Quiz 1 Flashcards
What is the age of the universe?
13.8 Ga (13.77 by NASA)
What are the main 4 observations that suggest a “singularity” (i.e. Big Bang)?
- The Hubble expansion of the universe
- The Cosmic Microwave Background
- Light elements appear to have existed at a particular ratio prior to the formation of starts
- As a cosmic cluster becomes denser, the larger the space becomes across clumps
What is the Hubble expansion of the universe?
The light from a distant object is redshifted (i.e. has lower, red, wavelength) and the amount of “shift” is proportional to the distance of the object
What is the Cosmic Microwave Background (CMB)?
The only remnant signal we have from the Big Bang. It is everywhere. It makes the universe just above absolute zero.
What is time zero?
The Big Bang
What was the Dark Ages?
A period of time where matter goes through phenomena known as decoupling and recombination. There were not stars, planets, comets. There were no photons (light).
When was the Dark Ages (Astronomy)?
~370,000 to ~several 100 million years after the Big Bang.
What was the only form of electromagnetism from the Dark Ages?
The Cosmic Background radiation.
What were the only elements to exist in the Dark Ages?
Hydrogen (H), Helium (He), and a whiff of Lithium (Li) and Beryllium (Be)
What are Population 1 (main sequence) stars?
Young, high metallicity stars (like our sun). They are mainly in the rim of the galaxy.
What are Population 2 stars?
Older, lower metallicity stars. These are concentrated in the central bulge of the galaxy.
What is a stellar nursery?
Where dust from an imploded supernova collapses under gravity, spins and rotates on itself to create new stars.
Where are Stellar nurseries located?
In dense clouds of dust and gas (nebula)
When was the Hadean period?
4.5 - 3.8 billion years ago.
What is significant about the Hadean period?
There is no primary rock record that have survived this period.
