What If? Lab
What if we could see the wind?
We can't see the wind. But we can see what it moves: leaves, flags, smoke and kites. What if the wind had a color? Let's imagine it with Olly!
Wind is moving air, and air is invisible. So people watch what the wind moves: smoke, leaves, flags, clouds and kites. Scientists even make wind maps from satellite pictures. Imagine the wind suddenly becoming visible, and follow the swirls, maps and kites that might appear.
Air is transparent, so we read the wind through tracers: smoke, leaves and waves on the Beaufort scale, clouds tracked by satellites, and aerosols in NASA's computer models. This thought experiment makes the wind itself visible and asks what we might notice about swirls, wind maps and flight.
The big question
Wind is air that moves. Air is see-through, so we can't see the wind.
What if the wind had a color? What might we see?
You can feel the wind and hear it whistle, but you can never see it. That is because wind is moving air, and air is see-through.
What if the wind were suddenly visible, like colored smoke drifting everywhere? In this thought experiment you can follow three paths: the swirls that wind makes around obstacles, the maps that show wind across the world, and the way kites and gliders ride the air.
Wind is invisible because air is transparent; every way of 'seeing' it relies on something the air carries or moves.
This thought experiment imagines the air itself made visible. It asks what that might reveal about how flow behaves around obstacles, how scientists already map winds from tracers such as clouds and aerosols, and how kites and gliders use moving air. It reasons from how wind is observed today; it cannot say how air could become visible.
Explore the idea
Make a prediction
On a calm day with no wind, which way does smoke go?
On a perfectly calm day, which way does smoke from a chimney drift?
At force 0 on the Beaufort scale, how does smoke behave?
- Straight up
- Sideways
- Down to the ground
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Established fact
We can't see the wind, but we can see what it moves.
Wind is invisible, so we read it from what it moves: smoke, leaves, clouds and kites (NOAA, NASA).
Wind is observed through tracers and instruments: the Beaufort scale, vanes and anemometers, satellite cloud tracking and model aerosols (NOAA, CIMSS, NASA).
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An idea scientists discuss
Wind with a color is pretend. We imagine what we might see.
Air won't become visible. What we might see if it did is an idea built from what scientists already know about moving air.
Every consequence of visible air here is reasoned from present knowledge and might differ greatly in reality.
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Established fact
When there is no wind, smoke goes straight up. In a breeze, leaves rustle.
The Beaufort scale, made in 1805, judges the wind by what it moves: calm means smoke rises straight up, and at force 2 leaves rustle.
The Beaufort scale (1805) maps wind speed to visible effects, from smoke rising vertically at force 0 to whole trees moving at force 7 (NOAA Storm Prediction Center).
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Established fact
A wind vane shows which way the wind blows.
A wind vane shows the wind's direction, and an anemometer measures its speed.
Wind direction is indicated by a vane and speed measured by an anemometer (NOAA JetStream).
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Established fact
Wind blowing past an island can curl into big swirls in the clouds.
When winds are pushed around an island, the air curls into chains of swirls called von Kármán vortices, and clouds make them visible.
Winds rerouted around an island form a vertical wall of whirling air that wraps into vortices shed alternately from both sides; clouds reveal the flow (NASA Earth Observatory).
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Established fact
A scientist named Theodore von Kármán explained these swirls long ago.
Physicist Theodore von Kármán first described these swirls in 1912, and their pattern depends on how strong the wind is.
Von Kármán described the process in 1912; per Carlos Torres of the Autonomous University of Baja California, the swirl pattern depends on wind intensity (NASA Earth Observatory).
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An idea scientists discuss
If we could see the wind, we might see it swirl behind houses and trees.
With visible wind, we might see swirls behind hills, trees and tall buildings, not just behind islands.
Visible air might expose lee eddies around every obstacle; their size and pattern for any one building cannot be estimated here.
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Established fact
Scientists watch clouds move in satellite pictures to find out about the wind.
Tracking clouds in satellite pictures taken one after another shows the wind's direction and speed. Professor Suomi of the University of Wisconsin–Madison pioneered the idea.
Successive satellite observations of clouds give wind direction and speed; the method, pioneered by Professor Suomi, took decades to become accurate enough for forecasts (CIMSS, University of Wisconsin–Madison).
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What the model shows
A NASA computer picture shows wind carrying dust and sea salt around the world.
A NASA computer model colors dust red, sea salt blue, sulfate white and carbon from fires green, showing how winds carry them around the world.
NASA Goddard's simulation of August 2006 to April 2007 shows winds dispersing dust, sea salt, sulfate and black and organic carbon worldwide (NASA SVS, Paint By Particle).
