3 ms·

In the plane, there are myriad hazards that, at effectively random times, are right nearby, close enough to sterilize your whole system if they go off then. Mos

In the plane, there are myriad hazards that, at effectively random times, are right nearby, close enough to sterilize your whole system if they go off then. Most of them -- supernovas and magnetar outbursts -- are not jets. Off-plane, nothing gets close enough to be a hazard except, if you are extra-unlucky, a jet pointed straight at you, which could as well happen were we are now. Above the plane of the disc, only jet sources near the "top surface" (if there were one) have less dust between them and us than when we were in it. Generally, being farther away is better. Before you can get far away from your galaxy, you spend a very great deal of time near or in it. Being someplace farther from hazards during that time is better than being nearer to them. The alternative would be to blast toward the rim, staying in the thick part, and spend the whole time getting to the rim at about as much risk as when you started.

LargoLasskhyfv 4y ago
> ...if you are extra-unlucky, a jet pointed straight at you, which could as well happen were we are now. Yes! That's the point :-) Edit: No matter if jet or not, if something like https://en.wikipedia.org/wiki/Ultraluminous_X-ray_source#/media/File:PIA24574-SS433-ULXray-20210709.jpg https://en.wikipedia.org/wiki/Ultraluminous_X-ray_source#/me... or https://en.wikipedia.org/wiki/Gamma-ray_burst#/media/File:Gamma-ray-burst-Mechanism.jpg https://en.wikipedia.org/wiki/Gamma-ray_burst#/media/File:Ga... or https://en.wikipedia.org/wiki/Blazar https://en.wikipedia.org/wiki/Blazar is pointed at us, we are toast, no matter where we are. Except for distance to origin. OTOH I don't see the danger from anything 'near' to us, going boom, when one of the poles of the rotational axis, no matter the emission mechanism, is not pointed at us. The omnidirectional stuff is just too weak. If not, we'd be toast anyways, here, or whereever else. So I'm still unconvinced by your reasoning, but thanks for trying to explain.
- moloch-hai 4y ago
  You neglect that supernovas and magnetar events are orders of magnitude more common than these focused jet events. When one of the former occurs nearby, there is no possibility of protection. Objects that threaten it drift in and out of range at random. We have been in range of such an object many times, and just got lucky that they did not go off at those times. Dust clouds shield you from some kinds of radiation, but make others radically more harmful. Jet phenomena are commonly long-lived, and avoided by steering away from where they point. You can steer only when you are moving. AGN jets come only from supermassive black holes, and we have only one of those. The only protection is distance, and distance is achieved by going. Gamma-ray bursts we detect have all been pointed at us, but all from distant galaxies.
  - LargoLasskhyfv 4y ago
    Yes, Yes. I'll shut up now. But not without asking whether that going would be achievable by any handwavy Sci-Fi means in the necessary time frames. And knowing in advance, before any wavefront is hitting us. /waving hands... ;-)
    - moloch-hai 4y ago
      Moving the solar system would take millions of years, but that is a useful timeframe if you are dodging random threats. For specific threats, you need to put your valuables in cans and boost those to someplace safer, choosing somewhere with resources to replace what you leave behind. For that to be doable you probably need to solve p-11B fusion, or something better we don't know anything about yet.

LargoLasskhyfv 4y ago

> ...if you are extra-unlucky, a jet pointed straight at you, which could as well happen were we are now. Yes! That's the point :-) Edit: No matter if jet or not, if something like https://en.wikipedia.org/wiki/Ultraluminous_X-ray_source#/media/File:PIA24574-SS433-ULXray-20210709.jpg https://en.wikipedia.org/wiki/Ultraluminous_X-ray_source#/me... or https://en.wikipedia.org/wiki/Gamma-ray_burst#/media/File:Gamma-ray-burst-Mechanism.jpg https://en.wikipedia.org/wiki/Gamma-ray_burst#/media/File:Ga... or https://en.wikipedia.org/wiki/Blazar https://en.wikipedia.org/wiki/Blazar is pointed at us, we are toast, no matter where we are. Except for distance to origin. OTOH I don't see the danger from anything 'near' to us, going boom, when one of the poles of the rotational axis, no matter the emission mechanism, is not pointed at us. The omnidirectional stuff is just too weak. If not, we'd be toast anyways, here, or whereever else. So I'm still unconvinced by your reasoning, but thanks for trying to explain.

moloch-hai 4y ago
You neglect that supernovas and magnetar events are orders of magnitude more common than these focused jet events. When one of the former occurs nearby, there is no possibility of protection. Objects that threaten it drift in and out of range at random. We have been in range of such an object many times, and just got lucky that they did not go off at those times. Dust clouds shield you from some kinds of radiation, but make others radically more harmful. Jet phenomena are commonly long-lived, and avoided by steering away from where they point. You can steer only when you are moving. AGN jets come only from supermassive black holes, and we have only one of those. The only protection is distance, and distance is achieved by going. Gamma-ray bursts we detect have all been pointed at us, but all from distant galaxies.
- LargoLasskhyfv 4y ago
  Yes, Yes. I'll shut up now. But not without asking whether that going would be achievable by any handwavy Sci-Fi means in the necessary time frames. And knowing in advance, before any wavefront is hitting us. /waving hands... ;-)
  - moloch-hai 4y ago
    Moving the solar system would take millions of years, but that is a useful timeframe if you are dodging random threats. For specific threats, you need to put your valuables in cans and boost those to someplace safer, choosing somewhere with resources to replace what you leave behind. For that to be doable you probably need to solve p-11B fusion, or something better we don't know anything about yet.