GLY 2100 Contact Information

Transcription

1 GLY 2100 Contact Information Instructor: Dr. Joe Meert Office: 274 Williamson Hall Phone: ; Mobile Office Hours: Th 5-77 or by appointment Text: Levin Earth Through TIme. TA: Alex Hastings, 261 Williamson Office Hours: TBA

2 GLY 2100 Grading Rubric 4 exams: Each worth 12.5% each Lab Exercises, Warm-ups and Practicals 40% Paper 10%

3 Outline of the Course A Little Bit of Philosophy: What is Science History of Geology: Players and Concepts Review Rocks, Minerals & Plate Tectonics Deep Time & Geochronology Fossils and Sedimentary Environments Hadean and Archean Life and Times The Proterozoic Eon The Ediacaran- Newest Period in Geology Paleozoic, Mesozoic and Cenozoic Controversies in Earth History

4 What is Science? Many people misunderstand how science knows things. This results in many people doubting science in favor of pseudoscience. We will briefly examine what science is, and how it differs from non-science.

5 What Science IS NOT It is NOT about proving things. It is NOT based on popular opinion. It is NOT about proving or disproving the existence of a deity. It is NOT a boring job performed by nerds (though I am a nerd). Science is NOT subjective.

6 What Science IS.. Science IS about disproving old ideas. Science IS atheistic in its pursuits (though scientists may be theists). Science is about natural systems. Scientists eschew popular ideas although the good ideas last. Science requires independent verification of results (i.e. it is objective) Science is exciting and dynamic. Geologists travel the world doing research in strange and exotic places.

7 The Fine Art of Baloney Detection (or: how to tell if you are dealing with pseudo-science) science) If someone claims this is proven,, then it is most likely NOT proven! If someone claims supernatural explanations should be part of science,, then you should beware what follows. If someone claims that to believe otherwise is to go against X religion. If the sentence is prefaced by Well, it s s only a theory ; ; then you know the person speaking is not a scientist and is about to sell you some baloney! Doubt any claim made in a commercial (trust me, I am not an actor, but I play one on TV). If someone claims we all have the same facts, we just start with different presuppositions, doubt them! If someone claims that science is subjective or that we create our own truths,, doubt them. If someone demands equal time for a theory before even testing their t ideas, you ve got a full blown baloney sandwich!

8 An Example of Pseudoscience Reiki: The claim is that every living being is surrounded by an energy cloud that needs adjustment from time to time. Reiki practitioners (charging $50/hour) claim to put the energies back in balance. This student and his parents all claim to be Reiki practitioners. We set up an experiment since the claim was made that Reiki would help plants grow faster and bigger.

9 Results

10 There are many examples of Pseudoscience The show Crossing Over where the host claims to speak with the dead. Just about any commercial. Young earth creationism. ESP-Extra Extra sensory perception. Anything on the radio show George Norry. Crop Circles. Intelligent Design

11 Facts, Theories and Hypotheses Fact: In science, facts are nothing more than observations. Facts can be observed by anyone at anytime. For example: Gravity is a fact Evolution is a fact Earth is spherical in shape is a fact Note: Facts are not disputed EVEN if we cannot explain WHY they are facts

12 Theories Theories are ideas that have been tested over and over again and found to be the BEST possible explanation for the observations (e.g. the FACTS). Theories can, do and should change through time (i.e. get better), but the underlying facts NEVER change. New theories replace old by explaining everything the old theory did and build upon the old theory. For example.

13 Gravity Newton s s theory of gravity is fine in everyday life. We use it everyday and it works well. Einstein noted that although Newton s s equations described most situations well, it fell apart when discussing the behavior of light, l so his equations explain eveything Newton did, but also explain something Newton s s equations could not. Therefore, Einstein s s theory of gravity is more encompassing than Newton s. When Einstein formulated his theory of gravity, apples did not remain r suspended in air awaiting the outcome.i.e. the underlying FACT of gravity exists no matter what the theory is to explain it. Note: We still do not have an all encompassing theory of gravity today!

14 Evolution Charles Darwin is credited with the theory of evolution. Darwin s theory explained that life changed slowly and gradually through the buildup of small changes. S.J. Gould noticed that some changes appeared saltatory and came up with the idea of punctuated equilibrium. Punk-eek explained the slow, gradual changes noted by Darwin, but also explained the saltatory changes observed in the fossil record. Therefore, punk-eek is a better theory than Darwin s original theory. While Gould was formulating his ideas, life did not produce clones waiting to see whose idea was better. Evolution continues to happen no matter what the ultimate explanation.

15 Science & Truth (Facts) 100% Truth Scientific Knowledge 0 Time

16 Hypotheses A hypothesis is colloquially referred to as an educated guess. I prefer an expected outcome of a research endeavor based on existing knowledge. In general, hypotheses are formulated to test certain aspects of well-grounded theories. The fun begins when the outcome is unexpected!

17 Important Points Science is about changing ideas. Science is about disproving things. Science cannot prove anything. If you require the safety and comfort of absolute knowledge, take a course in any religion or algebra. If you want the challenge of discovery, then stick with science. Science is about providing the best explanation for the facts of the world.

