Science Principle Animations in Code:The Invisible, Drawn Step by Step

While charging, lithium ions leave the cathode, cross the separator and slip between the graphite layers of the anode; electrons travel round the outside circuit.

Discharging reverses it: ions return to the cathode and electrons flow through the outside circuit, lighting the bulb.

After many cycles the film on the anode thickens and lithium dendrites grow; some lithium gets trapped and can’t return, so capacity shrinks.

ForBattery makers, energy storage, EV makers, battery materials

Light going from glass into air at a small angle mostly refracts out; only a little reflects back.

As the angle grows the refracted ray hugs the surface; at the critical angle no light gets out any more.

In a fiber the light travels beyond the critical angle, so every time it meets the boundary it reflects completely and keeps going.

ForTelecom operators, fiber and cable makers, photonics and laser firms

With the magnet sitting still beside the coil, the field through the coil doesn’t change and the meter reads zero.

Push the magnet in and the needle swings one way; pull it out and it swings the other. A changing field makes current flow.

A generator spins the coil in a magnetic field; the field through it keeps rising and falling, so the current alternates—AC power.

ForGrid companies, power producers, motor and electrical makers, school physics

The vaccine delivers harmless virus fragments—antigens—and immune cells learn what they look like.

Immune cells start making antibodies and leave behind memory cells that remember the shape.

When the real virus arrives, memory cells quickly churn out antibodies that coat and neutralize it, so you’re less likely to fall ill.

ForPharma and vaccine makers, disease control, hospitals, health education

Molecules must climb an energy hill to become products. Without a catalyst the hill is high and only a few make it over.

A catalyst opens a different route with a much lower hill—and isn’t used up itself.

At the same temperature most molecules now get over, products pile up quickly and the reaction speeds up.

ForChemical firms, new materials, catalysts and environmental materials, university chemistry

An earthquake first sends out P-waves; they travel fast and mostly jolt the ground up and down, doing less damage.

Then come S-waves: slower, shaking the ground side to side—they cause most of the damage to buildings.

A station near the epicenter catches the P-wave, works out location and strength, and an electronic alert races ahead of the S-wave—giving distant cities seconds to tens of seconds.

ForEmergency management, seismic and weather agencies, disaster museums, school safety

N-type and P-type silicon meet; electrons and holes at the junction cancel out, leaving a charged layer with a fixed built-in field.

Photons from sunlight knock electrons loose, each leaving a hole behind—they appear in pairs.

The built-in field pushes electrons to the N side and holes to the P side; connect a circuit and electrons loop round, lighting the bulb.

ForSolar makers, semiconductors and chips, power plants, science museums

Tilted slightly into the wind, air flows smoothly over and under the wing, producing some lift.

At a larger angle the air above moves faster with lower pressure and the air below presses harder—suction above, push below, more lift.

Too steep, and the airflow over the top breaks away into turbulence; the low-pressure zone collapses and lift drops sharply—a stall.

ForAerospace, drones, automotive and wind blades, flight training

Plaque builds up on the artery wall; the vessel narrows, less blood gets through and the heart muscle goes short of blood.

A catheter carries a balloon and stent to the narrowing; the balloon inflates, the stent expands with it and presses the plaque back.

The balloon deflates and withdraws; the stent stays to hold the artery open and blood flows freely again.

ForDevice makers, cardiology departments, physician training, patient education

An ordinary antenna radiates in all directions; energy spreads everywhere and little reaches the phone.

An array transmits together, each element slightly delayed, so signals add up toward the phone and cancel elsewhere.

As the phone moves, the delays are retuned and the beam swings to follow—full bars all the way.

ForOperators, telecom equipment makers, satellite and radar, IoT companies

The membrane lets only water through. With fresh water on one side and salty on the other, water seeps toward the salty side and its level rises—osmosis.

Press on the salty side; when the pressure matches the osmotic pressure, water stops moving across.

Press harder and water is forced back through the membrane while the salt stays behind—the other side fills with fresh water.

ForWater utilities, membrane makers, purifier brands, desalination projects

A neutron hits a uranium nucleus, which splits in two, releasing energy and two or three more neutrons.

Those neutrons hit more nuclei—one becomes two, two become four—and the reaction races ahead: a chain reaction.

Control rods soak up the extra neutrons so each fission triggers just one more; power holds steady for continuous generation.

ForNuclear operators, energy groups, nuclear science centers, university physics