Dark Matter Interactive (150.0K)
Look at telescope pictures of the Milky Way, and you’ll see countless stars, representing enormous mass. But there’s even more mass there that you can’t see! This Interactive will help you understand how astronomers know that. Set up a galaxy with no dark matter, and look at the speeds of the orbiting stars. Then increase the dark matter in steps, plotting the star velocities on the graph after each step. What happens to the velocities? Why? This Interactive will help you figure it out.
Just as our vision reveals only a tiny portion of the entire electromagnetic spectrum, so bright stars are a tiny fraction of all the forms of matter and energy in the universe. Here we will explore how it is found and arrayed in space.
Our studies of the motions of the outer portions of the Milky Way and most other galaxies reveal that the majority of their mass must be in the form of mysterious dark matter, now detected only by its gravitational influence on the motion of visible objects in the galaxy.
When we plot the graph of the vecloty of the stars versus their distance from the center, we get most interesting results. Here we will explore how dark matter is found and arrayed in space.
We can apply this interactive not just to stars within a given galaxy, but to galaxies within clusters of galalxies. If indeed the majority of their mass must be in the form of mysterious dark matter, then we will explore how it is found and arrayed in deep space.