Current Version of the Benchmarks Statements

By the end of the 8th grade, students should know that

• Because every object is moving relative to some other object, no object has a unique claim to be at rest. Therefore, the idea of absolute motion or rest is misleading. 10A/M1*
• Telescopes reveal that there are many more stars in the night sky than are evident to the unaided eye, the surface of the moon has many craters and mountains, the sun has dark spots, and Jupiter and some other planets have their own moons. 10A/M2

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• To someone standing on the earth, it seems as if it is large and stationary and that all other objects in the sky orbit around it. That perception was the basis for theories of how the universe is organized that prevailed for over 2,000 years. 10A/H1*
• Ptolemy, an Egyptian astronomer living in the second century A.D., devised a powerful mathematical model of the universe based on continuous motion in perfect circles, and in circles on circles. With the model, he was able to predict the motions of the sun, moon, and stars, and even of the irregular "wandering stars" now called planets. 10A/H2*
• In the 1500s, a Polish astronomer named Copernicus suggested that all those same motions could be explained by imagining that the earth was turning around once a day and orbiting around the sun once a year. This explanation was rejected by nearly everyone because it violated common sense and required the universe to be unbelievably large. Worse, it flew in the face of the belief, universally held at the time, that the earth was at the center of the universe. 10A/H3*
• Johannes Kepler, a German astronomer, worked with Tycho Brahe for a short time. After Brahe's death, Kepler used his data to show mathematically that Copernicus' idea of a sun-centered system worked well if uniform circular motion was replaced with uneven (but predictable) motion along off-center ellipses. 10A/H4*
• Using the newly invented telescope to study the sky, Galileo made many discoveries that supported the ideas of Copernicus. It was Galileo who found the moons of Jupiter, sunspots, craters and mountains on the moon, and many more stars than were visible to the unaided eye. 10A/H5
• Writing in Italian rather than in Latin (the language of scholars at the time), Galileo presented arguments for and against the two main views of the universe in a way that favored the newer view. His descriptions of how things move provided an explanation for why people might notice the motion of the earth. Galileo's writings made educated people of the time aware of these competing views and created political, religious, and scientific controversy. 10A/H6*
• Tycho Brahe, a Danish astronomer, proposed a model of the universe that was popular for a while because it was somewhat of a compromise of Ptolemy's and Copernicus' models. Brahe made very precise measurements of the positions of the planets and stars in an attempt to validate his model. 10A/H7**
• The work of Copernicus, Galileo, Brahe, and Kepler eventually changed people's perception of their place in the universe. 10A/H8** (SFAA)

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• Isaac Newton, building on earlier descriptions of motion by Galileo, Kepler, and others, created a unified view of force and motion in which motion everywhere in the universe can be explained by the same few rules. Newton's system was based on the concepts of mass, force, and acceleration; his three laws of motion relating them; and a physical law stating that the force of gravity between any two objects in the universe depends only upon their masses and the distance between them. 10B/H1*
• Newton's mathematical analysis of gravitational force and motion showed that planetary orbits had to be the very ellipses that Kepler had proposed two generations earlier. 10B/H2*
• The Newtonian system made it possible to account for such diverse phenomena as tides, the orbits of planets and moons, the motion of falling objects, and the earth's equatorial bulge. 10B/H3*
• For several centuries, Newton's science was accepted without major changes because it explained so many different phenomena, could be used to predict many physical events (such as the appearance of Halley's comet), was mathematically sound, and had many practical applications. 10B/H4
• Although overtaken in the 1900s by Einstein's relativity theory, Newton's ideas persist and are widely used. Moreover, his influence has extended far beyond physics and astronomy, serving as a model for other sciences and even raising philosophical questions about free will and the organization of social systems. 10B/H5*

