Definition of Science: American Heritage Science: • The observation, identification, description, experimental investigation, and theoretical explanation of phenomena. • Such activities restricted to a class of natural phenomena. • Such activities applied to an object of inquiry or study. • Methodological activity, discipline, or study: I've got packing a suitcase down to a science. • An activity that appears to require study and method: the science of purchasing. • Knowledge, especially that gained through experience. [Middle English, knowledge, learning, from Old French, from Latin scientia, from sciēns, scient-, present participle of scīre, to know.] These definitions, like most definitions, are not terribly informative or useful. For example, they would clearly allow sports commentating as a science, but that is obviously not what we mean.
Description of Science • Science is a human activity that seeks to provide explanations of observable natural phenomena by means of natural causes. • Science is the process of forming testable explanations of observations. • Science distinguishes itself more in • how it discards explanations • what/how it is willing to explain • what it regards as evidence than how it forms explanations. • In science, it is very important to distinguish • factual observations from interpreted observations • Assumptions, Observations, and Theories
Scientific explanations Scientific explanations must be • Testable (for a theory to be true, it must be at least possible to show it to be false) • Objective (it should not depend on the observer, the explanation should only depend on the external phenomena) • The phenomena that science describes must be open to observation and, if possible, experiment. Scientific explanations should be • Quantitative (you want to be able to say how much or when something will happen) • Predictive (you want to be able to predict, not just make up an explanation afterwards) • An explanation should explain non-occurrence as well as occurrence (e.g., why don't we find karst where there's granite or sandstone, but only found where there is limestone or dolomite, why do we not find oil in igneous rocks…) • Convergence of evidence • Rarely do observations or experiments "prove" a conclusion or a theory (You would need an experiment that could only be true if the theory were false. Nice work if you can get it….) • Instead, observations/experiments are consistent with some explanation. As more evidence is consistent with an explanation, confidence/acceptability grows, and we say it is favored by a "convergence of evidence" • In science, who made an observation or invented a theory should be irrelevant: it should be judged on its ability to explain observable phenomena, not the prestige of its author, or what journal it was published in, or where the author is from or at, or how many people agree. • "Researchers at Harvard," is not a reason to believe something in science. • "published in Proceedings of the National Academy of Science" isn't worth the ink to write it. • "Everyone knows that…" doesn't mean anything.
What Science Is Not • Super-natural explanations specifically are a priori excluded as scientific explanation and subject matter This does not mean super-natural phenomena or entities do not exist, nor that all scientists are atheists. It does mean that since the super-natural does not present itself for convenient study, science can not treat it scientifically. • Science deals mainly with what/how/why, but not Why Science does answer questions like "Why do animals need air?", "Does the earth have a beginning?" but not "Does the universe have a purpose?" • Science, and rational thought in general, do not deal with or Should or Good/Bad (provide values) At best, they help to choose actions to implement values. Basic physics can let you calculate what voltage you need to apply to your gutters to get them hot enough so that leaves burn up when they hit. Physics does not deal with whether this is a good thing or a bad thing (Whether burning leaves or setting your house on fire is good or bad.) Physics can help you design a fuel-efficient car: it does not tell you why or whether the tradeoffs are worth it. • Science is not just going out and gathering lots of observations then trying to explain them: generally, you have a very good idea what might be found before trying to observe/measure (think of mineral hardness) • Science is not "making no assumptions" and "everything must be tested/proven". • There are huge assumptions underlying science itself, and there are bodies of received knowledge that must be mastered in any science • In order to contribute usefully to a science and make any progress, the investigator trusts many observation, conclusions, and theories, largely on the basis of trusting the source, largely based on the source's accomplishments. • I have never personally seen a mid-ocean ridge or an active volcano nor most features of plate tectonics, but trust that they are what my predecessors say they are, because they have been very good at finding ores and oil and earthquakes. • (Received knowledge is not regarded as evil, but the necessary basis of discovered knowledge.)
Actualism and Conventionalism A scientist might subscribe to a theory and interpret it as actually being true (actualism) or being a useful equivalent to something that is true (conventionalism). This is more philosophical and metaphysical than really belonging to science per se. • A conventionalist explanation For instance, "longshore currents" do not exist in reality, but we can make some useful predictions of where junk ends up by ignoring swash and backwash and treating the net effect as longshore current. • An actualist explanation Hot magma sometimes comes out of volcanoes. There really is hot magma, and you can see it and measure it and touch it if you're brutally foolish.
Fundamental Assumptions underlying Science • The natural world is worth knowing about • The natural world works in a consistent and predictable way • Observations of phenomena are largely observer-independent (objective reality) This list is largely a set of faith-assertions, and without them science would be pointless and unworkable.
