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Dark matter
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Invisible matter inferred from gravity.
About 27% of the universe's energy content; it interacts gravitationally but not electromagnetically. Evidence: rotation curves, lensing and CMB. Candidates: WIMPs, axions.
Direct-detection experiments haven't found it.
Not antimatter or black holes (mostly).
In more detail
Dark matter is an unseen form of matter that interacts gravitationally and makes up about 27 percent of the universe's energy content. It is inferred from galaxy rotation, lensing and the CMB.
Real-world uses
- Dark matter shapes galaxies and galaxy clusters.
- Experiments search for dark matter particles underground.
- Astronomers detect the gravitational effects of dark matter in galaxy rotation curves and gravitational lensing.
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Frequently asked questions
What is dark matter made of?
Unknown. Candidates include weakly interacting massive particles and axions.
Is dark matter the same as dark energy?
No. Dark matter clumps, while dark energy drives accelerated expansion.
What is dark matter made of?
Its nature is unknown, though candidate particles such as weakly interacting massive particles are actively searched for.
Related topics in Particle Physics & Cosmology
Cosmic microwave background · Big Bang nucleosynthesis · Inflation · Dark energy · Critical density · Fate of the universe