Over the course of human history, people have developed many interconnected and validated ideas about the physical, biological, psychological, and social worlds. Those ideas have enabled successive generations to achieve an increasingly comprehensive and reliable understanding of the human species and its environment. The means used to develop these ideas are particular ways of observing, thinking, experimenting, and validating. These ways represent a fundamental aspect of the nature of science and reflect how science tends to differ from other modes of knowing.
It is the union of science, mathematics, and technology that forms the scientific endeavor and that makes it so successful. Although each of these human enterprises has a character and history of its own, each is dependent on and reinforces the others. Accordingly, the first three chapters of recommendations draw portraits of science, mathematics, and technology that emphasize their roles in the scientific endeavor and reveal some of the similarities and connections among them.
SCIENTIFIC INQUIRY
Fundamentally, the various scientific disciplines are alike in their reliance on evidence, the use of hypothesis and theories, the kinds of logic used, and much more. Nevertheless, scientists differ greatly from one another in what phenomena they investigate and in how they go about their work; in the reliance they place on historical data or on experimental findings and on qualitative or quantitative methods; in their recourse to fundamental principles; and in how much they draw on the findings of other sciences. Still, the exchange of techniques, information, and concepts goes on all the time among scientists, and there are common understandings among them about what constitutes an investigation that is scientifically valid.
Scientific inquiry is not easily described apart from the context of particular investigations. There simply is no fixed set of steps that scientists always follow, no one path that leads them unerringly to scientific knowledge. There are, however, certain features of science that give it a distinctive character as a mode of inquiry. Although those features are especially characteristic of the work of professional scientists, everyone can exercise them in thinking scientifically about many matters of interest in everyday life.
Science Demands Evidence
Sooner or later, the validity of scientific claims is settled by referring to observations of phenomena. Hence, scientists concentrate on getting accurate data. Such evidence is obtained by observations and measurements taken in situations that range from natural settings (such as a forest) to completely contrived ones (such as the laboratory). To make their observations, scientists use their own senses, instruments (such as microscopes) that enhance those senses, and instruments that tap characteristics quite different from what humans can sense (such as magnetic fields). Scientists observe passively (earthquakes, bird migrations), make collections (rocks, shells), and actively probe the world (as by boring into the earth's crust or administering experimental medicines).
In some circumstances, scientists can control conditions deliberately and precisely to obtain their evidence. They may, for example, control the temperature, change the concentration of chemicals, or choose which organisms mate with which others. By varying just one condition at a time, they can hope to identify its exclusive effects on what happens, uncomplicated by changes in other conditions. Often, however, control of conditions may be impractical (as in studying stars), or unethical (as in studying people), or likely to distort the natural phenomena (as in studying wild animals in captivity). In such cases, observations have to be made over a sufficiently wide range of naturally occurring conditions to infer what the influence of various factors might be. Because of this reliance on evidence, great value is placed on the development of better instruments and techniques of observation, and the findings of any one investigator or group are usually checked by others.
Science Is a Blend of Logic and Imagination
Although all sorts of imagination and thought may be used in coming up with hypotheses and theories, sooner or later scientific arguments must conform to the principles of logical reasoning—that is, to testing the validity of arguments by applying certain criteria of inference, demonstration, and common sense. Scientists may often disagree about the value of a particular piece of evidence, or about the appropriateness of particular assumptions that are made—and therefore disagree about what conclusions are justified. But they tend to agree about the principles of logical reasoning that connect evidence and assumptions with conclusions.
Scientists do not work only with data and well-developed theories. Often, they have only tentative hypotheses about the way things may be. Such hypotheses are widely used in science for choosing what data to pay attention to and what additional data to seek, and for guiding the interpretation of data. In fact, the process of formulating and testing hypotheses is one of the core activities of scientists. To be useful, a hypothesis should suggest what evidence would support it and what evidence would refute it. A hypothesis that cannot in principle be put to the test of evidence may be interesting, but it is not likely to be scientifically useful.
The use of logic and the close examination of evidence are necessary but not usually sufficient for the advancement of science. Scientific concepts do not emerge automatically from data or from any amount of analysis alone. Inventing hypotheses or theories to imagine how the world works and then figuring out how they can be put to the test of reality is as creative as writing poetry, composing music, or designing skyscrapers. Sometimes discoveries in science are made unexpectedly, even by accident. But knowledge and creative insight are usually required to recognize the meaning of the unexpected. Aspects of data that have been ignored by one scientist may lead to new discoveries by another.
LIVE SCIENCE
TOPIC NATURE
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The
earthquake
When an earthquake cracks open the Earth's surface, scientists now find there might be a limit to how far such rips will split, findings that could help map out what hazards quakes might pose.
When a fault in the surface gives way, the resulting earthquake can jump to nearby faults as well. This domino effect can make it very difficult to gauge how far a rupture might continue, especially in complex areas with overlapping fault segments, such as California's San Andreas fault system.
To learn more about the length to which a quake will rupture, scientists at the University of Nevada, Reno, investigated 22 past earthquakes around the world, including ones in California, Japan and New Zealand. Each of these quakes was caused by one side of a fault sliding against the other, a so-called strike-slip surface rupture. (One such breach caused the massive 1906 San Francisco quake.
