Beyond the horizon · 2 min
Looking far is looking back
Light takes time to travel. The view of a distant object arrives after the event that produced it.
✓Beyond the horizon
Light, time and the questions beyond our sky.
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Beyond the horizon · 2 min
A universe with a history
The hot Big Bang model describes an early hot, dense universe that expanded and cooled.
✓Beyond the horizon · 2 min
An ancient glow, everywhere
The cosmic microwave background is relic radiation from when the young universe became transparent to light.
✓Beyond the horizon · 2 min
A star is a balance
A star’s life is shaped by gravity, internal pressure and the energy generated inside it.
✓Beyond the horizon · 2 min
A boundary light cannot cross outward
A black hole has an event horizon: a boundary beyond which light cannot escape to a distant observer.
✓Beyond the horizon · 2 min
The Moon changes its appearance
Moon phases come from the changing view of the Moon’s sunlit half as it orbits Earth.
✓Beyond the horizon · 2 min
Read the light
A spectrum separates light by wavelength, revealing information hidden inside a single bright point.
✓Beyond the horizon · 2 min
What we infer from what we can see
Dark matter is inferred from gravitational effects that visible matter alone does not adequately explain.
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