tesla

Four witnesses to a single crossing. On November 10, 2017, the four MMS spacecraft flew through an invisible boundary in the solar wind where magnetic field lines reconfigure and release energy.

The magnetic field in this setup must be as smooth as glass: the slightest ripple would blur the signal. The engineers built two coils that cancel each other's field externally and packed them in three layers of ferromagnetic plates.

Radio astronomy began with the mysterious noise caught by the antenna of Karl Jansky and the rhythmic pulses that Jocelyn Bell Burnell playfully called 'little green men'.

A Tesla coil crackles, and a beam of light begins to rotate around it. The medium it passes through is still stable, but the field grows, and the rotation intensifies. This is not a trick but the behavior of special materials that couple electricity and magnetism. For such coupling, there is a fundamental limit — the Tellegen limit.

Light from a distant blazar, an active galactic nucleus whose jet points our way, travels for billions of years. Along the way, it triggers cascades of charged particles that the intergalactic magnetic field deflects sideways. This creates a blurred gamma-ray glow around the blazar: a secondary halo.

A neat stack of atomic layers lies on a substrate. An invisible beam of terahertz light shines down on it, with a magnetic field applied from the side. After reflection, the beam's polarization rotates slightly.

If you squeeze an ordinary piece of metal, it heats up — even those who have pumped a bicycle tire know that. But what happens if you squeeze a magnet in which atomic arrows refuse to freeze even at absolute zero?

Three satellites will drift apart in the heliocentric void, forming a triangle with sides of three million kilometers.

Magnetic sensors smaller than a match head can already detect weak fields — from a beating heart or a distant planet. But making them even more sensitive involves a trade-off: improve one part, and you lose performance in another.

Eight red giants — bloated old stars like the future Sun — are not behaving by the book. Their surfaces oscillate steadily, like a bell, but within this chime there are glitches: some tones are missing, and the rhythm breaks. Scientists suspected an invisible hand inside — a magnetic field — and tried to calculate its strength.

A thin sheet of graphene, just a few micrometers thick, was placed in a weak magnetic field, and it began to push the field out of itself, like a sponge squeezing out water. This effect, known as the Meissner effect, is the hallmark of a superconductor: a material that conducts electricity without loss.

In the dark cloud G351, where new stars are about to emerge from gas and dust, the magnetic field has bent into an hourglass shape. Such a shape is a sign that the field is not just watching star birth from the sidelines but is actively taking part. Scientists used the SOFIA telescope, mounted on an airplane, to see the dust in the cloud.

A white dwarf is what remains of a star like the Sun after it sheds its outer layers. What's left is a hot core the size of Earth but with a mass close to that of the Sun. A teaspoon of this material would weigh as much as a truck. Some of these stars have extremely strong magnetic fields — a billion times stronger than Earth's.

An ordinary superconductor expels magnetic fields, but this ring does the opposite: it creates a magnetic field inside itself. The ring is made of Fe(Te,Se) — a compound of iron, tellurium, and selenium that loses its electrical resistance at very low temperatures.

The VLA radio telescope peered into the Boomerang Nebula — a cloud inflated by the wind from a rapidly spinning neutron star. The new images reveal details as small as a lunar disk on the sky: an elongated core around the pulsar and a long arc curving around it from the north.

Two stars orbit so closely that their outer layers merge into a shared envelope. Matter flows from one to the other, like water spilling from an overfull cup into its neighbor. In this cosmic dance, where stars literally touch each other, astronomers have for the first time detected magnetic fields in large numbers.

A thin film of a bismuth-selenium compound sits on a substrate. A laser pulse lasting a millionth of a billionth of a second strikes it. Nearby, a magnet is switched on, with a field weaker than that of a fridge magnet.

Using a method similar to spectroscopy (magnetic sensing), scientists pass a current through a multilayer film and observe the orientation of the microscopic magnetic arrows inside. Previously, everything was predictable: in some materials, the arrows aligned only along the current, in others — strictly across it. But in bismuth ferrite with a platinum coating, a glitch occurred.