Big Bang
What is the big bang theory?
The universe began as a tiny/pin-sized point of all matter, energy and space
The point rapidly expanded (why?) and became what the universe is today, in about 13.7 billion years
What are auroras?
Don’t begin on earth
Are the results of a solar flare which is a mass of plasma that explore from the sun's surface which carry its own magnetic charge
The patterns and shapes of auroras are determined by the changing flow of charged particles and the varying magnetic fields.
How do seasons occur?
Due to the tilt of the axis, the sun hits more directly in the summer (and the revolution around the sun)
We are actually closer to the sun during the Northern Hemisphere’s winter
What is nucleosynthesis?
Light elements (hydrogen) can only form in a big bang process (the universe is mostly made of it)
What are the five types of galaxies?
Irregular
Spiral
Barred Spiral
Elliptical
Peculiar
What is a solar eclipse?
When the moon blocks the sun from our view
Can only happen near the new moon phase (why??)
Happens 2 to 5 times a year
Small shadow, one spot on Earth will only see a full solar eclipse every 300 years
What is cosmic background radiation?
Light is not the only radiation that scientists are able to observe from the early universe.
The early universe was very dense and due to the presence of opaque hydrogen plasma (electrons and protons)
- Radiation was scattered and trapped in the ‘fog’
380 000 years after the big bang the universe cooled (3000 K) and stable atoms formed.
- Scattered radiation was released
This light is received as microwave radiation. It was discovered by accident in 1963
What are black holes?
Remaining core after the supernova of a high mass star
- Even denser than neutron star
- so much gravity, light cannot escape
What is considered a lunar day?
the moon exerts the greatest influence, this can be shown by the fact that daily tidal oscillations repeat approximately every 24 hours and 50 min (one lunar day)
Name 4 pieces of evidence for the big bang theory
Ref Shift (Doppler Effect)
Cosmic Background Radiation
Nucleosynthesis
Hubble Expansion
Describe the lifecycle of our sun
Stable hydrogen fusion that powers our sun will continue as it has since the formation of the sun for about 1 billion more years.
As the hydrogen fuel begins to run out, helium fusion will occur releasing even more energy and forming heavier elements such as carbon and oxygen.
In about 5 billion years the heat from these reactions will tip the balance between collapse and expansion and the sun will grow into a red giant.
When no nuclear fuel remains, gravity will dominate and the sun will collapse into a small hot ball of gas, a white dwarf, and cool for over 100 billion years.
What is the oort cloud? What happens at this point?
The Oort Cloud is considered to mark the edge of the solar system as, beyond that the gravity of the stars begin to dominate that of the sun.
What is an amphidromic point?
Amphidromic Point - node or point, in our ocean near the center of an ocean basin where there is no tidal change.
Describe Red shift.
hen a light source and observer are moving closer the wave frequency increases
Spectrum appears shifted towards the short wavelength blue region
Squeeze - Blueshift
When a light source and observer are moving apart the wave frequency decreases
Spectrum appears shifted towards the LONG wavelength red region
Stretch - Redshift
What are the two competing forces that keep the sun functioning?
Two competing forces exist in balance:
Gravity - Attraction due to the large size would cause Sun to collapse on
itself
Electromagnetic - Heat from nuclear reactions causes atoms to vibrate and collide causing the Sun’s outward expansion
Compare and contrast Jovian and Terrestrial planets.
enormous size relative to the terrestrial planets.
They're also mostly made of gases like hydrogen, helium and ammonia rather than of rocky surfaces,
Mercury, Venus, Earth and Mars — are often called the "terrestrial planets" because their surfaces are rocky. Pluto also has a rocky, albeit frozen, surface but has never been grouped with the four terrestrials.
How are tidal bulges created?
- gravity is a force and it weakens with distance. We measure it from the centre of an object.
- high tide occurs when the moon is directly above the location of high tide.
- gravity of the moon (and sun) pulls on the water closest to the moon most, then some on the Earth and less on the water on the other side (leaving a bulge of water left behind)