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An idea scientists discuss
If we could see the wind, the sky might be like a wind map.
With visible wind, we might read the wind just by looking up, though we might still need satellites to see the whole world's winds at once.
Visible air might give a local, real-time view of flow, but global maps might still need satellites and models; the trade-off is speculation.
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Established fact
A kite flies when air moves past it. On calm days, you can run to help.
A kite flies when air moving past it makes enough lift. On days with little wind, you may need to run into the wind to launch it.
Lift on a kite depends most on the relative velocity of the air; wind speed normally increases with altitude in the boundary layer (NASA Glenn Research Center).
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Established fact
Gliders and hawks ride on warm air rising from the ground.
Gliders have no engine. They climb in pockets of rising air: wind pushed up over hills, or thermals rising from sun-warmed dark ground. Hawks and owls circle in thermals too.
Gliders always descend relative to the air but gain height in updrafts over hills and thermals over dark, sun-heated land; large gliding birds circle in thermals the same way (NASA Glenn).
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An idea scientists discuss
If we could see the wind, kite flyers might pick the best spot right away.
With visible wind, glider pilots might steer straight to the rising air, and kite flyers might see where the breeze is strongest.
Visible air might let soaring pilots locate thermals without instruments; how much it might change flying is beyond this experiment.
In our world
We can tell the wind is there by what it moves.
On a calm day, smoke goes straight up. In a breeze, leaves rustle and flags flap.
In 1805, Sir Francis Beaufort of the U.K. Royal Navy made a scale for judging the wind by what it does. NOAA still shares it. On land, force 0 is calm, when smoke rises straight up. At force 2, you feel wind on your face and leaves rustle. At force 3, light flags stretch out, and at force 5, small trees in leaf begin to sway.
Weather watchers also use tools. NOAA explains that a wind vane shows the wind's direction and an anemometer measures its speed.
The Beaufort scale, developed in 1805 by Sir Francis Beaufort of the U.K. Royal Navy and reproduced by NOAA's Storm Prediction Center, matches wind speeds in knots to visible effects: at force 1 (1–3 knots) smoke drift shows the direction, at force 4 (11–16 knots) dust and loose paper lift, and at force 6 (22–27 knots) wires whistle.
Instruments do the measuring: a wind vane for direction and an anemometer for speed (NOAA). Winds are named for the direction they blow from, so a north wind comes from the north.
Imagine visible wind
Let's pretend the wind is pink and swirly.
We might see it curl around houses and trees. We might see it lift a kite!
Now imagine the wind tinted like colored smoke. Behind every island, hill and tall building, we might see the air curl into swirls. Looking up, we might spot the wind speeding up higher above the ground, just where kites like to fly.
On a sunny afternoon, we might even see bubbles of warm air rising from dark ground, the kind that gliders and hawks circle in. These are ideas: we reason from what scientists already know about moving air.
Visible air might show directly the flow structures that are now inferred from tracers: eddies shed in the lee of obstacles, the way wind speeds up with height near the ground, and the updrafts and thermals that soaring pilots search for with instruments.
It might also make every wind map unnecessary, or it might simply overwhelm us, since the whole atmosphere is in motion. These are reasoned ideas; the scientific tools described below already let us 'see' much of this.
Why the wind is invisible
Air is see-through, so we can't watch it move.
Clouds and smoke float along with the wind. They show us where the air is going.
Air is made of gases, and we see right through it. So we watch the things it carries. NASA describes clouds as acting like the powder used to dust for fingerprints: they show the shape of the moving air.
When wind blowing over the ocean meets an island, the air flows around it and curls into chains of spinning swirls called von Kármán vortices. Satellites photograph these cloud swirls around the world. NASA says such swirls can form nearly anywhere that a flowing fluid, like air, is disturbed by a solid object.
Because air is transparent, observation relies on tracers. NASA Earth Observatory explains von Kármán vortices: winds rerouted around an island slow and form a vertical wall of whirling air, which wraps into vortices shed alternately off the two sides; clouds in the stream reveal the flow. Theodore von Kármán first described the process in 1912, and the pattern depends on wind intensity.
CIMSS at the University of Wisconsin–Madison notes that tracking clouds in successive satellite images to measure wind was pioneered by Professor Suomi, and that it took decades before such winds were accurate enough for forecasts.
Seeing the wind today
Kites fly when air rushes past them.
Gliders have no engine. They ride on rising warm air, just like hawks and owls!
