This web page introduces the concepts of density and buoyancy. The discovery in ancient Greece by Archimedes is described. The densities of various materials are given and temperature effects introduced. Links are provided to news and other resources related to mass density. This is part of the Vision Learning collection of short online modules covering topics in a broad range of science and math topics.
This activity is designed to define the biotic and abiotic characteristics found in a rocky intertidal ecosystem, to observe interactions between select living organisms and between themselves and their environment, and analyze which environmental and competitive factors may influence the particular pattern of density, diversity, or zonation found at a study site. The transect method and statistical analysis used for sampling population abundance and diversity in this activity is applicable to many other coastal and terrestrial habitats.
This site discusses the problems that a low density universe causes for the inflation theory. It also discusses the open vs closed universe theories and what is meant by critical density. Contains models and graphs to help explinations.
This inquiry-based curricular unit introduces middle school students to the concept of density through five hands-on experiments. In Activity 1, they handle five identical boxes, each filled with a material of differing density, to get a feel for the relationship among mass, volume, and density. Next, they devise methods to figure out the density of solid objects by using water displacement. Finally, they use their knowledge to determine how to calculate density without being given a formula.
This Flash animation lets students interactively explore how density is related to weight and volume. A cylinder filled with water rests on a scale. Use the mouse to “drop” a wood block, a rock, a canned food item, or a half-full jar of pickles into the water, then view the displacement and calculate the density. If the object floats, use the mouse to push it under the water to complete the calculation.
The article, “A spatial autocorrelation model of the effects of population density on fertility,” authored by Colin Loftin and Sally K. Ward, disputes the GGM model by introducing spatial autocorrelation as a way to take spatial interaction into consideration in studying the relationship between population density and fertility.
This chapter continues the examination and clarification of concepts relating to point objects, for which as argued in Chapter 1, appropriate, complex/ second order, concepts relate to words like ‘distribution’, ‘dispersion’, ‘density’, ‘pattern’ and ‘scale’ and, at higher level still, third order concepts relating to point process models, stationarity and isotropy/anisotropy.