[HN Gopher] Bright flash is a black hole jet pointing at Earth, ...
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Bright flash is a black hole jet pointing at Earth, astronomers say
Author : wglb
Score : 198 points
Date : 2022-12-05 15:33 UTC (2 days ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| 7373737373 wrote:
| How wide is this jet here? Does it cover the entire Milky Way?
| moloch-hai wrote:
| 8.5 billion light years away, vs. ~100,000 light years across.
| To cover the whole galaxy, from a point source it would need to
| spread out just 1 part in 100,000. So, probably.
|
| Yes, technically our galaxy is a lot bigger than 100,000 ly,
| but the part somebody looking out from Andromeda could see
| isn't.
| mensetmanusman wrote:
| How many years advance notice would we have before we knew that
| such an event was our fate? To be eaten by a black hole...
| cuSetanta wrote:
| Typically Active Galactic Nuclei (AGN) with the jets pointed
| directly at Earth are referred to as Blazars.
| (https://farm9.staticflickr.com/8300/7754600044_e7635a1c8f.jp...)
|
| But this event seems to be something a little different. Its a
| lot closer to us than a lot of blazars typically are, and the
| emission seems to infer a different source than is typically
| seens for blazars.
|
| Quite an interesting paper, will be cool to see how this might
| change our understanding of AGN and accretion of matter onto such
| objects.
| jcims wrote:
| >referred to as Blazars
|
| For me, legitimately one of the best names for anything ever.
| First time I heard the word it gave me goosebumps lol.
| mongol wrote:
| How about blazer? Any reaction to that?
| zikduruqe wrote:
| I'm partial to Thagomizer.
|
| https://en.wikipedia.org/wiki/Thagomizer
| unsupp0rted wrote:
| > The term thagomizer was coined by Gary Larson in jest. In
| a 1982 The Far Side comic, a group of cavemen are taught by
| a caveman lecturer that the spikes on a stegosaur's tail
| were named "after the late Thag Simmons".
| mattkevan wrote:
| My 5 year old surprised me when she pointed to the spikes
| on a dinosaur tail and said 'that's the thagomizer'. I
| knew about the cartoon and that it'd been adopted as the
| official term, but somehow wasn't expecting it to be
| taught in primary schools as standard dino anatomy.
| LegitShady wrote:
| thagomizer is a lot more fun to say than something
| technical like "distal tail bone spikes" or something
| similar.
| maxnoe wrote:
| The name comes from BL Lacertae (the prototypical object) and
| Quasar (A kind of Active Galactic Nucleus, that name is for
| quasi stellar, which it really isn't...)
| russellbeattie wrote:
| So you could say they're... Star Blazars?
|
| _" We're off to outer space... We're leaving mother Earth...
| To save, the human race! Our Star Blazers!"_
|
| (OK, so the spelling is off. But since I'm going to be humming
| this the rest of the day, might as well see if there's some 80s
| kids out there that will join in with me.)
| nathcd wrote:
| paper: https://arxiv.org/pdf/2211.16537.pdf
| gammarator wrote:
| Here's the paper by the discovery team:
| https://arxiv.org/abs/2211.16530
| subsubzero wrote:
| Wonder if this burst could have been seen with the naked eye?
| They mentioned it was visible on multiple spectrums.
| wumms wrote:
| > 8.5 billion lights years away--more than halfway across the
| universe
|
| Why is it halfway across? The universe's diameter is 93 billion
| ly. Shouldn't 8.5 billion be more like "ten percent across"?
| yayr wrote:
| universe is a relative word, and typically treats us at being
| at the center (which in the whole of reality is somewhat
| unlikely). So it only describes that part of reality observable
| by us. 8,5 bn ly refers to roughly half distance to all of the
| observable events in that observable reality at the time these
| events occured. Since 3D space presumably expands, it would now
| take much more time for any event in our observable "universe"
| to reach from one end of the observation limit to the other...
|
| by the way - if you want to go down further that rabbit hole a
| good place to start is to search for "levels of multiverse"
| anotheraccount9 wrote:
| (I'm not an astrophysicist). They possibly are referring to the
| initial age of the universe times the speed of light (13.8
| billion light-years), as if it was static.
|
| Like you infer, "[...] stuff is everywhere, light goes at c,
| stars and galaxies move, and the Universe is expanding."
|
| https://www.forbes.com/sites/startswithabang/2018/02/23/if-t...
