Reels tagged #physics
Lightning is five times hotter than the Sun
A bolt of lightning heats the air around it to about 30,000°C — roughly five times hotter than the surface of the Sun. That sudden heat is what makes the thunderclap.
The Eiffel Tower grows in summer
Iron expands when heated, so on hot days the tower can stand up to 15 cm taller — and lean slightly away from the sun.
Glass is not a slow-flowing liquid
Old cathedral windows are thicker at the bottom because of how they were made, not because glass flows. At room temperature glass is a solid.
Time itself slows down near a black hole
Gravity stretches time. Watch someone fall toward the event horizon and they appear to slow, redden and freeze forever — while for them, the fall takes only moments.
Black holes slowly evaporate
Stephen Hawking showed black holes leak faint radiation and shrink. A stellar-mass one would take about 10^67 years to vanish — far longer than the universe has existed.
GPS would fail without Einstein
Satellite clocks tick faster in weaker gravity and slower from speed. Without relativity corrections of about 38 microseconds a day, positions would drift kilometres off.
Quantum computers run colder than deep space
Superconducting qubits operate near 10 millikelvin — colder than the cosmic background — because the faintest heat destroys their fragile quantum states.
X-rays were discovered by an accidental glow
In 1895 Rontgen noticed a screen glowing across his darkened lab while working with a covered tube. Weeks later he imaged his wife's hand, and medicine could see inside a living body for the first time.
The laser was called a solution looking for a problem
When Theodore Maiman fired the first ruby laser in 1960, nobody knew what it was for. Today lasers cut steel, scan barcodes and carry the internet.
A table tennis ball can spin over 9,000 times a minute
That is why a ball can swerve mid-flight and kick sideways off the table. Top players read spin, not speed.
Nobody actually hangs in the air
Even the highest dunkers stay airborne under a second. "Hang time" is an illusion created by how a body moves once it leaves the floor.
Fibreglass poles added almost a metre to pole vault records
Bamboo and steel poles barely bent. Flexible poles store the run-up's energy and catapult the vaulter skyward.