E&SS Unit 1 vocabulary

Universe

The totality of space, time, matter, energy, and the physical laws that govern them.

Cosmology

The scientific study of the origin, structure, evolution, and ultimate fate of the universe.

Big Bang Theory

The scientific model stating that the universe began about 13.8 billion years ago in an extremely hot, dense state and has been expanding and evolving ever since.

Redshift

A shift of light toward longer, redder wavelengths that occurs when an object is moving away from an observer; the redshift of distant galaxies provides evidence that the universe is expanding.

Cosmic Background Radiation

Faint electromagnetic radiation left over from the early universe, primarily observed as the cosmic microwave background, which provides strong evidence for the Big Bang.

Energy

The capacity to cause change or do work; in the universe, energy exists in forms such as radiation, thermal energy, chemical energy, and nuclear energy.

Matter

Anything that has mass and occupies space; ordinary matter is composed primarily of atoms and subatomic particles.

Proton

A positively charged subatomic particle located in an atom's nucleus; the number of protons determines an element's atomic number.

Neutron

A subatomic particle with approximately the same mass as a proton but no electric charge, located in the atomic nucleus.

Electron

A negatively charged subatomic particle found in regions surrounding an atom's nucleus.

Quark

 any member of a group of elementary subatomic particles that interact by means of the strong nuclear force to build protons and neutrons

Atom

 The basic unit of matter and the smallest unit of an element that retains the chemical properties of that element, consisting of a nucleus surrounded by electrons.

Element

A pure substance made of atoms that all have the same number of protons. 118 known = 94 Natural + 24 Synthetic. 

Nucleosynthesis

The process by which atomic nuclei are created, including the formation of elements during the early universe, inside stars, and during stellar explosions.

Nuclear Fusion

A process in which light atomic nuclei combine to form a heavier nucleus, releasing enormous amounts of energy; fusion powers stars.

Nuclear Fission

A process in which a heavy atomic nucleus splits into smaller nuclei, releasing energy and often additional neutrons.

Photon

A discrete packet, or quantum, of electromagnetic radiation that carries energy and travels through a vacuum at the speed of light.

Star

A massive, luminous sphere of plasma held together by gravity, with nuclear fusion in its interior producing energy and light during most of its lifetime.

Solar System

The Sun and all objects gravitationally bound to it, including planets, dwarf planets, moons, asteroids, comets, and other smaller bodies.

Main Sequence

The longest and most stable stage of a star's life, during which it primarily fuses hydrogen into helium in its core.

Satellite

An object that orbits another object because of gravity; satellites can be natural, such as moons, or artificial, such as human-made spacecraft.

Supernova

A powerful stellar explosion associated with the death of certain massive stars or the destruction of a white dwarf in a binary system; supernovae can produce and distribute many heavy elements.

Black Hole

A region of spacetime where gravity is so strong that, within its event horizon, nothing—including light—can escape.

Nebula

A large cloud of gas and dust in space that can be the site of star formation or the remnant of a dying star.

Neutron Star

An extremely dense stellar remnant composed primarily of neutrons, formed when the core of a massive star collapses during a supernova.

Radiation

Energy transmitted through space or matter in the form of electromagnetic waves or particles.

Galaxy

A massive gravitationally bound system containing stars, gas, dust, dark matter, and other astronomical objects.

Planet

A large, nearly spherical astronomical body that orbits a star and has sufficient gravity to dominate its orbital region.

Moon

A natural satellite that orbits a planet, dwarf planet, or other astronomical body. Earth has 1, Jupiter has 115.

Light-Year

A unit of astronomical distance equal to the distance light travels through a vacuum in one year, approximately Distance = 9.46 x 10^15m.         Velocity = 3x10^8m/s (Speed of Light)

Astronomical Unit (AU)

A unit of distance approximately equal to the average distance between Earth and the Sun, about 150 million kilometers.

Force

Any push or pull

Strong Nuclear Force

The fundamental force that binds quarks together and, through its residual effects, helps hold protons and neutrons together within atomic nuclei.

Weak Nuclear Force

A fundamental force responsible for certain types of radioactive decay and for processes involved in nuclear reactions, including those occurring in stars.

Electromagnetic Force

 The fundamental force acting between electrically charged particles; it governs electricity, magnetism, chemical bonding, and electromagnetic radiation.

Gravity

The fundamental interaction by which objects with mass or energy attract one another; gravity governs the formation and motion of stars, planets, galaxies, and large-scale structures in the universe.

Comet

A small Solar System body composed primarily of ice, dust, and rocky material that orbits the Sun. When a comet approaches the Sun, solar heating causes some of its ice to vaporize, producing a coma and often a long tail of gas and dust that points generally away from the Sun.

Asteroid

A relatively small, rocky or metallic body that orbits the Sun, most commonly found in the asteroid belt between Mars and Jupiter. Asteroids are remnants of the early Solar System and provide evidence about the materials and processes involved in planetary formation.