| nicksrose7224 wrote:
| I think it's more likely they got it wrong and are referring
| to what they assume the size of the universe is. It's hard to
| grasp why the observable universe is 92 billion ly in
| diameter
| denton-scratch wrote:
| > Typically, such bright flashes in the sky are gamma-ray bursts
| --extreme jets of X-ray emissions that spew from the collapse of
| massive stars.
|
| Is that right? Surely gamma ray bursts are gamma rays, not
| X-rays. At least, shouldn't it say "extreme bursts of X-rays _and
| gamma rays_ [...] "?
| monocasa wrote:
| GRBs start, as their name suggest, as a burst of gamma rays,
| but have long tails of emiting of x-rays and other lower energy
| photons that we're more likely to notice.
| anigbrowl wrote:
| > From a rough calculation, the flash appeared to give off more
| light than 1,000 trillion suns
|
| Not a single astronomical photgraph
| BlueTemplar wrote:
| Overexposure issues...
| freddealmeida wrote:
| * blackholes are not confirmed science. It is theory and little
| evidence supports the theory. * Math is not reality, it is a
| description of reality that should require evidence * this could
| be many other things including plasma
| cthalupa wrote:
| Little evidence? We've got pictures of them a this point,
| friend. While we are not entirely sure on all of the specifics,
| and some things, such as the singularity, are likely a bit
| different than our current theories suggest, there's mountains
| of evidence that support the existence of black holes, or at
| the very least, something that is very very very very very very
| very similar to them on the macro level.
| wigster wrote:
| it's the focused beam of tortured souls escaping the event
| horizon that worries me.
| ordu wrote:
| Why do you think they were tortured? Maybe they were ejected
| for heavy drinking while waiting in a queue to a paradise. We
| do not know what is inside of a black hole, but funny ways of
| matter around a black hole seems like a result of drunkinness.
| How one can miss black hole while falling into it? Try to miss
| Earth while falling on it. No amount of gin seem to be enough.
| But they somehow managed to miss a black hole which is much
| heavier than Earth. They used a tremendous amount of gin to get
| into the right state of a mind. No wonder they were stripped of
| their right to a paradise and ejected from a queue.
| amelius wrote:
| What is the probability of something so far away pointing
| straight towards Earth? What is the angle in which this
| phenomenon spreads out into space?
| moloch-hai wrote:
| The big untouched mystery is how these things collimate the beam
| so exactly.
|
| In order for all the mass to end up going in exactly one
| direction, so focused, something would have to get them started
| off that way. Any sort of thermal phenomenon would need a
| parabolic reflector/nozzle.
|
| Currently favored is some sort of electromagnetic process that
| works like a particle accelerator, applying a linear electric
| field to highly-ionized nuclei over thousands or millions of km.
|
| The "geysers" coming out of Enceladus would likewise need
| parabolic nozzles to stay collimated, so must be similarly
| electromagnetic. Unfortunately the notion was first promoted by
| reviled "electric universe" enthusiasts, so astrophysicists need
| to file the serial numbers off before they can acknowledge it.
| beedeebeedee wrote:
| Is this going to annihilate us? I didn't see them mention any
| safety risks, but it sounds similar to a quasar to me (a non-
| astronomer), and I think if one of those is pointing at us, we're
| toast. If they just detected the light, and the matter is going
| 99.9% of the speed of light, does that mean we're toast tomorrow?
| Next week? Next year?
| evan_ wrote:
| If it is going to, would you even want to know?
| Gh0stRAT wrote:
| Well it seems like we've detected 3 other jets pointed straight
| at us as the black hole devoured a star so it seems like a very
| common event on a geological time scale. The fact that we
| managed to evolve and are still here is a decent sign.
|
| >The team says the black hole's jet may be pointing directly
| toward Earth, making the signal appear brighter than if the jet
| were pointing in any other direction. The effect is "Doppler
| boosting" and is similar to the amped-up sound of a passing
| siren.
|
| >AT 2022cmc is the fourth Doppler-boosted TDE ever detected and
| the first such event that has been observed since 2011.
|
| Also, I believe that as the universe's volume expands, the
| probability and intensity of being in the direct path of any
| particular such jet goes down. Then again, the frequency of
| these events may (or may not) be increasing at a rate that more
| than counteracts that. (I'm just speculating here, I'm not a
| cosmologist!)
