Earth's Place in Space and Scientific Method Vocabulary

A comprehensive vocabulary review set covering Earth's origin, the Big Bang Theory, scientific method processes, variable types, and solar system formation via the Nebular Hypothesis.

Theory

A well-substantiated explanation based on scientific laws, mathematical data, and facts that explains why something happens.

Law

A scientific principle that explains how something happens and is supported by facts equally as much as a theory.

Big Bang Theory

The most widely accepted theory of how the universe began, stating that $13.7\text{ billion years ago}$ the universe expanded from an extremely hot and dense point in space.

Singularity

An infinitely dense point only a few millimeters wide from which all matter, space, energy, and time exploded $13.7\text{ billion years ago}$.

Helium

The first chemical element in the universe.

Radiation Era

One of the two major stages of the universe's evolution, occurring prior to the matter era.

Matter Era

One of the two major stages of the universe's evolution, occurring after the radiation era.

Stellar Epoch

The current and latest stage of the universe's development, initiated when stars began to form within galaxies.

Milky Way Galaxy

The galaxy in which Earth is located.

Hierarchy of Organization Within the Universe

The structural ordering of the universe from largest to smallest: Universe, Galaxies, Solar Systems, and Planets, etc.

Hypothesis

An informed, testable statement of intent based on present understanding, written as an if / then statement.

Observation

The act of taking in information about objects and events using sight, hearing, touch, or taste.

Inference

Looking for patterns in observations to come up with an explanation for those observations.

Qualitative Observation

Observational data gathered using the senses about an object's characteristics or qualities, such as noting that it is very humid outside.

Quantitative Observation

Specific numerical information recorded as a quantity or amount using a measurement tool, such as recording humidity at $85\%$.

Control Group

The experimental group exposed to normal conditions, serving as the standard that all other groups are compared to.

Experimental Groups

The groups in an experiment that are changed or manipulated.

Independent Variable

The variable in an experiment that the scientist intentionally changes.

Dependent Variable

The variable that changes in response to the manipulation of the independent variable.

Nebular Hypothesis

The process explaining solar system formation through five sequential steps: collapse, spinning, flattening, condensing, and accretion.

Collapse (Solar System Formation)

The first step of solar system formation where a dust cloud collapsed due to a shockwave from a supernova.

Spinning (Solar System Formation)

The second step of solar system formation where gravitational collapse caused the material to start spinning.

Flattening (Solar System Formation)

The third step of solar system formation where the spinning motion caused the material to flatten.

Condensing (Solar System Formation)

The fourth step of solar system formation where material cooled and condensed into dust grains.

Accretion

The final step of solar system formation where dust grains smashed into each other to form planets and moons.