Physics How astronauts can feel weightless while gravity is still pulling on them
IntroductionAstronauts floating inside the International Space Station look like they are weightless. Yet gravity at orb...
Physics
Physics 
Physics Why does water take so long to heat and cool?
IntroductionWater often seems slow to heat up and slow to cool down compared with other materials. That everyday observa...
Physics What keeps a satellite from falling straight back to Earth?
IntroductionSatellites orbit Earth instead of falling straight down because they travel fast enough sideways that gravit...
Physics Why can you hear around corners but not see around them?
IntroductionWhy can you hear someone standing just out of sight around a corner, yet you cannot see them? The short answ...
Physics How mirrors create images that seem to exist behind the glass
IntroductionWhen you stand before a mirror, the person you see appears to be located behind the glass. That impression —...
Physics What makes a rainbow appear in a precise arc?
IntroductionA rainbow appears as a precise arc because of the way sunlight interacts with many tiny water droplets in th...
Physics Why does touching metal drain heat from your hand so quickly?
IntroductionWhen you touch a piece of metal on a cold day it feels startlingly cold, and when you touch a metal spoon fr...
Physics Why does pressure change the temperature at which water boils?
IntroductionWater’s boiling point is not a single fixed temperature; it depends on the pressure of the air or gas above ...
Physics What determines how far a rolling object will travel?
IntroductionHow far a rolling object travels depends on several physical factors working together: its initial speed and...
Physics Why do spinning wheels resist being tilted?
IntroductionWhen you try to tilt a spinning wheel—whether it’s a bicycle wheel held by the axle, a top, or a gyroscope—y...
Physics How does gravity bend light without touching it?
IntroductionGravity bends light without touching it because mass and energy change the shape of space and time. Light fo...
Physics What would happen if Earth suddenly stopped spinning?
IntroductionWhat would happen if Earth suddenly stopped spinning? This hypothetical question touches on physics, climate...
Physics Why do objects fall at the same rate regardless of their weight?
IntroductionWhy do heavy and light objects appear to fall at the same rate? This question touches on basic physics and e...
Physics How friction can both stop motion and make motion possible
IntroductionFriction is the force that resists motion between surfaces in contact. It might seem simply an obstacle that...
Physics What makes a parachute slow a falling person so dramatically?
IntroductionParachutes slow a falling person dramatically by increasing the resistance the air exerts on the body. This ...