Octopuses and cuttlefish have an amazing defense tactic. They can erect 3D spikes from their skin, hold them for an hour, then retract them and swim away.
Global sea level rise has been accelerating in recent decades, rather than increasing steadily, according to a new study based on 25 years of NASA and European satellite data.
At a very steady rate, unstable carbon-14 gradually decays to carbon-12. The ratio of these carbon isotopes reveals the ages of some of Earth's oldest inhabitants.