| dotnet00 wrote:
| Most of the threat from relativistic jets is from within ones
| own galaxy (and at worst, its local group). So, yes as the
| universe expands the risk from the latter should decrease,
| the risk from the former wouldn't really change due to
| expansion. The risk probably does still come down, but more
| due to age as larger clouds of gas get used up and spread
| around by supernovae, preventing enough mass from gathering
| for the things that produce relativistic jets.
|
| One possible answer to the Fermi paradox is that we're early
| because the universe may have only recently gotten calm
| enough for life to survive long enough to develop
| intelligence.
| peeters wrote:
| As far as I understand it, gravitational lensing would affect
| the trajectory of particles travelling different speeds
| differently. So it would seem entirely possible that the matter
| wouldn't even be pointed at us. That assumes that either is
| being significantly affected by gravity of course.
|
| Also bear in mind that though the light of 1000 trillion suns
| has been pointed at us, it's not like we have a second sun in
| the sky right now. It's really, really far away.
| czbond wrote:
| I'd believe the small percent of a percent of the sky we're in
| for it to be pointing at us is still a large swath of trillons
| of miles.
|
| And 850k years from now - our galaxy would have moved from it's
| location anyways. Some other galaxy will probably waltz into
| it.
| snarf21 wrote:
| Very interesting. Does this imply (assuming these jets have
| been occurring for a _very very_ long time) that we 'd be
| able to see the consequences of _other_ jets in other
| galaxies /planets? Said another way, have we ever observed
| something that could actually have been "... some other
| galaxy waltzing into it"?
| Gh0stRAT wrote:
| One of Earth's past mass extinction events is hypothesized
| to have maybe been caused by a gamma ray burst[0]. I don't
| know enough to speculate whether it could have been caused
| by one of these jets instead.
|
| [0] https://en.wikipedia.org/wiki/Late_Ordovician_mass_exti
| nctio...
| adgjlsfhk1 wrote:
| It's 8 billion light years away. We'll be fine.
| [deleted]
| 317070 wrote:
| If the matter is trailing at 99.99% the speed of light as
| reported, it gives us 800k years.
| cthalupa wrote:
| The matter was traveling at 99.99% the speed of light in
| the jet. While we generally consider space to be a
| friction-less vacuum for something like a spaceship, that
| isn't true for things like a stream of particles traveling
| across the universe. Even if the Earth stood still in this
| exact position for another 800,000 years (which it won't,
| since our galaxy is not stationary, nor is the solar
| system, and there is of course the expansion of space as
| well), very little of the physical matter from this jet
| would hit us.
| zdyn5 wrote:
| Wouldn't it give us way more than that? If it were
| traveling at 100% the speed of light it would take 8
| billion years right?
| sp332 wrote:
| The light has _already_ taken 8 billion years to get
| here. The particles have also been traveling for that
| time and are only 800,000 years away now.
| insanitybit wrote:
| For now!
| ck2 wrote:
| Hmm. If an alien race a million years older than humans
| eventually figured out how to make synthetic wormholes on demand
| for FTL when no other method existed, can we theorize what the
| endpoint might look like?
|
| (this is a "fun" but not kidding question)
| dotnet00 wrote:
| One idea is that they'd be one-directional, with a black hole
| on one end and a white hole on the other end. But considering
| that we haven't really seen any evidence of white holes
| existing, such a thing probably isn't possible.
|
| Other than that, a simple traversable wormhole entrance/exit
| would just look like a sphere where you see the other side sort
| of 'mapped' onto the surface.
| ck2 wrote:
| Oh wow, were the Hollywood versions in Contact and
| Interstellar vaguely based on that science?
|
| Will have to watch them again this weekend and double-check.
| dotnet00 wrote:
| I wouldn't necessarily say they're based on science since I
| don't really think there's enough concrete science on
| wormholes to say what they would look like precisely
| (although Interstellar did put some effort into visual
| accuracy: https://cerncourier.com/a/building-gargantua/).
|
| My reasoning is that just like a circle is formed on a 2d
| surface when 'bridging' two parts of it (the pencil through
| folded paper analogy), a bridge on a 3d surface should have
| a sphere as the hole (or maybe since it's technically a
| space-time bridge, it should be a hypersphere, which would
| still appear as a sphere to us 3d observers). Then, to not
| tear apart anything going through, it'd need to conserve
| 'symmetry' (so something that goes in comes out unchanged),
| so the light would go through unchanged, making it just
| appear like the view of the other side is mapped to the
| surface.
