World
What If the Sun Disappeared?
What happens if the Sun vanishes, including the eight-minute delay?
The Sun is about 150 million kilometres away. Light, and the gravitational influence in this simplified picture, take 8 minutes 19 seconds to cover that gap at c. If the Sun were removed 'now,' nothing on Earth would know until that packet of old sunlight and old curvature had finished arriving. Then the sky would go dark, and Earth's path would become the straight line it was already tangent to — inertial motion at about 30 kilometres per second. Temperature is a different clock. Oceans and rock hold heat. Eight minutes of darkness is a cloudy afternoon, not a freeze. Days and weeks are when a toy cooling curve starts to look grim over land; the deep ocean is slower still. This is a thought experiment with those delays written down, not a death-of-the-Sun simulation.
Change this
Results update as you move the controls.
Light itself takes 8 minutes 19 seconds to stop. Cooling is slower.
Your result
dark
status of the sky after cutoff
light-travel time 8 minutes 19 seconds
- Light-travel time from 1 AU
- 8 minutes 19 seconds
- Orbital speed kept as inertia
- 29,785 m/s
- Toy land-surface temperature
- -5 °C
- Straight-line distance since cutoff
- 2,558,538 km
- Missed fall toward the old Sun
- 21,879.98 km
499 s
107,225 km/h
exponential, τ = 14 days
What does that mean?
Light and, in this model, gravity cut off after 8 minutes 19 seconds. You asked about 24 hours after vanishing, which is 24 hours of actual darkness. Earth is now travelling in a straight line at 29,785 m/s (107,225 km/h), a tangent of 2,558,538 km since the cutoff, and it has 'failed to fall' toward the missing Sun by 21,880 km. A thin-layer toy temperature is -5 °C — illustration only. Oceans would still be holding most of their heat.
At a glance
- Hours you picked24 hours
- Light delay8 minutes 19 seconds
- One week168 hours
Timeline
0
Sun removed, far away
Earth is still bathed in 8-minute-old light. Orbits have not noticed.
8 minutes 19 seconds
Last sunlight, last tug
The sky goes black. Velocity is still 29,785 m/s; acceleration toward the Sun is now zero in this model.
Hours
Dark, not frozen
Land surfaces start to radiate away heat. This is weather going wrong, not an ice statue.
Days to weeks
Continents get bitter
The toy curve falls hard over land. Mixed-layer ocean heat still buffers coasts. No climate GCM lives here.
Years
A rogue Earth
A straight-line path has carried the planet far from 1 AU. Residual heat is geothermal and leftover ocean, not sunlight.
Compare scenarios
The eight-minute buffer
Photons leaving the photosphere right now are not here yet. The IAU astronomical unit divided by the defined speed of light is 499 seconds, which is 8 minutes 19 seconds. Until that clock runs out, noon still looks like noon. There is no faster messenger in known physics. After the last sunlight, the last of the old gravitational field in this model goes with it. You do not get a dark sky while still orbiting as if the Sun were there.
Straight on at 30 km/s
Earth is not being dragged in a circle by a string; it is falling, continuously, around the Sun. Remove the Sun and the acceleration toward it stops. The velocity remains. The path is then a straight line in an inertial frame, at the orbital speed of roughly 29.8 km/s. In an hour that is more than 100 000 kilometres of extra tangent. Relative to the old circular orbit the 'missed fall' toward the Sun is only ½ a t² with a ≈ 6 mm/s², so the first minutes look locally ordinary even after the dark arrives.
Cold is not instant
A planet is a heat reservoir. Air over land can drop tens of degrees in days once the energy source is gone; mixed-layer seawater takes months to years; the deep ocean is a longer battery still. Popular claims that Earth 'freezes in eight minutes' confuse the speed of light with the heat capacity of water. The toy curve on this page is an exponential for a thin surface layer. It is labelled as such. It is not a general circulation model, and it will not quote a fake paper about the last human city.
How we calculated this
Light-travel time is the IAU astronomical unit divided by the SI speed of light (physics.LIGHT_TIME_SUN_S). Orbital speed is 2π AU / sidereal year. After the delay, motion is inertial at that speed. A crude land-surface cooling curve T = Tcmb + (T0 − Tcmb) e^(−t/τ) with τ ≈ 14 days is shown only as an illustration of 'not instant'; ocean heat capacity is described in words, not modelled. No radiative-transfer code, no biosphere.
Go further
A curated rabbit hole from this question. Each link is a real experiment, not a random suggestion.
You might also like
What If the Moon Disappeared?
Take the Moon away and separate tonight's tides and darker skies from the slow, million-year question of Earth's tilt.
Explore
What If Earth's Atmosphere Disappeared?
Dial remaining pressure from today's sea-level air toward vacuum. Sound, sky, boiling water and radiation change on different clocks.
Explore
What If Everyone Disappeared?
A scientific succession timeline: power, water, plants, buildings. Pick a year and see a sober sketch of that moment.
Explore
What If Gravity Stopped?
Weight vanishes; velocity does not. Earth goes straight, air expands, people float. A thought experiment with a timer.
Explore
What If Light Travelled Slower?
Slow light as a local delay, then admit that changing c globally would break atoms. Slow glass and a new c are different ideas.
Explore
What If Earth Stopped Spinning?
Remove Earth's spin over a time you choose and see the leftover eastward speed, the winds, and the new length of a day.
Explore