύρταμος (); his nickname Θεόφραστος () was given by Aristotle, his teacher, for his "divine style of expression". He came to Athens at a young age and initially studied in Plato's school. After Plato's death, he attached himself to Aristotle who took to Theophrastus in his writings. When Aristotle fled Athens, Theophrastus took over as head of the Lyceum.
XenophanesXenophanes of Colophon (zəˈnɒfəniːz ; Ξενοφάνης ὁ Κολοφώνιος ksenophánɛːs ho kolophɔ̌ːnios; c. 570 – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer from Ionia who travelled throughout the Greek-speaking world in early Classical Antiquity. As a poet, Xenophanes was known for his critical style, writing poems that are considered among the first satires. He also composed elegiac couplets that criticised his society's traditional values of wealth, excesses, and athletic victories.
MetaphysicsMetaphysics is the branch of philosophy that studies the fundamental nature of reality. This includes the first principles of: being or existence, identity, change, space and time, cause and effect, necessity, actuality, and possibility. Metaphysics is considered one of the four main branches of philosophy, along with epistemology, logic, and ethics. It includes questions about the nature of consciousness and the relationship between mind and matter, between substance and attribute, and between potentiality and actuality.