Astronomy

The Age of the Universe

13.7 billion years

planet

A large body in space that orbits a star and does not produce light of its own

Solar nebula

A large cloud of gas and dust such as the one that formed our solar system

Einstein's Theory of Relativity

All motion is relative to what you define as a fixed point

Shape of the Universe

Flat in 3 dimensions, sum of matter seems to indicate a flat universe.

Step 3 of Nebular Theory

Material continues to clump together in the center and heats up forming a protosun.

Newton's Law

Newton's law of universal gravitation describes gravity as a force by stating that every particle attracts every other particle in the universe with a force

Planetesimal

One of the small asteroid-like bodies that formed the building blocks of the planets.

Differentiation

Process in where a planet separate into layers

Protoplanets

Regions of condensed matter that serve as a starting point for the formation of a planet.

Nebular Hypothesis

Solar system evolved from an enormous rotating cloud called the solar nebula

Step 2 of Nebular Theory

Spinning nebular cloud contracts (shrinks) and spins becomes a flattened disk

absolute magnitude

The actual brightness of a star

Step 4 of Nebular Theory

The material in the disk starts clumping together to form planetesimals (gravity) and when the temps. are high enough in the center, nuclear fusion begins and the protosun becomes a true sun (star!)

Hubble's Law

The observation that the farther away a galaxy is, the faster it is moving away.

sun

The star at the center of our solar system

Big Bang Theory

The theory that the universe originated in a huge explosion that released all matter and energy.

Special Relativity

Theory that explains why time runs slower the faster you move.

protoplanetary disk

a large disk-shaped cloud of dust and gas

gravitational force

an attractive force that acts between any two masses

What way do the planets rotate

counterclockwise

accretion

growth in size or increase in amount

Step 1 of Nebular Theory

nebula (cloud of gas and dust)

Hawking Radiation

radiation from a black hole, meaning everything gets sucked into the black hole

Redshift

shift of light to a longer wavelength as it moves away

frequency of light

speed of light/wavelength

Hubble's Law

states that the farther away a galaxy is, the faster it is moving away from us

Protosun

sun prior to the time when hydrogen fusion began in its core

Cosmological Principle

the assumption that the universe is isotropic and homogeneous, that the universe is the same everywhere

Steady State Theory

the universe has always existed and always will, in the state it is in now