Science & Nature

A region of spacetime where gravity is strong enough that nothing — not even light — can escape. Formed from collapsed massive stars, they range from a few solar masses to billions in galactic centers.

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About 4.54 billion years, dated from meteorites that formed at the same time as the solar system. Life appeared around 3.7 billion years ago; humans are the last few seconds on a 24-hour scale of Earth's history.

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Water evaporates, rises, cools, and condenses on tiny particles in the air (dust, pollen). When droplets grow heavy enough to overcome updrafts, they fall — as rain, or as snow/hail depending on temperature.

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Ice particles collide inside a storm cloud, separating positive and negative charges. When the voltage overcomes air's resistance, electricity discharges — up, down, or sideways. Thunder is the sound of air super-heat…

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Yes — but only two hues, roughly yellow and blue. Red and green look the same (grayish) to them. Their real superpower is smell (10,000× better than humans), not vision.

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The force that attracts anything with mass to anything else with mass. On Earth, it pulls at 9.8 m/s². Einstein reframed it as curved spacetime — mass bends the fabric of space, and things follow those curves.

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A 10–15 km asteroid struck what's now Mexico 66 million years ago. The impact triggered wildfires, blocked sunlight for years, and collapsed food chains. Non-avian dinosaurs died; birds — modern dinosaurs — survived.

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Plants use sunlight to combine water and CO₂ into sugar (glucose), releasing oxygen as a byproduct. Chlorophyll captures the light energy. Essentially every calorie humans eat traces back to this reaction.

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A giant magnet generated by liquid iron moving in the outer core. It deflects harmful solar particles (aurora is the visible remnant) and lets compasses work. The poles slowly wander and occasionally flip — last flip…

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Yes — every galaxy outside our local group is moving away from every other, and the rate is accelerating (attributed to 'dark energy'). Not into anything; space itself is stretching.

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Charged particles from the sun follow Earth's magnetic field to the poles and collide with atmospheric gases. Oxygen glows green at around 100 km and red much higher; nitrogen produces blue and purple fringes.

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A vaccine shows the immune system a harmless piece or weakened form of a pathogen so it can build antibodies and memory cells in advance. If the real pathogen arrives later, the response is faster and stronger than a…

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Earth's crust is broken into plates that move a few centimetres a year. Where they lock at a fault, stress builds until the rock fails and slips suddenly — that release of energy is the earthquake.

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