Topic
Machines
12 articles
History of science
Why is a keyboard in QWERTY order?
The letters on every phone and laptop are arranged in an order chosen for a machine nobody has used for fifty years. The famous explanation is that it was designed to slow typists down, and that is not what happened.
Physics
Why does a spinning coin whirr before it stops?
A coin flattens out, the rattle climbs to a frantic buzz, and then everything ends at once with a slap. Something in there is speeding up while the coin itself is slowing down, and the mathematics says it reaches infinity.
Mathematics
Why do headphones tangle in your pocket?
Nobody ties the knots. The cable goes in loose and comes out with three of them, and it happens to charging cables, skipping ropes and garden hose as well. Two physicists tumbled a string in a box three thousand times to find out why.
Technology
Why did the Millennium Bridge wobble?
A brand new footbridge opened across the Thames, swayed alarmingly under the crowd, and shut two days later for two years. Nothing was broken and nothing was undersized. The people crossing it were the missing part of the design.
Technology
Why does wifi go through walls but light doesn’t?
Both are the same kind of wave, traveling at the same speed, made of the same stuff. One crosses a brick wall without noticing it and the other cannot get through a sheet of paper. The difference is size.
Physics
Why does a bicycle stay up?
Standing still it falls over the moment you let go. Rolling, it will cross a field on its own with nobody on it. Everybody has heard the explanation involving spinning wheels, and somebody built a bicycle specifically to test it.
Technology
Why does your phone die in the cold?
You go outside with a healthy battery and the screen is black within twenty minutes. Bring the same phone indoors, plug in nothing at all, and most of that battery comes back. Nothing was ever spent.
Physics
Why doesn’t a spinning top fall over?
Set a top going and it leans at an angle that would flatten anything else on the table, then stays there, drifting round in a slow circle. Nothing is propping it up, and gravity has certainly not let go of it.
Technology
How does a chip add two numbers when it cannot count?
A phone works out sums faster than you can blink, and nothing inside it can count to three. So something else has to be doing the arithmetic.
Physics
How do noise-canceling headphones erase a sound?
Press one button on a plane and the engine roar drops away, while the passenger beside you stays perfectly clear. Nothing was plugged, and nothing was switched off.
Physics
Why is the back of the fridge warm?
Reach around the back of a refrigerator and the metal is warm. The one machine in the house whose whole job is making things cold turns out to be heating your kitchen, and the reason is sealed inside a pipe.
Physics
Why won’t a wheel full of weights turn forever?
Hang weights around a rim so that one side is always the heavy side, and the wheel should keep falling over itself and never stop. Engineers have drawn that wheel for eight hundred years. Not one has ever run.