Is it possible to travel through time? Einstein’s theory of relativity states that the stronger the gravitational pull on an object, the more time slows for that object. Scientists predict that if someone were to travel to a place with a lot of gravity, like near a black hole, time would pass more slowly for that person. In this video excerpt from NOVA’s "The Fabric of the Cosmos: The Illusion of Time," host and theoretical physicist Brian Greene takes a journey through space—and time—to illustrate what time travel might really be like.

Explore the origins of modern humans. Fossil evidence from Middle East caves and elsewhere has revealed some competitive advantages modern humans, known as *Homo sapiens*, are believed to have held over the more archaic human species, Neanderthals. For example, during the time in which the two species may have coexisted, *Homo sapiens* lived on high ground, from which they could survey the landscape and plan their hunting expeditions. Some scientists have theorized that the success of this strategy may have contributed to the demise of the valley-dwelling Neanderthals, who became extinct about 30,000 years ago. Adapted from NOVA.

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Learn about gerrymandering—the manipulation of district boundaries for political advantage—and see how geometry can be used to detect and help solve the problem in this video from NOVA. Use this resource to see how math can be used in a real-world situation and to stimulate thinking about models of population density.

Learn about the origins and meaning of “p-value,” a statistical measure of probability that has become a benchmark for success in experimental science, in this video from NOVA: *Prediction by the Numbers*. In the 1920s and 1930s, British scientist Ronald A. Fisher laid out guidelines for designing experiments using statistics and probability to judge results. He proposed that if experimental results were due to chance alone, they would occur less than 5 percent (0.05) of the time. The lower the p-value, the less likely the experimental results were caused by chance. Use this resource to stimulate thinking and questions about the use of statistics and probability to test hypotheses and evaluate experimental results.

Learn how NASA engineers identified and solved a problem with the F-1 rocket engine, in this video from NOVA: *Apollo’s Daring Mission*. Use this resource to stimulate thinking about the design process and to provide opportunities for students to define problems and test and evaluate designs.

Explore how probability can be used to help find people lost at sea, even when rescuers have very little information, in this video from NOVA: *Prediction by the Numbers*. To improve its search-and-rescue efforts, the U.S. Coast Guard has developed a system that uses Bayesian inference, a mathematical concept that dates back to the 18th century. The Search and Rescue Optimal Planning System (SAROPS) uses a mathematical approach to calculate probabilities of where a floating person or object might be based on changing ocean currents, wind direction, or other new information. Use this resource to stimulate thinking and questions about appropriate uses of statistical methods.

Learn how variations in Earth’s tilt and orbit create a predictable cycle of natural climate changes and consider how human emissions of carbon dioxide affect global climate in this video from NOVA. Use this resource to model Milanković cycles and to provide opportunities for students to make a claim about the influence of humans on Earth’s natural climate cycles.

Examine a mathematical theory known as the “wisdom of crowds,” which holds that a crowd’s predictive ability is greater than that of an individual, in this video from NOVA: *Prediction by the Numbers*. Sir Francis Galton documented this phenomenon after witnessing a weight-guessing contest more than a hundred years ago at a fair. Statistician Talithia Williams tests Galton’s theory with modern-day fairgoers, asking them to guess the number of jelly beans in a jar. Use this resource to stimulate thinking and questions about the use of statistics in everyday life and to make evidence-based claims about predictive ability.

Learn how scientists have definitively linked global warming to human activity in this video from NOVA: *Decoding the Weather Machine*. Use this resource to consider factors responsible for the accelerated rate of climate change and to illustrate the impacts humans can have on Earth’s climate systems.

Conceptualize quantum entanglement, the idea that particles can instantaneously influence each other even when they are spatially separated, in this video from NOVA: *Einstein’s Quantum Riddle*. Use this resource to visualize the idea of the Einstein–Podolsky–Rosen (EPR) paradox, or quantum entanglement, and to provide opportunities to communicate explanations.