| theGnuMe wrote:
| Imagine this is the end of a wormhole and it fries any planet
| at the exit.
| hiccuphippo wrote:
| The Vogons did tell us about the hyperspace expressway in
| advance but did we listen?
| ionwake wrote:
| (I can give you a "short" but not short answer to this)
| waltbosz wrote:
| https://en.wikipedia.org/wiki/Old-fashioned_(short_story)
|
| An Asimov story about stranded astro-miners who throw rocks into
| a black hole to generate x-rays with the hopes that they will be
| spotted by observers back on Earth. The throws are timed to spell
| out S-O-S.
| Mistletoe wrote:
| Sorry for a stupid question but I've seen it repeated on the
| internet many times that we can never observe anything actually
| falling into a black hole because it takes forever to actually
| fall in due to time lengthening the closer it gets. Is that
| true? It has never made sense to me, since we see effects of
| black holes all the time.
| lisper wrote:
| > Is that true?
|
| Probably. We don't know for sure because quantum effects
| might change things, and we don't yet have a theory of
| quantum gravity. The event horizon of a black hole is pretty
| much the one place in the universe where the effects of
| quantum gravity are most likely to manifest themselves, so
| one should hedge one's bets when making predictions in their
| vicinity.
|
| > It has never made sense to me, since we see effects of
| black holes all the time.
|
| Falling into a black hole is different from falling into a
| regular gravitational field. All kinds of weird shit happens
| before you reach the event horizon. Among other things, tidal
| forces rip you apart, heat you up, and turn you into a
| plasma. That plasma emits radiation, and that is what you see
| (because all that happens outside the event horizon).
| bmitc wrote:
| It all depends on the size of the black hole. HUGE black
| holes have weak tidal forces.
| lisper wrote:
| True, but the hole under discussion here is not one of
| those. (And it's important to note that big holes have
| weak tidal forces _at the event horizon_. They still
| probably have pretty significant tides close to the
| singularity, but God only knows what actually goes on in
| there).
| waltbosz wrote:
| https://en.wikipedia.org/wiki/Spaghettification
|
| I think spaghettification is my favorite word, maybe it's
| tied with defenestrate.
| BurningFrog wrote:
| So an observer near the black hole would see an eternally
| accumulating number of objects falling towards it, but
| crawling to a halt near the event horizon?
| cthalupa wrote:
| It depends on the sensitivity of the instruments. For human
| eyes looking out the window of a spaceship, they would be
| redshifted away to invisibility pretty quickly.
| MattPalmer1086 wrote:
| And the light getting increasingly red shifted until you
| can't really see it anymore.
| BurningFrog wrote:
| I see. Another way to think of "redshift" is "lower
| energy", so these things will disappear from sight
| another way.
| cthalupa wrote:
| You'll never directly see them fall in, but you will see them
| "disappear" pretty quickly as the light is redshifted past
| the point of visibility, etc.
|
| The more sensitive whatever tool you are using to detect the
| photons is, the longer you can watch, and something that
| approaches infinite sensitivity would be able to see you for
| a time period that also approaches infinity, but outside of
| the realm of the theoretical, anything falling in to the
| black hole will wink out of existence in a fairly large hurry
| once it reaches the event horizon.
|
| But things like accretion disks and these relativistic jets
| are happening outside of the event horizon, so they're not
| subject to these same concerns to begin with. For example,
| the accretion disk of Sagittarius A*, the supermassive black
| hole at the center of our galaxy, has an accretion disk that
| is roughly 1/100th of a light year, or about 25 times the
| size of our solar system. The event horizon, however, is only
| about 16 million miles - or a roughly 1/6th the distance
| between the sun and the earth. (These numbers are based on
| our current best estimates - and those estimates have changed
| frequently over the past 20 years as we get better data, but
| the general scale should be quite accurate)
| szundi wrote:
| AFAIK you never see it falling in as it just slows and
| turns into more red, but slowly.
| dotancohen wrote:
| The object falling in has its time dilated to forever - it
| will never actually experience the "getting there". Outside
| observers, on the other hand, will observe the "getting
| there" just as if the black hole were any other large mass.
|
| Or do I have that backwards...
| WrtCdEvrydy wrote:
| Yes, the outside observers can see the item falling into
| the blackhole while the object experiences more and more
| time dilation.
|
| If you were falling into a wormhole, you would die of old
| age before getting there while outside observers would see
| you fall in quickly.
