Dark Matter
- Star Institutes / Liu Academy
- Jun 2
- 2 min read
Dark Matter
Concept Explanation: Look at the stars and galaxies in the night sky. They contain all the matter we can see—planets, stars, dust, gas. But scientists have discovered that there's a mysterious, invisible substance that makes up about 27% of the universe's mass, much more than all the "normal" matter combined! This hidden substance is called dark matter. We can't see it, touch it, or directly detect it, but we know it's there because of its powerful gravitational effects. For example, galaxies spin much faster than they should if they only contained visible matter, suggesting something invisible is providing extra gravitational pull.
Real-World Connection/Why it Matters: Dark matter is one of the biggest mysteries in modern cosmology. Scientists use its gravitational effects to infer its presence. One key way is through gravitational lensing, where dark matter's gravity bends the light from distant galaxies, creating distorted or magnified images. Understanding dark matter is crucial for comprehending how galaxies form and evolve, the large-scale structure of the universe, and ultimately, what the universe is made of.
Simulation:
Simulating Gravitational Lensing: Use a large, clear glass bowl filled with water (representing a concentration of dark matter) and a laser pointer (representing light from a distant galaxy). Shine the laser through the center of the bowl onto a wall. Observe how the light beam spreads out or "lenses" around the bowl. Compare this to shining the laser without the bowl. Discuss how astronomers use this bending of light to map out invisible dark matter in space.
Key References:
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