18 Thinkers in Geology We reviewed some of the questions that the early geologists would like answers for. We developed a few ideas about how they might go about providing the answers. Let s s meet them

19 Niels Stensen (aka Nicolaus Steno) : 1697: Danish physician known for anatomical studies. He developed three simple observational rules for geology.

20 Scientific Evidence for the Age of Nicolas Steno s s 3 Principles of Geology Original Horizontality Superposition Original Lateral Continuity the Earth

21 Original Horizontality & Superposition Rocks were laid down individually and in horizontal layers. The rocks on the bottom are older than those on top.

22 Original Lateral Continuity Steno argued that a rock layer will extend continuously in all directions until it thins out or encounters a barrier.

23 Cross-Cutting Cutting Relationships Another very simple concept states that in order for a rock to be cut by another rock..the rock being cut must already exist. This was an idea formulated by Lyell ( ) 1875)

24 What is the order of events depicted here?

25 John Strachey ( ) 1743) Succession of Strata- By applying Steno s principles, he was able to trace the history of coal deposition and also recognized that the horizontal layers of coal rested on inclined layers of older strata (angular unconformity)

26 Conflicts in Early Geology Neptunists and Plutonists- Who are they? Neptunists- A. Werner (mineralogist of some fame ) 1817) argued that all rocks were deposited or precipitated in a global ocean. Plutonists- argued that all rocks had a fiery beginning (Hutton).

27 Werner s s Stages of Earth 1 st Stage rocks- hot steamy global ocean with all elements to form his oldest primary rocks 2 nd Stage Rocks- Subsidence and cooling of the ocean with the deposition of fossil bearing rocks transitional rocks 3 rd Stage- Flat-lying lying sedimentary rocks which he called alluvium

28 Hutton s s Disagreement James Hutton ( ) 1797) Physician and geologist saw the earth as a dynamic changing world. This was in contrast to Werner who saw phases that were thereafter unchanged. Hutton argued that the past history of our globe must be explained by what is happening now.

29 Uniformitarianism Processes that we see operating today, operated in a similar manner in the past. The rates of the processes may vary, but the fundamental laws of nature do not. For example, if I find a volcanic rock that is 50 million years old, I am safe in assuming that it formed in the same manner as a volcanic rock erupting today.

30 Actualism Strict Uniformitarianism works well for many geologic problems. John Playfair ( ) 1819) who was a friend of Hutton explained it thusly: Amid all revolutions on the globe, the economy of nature has been uniform and her laws are the only thing that have resisted the general movement. The rivers and rocks, the seas and the continents have all changed in all their parts, but the laws that describe those changes, and the rules to which they are subject, have remained invariably the same.

31 Unconformities Hutton also recognized unconformities and that those unconformities had a time connotation. In Scotland (his home) he noticed flat-lying lying rocks above tilted rocks. Siccar Point in Scotland

32 Faunal Succession William Strata Smith ( ). 1839). Engineer who built canals and restore springs (he dug!). Smith was really the first to recognize how fossils could be used to correlate strata as time equivalent. Fossils can be used to mark time in different parts of the world or in a sequence.

33 Cuvier and Catastrophism Georges Cuvier ( ) 1832)- He noticed faunal succession and confirmed Smith s ideas, but he also noticed that many fossils were separated in time by unconformities. He concluded that life was marked by a series of catastrophes (frightful ones). Cuvier argued that the most recent catastrophe was the Noachian flood.

34 Charles Lyell ( ) 1875) Lyell did not accept Cuvier s catastrophism. Argued that leaps in the fossil record were due to missing strata or other imperfections. The rivalry between the Catastrophists and the Uniformitarians was heated. Today, we know that slow gradual changes are punctuated by catastrophes.

35 Lyell s s Impact on Geology Lyell authored a 5 volume work called The Principles of Geology.. He discovered/illuminated the following ideas: Cross-cutting relatioships Inclusions of rock as an age tool (conglomerate contains pieces of older rock. His book detailed geologic knowledge to that point and was used in training geologists for quite some time.

36 Evolution & Darwin William Smith knew that organisms varied in the stratigraphic record, but not why. Charles Darwin was a naturalist and dabbled in geology and biology. He proposed a mechanism for change called natural selection. What is natural selection?

37 Darwin, Wallace and Malthus Darwin did not publish his work immediately, but did inform Lyell and Joseph Hooker (his friends) about his conclusions. Alfred Wallace in 1858 sent Darwin a paper to review that contained the elements of natural selection (he based his ideas on the works of Thomas Malthus). Lyell and Hooker wanted Darwin to get the credit so they arranged for a presentation by Wallace and Darwin to the Linnaean society. Darwin and Wallace are given dual credit for the discovery of natural selection. On the Origin of the Species was first published in 1859.

38 What is Evolution Today? Darwin proposed a mechanism for evolutionary change called natural selection. Mendel opened up the study of genetics which helped explain how traits were developed in the species. Genetic Variation and hereditability.

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