| OkayPhysicist wrote:
| Like the comment you were responding to, you have that
| backward.
| alonmower wrote:
| You would be ripped apart instantaneously while everyone
| outside of the black hole would see the light you emit as
| you're crossing the event horizon frozen in time. It's an
| optical effect, nothing magical is happening to you as
| you fall into the enormous mass
| OkayPhysicist wrote:
| You have that backwards. The person falling into the black
| hole falls straight towards the singularity as if it was
| any other massive object, straight through the event
| horizon without noticing anything change.
|
| The far away observer sees the falling one infinitesimally
| approach the event horizon, but never cross.
| dylan604 wrote:
| >The person falling into the black hole falls straight
| towards
|
| I guess you're assuming zero velocity by that person. But
| if there is velocity, wouldn't the fall not be straight
| towards but in an ever shrinking/decaying orbit
| trajectory?
| he0001 wrote:
| This "never cross" statement bends my mind. Doesn't it
| also mean that if we are observers, observing a black
| hole, we should not see an actual blackness as we should
| only see things that are slowly falling into the hole?
| Regardless of how much time that has been spent from the
| beginning of time? I mean the event horizon is the
| boundary but that never happen?
| cthalupa wrote:
| The light is increasingly redshifted, so for practical
| purposes it disappears from view quite quickly.
|
| The more sensitive the instrument, the longer you can
| observe, and this doesn't really have a limit - as
| sensitivity approaches infinity, so does the length of
| time you could continue to observe the object.
|
| But for practical purposes, we would not see a black hole
| as some sort of weird psuedo-magnet with all sorts of
| junk stuck to the edge of the event horizon.
| OkayPhysicist wrote:
| Because of time dilation, light emitted (or reflected off
| of) objects very near the event horizon end up getting
| spaced out over (almost infinite) amounts of time.
|
| For example, lets say you dropped a beacon that flashes
| every second into a black hole. As it approached the
| event horizon, you'd see the flashes only happen every 2
| seconds, 4 seconds, minute, hour, decade, etc. Meanwhile,
| the length of those flashes are getting longer at the
| same rate, while producing the same number of photons, so
| the light gets dimmer and dimmer.
| he0001 wrote:
| Another factor, that other things are falling into the
| whole, wouldn't that mean that the event horizon,
| relatively, gets closer to an earlier object? Meaning an
| object may reach the event horizon faster than it would
| originally or is that constant relatively where the
| object exist in its descend?
| birdiesanders wrote:
| Backwards
| cryptonector wrote:
| It is and it isn't true. Light from the falling object will
| be red-shifted, and eventually you won't be able to see it,
| but if you could see extremely long wave-length light, and if
| you could observe it for a _really_ long time, you 'd see
| light from that object asymptotically approach the universe's
| size as its wavelength, and you'd never see the object go
| over. But obviously it's not possible for humans to observe
| extremely long wavelength light, so you'd just see the object
| disappear when light from it red-shifts beyond the range you
| can observe.
|
| The object, meanwhile, does fall in from its perspective.
| rirze wrote:
| There's a difference between objects falling into the black
| hole versus material accreting on the black hole's horizon
| that can generate high energy beams.
| plonk wrote:
| https://math.ucr.edu/home/baez/physics/Relativity/BlackHoles.
| ..
|
| > So if you, watching from a safe distance, attempt to
| witness my fall into the hole, you'll see me fall more and
| more slowly as the light delay increases. You'll never see me
| actually get to the event horizon. My watch, to you, will
| tick more and more slowly, but will never reach the time that
| I see as I fall into the black hole. Notice that this is
| really an optical effect caused by the paths of the light
| rays.
|
| > This is also true for the dying star itself. If you attempt
| to witness the black hole's formation, you'll see the star
| collapse more and more slowly, never precisely reaching the
| Schwarzschild radius.
|
| I don't understand everything but it seems that the falling
| guy tends towards the event horizon, getting slower and
| slower relative to the observer, and never reaching it from
| the observer's point of view?
|
| Edit: this applies when observing something falling into the
| black hole. It doesn't apply to faraway objects that deviate
| because of the black hole's gravity well, so we can observe
| most of a black hole's effects.
| Mistletoe wrote:
| Yes they say this but how do we see the jet in the original
| linked article haha?
| wholinator2 wrote:
| The types of highly visible bright lights coming from
| black holes are not actually coming from inside the black
| hole. The gravitational potential of the well is so
| incredibly high that objects falling through it gain
| immense amounts of energy, thus giving of very high
| energy radiation, i.e. x-rays.
