The record was set by JR Central's L0 Series on the Yamanashi test line in Japan. It was a test run, not normal service, but it proves the system can stay stable at aircraft-like speeds.

Most steel-wheel high-speed trains run much slower because their wheels, rails and overhead wires all have limits. Maglev removes the wheel-on-rail limit once it lifts off, so engineers can chase higher speeds while still controlling the train from the guideway.

That does not mean it is friction-free. At 500 km/h, air resistance is the giant enemy, so the long nose, smooth body and tunnels are designed as carefully as the magnets.

Friction happens because no surface is truly smooth. Zoom in far enough and even shiny steel looks like a mountain range, and the bumps catch on each other.

On a normal train, wheels are useful because they carry weight and give grip. They also wear down, heat up and make noise. A floating maglev keeps the useful steering and support in magnetic fields instead.

Once a maglev floats, wheel friction disappears completely. Only the air is still in the way, which is why the nose is long and smooth, like a bullet.

That invisible push or pull around a magnet is called its magnetic field. You can't see it, but you can feel it, and it reaches through air.

The SCMaglev does not use one huge magnet under the floor. It uses superconducting magnet units mounted low on both sides of the vehicle, facing coils in the guideway walls.

Those train magnets stay magnetised on board, while the guideway coils react or are powered at just the right time. Keep scrolling and we'll zoom all the way inside to see why the onboard magnets can be so strong.

JR Central describes the levitation height as about 10 cm, or 3.9 inches. That is small to a passenger, but huge for a vehicle that weighs many tonnes.

The gap gives the train room for tiny guideway movements and makes contact less likely. It also leaves space for the rubber wheels to carry the train before lift-off and again as it slows down.

The train is not floating on air pressure like a hovercraft. It is hanging in a magnetic balance made by coils on both sides of the guideway.

Why does lift need speed? You'll see in the next step: the push comes from the train's magnets rushing past the walls. No rushing, no induced current; no induced current, no useful lift.

Below about 150 km/h, the L0 Series runs on rubber wheels. They support the train in stations, through points, and during the first part of acceleration and the last part of braking.

If guideway power is lost, the superconducting magnets do not instantly switch off. The train can coast, the lift fades as speed falls, and the wheels take the weight again.

Steel wheels are excellent, but at very high speed every contact problem gets harder: heat, vibration, noise and wear all grow. Maglev moves the main support force into magnetic fields instead.

That does not make the ride silent. Air rushing past the train and through tunnels still makes sound, so the shape of the nose and the route design matter a lot.

The wheels still earn their keep. They carry the train when it is slow, and wheel brakes are one of the backup ways to stop at low speed.

Each car carries superconducting magnet units on both sides. Their north and south poles alternate along the train, so each passing pole gives the guideway coils a changing magnetic field to react to.

The magnets are on the train, not the track, because superconducting magnets need cryostats and refrigerators. It is easier to keep that cold equipment with the vehicle than to chill the whole route.

These magnets stay on during the trip. They do not need to be rapidly switched for lift; the moving train provides the changing field.

Each levitation and guidance coil is shaped like a figure 8: a top loop and a bottom loop, wired so their currents flow in opposite directions. The track does not feed these coils with power for lift.

When a train magnet passes right at the middle of the 8, the magnetic changes in the two halves mostly cancel. If the train is a bit low, the balance is broken and current appears in a direction that lifts it back up.

That is why the system needs speed. A still magnet sitting beside a loop does not keep making new current; a moving magnet does.

This is called electromagnetic induction, discovered by Michael Faraday in 1831. A moving magnet near a loop of wire makes current flow, with no battery needed.

Electricity flowing in a loop always makes its own magnetic field. Nature arranges that new field to oppose the change that caused it. Here, the loop's field pushes the train back toward the correct height.

Guidance works the same way sideways. If the train drifts toward one wall, the coils on that side react more strongly and push it back toward the centre, while the far side reacts less.

A magnet you can switch with electricity is called an electromagnet. In SCMaglev, the propulsion coils are fixed in the guideway walls, and power converters beside the track decide which poles they become.

Those converters are inverters: machines that turn grid electricity into carefully timed three-phase AC. Three-phase means three currents rising and falling in a repeating pattern, which makes the north-south poles move along the wall.

The train's superconducting magnets lock onto that moving pattern. Coils ahead attract; coils just behind can repel. The vehicle has no onboard traction motor doing the pushing.

The driver or onboard crew does not steer each coil by hand. A control centre plans the speed profile, while sensors along the guideway report where the train is so the wave stays lined up with it.

Only the section of guideway around the train needs to be energised. Section switches hand power from one block to the next as the train passes, instead of lighting up the whole route.

That saves energy and keeps control local. If a train is not in a section, its propulsion coils do not need to make a travelling magnetic wave.

Engineers call this a linear synchronous motor. Linear means a normal spinning motor has been unrolled along the track. Synchronous means the train's magnets move in step with the travelling magnetic wave.

Speed is changed by changing the frequency of the AC current. Higher frequency makes the magnetic wave travel faster, so the train is pulled faster. Lower frequency slows the wave.

For braking, the converters shift the wave so it lags behind the train and pulls backward. Much of the motion energy can flow back as electricity, called regenerative braking; backup eddy-current, disk, aerodynamic and low-speed wheel brakes are also available.

