Astronomy/cosmology questions...

[Lorizael]

So part of the answer is that, for solar flares, the extra protection isn't really necessary. The ISS is in a low orbit that is still fairly well protected by Earth's magnetic field. You also get a day or two of warning, so the crew can move to more shielded areas of the station when necessary. That is, the aluminum hull of the space station does an alright job of deflecting particle radiation, and you can put more shielding in particular places.

The greater threat is from cosmic rays, and the current solution is to basically do nothing. Cosmic rays rain down constantly, so you'd need a constantly powered magnetic field over a large volume of space (because you're redirecting the rays rather than stopping them cold), which would take a lot of energy, and it turns out that being in the middle of a very powerful magnetic field could be dangerous, too, so there are engineering hurdles to overcome there.

[Buster's Uncle]

Cosmic rays are wave radiation?

I'm asking for a friend in the Fantastic Four.

[Lorizael]

Nope, they're particles, too, usually protons or naked atomic nuclei. But if they hit something they decay into a shower of secondary particles and some genuine gamma radiation.

[Buster's Uncle]

When they did that power generation test with a conductive tether, the one that melted from all the juice it produced, any idea how much drag?  I never heard anything about that in the reporting...

[Lorizael]

* Lorizael does some googling.

Wow, uh, I had never even heard of that experiment before! Interesting. I don't think drag would be much more of an issue than normal, but I can't find anything about that.

[Buster's Uncle]

Well, it's passing through Earth's magnetic field to generate 'letricity.  Q.E.D, the energy has to come from SOMEwhere - there's got to be drag, since the power source seems to be kinetic energy.

-I was just thinking about an emergency power source...

[Lorizael]

Yeah, on that end... they measured a voltage of 3500 V and a current of about half an amp, so that's ~1750 W (Joules/second) being generated, which is drained from the shuttle's kinetic energy. Shuttle's mass was 10,500 kg and moving at like 7-8 km/s, which gives it roughly 300 billion joules of energy. So I think it would take a long time to slow it down appreciably by this method, unless there's some other factor I'm missing.

[E_T]

IIRC, the tether was oriented to be above the station.  Part if the drag could be tidal effects from the total object weight, maybe?  Or does out help speed it up and In would slow it down (from tidal effects)?

But, if the tether is oriented inwards, would it produce less or more and would the "drag" be the same?

It did generate a lot more than they anticipated, so why not go with shorter ones, so that the ones they can make now will be able to take the reduced load?

[Buster's Uncle]

[E_T]

oh kkkkk.....

[Lorizael]

Look, if your error bars from observation are an order of magnitude greater than the error in your pi approximation, it doesn't really matter what number you use for pi. 3 is fiiiiine. 1 lets you pretend it's not even there, which lessens the odds you make some dumb math mistake.

[E_T]

Yeah, but Who ordered a Magnitude?

[Geo]

Yeah, but Who ordered a Magnitude?

He did.

[ColdWizard]

So, with SN 2019bkc, it could be a stripped helium star with a companion neutron star (but they didn't detect helium in the spectral readings and it's odd to have massive stars in the intergalactic medium), or a merger between a white dwarf and a neutron star or stellar mass black hole if small amounts of calcium was ejected. Where the other possibilities of a double detonation or an intermediate mass black hole tidal disruption event don't quite fit as well. Am I reading any of this correctly?

[Lorizael]

How'd you come across this article? I haven't really seen any press about it.

This is pretty far outside my area of expertise (at least as far as astronomy goes), but I don't see anything blatantly wrong with your reading. It seems this whole class of events is pretty new and poorly understood at present.