did you know you can tell how far away lightning is?

maths you actually wanted to know.

flash

count the seconds until you hear the sound…

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boom

watch the storm…

did you know you canwork out whether a bigger pizza is actually better value?

a bit of division can help you find out which pizza gives you more for your money.

did you know you canestimate a building’s height using its shadow?

all you need is some simple geometry, a shadow and a bit of multiplication.

did you know you cancalculate how much time speeding really saves?

a little maths can show you the real difference it makes (and whether it’s worth it).

did you knowyou can tell how far away lightning is by counting seconds?

sound travels about a mile every five seconds. count the gap between flash and bang, and you know where the storm is.

did you knowyou can calculate how far away the horizon is?

standing at sea level, the horizon is only about 5 km away. from a cliff top it can be ten times that.

did you knowTikTok has to predict whether you’ll swipe away?

every video you’re shown won a quiet auction of predicted watch time, likes, shares and swipe-away risk — scored in real time.

did you knowGoogle Maps uses graph maths to find the fastest route?

every junction becomes a node, every road an edge with a cost — then a classic algorithm finds the cheapest path through.

did you knowSpotify can measure how similar two songs are?

songs and listeners can be placed as points in a giant mathematical space — and taste becomes a matter of distance.

did you knowairlines overbook flights on purpose?

a predictable share of passengers never show up, so airlines sell the empty seats twice — and probability tells them how far to push it.

did you knowyour bank spots fraud in milliseconds?

every payment is scored against your own history — where, when, how much, how often — before it’s approved.

did you knowcompound interest grows money absurdly fast?

interest earning interest is exponential growth — and exponential growth is the thing human intuition is worst at.

did you knowa day on Venus is longer than a year on Venus?

Venus takes about 243 Earth days to spin once, but only about 225 to orbit the Sun — and it spins backwards.

did you know23 people can be enough for a birthday match?

a small room hides a surprisingly large number of pairs.

did you knowswitching doors can double your chances?

one prize, three doors, and a host who knows more than you do.

did you knowa coin has no memory of its last flip?

five heads in a row do not make a fair coin owe you tails.

did you knowsix numbers can hide millions of combinations?

a tiny-looking ticket sits inside a huge mathematical space.

did you knowan accurate alarm can usually be wrong?

when something is rare, the ordinary cases can swamp the signal.

did you knowone is often the most common first digit?

some collections of numbers have a surprisingly lopsided favourite.

did you knowa deck of cards has an absurd number of orders?

52 ordinary cards create a number with 68 digits.

did you knowrandom arrivals make long bus gaps find you?

you are more likely to land inside a long gap than a short one.

did you knowa new road can make everyone's journey slower?

a shortcut for each driver can become a bottleneck for everyone.

did you knowa million items can take just twenty checks?

every good question throws away half the possibilities.

did you knowa damaged QR code can still know the answer?

some of those little squares carry a mathematical backup.

did you knowyour GPS needs Einstein to keep good time?

satellite clocks tick differently, and tiny timing errors mean big distances.

did you knowthe internet sends your photo in little pieces?

your message travels like a stack of labelled parcels.

did you knowone random character can multiply the possibilities?

length grows a search space by multiplication, not addition.

did you knowa JPEG saves space by letting details go?

your photo becomes a recipe of patterns, with some ingredients rounded away.

did you knowheadphones can fight noise with more sound?

an upside-down pressure wave can make the world quieter.

did you knowa bubble is solving a geometry problem?

the roundest answer uses the least surface to hold the air.

did you knowhexagons make beautifully economical honeycombs?

six sides pack equal spaces together with very little wall.

did you knowsunflower spirals hide a special angle?

a turn of about 137.5 degrees keeps new growth from lining up.

did you knowa giant ant would need a serious redesign?

doubling its length makes eight times the animal.

did you knowa rainbow is really a circle?

the ground hides the rest of the geometry.

did you knowblue skies and red sunsets share one explanation?

air scatters short wavelengths much more strongly.

did you knowa snowflake's six-fold shape starts with molecules?

tiny crystal rules become patterns you can see.

did you knowa hot road can borrow a piece of the sky?

bent light can put the sky where you expect the ground.

did you knowthe Moon is slowly moving away from us?

Earth's tides pass a little rotational energy into the Moon's orbit.

did you knowa tiny Moon can hide an enormous Sun?

apparent size depends on distance as well as diameter.

did you knowsummer comes from a tilt, not a closer Sun?

tilted sunlight changes both the length and the intensity of a day.

did you knowastronauts float because they keep falling?

their spacecraft is falling around Earth right alongside them.

did you knowevery star you see is a message from the past?

light travels fast, but the universe is very big.

did you knowa tiny dip in starlight can reveal a planet?

a distant world's silhouette can give away its size.

did you know42 imaginary paper folds could reach the Moon?

doubling starts quietly, then gets completely out of hand.

did you knowevery flat world map has to distort something?

flattening a sphere always asks you to make a trade-off.

did you knowa shorter ruler can make a coastline longer?

smaller measurements discover bends that bigger ones skip.

did you knowa longer swing keeps a slower rhythm?

for small swings, length matters much more than the bob's mass.

did you knowan octave is a doubling you can hear?

440 vibrations a second and 880 belong to the same musical family.

did you knowyour microwave has invisible hot and cold spots?

reflected waves can reinforce each other in some places and cancel in others.

did you knowtwo twenty-percent discounts do not make forty?

the second discount works on a price that has already shrunk.

did you knowhot coffee loses its heat faster at the start?

the gap between your drink and the room drives the cooling.

did you knowa satellite dish uses geometry to catch a whisper?

one carefully chosen curve gathers faint signals into a single spot.