| nine_k wrote:
| Think about the tidal forces that a piece of matter is
| experiencing near a black hole, but still far away from
| the even horizon. They deform the matter very violently,
| hearing it so much that its normal heat radiation goes to
| the X-ray wavelengths.
| Mistletoe wrote:
| Ah I see. Thank you everyone that responded!
| plonk wrote:
| No source now, but I think I've read that the jet is
| matter that's far enough from the black hole to escape
| it, accelerated during its rotation.
|
| The wiki page isn't very clear about how the jet is
| created:
| https://en.wikipedia.org/wiki/Tidal_disruption_event
| dcminter wrote:
| As I understand it (based entirely on pop sci books and
| articles) they're purely from the accretion disk i.e.
| nothing inside the event horizon. I don't think the exact
| mechanism is agreed upon beyond that.
| [deleted]
| rssoconnor wrote:
| FWIW, I asked my physicist friend this question one time. He
| said while an outside observer would never see a "massless
| test particle" enter the event horizon due to time dilation
| effects, real particles have mass and their own gravitational
| field, and thus due to complicated stuff they can eventually
| been seen passing through or otherwise somehow merging with
| the event horizon.
| ars wrote:
| You are correct, and it means black holes can never actually
| form, because it would take an infinite amount of time for
| them to form.
|
| > since we see effects of black holes all the time.
|
| We do not, we see super massive objects, or black holes in
| progress, but no actual black holes.
| at_a_remove wrote:
| Once a black hole -- a collapsar -- forms, and you want to
| toss something into it, it is best to imagine _two_
| timelines.
|
| From the point of view of the object being hurled into the
| black hole, things proceed more or less normally: you
| accelerate as you fall, but light behind you becomes
| curiously more blue and brighter. You eventually reach the
| event horizon, which ought to be called EH-sub-0, because it
| is only the _first_ event horizon. It might be helpful to
| think of a black hole 's interior as infinitely layered event
| horizons, event horizons "all the way down." You'd note a
| restriction of movement -- "up" (away from the black hole) is
| no longer a possibility; every direction is some variation of
| down, perhaps down and to the left, down and east, whatever,
| but always _down_. Eventually tidal forces take over
| depending on the size of the thing -- you might notice them
| before or after the outmost event horizon, and
| "spaghettification" occurs even as you are pummeled with
| X-rays and gamma radiation from behind (millennia of
| impacting photons blueshifted and jammed into a smaller
| timeline).
|
| From the outside, however, your astronaut or thrown Cylume
| lightstick becomes more and more red, and dim, slowly
| approaching that event horizon but you'll never see it get
| there as it now emits infrared and not much of that. You
| switch on your FLIR and you can see it, for a while, but it
| grows dimmer and eventually disappears off of that.
| Eventually it emits very weak radio waves, and you lose track
| of the thing, but even if you spent a million years building
| longer and longer antennae, you'd never see it hit.
|
| The effects you see of a black hole are 1) gravitational
| lensing (photons bending in their trajectory around the
| exterior of a black hole, just above the outermost event
| horizon), 2) the formation of an accretion disc (as matter
| swirls into it, growing hot from friction and compression),
| 3) absolute blackness if you managed to get a "transit" of
| something particularly large across a light path, 4) other
| knock-on gravitational effects, like disturbed orbits.
| bmitc wrote:
| The visible effects we see for black holes are things from
| well outside the event horizon, where black holes behave as
| just another gravitational object. Things, i.e. gas, can
| rotate and swirl around them. Since the black hole can be
| rotating and the gas being slung around violently, it can
| emit radiation. If I understand correctly, the jets for
| supermassive black holes can extend out to sizes comparative
| to the containing galaxy's diameter.
|
| Here's a nice simulation showing this in action (article in
| description): https://youtu.be/g1aW8TDOm4A
|
| The YouTube channel Kurzgesagt also has some pretty good
| illustrations and animations.
| monocasa wrote:
| The effects aren't limited to just falling in. Once you pass
| the event horizon it's game over, but remarkably little
| matter from, say a star falling in, will actually reach the
| event horizon. For one example, a lot of particles get swept
| up in the magnetic maelstrom surrounding spinning black holes
| and are shot away from the poles at near the speed of light.
| That's what we're seeing here.