Misconceptions about Science • There is not some magical "scientific method" that is guaranteed to work. There are a number of different scientific techniques, none of which are guaranteed. • Some sciences like physics and biology can use controlled experiments, others like geology and astronomy cannot (or at least not often) • Some topics are more amenable to expensive measurements leading to firm conclusions, other topics lead more to lots of measurements and statistical analysis with less solid conclusions. • There is no grand board that decides whether something is designated hypothesis or theory or a law. There is often even disagreement over observations. • Science is not value-free, but seeks to be objective • My own area of interest is groundwater exploration. The reason I like groundwater exploration is that water is a basic human need, my faith demands that I help those less fortunate, and I have a lot of talents that are relevant (values) • Water supplies are there or not, regardless of my individual feelings or desires (objective). • Observations ("Facts") are not always right, and can lead you into a whole set of other mistakes. For instance, you can determine the wrong hardness for a mineral, and then be led to a false conclusion about what mineral it is, thence to a wrong conclusion about the rock…
Major Elements of Science • Science involves three major elements, and emphasizes keeping them clearly distinguished. • Assumptions (a.k.a doctrine, dogma, postulates) • Ideas accepted without testing, such as Aristotelian logic. Taken on faith. • Observations (a.k.a experiment, empirical knowledge, ‘facts’) • Objectively observed phenomena, and the circumstances. • This includes both what does and does not occur. • Observations can be wrong, and they can be poorly made or mis-interpreted. • Theory (a.k.a explanation, conjecture, conclusions, hypothesis, theory, model ) • Theory is an explanation of observable phenomena in terms of other observable phenomena • Theory (a framework of principles) is used in the sense of hypothesis (unproven explanation of accepted observations). • Model is also used in the sense of explanation, but is generally applied to a particular situation. • A model or theory is good or bad based on whether it explains a set of observations and fits with other assumptions. • A theory/model can never be proven to be true, only to be not-yet-known-to-be-false. In order to be "true" or true enough, it must be possible for the explanation to be shown to be false. • Examples: • Uniformitarianism is not a theory, because you could not show it to be false • Plate tectonics is a theory because you could show that locations don't move relative to each other, or that locations on a single plate move relative to each other (plate motion has become an observation due to high precision surveying) • In other realms, theory is used to denote a set of basic assumptions (doctrine, dogma) used in explanations [this definition is common in law, like theory of contributory negligence], or to denote derisively that something is not an observation. A given set of claims may be taken as fact in one situation when it is considered theory in another. (Newton's Theory of Motion is taken as true when explaining plate motions.) • Sometimes, these distinctions get complicated and blurry.
Examples of Major Elements from Geology • Uniformitarianism (the present is the key to the past) <= doctrine/dogma • Partial melting of basaltic rock produces andesitic rock <= empirical result • The rocks in the Andes mountains have largely resulted from partial melting of subducted oceanic crust <= theory (or composite of several theories)
Theory-laden Observations • Consider this typical fieldnotes entry: "There is a fault displacing the lower sediments and metamorphic rocks exposed by the river at (X_Coords, Y_Coords)" • Even though it sounds like a simple statement of fact, this is really a composite of many observations, assumptions, theories, and explanations. • We have observed that the upper rocks are horizontally layered, and interpreted this as meaning they're sediments, and observed no layering in the lower black rocks and interpreted that as metamorphic or igneous rocks. (lots of assumptions behind that distinction, too) • We've assumed lateral continuity of sediments, and interpreted the observed displacement (note blue-green lines) as being caused by a fault, shown in yellow. • We've accepted that streams carve their own valleys (theory or assumption) and interpret the outcrop as having been exposed by the stream. We would accept this as a factual observation when trying to unravel the geologic history of this area and interpret it in terms of geological processes as normal science (more later), but might question these if they led to serious discrepancies with expectations.
Recognizing good science William Shakespeare, King Henry IV, Part I, Act III, scene I Glendale: I can call up spirits from the vasty deep. Henry Percy Hotsdale: Why, so can I, or so can any man, But do they come when you do call them? Glendale: And I can teach thee, cousin, to command The devil. Henry Percy Hotsdale: And I can teach thee, coz, to shame the devil By telling the truth; tell the truth and shame the devil! If thou have power to raise him, bring him hither, And I’ll be sworn I have power to shame him hence. O, while you live, tell truth, and shame the devil! Mt 7, 15-20 (NAB) Jesus said to his disciples: "Be on your guard against false prophets, who come to you in sheep's clothing but underneath are wolves on the prowl. You will know them by their deeds. Do you ever pick grapes from thornbushes, or figs from prickly plants? Never! Any sound tree bears good fruit, while a decayed tree bears bad fruit. A sound tree cannot bear bad fruit any more than a decayed tree can bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. You can tell a tree by its fruit." Put up or shut up! The proof (test) of the pudding (dessert) is in the eating. (That is, a dessert is good depending solely on whether it tastes good, not in the ingredients, or a fancy name, or fancy preparation techniques.)
Philosophy of Science Philosophy of science is an attempt at a philosophical description or prescription of when a theory replaces another. • Role in Science • Scientists do not actually worry about or have many discussions about philosophy of science issues. • There is little if any tendency to discuss whether something is really science or not, sometimes even when there should be. • We do discuss whether something is an observation, a valid observation, theory, assumptions, etc. • None of the algorithmic theories of science (none of which would be called theories in science) explain the actual process well, and attempting to follow them generally wastes much time. • Often, a theory is used even though known to be not true because it is easy to work with and is close enough. For example, most surveying is done on the assumption of a flat earth.