NASA explains that a kite flies when air moving past it makes a lifting force bigger than the kite's weight. On days with little wind, you may need to run into the wind to launch it. The wind usually gets faster higher up, so a kite can fly well once it is aloft.
Gliders are aircraft with no engine. NASA says they are always sinking through the air, but pilots find pockets of rising air: wind pushed up over a hill, or warm air rising from dark ground, called thermals. Hawks and owls circle in thermals to climb without flapping.
NASA Glenn: kite lift depends most on the relative velocity between air and kite, so flyers can run on calm days; wind speed normally increases with altitude through the atmospheric boundary layer. The Wright brothers often flew their gliders as tethered kites to measure aerodynamic characteristics.
Gliders have lift, drag and weight but no thrust, and always descend relative to the surrounding air. They stay aloft by finding updrafts, from wind forced over ridges or from thermals over sun-heated dark ground. NASA's Goddard models go further, simulating how winds carry dust, sea salt, sulfate and carbon around the globe.
Amazing facts
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The Wright brothers flew their gliders like kites to test them.
The Wright brothers often flew their gliders as kites on a line to learn how air pushed on them.
The forces on a kite resemble those on an airplane so closely that the Wright brothers often flew their gliders as tethered kites to find their aerodynamic characteristics (NASA Glenn).
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A man named Francis Beaufort made a wind scale more than 200 years ago.
The Beaufort wind scale was developed in 1805 by Sir Francis Beaufort of the U.K. Royal Navy, and NOAA still shares it today.
Sir Francis Beaufort developed his scale in 1805; NOAA's version gives each force a speed range in knots and its effects on water and land.
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Hawks and owls can climb high without flapping, by circling in warm rising air.
Large gliding birds such as hawks and owls circle inside thermals to gain height without flapping their wings, just as glider pilots do.
Large gliding birds circle within thermals to gain altitude without flapping, the same technique sailplane pilots use (NASA Glenn).
Words to know
- wind vane
- a tool that turns to show which direction the wind is coming from
- anemometer
- a tool that measures how fast the wind is blowing
- Beaufort scale
- a scale from calm to hurricane that describes wind by what it does to smoke, trees and the sea
- vortex
- a spinning swirl of air or water; more than one are called vortices
- thermal
- a rising pocket of warm air
- glider
- an aircraft that flies without an engine
Discovery challenge
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What does a wind vane show us?
What does a wind vane tell you about the wind?
Which property of the wind does a vane indicate?
- Which way the wind is coming from
- How warm the air is
- How much rain has fallen
Show the answer
Which way the wind is coming from
Which way the wind is coming from!
Its direction. An anemometer measures the wind's speed.
Direction, named for where the wind blows from; an anemometer gives speed (NOAA).
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When wind blows past an island, what can the clouds make?
What shapes can clouds make when wind flows around an island?
Wind diverted around an island can produce which cloud pattern?
- Chains of swirls
- Straight stripes
- Perfect squares
Show the answer
Chains of swirls
Big swirls, like curls of soft-serve ice cream!
Chains of swirls called von Kármán vortices.
Von Kármán vortex streets, shed alternately from each side of the island (NASA).
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What does a kite need to fly?
What does a kite need to make the lift that holds it up?
According to NASA, the most important factor in a kite's lift is…
- Air moving past it
- Bright sunshine
- Warm weather
Show the answer
Air moving past it
Air moving past it. On calm days, you can run!
Air moving past it. With little wind, running into the wind can help.
…the relative velocity of the air going past the kite (NASA Glenn).
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Gliders have no engine. How do they go up?
How can a glider, with no engine, climb higher?
How does a glider gain altitude despite having no thrust?
- By flying in rising air
- By flapping its wings
- By using a magnet
Show the answer
By flying in rising air
It rides on rising warm air, like a hawk.
By finding rising air, such as wind pushed up a hill or a warm thermal.
By finding updrafts or thermals rising faster than it sinks (NASA Glenn).
Experiments to try
- Watch What If? Lab What if the wind stopped blowing? Wind is air rushing from places of high pressure to places of low pressure. It carries heat, water and weather around the world, lifts seeds to new homes and has pushed sailing ships across oceans. Imagine all the air going still, and follow what might change.
- Watch What If? Lab What if fog never lifted? Fog is a cloud resting on the ground, made of tiny water droplets floating in the air. Most morning fog disappears as the Sun warms the ground. Imagine fog that never lifted: travel would be slower, but in some dry places people already use nets to catch drinking water from fog.
- Watch What If? Lab What if the continents stopped moving? Earth's outer shell is broken into giant plates that creep along just a few centimeters a year. Where they meet, they build mountains and cause earthquakes and volcanoes. Imagine the plates stopped: rain, ice and wind would keep wearing the land down, but nothing would push new mountains up.
