Transcript Cosmology - Paramus Public Schools

Do Now – Answer in Notebooks
1. Can our sun supernova? Why or why
not?
2. When is a star considered born? What do
we call it before this?
3. After all the hydrogen is fused to helium,
what element will stars form?
Cosmology
How did our universe form?
• The study of the universe – its nature,
origin and its evolution
Big Bang Theory
• Theory that the
universe began as
a point and has
been expanding
ever since
• About 13.7 billion
years ago
• EXPANSION rather
than an explosion
Steady State Theory
• Universe looks the same on large scales
to all observers
• Matter is created and added as universe
expands
• Density remains the same
Possible Outcomes*
• Open Universe – Expansion will never stop
• Closed Universe – Expansion stops and
turns into contraction
• Flat Universe – Expansion slows to a halt
* Based on Big Bang Model
Background Noise
• Cosmic background radiation:
– Weak radiation left over from the
early hot stages of the Big Bang
expansion of the universe
• Discovered in 1965 in a lab in Holmdel,
New Jersey
Background Noise Continued…
• Average temperature of CBR is 2.735 K
(-270°C)
• Earth’s atmosphere blocks most of the
radiation. Best seen by satellites or high
altitude balloons
COBE
• Cosmic Background
Explorer
– Orbiting observatory
used to map
radiation in detail
(1989)
• WMAP: Wilkinson
Microwave Anisotropy
Probe (2001)
On your own…
Questions 4-8