Transcript Geller Notes with homework assignment

Honors 228 Astrobiology
Prof. Geller
Meeting #2 - Physical Origins
Presented
23 January 2003
Overview of Chapter 1
• 1.1 Life Elsewhere
– discussed 1st meeting
• 1.2 Worlds Beyond Imagination
– distances between worlds
– distances between stars
– communications between star systems
• 1.3 Stuff of Life
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birth and death of stars and planets
origin of the chemical elements
chemistry review
formation of solar system
other solar systems
Another Word about
Astrobiology
• 1.5 The new science of astrobiology
– How new is it?
– What is new about it?
– Astrobiology according to Geller
• ODDS
– origins
– development
– distribution
– search
Group Questions from Last
Period
• Question #1:
– A) Can life exist in places that never receive
sunlight?
• If Yes » What types of life forms could exist?
• If No » Cite the physical reasons why life cannot
exist without sunlight.
– B) What elements are the most important for the
existence of life? Explain your reasoning.
Group Questions from Last
Period
• Question #2:
– A) Consider the following statement:
• "For a life form to exist, liquid water must be present in the local
environment in at least small amounts or for short time periods."
• Do you agree or disagree with this statement.
• If You Agree » Explain why liquid water is necessary.
• If You Disagree » What type of life could exist and what would
the environment be like?
– B) We know that there are 9 planets orbiting the Sun in our
solar system. Would you expect there to be other planets
orbiting other stars outside our solar system? Explain why
or why not.
Group Questions from Last
Period
• Question #3:
– A) Can any forms of life exist in environments with
temperatures much greater than 100°C (the boiling point of
water) or much less than 0°C (the freezing point of water)?
• If Yes » What types of life forms could exist at either of these
temperatures? State the form of life and the corresponding
temperature.
• If No » Cite the physical reasons why life cannot exist at either of
these temperatures.
– B) Circle the elements that must be present for life to exist.
Explain your reasoning for each choice. (listed are hydrogen,
potassium, zinc, oxygen, calcium, uranium, magnesium,
sulfur, carbon, nitrogen, iron, and sodium)
Group Questions from Last
Period
• Question #4:
– A) Describe an environment on Earth that
would not allow any form of life to exist. Cite
specific examples and explain why these
environments cannot support life.
– B) Do scientists have evidence that indicates
whether life exists anywhere other than Earth?
Explain your reasoning.
Sample Phase Diagram
Density vs. Temperature (water)
Homework Assignment
• Compare and contrast the differences and
similarities between the big bang origin of
the universe and the formation of the solar
system.
– minimum 2 typed pages of thoughtful prose
– consider class discussion, material from book,
and material from HNRS 227