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• As a young man, Albert Einstein, a German scientist, formulated the special theory of relativity, which brought about revolutionary changes in human understanding of nature. Among the counterintuitive ideas of special relativity is that the speed of light is the same for all observers no matter how they or the light source happen to be moving. In addition, nothing can travel faster than the speed of light. 10C/H1*
• The special theory of relativity is best known for stating that any form of energy has mass, and that matter itself is a form of energy. Even a tiny amount of matter holds an enormous amount of energy. This relationship is described in the famous relativity equation E = mc², in which the c in the equation stands for the immense speed of light. 10C/H3*
• A decade after Einstein developed the special theory of relativity, he proposed the general theory of relativity, which pictures Newton's gravitational force as a distortion of space and time. 10C/H4*
• Einstein's development of the theories of special and general relativity ranks as one of the greatest human accomplishments in all of history. Many predictions from the theories have been confirmed on both atomic and astronomical scales. Still, the search continues for an even more powerful theory of the architecture of the universe. 10C/H5*
• Under everyday situations, most of the predictions of special relativity are nearly identical to those of classical mechanics. The more counterintuitive predictions of special relativity occur in situations that humans do not typically experience. 10C/H6**

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• Prior to the 1700s, many considered the earth to be just a few thousand years old. By the 1800s, scientists were starting to realize that the earth was much older even though they could not determine its exact age. 10D/H1*
• In the early 1800s, Charles Lyell argued in Principles of Geology that the earth was vastly older than most people believed. He supported his claim with a wealth of observations of the patterns of rock layers in mountains and the locations of various kinds of fossils. 10D/H2*
• In formulating and presenting his theory of biological evolution, British naturalist Charles Darwin adopted Lyell's claims about the age of the earth and his assumption that the processes that occurred in the past are the same as the processes that occur today. 10D/H3*

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• As soon as fairly accurate world maps began to appear, some people noticed that the continents of Africa and South America looked as though they might fit together, like a giant jigsaw puzzle. This led some to speculate that they might have once been part of a single giant land mass that broke into pieces and then drifted apart. This idea was repeatedly suggested and rejected because it was hard to imagine that anything that large and apparently immobile could move. 10E/H1*
• Early in the 1900s, Alfred Wegener, a German scientist, reintroduced the idea of moving continents, adding such evidence as the underwater shapes of the continents, the similarity of life forms and land forms in corresponding parts of Africa and South America, and the increasing separation of Greenland and Europe. Even with this evidence and the realization that the earth was old enough for this to have occurred, very few contemporary scientists adopted Wegener's theory because he lacked a plausible mechanism for the movement of continents. 10E/H2*
• In the 1960s, scientists noted that earthquakes occur much more frequently in certain areas, that the rock around mid-ocean ridges is progressively older the farther it is from the ridge, and that this gradient is symmetrical on either side of the ridge. This evidence, coupled with a scientifically sound physical explanation for how continents could move, transformed the idea of moving continents into the theory of plate tectonics. 10E/H3*
• Scientists continue to study the motions of the earth's plates and the phenomena those motions cause in an attempt to better understand the internal composition of the earth and the processes taking place within it. 10E/H4**

Current Version of the Benchmarks Statements

By the end of the 8th grade, students should know that

• More than 2000 years ago, Greek philosophers formulated the idea of atoms as being simple particles beyond the reach of human senses and with the existence of a void between them. 10F/M1a*
• Aristotle and other thinkers held that four elements (fire, air, water, and earth) composed all of matter. While the idea of atoms received little attention, Aristotle's four elements became the dominant idea. 10F/M1b*
• Antoine Lavoisier's work was based on the idea that when materials react with each other, many changes can take place but that in every case the total amount of mass afterward is the same as before. He successfully tested the concept of conservation of mass by conducting a series of experiments in which he carefully measured all the substances involved in burning, including the gases used and those given off. As a result, the phlogiston theory was replaced by a theory based on the role of oxygen in burning. 10F/M4*
• Ancient civilizations in China, India, the Middle East, and the Mediterranean developed explanations about matter not by experimentation but by observing the natural world and by using logic and rational thought. 10F/M6**
• Up until the 1700s, the prevailing idea was that materials contained a substance called phlogiston, which had mass, and that when an object burned, it gave off phlogiston, which carried away the mass. This view confirmed what people saw: When a piece of wood was burned, all that was left was a residue of ashes that had far less mass than the wood. 10F/M7** (SFAA)

