1. Janet McLarty-Schroeder
Astronomy 104
Janet McLarty-Schroeder

2. Welcome to Astronomy!

3. What is a Science? (And why do I have to take one?)
Science is a process! It is how we go about finding an answer to a question or solving a problem.
Everyone should have a good method of solving problems and have some understanding of the world around them.

4. The Scientific Method Assumptions Rules Model Experiments Predictions
Measurements

5. Scientific Theories n A scientific theory is “good” if it:
m Accurately describes a large class of observations with a model that contains only a few arbitrary elements.
m Makes definite, accurate predictions about the results of future observations.
n You can never prove anything. The next observation may contradict some element of the model.
A scientific theory is disproved when a single observation disagrees with the model. Scientists must revise, even scrap, existing theories to accommodate new observations.
n A particular scientific theory may not be unique. It must be repeatable!

6. Pseudoscience
A pseudoscience is a body of hypotheses treated as true without a consistent, comprehensive body of experimental evidence.
A pseudoscience is identified not by the subject matter, but by its method of treating evidence.
Astrology has respectable origins in ancient cosmologies, but its modern implementation is usually for fun or commercial exploitation of the
gullible. Its primary failures as a science include (1) predictions that are wrong are not used to improve the model, and (2) the parameters and rules are vaguely defined or just arbitrary.

8. Astrobiology as a Science
Astrobiology- the study of life in the Universe
Concerns the study of conditions conducive to the formation of life, looking for such conditions on other planets, and around other stars; and looking for the actual occurrence of life elsewhere.
Seeks to reveal the fundamental connections between living organisms and the places where they reside.
Asks three fundamental questions:
How does life begin and evolve?
Does life exist elsewhere in the universe?
What is life’s future on Earth and beyond?

9. The Study of Life in the Universe
This has become a real SCIENCE!
We can challenge hypotheses concerning
how life evolved on Earth
similar conditions needed for life exist on other worlds
We have new techniques and new equipment that let us gather and examine data as we have never had before!
Let’s look at how we will attack each of the 3 questions posed.

10. Studying the Origin and Evolution of Life
In studying the origin and evolution of life on Earth you find three basic questions:
When did fossil organisms live?
radiometric dating (age-dating) – developed mid-1900s
What was Earth like at the time that ancient organisms lived?
The study and analysis of many ancient rocks and the fossils found within
How are modern organisms related to one another and to their ancient ancestors?
Genetic analysis.

11. Searching for Life Beyond Earth
We observe planets and moons in our Solar System telescopically and via spacecraft.
Beyond our SS we are at the mercy of telescopic technologies.
Telescopes can give us images and, using spectroscopy, can give us composition, surface temperature, and rotation rate.
We can also look for signals. (SETI)

12. The Future of Life on Earth and Beyond
Scientists use computer models of how the Sun and Earth will change over time.
We have models to try to predict climate changes due to human activity.
Models to try to understand the affects of everything from global warming to deforestation to the hole in the ozone layer.

13. A Question: Universality?
The laws of Physics appear to be universal.
The laws of Chemistry seem to be universal.
Are the laws of Biology universal?
If so, how and why?
If not, how and why not?