Comment on A rogue object so strange, scientists aren’t sure what to call it.
Gust@piefed.social 3 days agoI dont think you’re quite understanding how big 6 orders of magnitude is. 4000000/r2 still falls off way slower than 1/r2.
Also the funnel diagram of the earth’s magnetic field you’re referring to is a near field effect. In the far field regime the only field components that stay strong enough to be relevant are those parallel to the axis of the dipole; a dipole is functionally identical to a bar magnet if you’re measuring it from far enough away. If my understanding of solar wind is correct and the aurora refers to an interaction that occurs between the earth’s magnetic field and particles near the sun, we’re definitely in the far field regime
deranger@sh.itjust.works 3 days ago
I don’t think you’re quite understanding the distances involved in what I’m getting at. The particle flux is minuscule, and it’s not the magnetic field that’s attracting particles. It’s only guiding the particles that were already headed towards the planet.
This planet would have great aurorae if it were near a star, but it’s not, so the magnetic field strength is kind of a moot point.
Gust@piefed.social 2 days ago
The absolute distance is strictly irrelevant given this is a relative comparison between two magnetic fields. The one that is 6 orders of magnitude higher will maintain that 6 orders of magnitude difference exactly the same at a distance of 100m as it will at a distance of 100au. That means that the stronger field will maintain the minimum strength required to “guide” particles towards the dipole at a greater distance than the weaker magnetic field would. I feel you if you’re only trying to argue that it would still need to be within some neighborhood of some star to produce an aurora, but your posts read like you’re claiming 6 orders of magnitude on the magnetic field makes no difference on how close that object would need to be to produce an aurora, which is flatly incorrect.
deranger@sh.itjust.works 1 day ago
The absolute distance is extremely relevant to how many particles reach the planet, which in turn is extremely relevant to how bright the aurora is.
Gust@piefed.social 1 day ago
That is correct. It also has nothing to do with the original claim I made and you disagreed with, which is that the object with the greater magnetic field would be able to attract particles from farther away.
wewbull@feddit.uk 2 days ago
No star = no charged particles = no lights. Doesn’t matter how big the magnetic field is.
That’s all he’s saying.
plyth@feddit.org 2 days ago
From how far could the planet guide particles into its aurora?