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Announcements. Reading assignment for next time: read Chapter 2 of Foundations of Modern Cosmology Homework for next time: see last slide. The Anthropic Principle. The properties of the universe are “just right”. Why? Is it because we are here or are we here because they are just right?.
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Announcements • Reading assignment for next time: read Chapter 2 of Foundations of Modern Cosmology • Homework for next time: see last slide
The Anthropic Principle The properties of the universe are “just right”. Why? Is it because we are here or are we here because they are just right?
Creation myths reflect the culture Symbols found in Dreamtime art The Australian aborigine Dreamtime
Most creation myths give humans and Earth a central role Anthropocentrism
If things didn’t go well for humans it was because of a vengeful god
The Christian Genesis and the expulsion of Adam & Eve from the Garden of Eden The snake is given human-like characteristics and the vengeful God punishes the transgressors
Hindu Cosmology involves lots of creation, destruction and sacrifice
The Celtic peoples were hunters so their myths involve lots of animals
Egyptian creation myths involved many gods and battles between them
Mesoamericans were big on sacrifice and wars between the gods
The Scientific Method is based on induction rather than deduction Induction is to extrapolate the general principle based on limited observations. Deduction is to start with a general principle and attempt to apply it to specific cases. Because the process starts with induction, no scientific theory can ever be proven true, it can only be proven false.
The scientific method is a closed cycle, it doesn’t have an end An example of the never ending cycle: the theory of gravity
The five characteristics of a “good” scientific theory 1. Relevance Must be relevant to the field. A theory that is irrelevant to astronomy may be relevant to biology, geology or some other field. A theory on how the pyramids were built may be relevant to archeology but it is irrelevant to cosmology (though there may be some astronomical relevance).
2. Falsifiability A scientific theory must be capable of being shown false. The theory that the moon is made of green cheese is a valid scientific theory. It was proven false by the Apollo missions. The theory that a supreme being rules over the universe is not scientific. Unless we can prove He doesn’t exist, the theory cannot be shown to be false.
3. Consistent • A scientific theory must be consistent with the existing science. • Example: Einstein’s Special Theory of Relativity • It is consistent with Newtonian mechanics if the relative velocity is small compared to the speed of light.
4. Simplicity What is simple to one may be complex to another. Apply Occam’s Razor: all things being equal, the simpler theory is more likely correct.
5. Predictability A good theory must be able to predict behavior that has not yet been observed. Closely related to fasifiability. Einstein’s theory of General Relativity predicted gravitational lensing. It was first observed in the total solar eclipse of 1919. It has since been observed many times.
Homework for next time Babylonian Mesoamerican Hindu Tasmanian or Australian Chinese