When a fault in the surface gives way, the resulting earthquake can jump to nearby faults as well. This domino effect can make it very difficult to gauge how far a rupture might continue, especially in complex areas with overlapping fault segments, such as California's San Andreas fault system.
To learn more about the length to which a quake will rupture, scientists at the University of Nevada, Reno, investigated 22 past earthquakes around the world, including ones in California, Japan and New Zealand. Each of these quakes was caused by one side of a fault sliding against the other, a so-called strike-slip surface rupture. (One such breach caused the massive 1906 San Francisco quake.
Three Tornadoes Confirmed in Massachusetts
Storm survey teams from the National Weather Service (NWS) in Boston have confirmed that three tornadoes touched down in Massachusetts on June 1, including the biggest and deadliest for the state in 16 years.
The largest of the three tornadoes had winds of up to 160 mph (257 kph) and was rated an EF-3 on the tornado damage scale. The powerful twister killed four people and injured 72 in the town of Westfield. Two EF-1 twisters have also been confirmed, according to the NWS storm survey report. The outbreak was the state's biggest since 1997, when six tornadoes touched down on July 3, according to the National Climatic Data Center (NCDC).
Tornadoes in Massachusetts are rare, but not unheard of — even bigger twisters will occasionally strike the state. The last time a deadly tornado struck Massachusetts was May 29, 1995, according to the NCDC. That tornado, an EF-4 on the tornado damage scale, killed three people in the town of North Egremont. Until June 1, the state had not seen a tornado stronger than an EF-2 or a tornado-related death since that outbreak in 1995.
The largest of the three tornadoes had winds of up to 160 mph (257 kph) and was rated an EF-3 on the tornado damage scale. The powerful twister killed four people and injured 72 in the town of Westfield. Two EF-1 twisters have also been confirmed, according to the NWS storm survey report. The outbreak was the state's biggest since 1997, when six tornadoes touched down on July 3, according to the National Climatic Data Center (NCDC).
Tornadoes in Massachusetts are rare, but not unheard of — even bigger twisters will occasionally strike the state. The last time a deadly tornado struck Massachusetts was May 29, 1995, according to the NCDC. That tornado, an EF-4 on the tornado damage scale, killed three people in the town of North Egremont. Until June 1, the state had not seen a tornado stronger than an EF-2 or a tornado-related death since that outbreak in 1995.
More Storms Threaten On 'Super Outbreak' Tornado Anniversary
People are hunkering down today for what could be the worst severe weather of the year — and it just happens to come on the same day in history as the largest tornado outbreak of all time.
On April 3 and 4, 1974, 148 tornadoes swept across 13 Midwestern and Southern states during the largest outbreak of tornadoes in U.S. history. The killer tornadoes — together called the Super Outbreak — claimed 330 lives.
A satellite image from 1974 shows the outbreak in progress. Three squall lines — severe thunderstorms that form along or ahead of a cold front — roared east at 5 p.m. EDT (2100 GMT) on April 3. [Infographic: Tornado! An Inside Look at Tornado Season]
Killer Waves Approaching
Caroline and J.T. Malatesta of Mountain Brook, Ala. survived the killer Asian tsunami while on vacation in Thailand. This mountain top photo was taken December 26, 2004 from about 400 feet above the sea on December 26, 2004.
People are hunkering down today for what could be the worst severe weather of the year — and it just happens to come on the same day in history as the largest tornado outbreak of all time.
On April 3 and 4, 1974, 148 tornadoes swept across 13 Midwestern and Southern states during the largest outbreak of tornadoes in U.S. history. The killer tornadoes — together called the Super Outbreak — claimed 330 lives.
A satellite image from 1974 shows the outbreak in progress. Three squall lines — severe thunderstorms that form along or ahead of a cold front — roared east at 5 p.m. EDT (2100 GMT) on April 3. [Infographic: Tornado! An Inside Look at Tornado Season]
Killer Waves Approaching
Caroline and J.T. Malatesta of Mountain Brook, Ala. survived the killer Asian tsunami while on vacation in Thailand. This mountain top photo was taken December 26, 2004 from about 400 feet above the sea on December 26, 2004.
Water Flows through the streets of Sri Lanka
Credit: AP Photo/Gemunu Amarasinghe
Tidal waves wash through houses at Maddampegama, about 60 kilometers (38 miles) south of Colombo, Sri Lanka, Sunday, Dec. 26, 2004. Massive waves triggered by earthquakes crashed into villages along a wide stretch of Sri Lankan coast on Sunday, killing more than 2,100 people and displacing a million others.
Coastal landslides
Credit: Randy Jibson, USGS
The Haiti quake caused massive landslides along the coast. This photo was taken near Nan Diamant.
Credit: AP Photo/Gemunu Amarasinghe
Tidal waves wash through houses at Maddampegama, about 60 kilometers (38 miles) south of Colombo, Sri Lanka, Sunday, Dec. 26, 2004. Massive waves triggered by earthquakes crashed into villages along a wide stretch of Sri Lankan coast on Sunday, killing more than 2,100 people and displacing a million others.
Coastal landslides
Credit: Randy Jibson, USGS
The Haiti quake caused massive landslides along the coast. This photo was taken near Nan Diamant.
