What does 100 look like? Sound like? Feel like? In this video from Curious George, explore the many ways to measure 100 things. ***Access to Teacher's Domain content now requires free login to PBS Learning Media. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

This document presents a number of theories, both plausible and implausible or even humorous, for the extinction of the dinosaurs. Links to a glossary are embedded in the text. A reading list and links to related sites are also provided.

Advising guidelines put together at the University of Arkansas as the undergraduate program grew and developed. Presented at the 2012 SPIN-UP conference in Austin and the PhysTEC leadership meeting at the AAPT summer meeting in Edmonton.

This iOS app requires students to use a ten frame to fill in the remaining addend with contrasting chips and then count them to tell how many more to make ten. The app can be set to build sequentially or it can be set to give random values. Additionally, the app includes an option to show number sentences when the problem is complete.

This activity includes an assessment, analysis, and action tool that can be used by classrooms to promote understanding of how the complex current issues of energy, pollution, supply and consumption are not just global but also local issues.

This animation displays one year of Outgoing Long-wave Radiation (OLR) Terra-CERES data (March 1, 2000 to May 25, 2001) with a 14-day boxcar average. Endpoints have the average re-weighted for the smaller amount of data. The data are 2.5 degree resolution.

This animation displays one year of Reflected Solar Radiation (RSR) Terra-CERES data (March 1, 2000 to May 25, 2001) with a 14-day boxcar average. Endpoints have the average re-weighted for the smaller amount of data. The data are 2.5 degree resolution.

This animation is a montage of short clips taken from animations the SVS has created over the past 15 years.

In 1948, Melville J. Herskovits established the African Studies program at Northwestern University. It was the first of its kind at a major research university in the United States, and since its creation, it has also been actively involved with collecting historic maps of Africa. This particular online collection draws on this legacy of preservation and acquisition, and all told, it contains 113 antique maps of Africa dating from the middle of the sixteenth century to the early twentieth century. Visitors can utilize a search engine to look through the maps, or they may also browse by title, cartographer, or date. There are a number of real finds here, including Frederik de Wit's 1708 map of North Africa (titled "Barbaria") and an early map of Zanzibar from 1740.

In this 15 minute video, Mary Holden and her 4th/5th grade class reason about the appropriateness of different computational methods (base-ten blocks, calculators, mental math, or paper and pencil) to specific problems. The video includes a description of how the teacher manages her multi-level class and encourages hands on exploration and discussion in small group learning sessions. At the conclusion of the video are reflection questions for professional development.

The transit of Venus is a rare astronomical event that has been well documented throughout history. The most recent transit occurred in June of 2004, and the one before that took place more than 100 years earlier in 1882. This site from the South African Astronomical Observatory provides information and first-hand observations of the 1882 event from Wellington, South Africa. Just prior to the event, an observatory was erected at the Huguenot Seminary for girls, and some of the historical observations made from that site in 1882 are provided here for your perusal.

This article and included graphs,from the web site accompanying the FRONTLINE NOVA special What's Up with the Weather?, reveals how atmospheric carbon dioxide, methane, and nitrous oxides from coal- and oil-burning power plants, cars, and other fossil-fuel-burning sources have climbed along with the world population, with as yet unknown effects on the climate system.

This page from the Volcano World website contains a summary account of the 1959 eruption at Kilauea Iki which is illustrated by photographs and videos.

This video adapted from the Valdez Museum & Historical Archive, explores what happened during the Great Alaska Earthquake of 1964 through original footage, first-person accounts, and animations illustrating plate tectonics. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

In this animation of total ozone, the luminance values of the colors bounding areas of missing data are used in interpolating over these regions. The missing data are mapped to the grayscale portion of the color map.

In this animation of total ozone, the luminance values of the colors bounding areas of missing data are used in interpolating over these regions. The missing data are mapped to the grayscale portion of the color map.

In this animation of total ozone, the luminance values of the colors bounding areas of missing data are used in interpolating over these regions. The missing data are mapped to the grayscale portion of the color map.

An exercise on the effects of flooding that took place in the upper Mississippi River drainage basin in 1993, using before and after satellite images.

This movie shows a total eclipse of the Sun which occurred in 1994. It is accompanied by a link to a written description of the Sun's physical characteristics.

El Nino, a periodic warming of the Eastern Pacific Ocean, is among Earths most powerful phenomena. Satellite, ship, and buoy observations show the 1997-98 event as the strongest on record. Visualizing how sea-surface height, sea-surface temperature, and sea-surface winds differ from normal conditions reveals the events magnitude.

This simulation shows time-dependent 1D quantum bound state wavefunctions for a number of different wells. Position, momentum, parity, energy, and current can all be viewed, with phase shown with color. Eigentstates can be selected using the energy level diagram. Multiple-energy-eigenstate wavefunctions can be created through changes in the amplitude and phase of the basis states using spinors. Postion and energy measurements can be taken, resulting in new states of the system.

This simulation explores the transitions between quantum states in a number of 1D systems. The time-dependent wavefunction is displayed. An electric field resonant with the transition between states is applied and the changes in the wavefunction with time are tracked. The dipole transition probability is displayed for different initial to final state transitions, and the user may select the transition they wish to observe.

3D interactive model of 1H-indene C₉H₈ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1H-pyrazole C₃H₄N₂ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1H-pyridine-2-thione C₅H₅NS for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1H-pyrrole C₄H₅N for demonstrating molecular geometry, vibrations, symmetry and orbitals.

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Materials * Completed monthly weather recording sheet * Crayons * Sentence strips with frames (see below) * Student worksheet Actions Every day for a m...

3D interactive model of 1R_2S-1_2-diaminocyclohexane C₆H₁₄N₂ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1R_2S-1_2-dimethylcyclopentane C₇H₁₄ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1R_3S-1_3-dimethylcyclopentane C₇H₁₄ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1R-camphene C₁₀H₁₆ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1R-camphor C₁₀H₁₆O for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1S_2R-1_2-diphenylethane-1_2-diol C₁₄H₁₄O₂ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1S_2S-1_2-diaminocyclohexane C₆H₁₄N₂ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1S_2S-1-ethyl-2-methylcyclopentane C₈H₁₆ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1_10-phenanthroline C₁₂H₈N₂ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1_1_1_2_2_2-hexafluoroethane C₂F₆ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1_1_1_2_2-pentafluoroethane C₂HF₅ for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1_1_1_3_3_3-hexafluoropropan-2-ol C₃H₂F₆O for demonstrating molecular geometry, vibrations, symmetry and orbitals.

3D interactive model of 1_1_1-trichloroacetonitrile C₂Cl₃N for demonstrating molecular geometry, vibrations, symmetry and orbitals.