Tgtbt: Justina Marsh And Peter Marsh

Justina Marsh and Peter Marsh discuss The Universe - The Universe is all of space and time (space-time) and its contents,[ which includes planets, moons, minor planets, stars, galaxies, the contents of intergalactic space and all matter and energy. The size of the entire Universe is still unknown. The earliest scientific models of the Universe were developed by ancient Greek and Indian philosophers and were geocentric, placing Earth at the centre of the Universe. Over the centuries, more precise astronomical observations led Nicolaus Copernicus to develop the heliocentric model with the Sun at the centre of the Solar System. In developing the law of universal gravitation, Sir Isaac Newton built upon Copernicus's work as well as observations by Tycho Brahe and Johannes Kepler's laws of planetary motion.Further observational improvements led to the realization that our Solar System is located in the Milky Way galaxy, which is one of many galaxies in the Universe. It is assumed that galaxies are distributed unif