CORRECTION: Because science relies on observation and because the process of science is unfamiliar to many, it may seem as though scientists build knowledge directly through observation. Observation critical in science, but scientists often make about what those observations mean. Observations are part of a complex process that involves coming up with ideas about how the natural world works and seeing if observations back those explanations up. Learning about the inner workings of the natural world is less like reading a book and more like writing a non-fiction book trying out different ideas, rephrasing, running drafts by other people, and modifying text in order to present the clearest and most accurate explanations for what we observe in the natural world. To learn more about how scientific knowledge is built, visit our section .
For example in the 1820s astronomers noticed that the planet Uranus didn't move in the way it should have done if they used Newton's theories to do the calculations. Several astronomers independently came up with the hypothesis that there was another planet outside Uranus. The hypothesis was mathematical and predicted where in the sky to look for this planet.
Fact: are statements that we know to be true through direct . In everyday usage, facts are a highly valued form of knowledge because we can be so confident in them. Scientific thinking, however, recognizes that, though facts are important, we can only be completely confident about relatively simple statements. For example, it may be a fact that there are three trees in your backyard. However, our knowledge of how all trees are related to one another is not a fact; it is a complex body of knowledge based on many different and reasoning that may change as new is discovered and as old evidence is interpreted in new ways. Though our knowledge of tree relationships is not a fact, it is broadly applicable, useful in many situations, and synthesizes many individual facts into a broader framework. values facts but recognizes that many forms of knowledge are more powerful than simple facts.
: In everyday language, a is a rule that must be abided or something that can be relied upon to occur in a particular situation. Scientific laws, on the other hand, are less rigid. They may have exceptions, and, like other scientific knowledge, may be modified or rejected based on new evidence and perspectives. In science, the term usually refers to a generalization about and is a compact way of describing what we'd expect to happen in a particular situation. Some laws are non-mechanistic statements about the relationship among observable phenomena. For example, the ideal gas law describes how the pressure, volume, and temperature of a particular amount of gas are related to one another. It does not describe how gases behave; we know that gases do not precisely conform to the ideal gas law. Other laws deal with phenomena that are not directly observable. For example, the second law of thermodynamics deals with entropy, which is not directly observable in the same way that volume and pressure are. Still other laws offer more mechanistic explanations of phenomena. For example, Mendel's first law offers a of how genes are distributed to gametes and offspring that helps us make about the outcomes of genetic crosses. The term may be used to describe many different forms of scientific knowledge, and whether or not a particular idea is called a law has much to do with its discipline and the time period in which it was first developed.
Wolff, J.O. & Krebs, C.J. (2008) Hypothesis testing and the scientific method revisited. Acta Zoologica Sinica, 54, 383-386.
Over-arching theories are so important because they help scientists choose their methods of study and mode of reasoning, connect important phenomena in new ways, and open new areas of study.
Such over-arching theories encompass many subordinate theories and hypotheses, and consequently, changes to those smaller theories and hypotheses reflect a refinement (not an overthrow) of the over-arching theory.
For example, when punctuated equilibrium was proposed as a mode of evolutionary change and was found supporting the idea in some situations, it represented an elaborated reinforcement of evolutionary theory, not a refutation of it.
CORRECTION: When scientists are portrayed in movies and television shows, they are often ensconced in silent laboratories, alone with their bubbling test-tubes. This can make science seem isolating. In fact, many scientists work in busy labs or field stations, surrounded by other scientists and students. Scientists often collaborate on studies with one another, mentor less experienced scientists, and just chat about their work over coffee. Even the rare scientist who works entirely alone depends on interactions with the rest of the scientific community to scrutinize his or her work and get ideas for new studies. Science is a social endeavor. To learn more, visit our section on the .
One example will illustrate my frustration with political ecology. Dirzo et al. (2014) in a recent Science paper give an illustration of the effects of removing large animals from an ecosystem. In their Figure 4, page 404, a set of 4 graphs purport to show experimentally what happens when you remove large wildlife species in Kenya, the Kenya Long-term Exclosure Experiment (Young et al. 1997). But this experiment is hopelessly flawed in being carried out on a set of plots of 4 ha, a postage stamp of habitat relative to large mammal movements and ecosystem processes. But the fact that this particular experiment was not properly designed for the questions it is now being used to address is not a problem if this is political ecology rather than scientific ecology. The overall goal of the Dirzo et al. (2014) paper is admirable, but it is achieved by quoting a whole series of questionable extrapolations given in other papers. The counter-argument in conservation biology has always been that we do not have time to do proper research and we must act now. The consequence is the elevation of expert opinion in conservation science to the realm of truth without going through the proper scientific process.
CORRECTION: The feats accomplished through the application of scientific knowledge are truly astounding. Science has helped us eradicate deadly diseases, communicate with people all over the world, and build that make our lives easier everyday. But for all scientific innovations, the costs must be carefully weighed against the benefits. And, of course, there's no guarantee that solutions for some problems (e.g., finding an HIV vaccine) exist though science is likely to help us discover them if they do exist. Furthermore, some important human concerns (e.g. some spiritual and aesthetic questions) cannot be addressed by science at all. Science is a marvelous tool for helping us understand the natural world, but it is not a cure-all for whatever problems we encounter.
CORRECTION: Because of some vocal individuals (both inside and outside of science) stridently declaring their beliefs, it's easy to get the impression that science and religion are at war. In fact, people of many different faiths and levels of scientific expertise see no contradiction at all between science and religion. Because science deals only with phenomena and explanations, it cannot support or contradict the existence of entities like God. To learn more, visit our side trip .