Niobium-titanium is a low-temperature superconductor. It needs liquid helium temperatures, about 4 kelvin, before it can carry huge current with no electrical resistance.

The same kind of wire is inside hospital MRI scanners and the giant magnets of the Large Hadron Collider at CERN, the world's biggest science machine.

JR Central has also tested newer high-temperature superconducting magnets. They still need deep cold, but not as extreme as liquid-helium magnets, which could make future train magnets simpler to cool.

A straight wire with current makes a magnetic field around itself. Wind the wire into a loop and the fields from all the turns add together through the middle.

The racetrack shape fits along the side of the train, where it can face the guideway coils. Engineers stack many turns so the magnet is strong without needing a giant block of iron.

Because the wire is superconducting, a large current can keep circling after the magnet is charged. That is why the train can carry a powerful field without dragging a huge battery for the magnet itself.

A flask keeps soup hot with an empty vacuum between two walls, so heat can't easily cross. A cryostat uses the same trick, plus shiny shields that bounce heat away like mirrors.

The train carries cryocoolers, which are small refrigerators for extreme cold. They remove the heat that leaks in through supports, wires and vibration, so the superconducting coil stays below its limit.

If a magnet ever warms too much, it can lose superconductivity in a sudden event called a quench. Engineers design protection circuits so the stored energy is safely handled instead of damaging the coil.

−273.15 °C is called absolute zero: the coldest anything can ever be, because you can't jiggle less than not at all. Empty space between the stars is about −270 °C.

The SCMaglev's low-temperature superconducting magnets work near 4 kelvin, which is about −269 °C. That is not just cold; it is colder than natural places on Earth.

At that temperature, ordinary engineering problems become strange. Rubber, seals, metals and wires all shrink or change, so the cryostat has to be designed for deep-cold stress.

Helium stays liquid at a colder temperature than anything else, which is exactly why it has been used for niobium-titanium magnets. Liquid nitrogen is much easier, but it is far too warm for this older superconducting wire.

The train also carries cryocoolers: refrigerator machines that keep removing heat during the whole trip. They are powered from the train's onboard electrical system.

Future high-temperature superconducting magnets can work at warmer cryogenic temperatures. Warmer still means extremely cold, but it can reduce helium plumbing and make maintenance easier.

Resistance is the way a material slows electric current and turns some of its energy into heat. In a normal magnet coil, that heat would waste power and could damage the insulation.

When niobium-titanium is cold enough, it becomes superconducting. The current can keep moving without that electrical drag, so the magnet can stay strong after it has been charged.

There are limits: too much heat, too much current or too strong a field can knock the wire back to normal. That is why the cooling and monitoring systems are part of the magnet, not an optional extra.

A normal electromagnet needs a power supply all the time because resistance keeps stealing energy. The lost energy becomes heat, so big normal magnets need cooling even when they are not superconducting.

For a train magnet, that would be a problem. Carrying enough onboard power to feed a huge normal coil continuously would be heavy and wasteful.

Superconductivity solves that specific problem: once the current is started in the closed loop, there is no resistance trying to drain it away.

These teams are called Cooper pairs. Put simply, the paired electrons move in step with the whole crowd, so the atoms can't knock them off course one at a time.

The exact quantum physics is deep, but the useful result is simple: no electrical resistance. That means no steady heat loss from the current in the superconducting coil.

Heat ruins it. Warm the wire up even a little too much and the jiggling atoms break the pairs apart, and the resistance comes right back.

This is called persistent current mode. The magnets are charged up once, then the superconducting loop is closed so the current keeps circulating.

No power cable is needed to keep that magnet current going, but the magnet system still needs power for refrigerators, sensors and control electronics.

If cooling fails badly, protection systems safely dump the stored magnetic energy. In normal operation, the current simply keeps going while the train runs.

The chain has two different coil jobs. The passive figure-8 coils make lift and guidance by induction, so they need the train to be moving. The powered propulsion coils make the travelling wave that moves the train.

The onboard superconducting magnets connect both jobs. They induce currents for lift, and they lock to the powered wave for propulsion.

Passenger power is handled without a roof pantograph at high speed. SCMaglev uses contactless induction power collection from guideway coils, the same basic idea as wireless charging but much larger.

The Chuo Shinkansen is planned as a new route, not a faster version of the existing coastal Tokaido Shinkansen. Much of it runs through tunnels so the route can be straighter.

A straighter route matters because passengers feel sideways force in curves. At very high speed, even gentle curves need lots of space, so engineers choose tunnels and large-radius curves where possible.

The train does not simply run at record speed everywhere. Operations control sets a speed profile: accelerate, cruise, slow for curves or stations, then brake smoothly.

At the train, there is no diesel exhaust because propulsion power comes through the guideway. The environmental story depends on the power plants feeding the grid and on the concrete, tunnels and equipment built for the line.

Regenerative braking helps by sending some energy back when the train slows. It cannot recover everything, because air drag and electrical losses still turn some energy into heat.

Safety does not depend on one perfect system. If the main power fails, the train can coast, onboard batteries can keep essential systems alive, and the vehicle settles onto wheels as speed drops.