SVSU PHYS 106C Keen Chp 1

Astronomy

Astronomy

The study of celestial objects such as moons, planets, stars, nebulas, and galaxies

Universe

The totality of space, time, matter, and energy

Order of magnitude

Basic scale of physical quantities in terms of powers of 10

Scientific notation

a way to write very large or very small numbers using the from a x 10^b where the coefficient is any real number & the exponent is an integer

planet

A body that orbits a star and is massive enough for self-gravity to have it into spherical shape and to have cleared smaller objects from the neighborhood of its orbit

satellite

any object that orbits a larger object

star

a sphere of gas, such as the sun, that produces energy via nuclear fusion in its core

planetary system

a star and its orbiting planets

Galaxies

Millions to billions of gravitationally bound stars. Galaxies also include gas, dust, and dark matter

Galaxy cluster

a collection of hundreds or thousands of galaxies bound together by gravity

Super cluster

a collection of galaxy clusters; the largest type of object in the universe

Astronomical unit (AU)

the average distance from the sun to the earth

Light year (ly)

the distance that light travels in a year

Parsec (pc)

a unit often used for very large distances

Dust

the smallest bits of solid matter in the universe, composed of atoms such as carbon and silicon

Atom

The fundamental building block of matter, consisting of a dense central nucleus, surrounded by cloud of negatively charged particles

Subatomic particle

any particle smaller than an atom. subatomic particles include protons, neutrons, and electrons.

Scientific method

a body of techniques for acquiring new knowledge that includes systematic observation, experimentation, and theorizing

Hypothesis

a proposed explanation for a phenomenon that must be rigorously tested by experiments

Theory

the explanation for a phenomenon that has undergone extensive testing and is generally accepted to be accurate

pseudoscience

a claim, belief, or practice that is presented as a scientific but does not adhere to a valid scientific method, lacks supporting evidence or plausibility, and/or cant be reliably tested

Astrology

the belief that there is a relationship between astronomical phenomena and events in the human world

Climate change

a significant, long-term change in the statistical distribution of weather patterns