Philosophies of Science or how science progresses • Bacon • Problem comes up, scientist gathers facts, forms a hypothesis, predicts based on hypothesis, tests the hypothesis • This describes new sciences with new techniques very well (early days of isotope geology or remote sensing, for example), but Baconian science is largely derided as "stamp collecting" by more established fields • Popper • Science progresses by making clearly falsifiable assertions (hypotheses) and hypothesis testing. • Falsifiability and verisimilitude (approach to truth). • One strategy is to try to produce and test as many hypotheses as possible, because then you would make very rapid progress. • This might work, if it weren't so easy to tweak a hypothesis to dodge contradictory evidence. For example, many scientific debates focus on what data should and shouldn't be included as legitimate observations. • Kuhn • Science works in two modes: normal and revolutions (paradigm shifts). • Paradigm is theoretical perspective from which subject is viewed (e.g. plate tectonics, or pre-plate tectonics theories which tended towards the very arm-waving elevator tectonics). • Normal science is gathering observations on particular situations and using the paradigm to explain them. Most of the time is spent in Normal mode. • Contradictions may occur between the paradigm and observation, and are explained within the theory or by minor adjustments or additions. (e.g. hot spots added onto plate tectonics) or pointedly ignored. When enough contradictions accumulate, the science enters a period of un-ease and other theories may gain adherents. (e.g., elevator tectonics for Archean). Eventually (hopefully), a better theory is developed and accepted. • Normal science and Scientific revolutions. Theory as Paradigm • This seems to describe geology fairly well, and sounds reasonably like it works. • Chamberlin's Multiple Working Hypotheses (popular in geology) from Chamberlain (1890) athttp://www.for.nau.edu/mosaddphp/courses/for690/downloads/Chamberlin1890.pdfor http://www.cof.orst.edu/cof/fs/gradprog/courses/radosevich/studies.htm To avoid this grave danger, the method of multiple working hypotheses is urged. It differs from the simple working hypothesis in that it distributes the effort and divides the affections. It is thus in some measure protected against the radical defect of the two other methods. In developing the multiple hypotheses, the effort is to bring up into view every rational explanation of the phenomenon in hand and to develop every tenable hypothesis relative to its nature, cause or origin, and to give to all of these as impartially as possible a working form and a due place in the investigation. The investigator thus becomes the parent of a family of hypotheses; and by his parental relations to all is morally forbidden to fasten his affections unduly upon any one.
Geology from Kuhnian Perspective • Dogmas (Postulates accepted without question) • Uniformitarianism (Present is key to past) • Acceptance of physics, chemistry, biology • Old earth • What is (sort of) accepted as fact? Chemistry, Physics, Meteorology, Biology (sort of) • What is important • Distribution of rocks and sediments and fractures in rocks • Identity, composition (chemical and isotopic), and arrangement of minerals within a rock • Origin of rocks and their distribution • Depositional and intrusive sequences and gaps therein, along with ages • What counts as observation Field studies, chemical analyses, geophysical measurements, airphotos, topography, well logs, specimens…
Example Project: Groundwater Discharge in GMD3 • GMD3 is a Groundwater Management District in southwestern Kansas. I had previously done work for them, and I was contacted with the following amazingly well-constructed question: There is a fault in our district, and we're wondering if it's causing significant water loss. • Since I'm trained in groundwater exploration and remote sensing, my immediate solution was to • get Landsat data, • examine the images to find groundwater discharge zones marked by lush vegetation fed by groundwater, • determine the total area in groundwater discharge, • estimate evapotranspiration rate • Multiply to find total evapotranspiration from the groundwater discharge zones • The project proved fairly straightforward normal science. • The biggest problems encountered were • Areas of vegetation that might be natural or might be artificial • An unexpected requirement to deliver results in person. • See http://www.iwu.edu/~gpouch/gsa/
Example Project: PaleoSeismology from Landsat or Airphotos • When there are earthquakes that shake under-consolidated sediments enough, the formation compacts catastrophically (liquefacts) and water shoots out carrying sand: sand volcanoes. • Such features are the only pre-historic evidence of most earthquakes. • Sand volcanoes leave circular mounds a few meters across and a few centimeters thick. • There are also sand dikes, which can be as thick as a half meter but are usually much smaller. • Presently, these are found by canoeing up and down rivers looking for fresh bluffs that expose sand dikes. Once you find them, you can try to find embedded charcoal and get C-14 dates, from which you can get a recurrence interval to use for seismic hazard assessment. • Since I'm trained in remote sensing, a friend from graduate school asked if these might be visible with satellite imagery or airphotos. • My immediate reaction was almost certainly not on Landsat (too coarse) and probably not on airphotos. (too small, not enough sand to make much difference in soils or vegetation to be visible…) • However, I got talked into looking at a few anyway (Thanks to Bill Gates for TerraServer). • It turns out they show up on airphotos in a lot of locations, not as thin lines of well-drained soils (expected) but as sharp, linear boundaries between poorly and well-drained soils. • This is is a work in progress, and it hasn't gotten to drilling or digging yet. • See http://www.iwu.edu/~gpouch/seismo/AirphotoImages/