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• In the late 1700s and early 1800s, the idea of atoms reemerged in response to questions about the structure of matter, the nature of fire, and the basis of chemical phenomena. 10F/H1**
• Lavoisier pioneered a new approach to chemistry based on the modern definition of an element and quantitative methods. His system for naming substances and describing their reactions in terms of the elements that make them up contributed to the rapid growth of chemistry by enabling scientists everywhere to share their findings about chemical reactions without ambiguity. 10F/H2*
• In the early 1800s, British chemist and physicist John Dalton united the concepts of atoms and elements. He proposed two ideas that laid the groundwork for modern chemistry: first, that elements are formed from small, indivisible particles called atoms, which are identical for a given element but different from any other element; and second, that chemical compounds are formed from atoms by combining a definite number of each type of atom to form one molecule of the compound. 10F/H3*
• Dalton figured out how the relative weights of the atoms could be determined experimentally. His idea that every substance had a unique atomic composition provided an explanation for why substances were made up of elements in specific proportions. 10F/H4**
• Since Lavoisier and Dalton, the system for describing chemical reactions has been vastly extended to account for the configuration taken by atoms when they bond to one another and to describe the inner workings of atoms that account for why they bond as they do. 10F/H5*

There are no longer any benchmarks assigned to this grade level in this section in the current version of Benchmarks.

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• The unexpected discovery that minerals containing uranium darken photographic film, as light does, led to the idea of radioactivity. 10G/H1a*
• In their laboratory in France, Marie Curie and her husband, Pierre Curie, isolated two new elements that caused most of the radioactivity of the uranium mineral. They named one radium because it gave off powerful, invisible rays, and the other polonium in honor of Madame Curie's country of birth, Poland. 10G/H1b*
• Ernest Rutherford of New Zealand and his colleagues discovered that the heavy radioactive element uranium spontaneously splits itself into a slightly lighter nucleus and a very light helium nucleus, leading to the realization that one kind of atom may change into another kind, and that therefore an atom must be made up of smaller parts. 10G/H2*
• Otto Hahn and Fritz Strassmann, German chemists, found that when they struck uranium with a beam of neutrons, barium was unexpectedly produced. Austrian physicist Lise Meitner, who had earlier worked with Hahn and Strassmann on the decay patterns of uranium, was the first to suggest that the barium could have resulted from the splitting of the uranium nucleus into two middleweight nuclei and one or two extra neutrons. 10G/H3a*
• In proposing that a uranium nucleus could split, Meitner had to account for the energy that would be released when the newly formed nuclei accelerated away from each other. She suggested it could come from the conversion of mass to energy predicted by Einstein's theory of special relativity. 10G/H3b*
• Enrico Fermi, an Italian working with colleagues in the United States, showed that the extra neutrons trigger more fissions in uranium nuclei and so create a sustained chain reaction in which a prodigious amount of energy is given off. 10G/H3c*
• A massive effort went into developing the technology for the production of nuclear fission bombs used against Japan in World War II. The hydrogen bomb, which uses nuclear fusion, was developed shortly after World War II. Another important development of this era was the nuclear reactor, in which nuclear energies are released in a controlled fashion for the production of electrical energy. 10G/H4a*
• Nuclear weapons and energy remain matters of public concern and controversy. 10G/H4b
• Radioactivity has many uses other than generating energy, including in medicine, industry, and scientific research in many different fields. 10G/H5

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• The theory of natural selection grew out of efforts to determine how species change over time. 10H/H1*
• Prior to the 1800s, the most widespread belief was that all known species were created and remained unchanged throughout history. 10H/H2a*
• By the mid-1800s, some scientists believed that species evolved from earlier species. 10H/H2b*
• Darwin argued that certain biologically inherited characteristics give an organism an advantage in surviving and reproducing compared to other organisms of the same species. The offspring would also inherit and pass on those advantages, and over generations the accumulation of these inherited advantages would lead to a new species. 10H/H3*
• Darwin published his theory in the mid-1800s in Origin of Species. Its dramatic effect on biology can be traced to his use of clear and understandable argument, the inclusion of a massive array of evidence to support the argument, comparison of natural selection to the selective breeding of animals in wide use at the time, and the utility of the theory as a unifying framework for guiding future research. 10H/H4*
• A mechanism that explained the origin of variation within species was suggested by several lines of evidence: findings from Gregor Mendel's experiments on the inheritance of traits in plants, the identification of genes and how they are sorted in reproduction, and the discovery of the mutability and near universality of the genetic code found in DNA. 10H/H5*
• By the 1900s, nearly all scientists had accepted Darwin's basic idea of evolution through natural selection. Today, scientists continue to work out the details of the evolutionary history of specific organisms. 10H/H6ab*
• The lack of acceptance of scientific arguments for natural selection by some members of the general public has been affected by their discomfort with its implications, such as the relation of humans to other animals, and their religious beliefs about when and how the world and living things in it were created. 10H/H6c*

