The Invisible Majority
Everything we can see — stars, planets, gas — makes up less than 5% of the universe.
The rest is:
Dark matter (~27%)
Dark energy (~68%)
What Is Dark Matter?
Dark matter:
Does not emit or reflect light
Interacts via gravity
Holds galaxies together
Without dark matter, galaxies would spin so fast that stars would fly apart.
Evidence includes:
Galaxy rotation curves
Gravitational lensing
Large-scale structure of the universe
What Is Dark Energy?
Dark energy is even more mysterious. It appears to:
Drive the accelerated expansion of the universe
Act opposite to gravity on cosmic scales
We don’t know what dark energy is — only how it behaves.
Why This Matters
Dark matter shapes galaxies.
Dark energy controls the universe’s fate.
Understanding them is one of the greatest challenges in modern physics.
Key Takeaways
Most of the universe is invisible
Dark matter binds galaxies
Dark energy accelerates expansion
Major mysteries remain unsolved