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The Milky Way Has Giant Bubbles at Its Center (theatlantic.com)
108 points by _zhqs on Sept 21, 2019 | hide | past | favorite | 25 comments


E-print can be found at https://arxiv.org/abs/1909.05534 .

Some years ago something similar was found in the form of Fermi bubbles; a discovery given the Bruno Rossi Prize. The difference is the frequencies that the structures were found and their size. Fermi bubbles were identified by γ-ray imagining and are far more massive (many thousands of light years in size); both put together makes them far more energetic as well.

An interesting part with this discovery is the correspondence between radio and X-ray emissions in this bipolar radio structure. The radio bubbles appear to exactly bound the plasma detected using X-rays.


I found a picture of the filaments with some related information: https://courses.lumenlearning.com/suny-astronomy/chapter/the...


> Our supermassive black hole is in a quiet chapter of its life, but astronomers suspect that it has previously experienced this active phase.

That's what always freaks me out about astronomy. We don't know what Sagittarius A is up to at the moment. We will know in 26400 years.


If it makes you feel any better, the concept of "at the moment" doesn't really have a meaning at relativistic distances - simultaneity isn't defined. In any sense that practically matters, what Sagittarius A is up to "right now" in our frame of reference is what we see it doing in our telescopes. Although there is a sense in which it happened 26400 years ago, any event further into the future than that is, for us, just as nonexistent as next week.

Ironically, HN seems to be confused as to whether you made this comment 15 minutes or 1 hour ago, depending on whether I'm in "Add Comment" or the main thread. Different frames of reference, perhaps?

(edit: all comments are incorrectly marked as being 20 minutes old in the main thread) (edit2: and my comment is only visible to me, apparently. HN is broken.) (edit3: huge lag between edits and public visibility of said edits from a non-logged-in browser)


> huge lag between edits and public visibility of said edits from a non-logged-in browser

As the saying goes, "there are 2 great unsolved problems in computer science:, naming objects, cache invalidation, and off by one errors."

In case you haven't noticed, to reduce server pressure, a logged-in user sees comments in real time, but a guest only sees the cached version of the page that only updates slowly. When Hacker News sees an explosive amount of traffic, logging out is a way to help. The last time it happened was when Donald Trump was elected.


>That's what always freaks me out about astronomy. We don't know what Sagittarius A is up to at the moment. We will know in 26400 years.

Doesn't it make more sense to freak out because we won't know in 26400 years? Or, for that matter, not even get to know what will happen in 100 years?


Sure, humanity might die out. And nobody will see it. That freaks me out too :-)


For sure. But we're pretty far off axis, so I doubt that we'll get heavily irradiated.


Either way, it wont suddenly turn "on" overnight. These things ramp up and down instantly on cosmological scales, which means many thousands/millions of years in our world.


> Either way, it wont suddenly turn "on" overnight. These things ramp up and down instantly on cosmological scales, which means many thousands/millions of years in our world.

Some supermassive black holes have been caught briefly turning on, over timescales on the order of weeks-months. Tidal disruption events, where a star wanders too close to a SMBH, can result in luminous accretion with significant accretion rates (e.g., Figure 3 of [0]). As the material of the star falls into the SMBH or is blown away, the luminosity drops off, with a predicted decay of t^(-5/3).

[0] https://physicstoday.scitation.org/doi/full/10.1063/PT.3.238...


There may be a form of information transfer that’s much faster than light, on the longitudinal axis of gravity.


Could you elaborate? This would be news to me


Light gets slowed down whenever it passes through any medium. For example, it can take thousands of years for the light produced by fusion in the Sun to reach the surface of the photosphere. Neutrinos, on the other hand, can pass through the Sun largely unimpeded and reach us far more quickly. This is in spite of the fact that neutrinos do not travel as fast as light in a vacuum.

The same possibility holds true for gravitational waves, since they are unimpeded by matter as well. They even have the advantage of propagating at the speed of light, unlike neutrinos.


This seems to be a common misconception because of the way the property is named. What we’re referring to is the maximum speed of information through the fabric of space time. Light (photons) travel at that speed when unimpeded, as do neutrinos, gravity waves, magnetic effects and anything on the electro magnetic spectrum.

‘Slowing’ down light by putting it in a reflective cylinder, water or fiber optic cable doesn’t change the nature of the universe or help achieve faster than light information exchange - it just means some photons are experiencing a traffic jam.


The premise of your argument is flawed.

> For example, it can take thousands of years for the light produced by fusion in the Sun to reach the surface of the photosphere

This is not due to free travel of light through a transparent medium with a high index of refraction or due to gravity. Through a large part of the sun energy is transported by convection and even in the radiative zone photons get frequently absorbed and remitted, the mean free path is below 1cm.


> Astronomers can’t completely explain them, but they have given them familiar labels, naming them after the earthly things they resemble: the pelican, the mouse, the snake.

Humm it seems we have gone full circle.


So are these basically remnants of jets?


Isn't this just a quasar, but on a larger scale?


It’s a quasar on a significantly smaller scale.


I speculate that these bubbles (and the other bubbles) are gigantic elementary particles emerging from the black hole.


That would require a truly absurd distortion of the definition of "elementary particle". In particular, you'd need elementary particles to be able to contain enormous numbers of other elementary particles (which makes the term pretty meaningless).

Why do you think such a thing?


The Tau lepton is ~3000x more massive than the Electron lepton. I see no reason to doubt that there are more massive leptons or bosons. I speculate that they can be predicted along something called the Regge Scale.

I imagine the black hole behaves like a supermassive accelerator, and the energy actually escapes as extra-super-massive "elementary particles" which we can't build telescopes big enough to sense, and basically flow through our own bosonic field like bigger waves. (Perhaps we can see them decay-spiraling through the "gas clouds".)

And at various harmonic reaches of these singular mass-energy units, they decay into the more common and stable particles, feeding stars and fuzzing up Magellan.

Another reasoning: When you put quarks together, and put the results together with some leptons, you get more massive things like atoms, molecules, and all "matter". Quarks are stackable. Leptons are cumulative. The Higgs Boson is already very massive, and isn't stable on Earth, but maybe it is stable in the black hole, and can scale to whatever mass the fabric of that energy-space requires.

Personally, I think the black hole ultra-collides quarks and leptons into highest energy "elementary particles", and that energy feeds these bubbles, which can be described as ultimo-massive bosons decaying, into lesser boson and also leptons and quarks, far out away from the black hole. I would not be surprised if one day it was found that astral bodies tended to form along some predictable distances from galactic center; where the bosonic field is decaying very predictably into the stuff that fuels the creation of those same astral bodies.


I have no idea is this is bullshit or not but I really enjoyed reading or sand totally can picture what you’re saying!


For those downvoting, I suspect this comment is to be interpreted as an attempt at humor.


nope, they serious!




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