Current Version of the Benchmarks Statements

By the end of the 8th grade, students should know that

• Throughout history, people have created explanations for disease. Some have held that disease has supernatural causes. Others have used careful observation and reasoning to propose natural causes. 10I/M1*
• French chemist Louis Pasteur demonstrated that spoilage and fermentation occur when microorganisms enter from the air, multiply rapidly, and produce waste products. He showed that spoilage could be avoided by keeping germs out or by destroying them with heat. 10I/M2bc*
• German physician Robert Koch used a set of criteria to evaluate whether specific germs caused anthrax. He and others then used the criteria to identify the germs that cause numerous other diseases. 10I/M2d*
• Pasteur found that infection by disease organisms (germs) caused the body to build up an immunity against subsequent infection by the same organisms. He then produced vaccines that would induce the body to build immunity to a disease without actually causing the disease itself. 10I/M3*
• Investigations of the germ theory by Pasteur, Koch, and others in the 19th century firmly established the modern idea that many diseases are caused by microorganisms. Acceptance of the germ theory has led to changes in health practices. 10I/M4*
• In medicine, as in other fields of science, discoveries are sometimes made unexpectedly, even by accident. But knowledge and creative insight are usually required to recognize the meaning of the unexpected. 10I/M5
• The improvement of microscope lenses and design in the 1600s led to discovery of a vast new world of microscopically small plants and animals, among them bacteria and yeasts. Because most microorganisms do not cause disease, they are present even in healthy individuals. Therefore, the discovery of those microorganisms did not suggest what effects they might have on humans and other organisms. 10I/M6** (SFAA)
• Current health practices emphasize sanitation, the safe handling of food and water, the pasteurization of milk, isolation, and aseptic surgical techniques to keep germs out of the body; vaccinations to strengthen the body's immune system against subsequent infection by the same kind of microorganisms; and antibiotics and other chemicals and processes to destroy microorganisms. 10I/M7** (BSL)
• After the discovery of germs, biologists turned to the identification and investigation of microorganisms, discovering thousands of different bacteria, viruses, yeasts, and parasites and gaining a deeper understanding of the interactions between organisms. 10I/M8** (SFAA)

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• Today, the modern technology of high-power imaging and biotechnology make it possible to investigate how microorganisms spread, how they cause disease, how the immune system combats them, and even how they can be manipulated genetically. 10I/H1** (SFAA)

Current Version of the Benchmarks Statements

By the end of the 5th grade, students should know that

• In the 1700s, most manufacturing was still done in homes or small shops, using small, handmade machines that were powered by muscle, wind, or moving water. 10J/E1** (BSL)

Current Version of the Benchmarks Statements

By the end of the 8th grade, students should know that

• In the 1800s, new machinery and steam engines to drive them made it possible to manufacture goods in factories, using fuels as a source of energy. In the factory system, workers, materials, and energy could be brought together efficiently. 10J/M1*
• The invention of the steam engine was at the center of the Industrial Revolution. It converted the chemical energy stored in wood and coal into motion energy. The steam engine was widely used to solve the urgent problem of pumping water out of coal mines. As improved by James Watt, Scottish inventor and mechanical engineer, it was soon used to move coal; drive manufacturing machinery; and power locomotives, ships, and even the first automobiles. 10J/M2*

Current Version of the Benchmarks Statements

By the end of the 12th grade, students should know that

• The Industrial Revolution developed in Great Britain because that country made practical use of science, had access by sea to world resources and markets, and had people who were willing to work in factories. 10J/H1*
• The Industrial Revolution increased the productivity of each worker, but it also increased child labor and unhealthy working conditions, and it gradually destroyed the craft tradition. The economic imbalances of the Industrial Revolution led to a growing conflict between factory owners and workers and contributed to the main political ideologies of the 20th century. 10J/H2
• Today, changes in technology continue to affect patterns of work and bring with them economic and social consequences. 10J/H3*