- Watch What If? Lab What if clouds were made of candyfloss? Puffy clouds look like giant balls of candyfloss (cotton candy), but they are really made of tiny water droplets or ice crystals, and the water in a big one weighs about as much as 100 big African elephants. Imagine clouds spun from sugar instead, and find out what real clouds are made of.
Explore next
- Watch What If? Lab What if the wind stopped blowing? Wind is air rushing from places of high pressure to places of low pressure. It carries heat, water and weather around the world, lifts seeds to new homes and has pushed sailing ships across oceans. Imagine all the air going still, and follow what might change.
- Watch What If? Lab What if fog never lifted? Fog is a cloud resting on the ground, made of tiny water droplets floating in the air. Most morning fog disappears as the Sun warms the ground. Imagine fog that never lifted: travel would be slower, but in some dry places people already use nets to catch drinking water from fog.
- Watch What If? Lab What if the continents stopped moving? Earth's outer shell is broken into giant plates that creep along just a few centimeters a year. Where they meet, they build mountains and cause earthquakes and volcanoes. Imagine the plates stopped: rain, ice and wind would keep wearing the land down, but nothing would push new mountains up.
- Watch What If? Lab What if clouds were made of candyfloss? Puffy clouds look like giant balls of candyfloss (cotton candy), but they are really made of tiny water droplets or ice crystals, and the water in a big one weighs about as much as 100 big African elephants. Imagine clouds spun from sugar instead, and find out what real clouds are made of.
- Watch Try it What If? Lab What if Earth had no atmosphere? Earth's air works like a jacket: it keeps heat in and carries it around. Take the air away in our model of a sandy patch of ground on the equator, and the coldest part of the night drops from about 13 °C to about 2 °C.
- Watch Try it What If? Lab What if there were no greenhouse gases? Greenhouse gases such as carbon dioxide and water vapor hold some of Earth's heat in, like a blanket. Take them all away in our energy-balance model and Earth's average temperature falls from about 15 °C to about −19 °C, well below freezing.
- Watch Try it What If? Lab What if there were more greenhouse gases? Adding greenhouse gases makes it harder for Earth's heat to escape, so the planet warms until it balances again. In our model a small change in how freely heat escapes warms Earth by about 2.6 °C, and the oceans make the warming take years.
- Watch Try it What If? Lab What if Earth were covered in ice? White ice bounces sunlight back to space, so an icy planet soaks up less of the Sun's warmth. In our energy-balance model, making Earth reflect 60 percent of its sunlight instead of 30 percent drops its average temperature from about 15 °C to about −23 °C.
For parents & teachers
What children will learn
- Wind is moving air, which is invisible, so we observe it through what it moves.
- The Beaufort scale, wind vanes and anemometers describe and measure the wind.
- Clouds reveal swirling flow behind islands, and satellites track clouds to map winds.
- Kites and gliders use moving and rising air; thought experiments separate facts from ideas.
Recommended ages: 4 to 17 · About 15 minutes
Talk about it
- What clues tell you the wind is blowing right now?
- If you could see the wind, where do you think it might swirl around your home or school?
- Why is it important to say that some of these outcomes are only ideas?
Try at home or in class
- Be a Beaufort wind watcher: look out of a window or stand in the yard, check smoke, leaves, flags and small trees, and use NOAA's Beaufort Wind Scale to give today's wind a force number.
- Build NOAA's paper-cup anemometer from its Build Your Own Weather Station activity (paper cups, straws, a paper punch, a stapler and a pencil with an eraser). A grown-up handles the straight pin. Count the turns in one minute outside on a breezy day.
Key vocabulary: wind vane, anemometer, Beaufort scale, vortex, thermal, glider
Where these facts come from
- Beaufort Wind Scale , NOAA Storm Prediction Center
- Origin of Wind , NOAA JetStream
- Build Your Own Weather Station , NOAA National Ocean Service
- Cloudy Curls , NASA Earth Observatory
- Two Views of Von Kármán Vortices , NASA Earth Observatory
- Satellite Winds (Satellite Meteorology module 6) , CIMSS, University of Wisconsin–Madison
- Paint By Particle , NASA Scientific Visualization Studio
- Kite Launch and Flight , NASA Glenn Research Center
- Beginner's Guide to Kites , NASA Glenn Research Center
- Gliders , NASA Glenn Research Center
Checked, not yet human-reviewed. Last updated October 24, 2026. Spotted a mistake? Tell us.