## UNIVERSE SANDBOX overview

*Universe Sandbox* is a powerful and realistic interactive space and gravity simulator. Players can witness scale space simulations of our solar system and galaxy, but they can also see what happens when they manipulate the properties of planets and stars (e.g. mass) or add new bodies in space. The value of *Universe Sandbox* is its openness, overall accuracy, and impressive visual graphics as it invites players to explore, tinker, and discover their universe in an immersive experience.

## Experience breakdown

## Lesson Plan Overview

In this activity, students develop their understanding of gravity, mass, and density within multiple learning contexts. Students gain a deeper appreciation for the terms accretion and differentiation and are introduced to the idea of differentiation as a model for explaining planetary structure (i.e., core and mantle).

Students are shown foam, rubber, and steel balls mixed in a jar. The students are instructed to shake the jar and make observations. (The steel balls moved to the bottom, the rubber congregated in the middle and the foam balls went to the surface). Students engage in a dialog about why this result should be expected.

Then, students are shown a scenario in *Universe Sandbox *that presents three types of objects randomly distributed with an initial velocity of zero with each type having a unique density but same size. Students run the simulation and explain the outcome of the scenario.

Students are then shown a different scenario in *Universe Sandbox* that presents three types of objects randomly distributed with an initial velocity of zero. Each one has a unique density but different size (the smallest size has the largest density. Students run the simulation and explain the outcome of the scenario.

Finally, students are shown a scenario in *Universe Sandbox* that presents three types of objects randomly distributed with an initial velocity of zero. But here, students are asked to create the conditions for a given outcome (i.e., red objects in the center, green objects in the middle, and white objects on the outside).

## Learning Objectives

- Students will understand the relationship between density, mass, volume.
- Students will understand the relevance of the terms accretion and differentiation.
- Students will understand that if a planet is differentiated, at one time it had to be molten. This is one reason we know that the earth was once molten.
- Students will determine structure of molten objects by using density and an understanding of differentiation.
- Students learn how to use simulations to test hypotheses and experimental design. Changing ONE thing and looking for an outcome based on that change.
- Students postulate that when gravity is present, density determines the location of objects free to move relative to each other.

## Lesson Steps

Step 1: Students are shown foam, rubber, and steel balls mixed in a jar. The students are instructed to shake the jar and make observations. (The steel balls moved to the bottom, the rubber congregated in the middle and the foam balls went to the surface).

Step 2: Students engage in a dialog about why this result should be expected.

** NOTE**: Students usually mention weight or size as important variables, but further discussion and examples brings students into conflict with this notion and leads to the development of mass density as mass/volume.

Step 3 (optional): Students can be given a balance and graduated cylinder with water to actually determine the mass of the three types of ball and their volumes (water displacement and hence their densities).

Step 4: Open Universe Sandbox, load the “Simple Cohesion” scenario, and run it. In this scenario, there are many spheres of three types distributed randomly on the screen. One with the mass of the Moon, one with a mass greater than the Moon, and one with a mass less than the Moon.

** NOTE**: When the scenario begins, the gravitational forces act on the particles and they are attracted to each other to form a collection of spheres (modeling accretion). The students zoom in to inspect and find that the more dense objects are clustered in the center (modeling differentiation) just like the balls in the jar.

Step 5: Students reflect on the scenario results. The facilitator should make sure that terms, such as gravity, density, accretion, differentiation are correctly used in the discussion.

Step 6: Students load the “Large Small Particle Collision” scenario. This scenario was the same as scenario 1, but we changed sizes of the objects to eliminate the misconception associated with size, weight, and density. This scenario reinforces that density, not size determines the differentiation of the material.

Step 7: Students reflect on the scenario results. The facilitator should make sure that terms, such as gravity, density, accretion, differentiation are correctly used in the discussion.

Step 8: Students load the “Challenge: Form a Planet” scenario. Students will see a screen of red, white, and green balls of the same size and mass. They are to create a “planet” with green balls at the center, white balls in the middle and red balls on the outside. Students accomplish this by manipulating the densities of the objects.

Step 9: Students debrief and the facilitator helps them see the simulation as a possible model for planetary formation. This is done by making connections to the Earth having a dense core and less material as one moves to the Earth’s surface.

** NOTE**: Differentiation in a planet indicates that at one time, the planet had to be molten (i.e., wasn’t always solid).

## STANDARDS

### Common Core - English Language Arts

##### Science & Technical subjects

CCSS.ELA-Literacy.RST.6-8.3 Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.

##### Speaking and Listening

CCSS.ELA-Literacy.CCRA.SL.1 Prepare for and participate effectively in a range of conversations and collaborations with diverse partners, building on others’ ideas and expressing their own clearly and persuasively.

### ISTE NETS - Digital Age Skills

##### 1. Creativity and Innovation

**Students demonstrate creative thinking, construct knowledge, and develop innovative products and processes using technology.**

Apply existing knowledge to generate new ideas, products, or processesUse models and simulations to explore complex systems and issuesIdentify trends and forecast possibilities

##### 2. Communication and Collaboration

**Students use digital media and environments to communicate and work collaboratively, including at a distance, to support individual learning and contribute to the learning of others.**

Interact, collaborate, and publish with peers, experts, or others employing a variety of digital environments and mediaCommunicate information and ideas effectively to multiple audiences using a variety of media and formats