Music Music Music This kinesthetic activity models the life of a large star that is many times the mass of our sun. Each person involved in this activity represents a bit of the material that goes into making such a star. As the activity begins, everyone is dancing or moving around freely, just bits of matter that are hanging out in some particular spot in space. As these bits of matter come close to one another they start clumping together more and more due to gravity. After a while this matter is clumped tightly enough to form a star. In our activity the participants at the edges form a ring facing inward as the outer shell of the star, with their hands raised to represent the inwardly directed force of gravity. The participants in the center face outward representing the core of the star with their hands also raised to represent the energy generated by the fusion of hydrogen at the center of the star. These two forces remain in balance for most of the star's life; we call this a main sequence star. Eventually, the star runs out of hydrogen to fuse in the core, and the balance of gravity and energy from fusion is broken. When this happens gravity wins, and the participants in the core of the star drop their hands and move slightly closer together. The participants in the shell never lower their hands as gravity is always in effect. The slight decrease in the size of the core makes it hot and dense enough to start fusing helium. The participants in the core raise their hands once more as energy is again being generated at the center of the star. Participants in the shell take a step outward to represent the surge in energy making the star larger than it was during the main sequence phase. The star has become a red giant. Eventually the core of the star runs out of helium to fuse. When this happens the participants in the core once again drop their hands and move slightly closer together. Like before, the decrease in core size makes the core hot enough to start the next level of fusion. The participants in the core raise their hands once more. Participants in the shell again take a step outward to represent another surge in energy making the star even larger. With the largest stars, this process repeats several more times until finally the core of the star is made of iron. This time when the core runs out of fuel for fusion the participants at the core drop their hands and once again move closer together, but this time there is no next level of fusion. As fusing iron actually takes energy instead of generating energy. The force of gravity wins out and the participants in the shell move inward as the star begins to collapse. As this happens the core gets denser and heats up so the participants in the core give one last big push as they move even closer together. The participants in the shell move inward, hit the core's final push of energy and rebound, exploding out into space in what we call a supernova explosion. This shell material is now available to be used in the formation of another star. The remaining participants from the core now get as close together as possible as the core collapses in on itself. They represent the neutron star or black hole that is left behind. Music Music