Wielding (quantum) fields!

Quantum field theory takes an infinite number of field configurations and add them up with the proper weighting to come to a single conclusion. The Standard Model is one well-known example, but this could be much, much more useful. For example, we could predict readings on compasses – something we can’t do right now – at different altitudes as climbers go up mountains. It might sound simple, but gravity, and all the infinite number of fields generated by planet earth, are actually incredibly complicated.

 

Gaussian free field model by Samuelswatson via Wikipedia.

What has Juno found on Jupiter? Part II – It’s magnetic

Built with a 20 radius and designed to spin, Juno is made to measure the magnetic field of Jupiter. Thanks to Juno, we now know that the planet’s dipole is the opposite way round (North and South) to Earth, and tilted ~10^o from its rotational axis. The strength of the magnetic field (20 x that of Earth’s!) allows us to calculate how long a day is on Jupiter – because we can’t tell just by looking at the bands: they seem to move in opposite directions to each other and at different speeds! It also allows Jupiter to deflect solar winds as far out as 6 million km from the planet and hold onto its atmosphere. At this point, we also see weird effects that Juno is attempting to explain, such as ring-like features, known as Kelvin-Helmholtz instabilities, which scientists think may travel along the planet’s magnetic field lines. As well as the dipole, these include weaker quadrupoles and octupoles.

 

Jupiter's magnetosphere showing the Io Plasma Torus (in red). Yned via Wikipedia Commons.