VOCAB: Unit 1

Question 1

Hypothesis*

Answer 1

An educated guess based upon an observation

Question 2

Theory*

Answer 2

Summarizes a hypothesis that is supported by repeated testing and observation

Question 3

Law*

Answer 3

Explains a body of observations

Question 4

Big Bang Theory

Answer 4

An effort to explain what happened at the very beginning of the Universe

Question 5

Singularity*

Answer 5

An area in space-time where gravitational force is so high that all laws of physics break down and don’t apply

Question 6

Gigantic Expansion

Answer 6

Like a tiny balloon, which in the smallest fraction of time, expands and expands

Question 7

3 Pillars of Proof* (supports the Big Bang Theory)

Answer 7

Hubbles’ Law, Characteristics of CMB radiation, Abundance of Light Elements

Question 8

Hubble Space Telescope?

Answer 8

Huge optical telescope into Earth’s orbit

Question 9

Doppler Shift/Effect

Answer 9

Apparent change in sound

Question 10

Hubble Law*

Answer 10

V = Hd
V = speed 
d = distance away from the sun
H = the hubble constant

Question 11

Shpere-Shaped*

Answer 11

Positive Curvature, a closed universe

Question 12

Saddle-Shaped*

Answer 12

Negative Curvature, a open universe

Question 13

Flat-Shaped*

Answer 13

Not curved, a flat universe, expands forever

Question 14

Conventional Matter

Answer 14

Stars, planets, asteroids, comets etc

Question 15

Dark Matter*

Answer 15

Gives off no electromagnetic energy

Question 16

Dark Energy*

Answer 16

It repels matter

Question 17

Light Year

Answer 17

The distance that light takes to travel in 1 year

Question 18

Trigonometric Parallax*

Answer 18

Relies on an object appearing to be at a different place relative to the background, depending on your viewpoint

Question 19

Hertzprung-Russell Diagram

Answer 19

Relating to the luminosity of stars to their temperature

Question 20

Intrinsic Brightness

Answer 20

What the ‘true brightness’ of the star is

Question 21

Apparent Brightness

Answer 21

The brightness you see from Earth

Question 22

Cepheids

Answer 22

A variable star having a regular cycle of brightness w/a frequency related to its luminosity, allowing estimation of its distance from earth

Question 23

Andromeda

Answer 23

Spiral-shaped clump of stars, within it there was a Cepheid star

Question 24

Andromeda Galaxy*

Answer 24

Our closest neighbouring galaxy, bigger than the milky way

Question 25

Local Group

Answer 25

A group of about 40-50 galaxies in our immediate environment

Question 26

Milky Way Galaxy

Answer 26

Home to our Solar System

Question 27

Triangulum Galaxy

Answer 27

Smallest of the 'big three'

Question 28

Orion Arm

Answer 28

A rotating spiral-armed galaxy

Question 29

Element*

Answer 29

Substance that can't be broken down any simpler

Question 30

Atom*

Answer 30

Particle of matter that has the unique properties of an element, consist of a central nucleus

Question 31

Nucleus*

Answer 31

Contains protons and electrons, and sometimes neutrons

Question 32

Protons*

Answer 32

Particles that are positively charged

Question 33

Neutrons*

Answer 33

Particles that have no charge

Question 34

Electrons*

Answer 34

Particles that are negatively charged

Question 35

Ion*

Answer 35

An atom w/ a +(deficiency of electrons) or -(extra electrons) charge

Question 36

Isotope*

Answer 36

All atoms of a particular element the that have the same # of protons, but different number of neutrons

Question 37

Mass number

Answer 37

Sum of protons and neutrons in the nuclei

Question 38

Radioactivity

Answer 38

Spontaneous break down of unstable atoms of an element, w/ the production of energy and other particles

Question 39

Supernova

Answer 39

Explosive death of a massive star

Question 40

Atomic number

Answer 40

Number of protons in the nucleus of the atom

Question 41

Deuterium

Answer 41

Isotope of Hydrogen, 2H

Question 42

Supernovae

Answer 42

Explosion of a big star releases so much heat and pressure that all the heavy elements can be produced

Question 43

Nebular Hypothesis*

Answer 43

Suggests that the Solar System formed over a relatively brief span of time and all as a unit, from a nebula of interstellar gas

Question 44

Red Giant

Answer 44

When a star runs out of H

Question 45

Momentum

Answer 45

Measure of an object's tendency to move at a constant speed along a straight path

Question 46

Angular Momentum

Answer 46

Measure of the amount of spin of an object

Question 47

Conservation of Angular Momentum

Answer 47

If no outside force acts on a spinning object, objects angular momentum will not change w/time no matter hot the object interacts w/others

Question 48

Dew Point Temperature

Answer 48

Temperature to which air must be cooled to reach water saturation, after which water molecules begin to form

Question 49

Accretion

Answer 49

Process of growth/sticking together

Question 50

T Tauri Stars

Answer 50

A class of stars believed to be similar to how the Sun would have looked at the time of its formation. Strong winds

Question 51

Bombardment Rate

Answer 51

Number of collisions

Question 52

Fission*

Answer 52

Releases heat energy by splitting atoms

Question 53

Fusion*

Answer 53

Combing atoms to create larger ones. Powers the sun