What are the expanding rings called that spread out when a pebble drops into still water?
AnswerRipples
The disturbance travels outward as small circular waves, forming rings that grow wider.
Science · Facts & stats
Ring facts & stats
7 fact-checked facts about rings in nature and science, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
Despite its name, what shape is a boxing ring?
AnswerSquare
Boxing rings are square platforms enclosed by ropes, even though they are called rings.
Going deeper
What are Saturn's rings made mostly of?
AnswerWater ice
The rings are countless orbiting pieces, from tiny grains to house-sized chunks, mostly frozen water.
Which of these planets also has a ring system?
AnswerNeptune
All four giant planets have rings, though only Saturn's are bright; the others are faint and dark.
What is a ring-shaped coral reef surrounding a lagoon called?
AnswerAtoll
Atolls often form when coral keeps growing around a volcanic island that slowly sinks beneath the sea.
Expert level
In geometry, what is the ring-shaped region between two concentric circles called?
AnswerAnnulus
Its area is π(R² − r²): the area of the big circle minus the area of the small one.
How were the rings of Uranus discovered in 1977?
AnswerA star blinked as they passed in front of it
Astronomers watching a star about to pass behind Uranus saw it dim several times, revealing thin rings.
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