Earth & Space Science

What is Science? Science - an organized way of gathering and analyzing evidence about the natural world Knowledge gained through experience Accumulated through observation and or experimentation Facts gained by systematic study Science is more than a body of knowledge, it is a way of thinking - Carl Sagan

Assumptions to do Science Order in the Universe Human mind is capable of comprehending this order If conditions are the same, the results of any study or experiment will be the same

Good scientists exhibit certain traits Curiosity Honesty An open mind Willingness to be wrong and make mistakes Ask good questions Skepticism The School of Athens - Raphael (1511)

The Scientific Method 1. Inductive reasoning 2. Deductive reasoning Thinking scientifically involves the development of knowledge by observation and experimentation Two ways to approach an experiment: 1. Inductive reasoning Vs. 2. Deductive reasoning specific to general general to specific

The Scientific Method The scientific method is more like a cycle than a series of steps Hypothesis – an educated guess based on observation. – Can be tested by experimentation Hypothesis Prediction Test Prediction

Case Study Ignaz Semmelweis (1856) Observations: Childbirth deaths are 5 times higher from clinics staffed by doctors and medical students than clinics staffed by nurses and midwifes due to “childbirth fever” Doctors often performed autopsies and nurses did not Semmelweis

Case Study Ignaz Semmelweis (1856) Hypothesis: Doctors transmit “cadaveric matter” to their patients If a doctor performs an autopsy, then their hands would be contaminated with “cadaveric material” which may kill a patient who is exposed to this material. Prediction: If Doctors washed their hands it would eliminate cadaveric matter from being transmitted to patients

Experimental Design – experiment designed to test the hypothesis Case Study Experimental Design – experiment designed to test the hypothesis Control – nothing changes (no new variable added) (doctors do not wash hands) Independent variable – what changes (doctors wash off “cadaveric material”) Dependent variable – changes in response to independent variable – what you measure for results (# patients getting “childbed fever”)

Case Study Data Collection Quantitative data = numbers obtained by counting or measuring (# of patients affected, % concentration of soap used etc.…) Qualitative data = descriptive observation (severity of symptoms, age of patients, first birth? etc.…)

Case Study Results and Analysis Childbirth deaths reduced when doctors washed their hands Conclusions Did the experiment support the hypothesis? What new hypotheses can be made and tested? In biology, not all hypotheses can be tested in a controlled experiment (Does taking prenatal vitamins during pregnancy cause a higher IQ?) Transmission of “cadaveric material” caused “childbirth fever”

Case Study So what affect did this have on the scientific community? Semmelweis's observations conflicted with the established scientific and medical opinions of the time. His ideas were rejected by the medical community. Semmelweis could offer no acceptable scientific explanation, and some doctors were offended at the suggestion that they should wash their hands. Semmelweis's practice earned widespread acceptance only years after his death, when Louis Pateur confirmed the germ theory (1890s)

Scientific Theory Theory = a well-tested explanation that unifies a broad range of observations and hypotheses Theories have been tested and supported by many lines of evidence They are the dominant view among scientists Examples: Relativity (gravity), Cell, Germ, Natural Selection, Evolution

Scientific Law Law = a statement based on repeated experimental observations that describes some aspect of the universe. Example: Newtons Law of Universal Gravitation

Review: The Scientific Method The scientific method is a process of observing natural phenomena, which leads to asking questions, and offering explanations that can be scientifically tested. Observation Hypothesis Prediction Experiment Analysis Conclusion

Branches of Earth Science

Astronomy The study of objects beyond Earth’s atmosphere. Astronomers study the universe and everything in it, including Earth.

Meteorology The study of the air that surrounds our planet. Meteorologists study the forces and processes that cause the atmosphere to change and produce weather. They also try and predict weather and its effect on Earth’s climate.

Geology The study of the materials that make up Earth and the processes that form and change these materials. Geologists identify rocks, study glacial movement, interpret Earth’s history etc.

Oceanography The study of Earth’s oceans, which cover nearly three-fourths of the planet. Oceanographers study the creatures that inhabit salt water, measure properties of the oceans, and observe different processes.

4 Earth Systems (Spheres)

Lithosphere The rigid outer shell of the planet, including the crust and the mantle.

Hydrosphere Made up of the water in the oceans, seas, lakes, rivers, glaciers and in the atmosphere

Atmosphere The blanket of gases that surrounds our planet. Functions of the Atmosphere – respiration, protection from the Sun’s radiation, regulate planet’s temperature.

Biosphere Includes all organisms on Earth as well as the environments in which they live.

Energy on Earth Earth is powered by two (2) different energy sources. The Sun Earth’s Interior

Why the SI System Matters Units of Measurement Any measurement that you make without the knowledge of the uncertainty is MEANINGLESS. - Walter Lewin Why the SI System Matters

English System Inch = legally, 3 barleycorns. Palm = 3 inches Shaftment = Width of the hand and outstretched thumb, 6 1⁄2 inches before 1066, 6 thereafter Link = 7.92 inches or one 100th of a chain.[5] Span = Width of the outstretched hand, from the tip of the thumb to the tip of the little finger, 3 palms = 9 inches Foot = Prior to the Anglo-Saxon invasions, the Roman foot of 11.65 inches (296 mm) was used. The Anglo-Saxons introduced a North-German foot of 13.2 inches (335 mm), divided into 4 palms or 12 thumbs, while the Roman foot continued to be used in the construction crafts. In the late 13th century, the modern foot of 304.8 mm was introduced, equal to exactly 10⁄11 Anglo-Saxon foot. Cubit = From fingertips to elbow, 18 inches.

International System of Units (SI Units) the modern form of the metric system, and is the most widely used system of measurement. It comprises a coherent system of units of measurement built on seven base units. Meter: (1793): 1/10000000 of the meridian through Paris between the North Pole and the Equator. (1983): The distance travelled by light in vacuum in 1/299792458 second.

Length In science we always use the metric system for measurements. SI Unit = Meter (m)

Area and Volume Area Volume Length x width Unit = m2 Length x width x height Unit = cubic meter m3

Temperature Degrees Kelvin (K)

Density Density = mass per unit volume the amount of matter that occupies a given space g/cm3