Astronomy 141 - Life in the Universe - Autumn Quarter 2009

By Richard PoggeScience Education Courses Natural Sciences Astronomy

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Astronomy 141 - Life in the Universe - Autumn Quarter 2009 episodes

October 15, 2009 Lecture 16: DNA and Heredity
DNA and RNA are the key molecules of living cells. DNA plays a vital role
in storing and transmitting the hereditary information that constitutes
the "operating instructions" of living cells; how to construct the functional
and structural proteins that perform vital cell functions, control
developmental pathways, and basically "build" the organism. RNA is the
crucial actor in protein synthesis and other cell functions. Mutations,
changes in the DNA coding, are the molecular basis for evolution,
providing the genetic variation required by natural selection.
Understanding the molecular basis of heredity and evolution gives us
important insights into the functional requirements for life. Recorded
live on 2009 Oct 15 in Room 1005 Smith Laboratory on the Columbus campus
of The Ohio State University.
47 min
October 14, 2009 Lecture 15: The Chemistry of Life
What is the basic chemistry of living organisms?
We introduce the requirements for metabolism (raw
materials and energy), the ATP/ADP energy cycle in cells, auto- and
heterotrophs, photosynthesis and chemosynthesis, and the role played by
liquid water. The goal of today's lecture is to seek insights into the
basic requirements for life from a consideration of the needs of the
cells' chemistry. Recorded live on 2009 Oct 14 in Room 1005 Smith
Laboratory on the Columbus campus of The Ohio State University.
46 min
October 13, 2009 Lecture 14: Cells
Cells are the basic structural and functional unit of all life on Earth.
This lecture reviews the basic building blocks of cells, the main
chemical components, the two basic types of cells (Prokaryotes and
Eukaryotes), and introduces the Phylogenetic Tree of Life, the way
biologists order life by their biochemical and genetic relationships.
Understanding life at the cellular level gives us important insights
into the nature and history of life on Earth, and clues as to what we
might look for elsewhere. Recorded live on 2009 Oct 13 in Room 1005
Smith Laboratory on the Columbus campus of The Ohio State University.
46 min
October 12, 2009 Lecture 13: What is Life?
How do we define life? This lecture reviews the six basic criteria
for living systems described by biologists: order, reproduction, growth and
development, energy utilization, reaction to environment, and evolution
that characterize life. The last third of the lecture is an admittedly
whirlwind review of natural selection (I got off my stride and got a
little rushed for time at the end). The goal is not a complete survey
of current biological thought, but to highlight those characteristics of
"life" that may best inform us as to how to look for signs of life
elsewhere in the Universe. Recorded live on 2009 Oct 12 in Room 1005
Smith Laboratory on the Columbus campus of The Ohio State University.
47 min
October 08, 2009 Lecture 12: Climate Regulation and Climate Change
What are the main mechanisms of climate regulation and climate
change that have operated through Earth's history? The Earth's
climate is regulated by a Carbon Dioxide thermostat that is the
interaction between the Greenhouse Effect and the CO2 Cycle. I describe
the CO2 cycle and its role in regulating global temperature. I will
then discuss other influences on climate, and periods of glaciation (ice
ages) in the recent and distant past, including the possible Snowball
Earth events in the early and late Proterozoic Eon. Recorded live on
2009 Oct 8 in Room 1005 Smith Laboratory on the Columbus campus of The
Ohio State University.
46 min
October 07, 2009 Lecture 11: The History of the Earth
How have we pieced together the geological history of the Earth?
This lecture reviews the different types of rocks and the cycle
of transformation between them, with particular emphasis on stratigraphy.
I will outline the 4 major Eons in Earth's history, and focus on the
earliest Hadean Eon which proceeded from the formation of the Earth to
the end of the epoch of Heavy Bombardment. The Hadean Eon saw the formation
of the primordial atmosphere of the Earth and the formation of the Oceans.
Recorded live on 2009 Oct 7 in Room 1005 Smith Laboratory on the Columbus
campus of The Ohio State University.
43 min
October 06, 2009 Lecture 10: The Earth's Atmosphere Erratum
This lecture was to be about the Earth's atmosphere, its composition and
structure, the greenhouse effect, and the primordial atmosphere, but
about 2 seconds into the lecture, unbeknownst to me, the battery
compartment on my digital voice recorder came open in my pocket. At the
end of lecture, I took it out of my pocket to turn it off and the
battery didn't come with it. Oops! Fail. My apologies, I'll put in
some work to prevent a recurrence in future lectures. Recorded live on
2009 Oct 6 in Room 1005 Smith Laboratory on the Columbus campus of The
Ohio State University.
2 min
October 05, 2009 Lecture 9: Inside the Earth
What is the interior structure of the Earth and how does it drive the
Earth's magnetic and geologic activity? We will review our current
knowledge of the interior of the Earth, how we measure it using
Seismology, the origins of the Earth's magnetic field, and discuss the
workings of plate tectonics. the Earth is a dynamic, geologically
active world, which has interesting implications later for understanding
the past and future history of life on Earth. Recorded live on 2009 Oct
5 in Room 1005 Smith Laboratory on the Columbus campus of The Ohio State
University.
43 min
October 02, 2009 Lecture 8: The Cosmological Revolution - The Depths of Space and Time
Cosmology is the study of the entire Universe as a physical system. The
past century has witnessed a revolution in cosmological thought that has
revealed the vastness of space and the depths of cosmic time, a revolution
that is still playing out in the present day. The lecture will review the
Earth's place in the Universe, the age of the Universe as reckoned by the time
since the Big Bang, and the origin of the elements. We will return to
many of these topics later in the course, but this presents the big
picture. Recorded live on 2009 Oct 2 in Room 1005 Smith Laboratory on
the Columbus campus of The Ohio State University.
47 min
October 01, 2009 Lecture 7: The Biological Revolution - What is Life?
What is the nature of life? In this lecture I will review the revolution
in biological thinking that has dramatically changed how we view life.
I will review such persistent ancient ideas as spontaneous generation
and why it took so long to disprove this notion, the impact of the
microscope on biology, and the discovery of the laws and agency of heredity.
This is obviously a highly-selective view of a vast topic, and my goal is
to highlight those episodes in the history of biology that inform us about
the nature of science (its successes and failures), and which we will concern
ourselves with in the rest of the course. Listeners will note that I do
not introduce Evolution (more precisely, Natural Selection) since that
is a huge other topic for another day. Recorded live on 2009 Oct 1 in
Room 1005 Smith Laboratory on the Columbus campus of The Ohio State
University.
45 min