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This kinesthetic activity models the life of a large star

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that is many times the mass of our sun. Each person involved in this activity

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represents a bit of the material that goes into making such a star.

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As the activity begins, everyone is dancing or moving around freely,

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just bits of matter that are hanging out in some particular spot in space.

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As these bits of matter come close to one another they start clumping together more and

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more due to gravity. After a while this matter is clumped

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tightly enough to form a star. In our activity the participants at the

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edges form a ring facing inward as the outer shell of the star, with their hands

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raised to represent the inwardly directed force of gravity. The

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participants in the center face outward representing the core of the star with their

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hands also raised to represent the energy generated by the fusion of hydrogen at the

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center of the star. These two forces remain in balance

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for most of the star's life; we call this a main sequence star.

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Eventually, the star runs out of hydrogen to

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fuse in the core, and the balance of gravity and energy from fusion is broken.

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When this happens gravity wins, and the participants in the core of the

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star drop their hands and move slightly closer together. The

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participants in the shell never lower their hands as gravity is always in effect.

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The slight decrease in the size of the core makes it hot and dense enough to start

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fusing helium. The participants in the core raise their hands once more

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as energy is again being generated at the center of the star. Participants

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in the shell take a step outward to represent the surge in energy making the star

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larger than it was during the main sequence phase. The star

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has become a red giant. Eventually the core

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of the star runs out of helium to fuse. When this happens the participants

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in the core once again drop their hands and move slightly closer together.

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Like before, the decrease in core size makes the core hot enough to start the

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next level of fusion. The participants in the core raise their hands once

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more. Participants in the shell again take a step outward to represent another

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surge in energy making the star even larger. With the largest

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stars, this process repeats several more times until finally the core of the

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star is made of iron. This time when the core runs out of fuel

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for fusion the participants at the core drop their hands and once again move

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closer together, but this time there is no next level of fusion.

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As fusing iron actually takes energy instead of generating energy.

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The force of gravity wins out and the participants in the shell move inward

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as the star begins to collapse. As this happens the core gets denser

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and heats up so the participants in the core give one last big push

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as they move even closer together. The participants in the shell move

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inward, hit the core's final push of energy and rebound, exploding out into

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space in what we call a supernova explosion. This shell material is

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now available to be used in the formation of another star.

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The remaining participants from the core now get as close together as possible as the core

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collapses in on itself. They represent the neutron star or black hole

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that is left behind.

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