Physics study guide - Topic 1 Flashcards
KNOW YOUR GOD DAMN KEYWORDS.
UNIVERSE- All of space, all starts, moon, planets etc. All that contain energy.
COSMOLOGY- When you study cosmology you study how the universe was created, the big bang teory.
PARTICLE PHYSICS- When you studtv particle physics then you study subatomic particles, protons, neutrons and electrtons.
What is a celestial body?
All objcts in space that contain energy, such as stars and planets.
Write a description of each celestial body in your digital notebook. Try to use your own words.
-Asteroids
An asteroid is a much smaller object and less rounded than a planet. The asteroid is also circling a star.
-Star
A star is a giant ball of superheated elements held together by gravity (sun)
-Planet
A planet is a large “round” object with its own gravity that orbits a star.
-Galaxy
A galaxy is a group of stars, gas and other other celestial objects which are bound together by gravity. It may also contain dark matter.
-Moon
A moon is a large object which has its own gravity that orbits a planet. Usually rounded in shape.
Know the different types of Celestial bodies.
Galaxy, Starts, Planets, Moons, Astreoids
How do we know that the Universe is expanding?
Because of the redshift
What are the different types of galaxies?
There are spiral, elliptical (looks like an oval) and irregular galaxies.
What is the redshift?
The colour of a galaxy could be violet but when the light travels through space as it expands the light ray stretches out getting longer and longer so when it reaches earth it could be red or maybe even a radio wave. Even though the light may have started out as violet in a galaxy, far far away.
What is the Big Bang Theory and what does it say about how our universe was created?
The theory that the universe started with only a single point (a singularity) and it’s still expanding. The theory says that at one point in time all matter in the entire universe was gathered in a single point, a singularity. That single point then “exploded”, hence the big bang name, and from then on the universe has been expanding, ever onwards.
What is a Light Year and what do we use it for?
A lightyear is a measurement of how far light travels in a calendar year and we use it to measure distance in space.
