Twig Science Grade 8 (2021)

Gravity Pitch

Imagine a gigantic pitcher standing on Earth, ready to hurl a huge baseball. What will happen as the ball is thrown harder and harder? Find out with the Gravity Pitch Gizmo. Observe the path of the ball when it is thrown at different velocities. Throw the ball on different planets to see how each planet's gravity affects the ball. 5 Minute Preview

Moonrise, Moonset, and Phases

Gain an understanding of moonrise and moonset times by observing the relative positions of Earth and the Moon along with a view of the Moon from Earth. A line shows the horizon for a person standing on Earth so that moonrise and moonset times can be determined. 5 Minute Preview

Phases of the Moon

Understand the phases of the Moon by observing the positions of the Moon, Earth and Sun. A view of the Moon from Earth is shown on the right as the Moon orbits Earth. Learn the names of Moon phases and in what order they occur. Click Play to watch the Moon go around, or click Pause and drag the Moon yourself. 5 Minute Preview

Seasons: Earth, Moon, and Sun

Observe the motions of the Earth, Moon and Sun in three dimensions to explain Sunrise and Sunset, and to see how we define a day, a month, and a year. Compare times of Sunrise and Sunset for different dates and locations. Relate shadows to the position of the Sun in the sky, and relate shadows to compass directions. 5 Minute Preview

Solar System

Explore our solar system and learn the characteristics of each planet. Compare the sizes of planets and their distances from the Sun. Observe the speeds of planetary orbits and measure how long each planet takes to go around the Sun. 5 Minute Preview

Cladograms

Based on the similarities and differences between different organisms, create branching diagrams called cladograms to show how they are related. Use both morphological data (physical traits) and molecular data to create the simplest and most likely cladograms. Five different sets of organisms are available. 5 Minute Preview

Embryo Development

Explore how a fertilized cell develops into an embryo, a fetus, and eventually an adult organism. Compare embryo development in different vertebrate species and try to guess which embryo belongs to each species. Use dyes to trace the differentiation of cells during early embryo development, from the zygote to the neurula. 5 Minute Preview

Human Evolution - Skull Analysis

Compare the skulls of a variety of significant human ancestors, or hominids. Use available tools to measure lengths, areas, and angles of important features. Each skull can be viewed from the front, side, or from below. Additional information regarding the age, location, and discoverer of each skull can be displayed. 5 Minute Preview

Coral Reefs 1 - Abiotic Factors

Explore the abiotic factors that affect Caribbean coral reefs. Many factors can be manipulated in this simplified reef model, including ocean temperature and pH, storm severity, and input of excess sediments and nutrients from logging, sewage, and agriculture. Click "Advance year" to see how the reef responds to these changes. 5 Minute Preview

Coral Reefs 2 - Biotic Factors

In this followup to the Coral Reefs 1 - Abiotic Factors activity, investigate the impacts of fishing, disease, and invasive species on a model Caribbean coral reef. Many variables can be manipulated, included intensity of fishing, presence of black band and white band disease, and the presence of actual and potential invasive species. Click "Advance year" to see the impacts of these biotic changes. 5 Minute Preview

Ocean Mapping

Use a sonar on a boat to remotely measure the depth of an ocean at various locations. Describe multiple points on the ocean floor using their latitude, longitude, and depth. View maps of ocean depth in two and three dimensions, and use these maps to plot a safe route for ships to follow. 5 Minute Preview

Waves

Observe and measure transverse, longitudinal, and combined waves on a model of a spring moved by a hand. Adjust the amplitude and frequency of the hand, and the tension and density of the spring. The speed and power of the waves is reported, and the wavelength and amplitude can be measured. 5 Minute Preview

Fruit Production - Middle School

As an agricultural scientist, students help a strawberry farmer who is having problems with low fruit production. Students learn about the factors involved in fruit production including plant nutrients, pollination and bees, and the interaction with the environment. Video Preview

Heredity and Traits - Middle School

As a bee scientist, students help a honey farm that has low honey production due to wasps. Students learn about bees, heredity and traits to determine which traits will help the bees defend their hives against the wasps. They then pick a new queen bee to pass on these traits to the bee colony. Video Preview