| freddealmeida wrote:
| maybe? could be? possibly? Highly doubtful and impossible to
| verify
| habibur wrote:
| > 8.5 billion lights years away--more than halfway across the
| universe
|
| That was the first number I was looking for.
|
| Not a threat to earth. It's not even in our galaxy.
| JoeAltmaier wrote:
| I don't know, its pretty bright. Maybe this periodic flash-fry
| is what created life on earth!
| geeky4qwerty wrote:
| "From a rough calculation, the flash appeared to give off more
| light than 1,000 trillion suns."
|
| Can any space geeks chime in on this one?
|
| Does this mean the emission of light from the sun at a single
| point in time x 10^15? My brain pretty much divides by zero even
| trying to comprehend such a large number and I'm just trying to
| grasp the relationship of the emitted light to our sun.
| dylan604 wrote:
| > My brain pretty much divides by zero even trying to
| comprehend such a large number
|
| I've tried using this line in the wrong company that wasn't
| math oriented, and it fell flat.
|
| It's also amusing your use of this phrase, as in a lot of the
| astronomy circles I've seen/read, there's a joke that black
| holes are where god divided by zero. So it felt very apropos to
| me in this context too.
| londons_explore wrote:
| That would be assuming the same amount of light was emitted in
| all directions. But we have no indication that that was the
| case.
| jvanderbot wrote:
| I roughly translate this to 10^15 x more photons per square
| meter of surface area at some standard distance.
| yourapostasy wrote:
| Whoah, this goes way beyond Sarah Connor: "Anybody not wearing
| two million sunblock is gonna have a real bad day".
| cuSetanta wrote:
| As others have said, its not quite the same as the Sun's
| output, but it is still an incredible amount of light.
|
| I have studied blazars fairly extensively in the past and you
| are right that the brain cant really fathom the 'real world'
| appearance of these things. I resort to just thinking in terms
| of number of photons and avoid thinking about the rest, as it
| tends to result in a lot of existential dread and drinking.
| swamp40 wrote:
| > jet speed is 99.99% the speed of light
|
| Does that mean a wave of particles is coming at us right behind
| the light flash?
| cthalupa wrote:
| No. The light from these jets travels many many magnitudes
| farther than the actual material. You wouldn't want to be
| within a few million light years of it but these particles have
| mass and will be slowed by all of the matter they interact with
| in space. The vacuum of space still has roughly an atom per
| cubic centimeter, which really adds up over the distances we're
| talking about here.
|
| Edit: Left out a fairly important word. few million light
| years*
| Renevith wrote:
| That was my first thought too. But even at that speed, we have
| quite a bit of time. Since the particles are 0.01% slower than
| the light that just reached us, the particles would arrive in:
| 8,500,000,000 light years away * 0.01% speed of light = 850,000
| years. Humanity will be unrecognizable by that point.
| grayfaced wrote:
| Wouldn't the galatic rotation mean the earth will be
| somewhere far away when the jet travels that far?
| suzzer99 wrote:
| Yes, that and both galaxies careening through space on
| different trajectories.
| garblegarble wrote:
| That got me wondering how far we'd move - if my maths is
| correct then in 850,000 years time our solar system will
| have travelled 652 light years around the galactic core
| (230 km/sec * 850,000 years)!
| d0mine wrote:
| How wide is the beam? (given how far it started) Light-
| years?
|
| Is it still dangerous at this point? (If its energy is
| spread over a giant area radius billions light-years)
| [deleted]
| mynegation wrote:
| On the flip side that also means that we might flow into a
| burst travelling through space without any warning (?)
| JW_00000 wrote:
| When doing such a calculation, would you need to take into
| account the fact that space is expanding while the particles
| are traveling? (And will have expanded a bit more in the time
| it takes for the particles to reach us than in the time it
| took for the light to reach us.)
| swamp40 wrote:
| A couple more 9's changes that drastically though. Maybe
| someone just truncated at 2 decimal places?
| [deleted]
| 22SAS wrote:
| If it is 8.5 billion light years away and was traveling at
| the speed of light (100% instead of 99.99%) wouldn't it take
| 8.5 billion light years? Wonder how you got to the 850K years
| figure.
| Victerius wrote:
| By his logic, an object moving at 0% of the speed of light
| would arrive instantly.
| alanbernstein wrote:
| An object moving 0% _slower_ than the speed of light
| would arrive instantly _after the light arrives_ , yes.
| monocasa wrote:
| They're saying the difference between the time the light
| gets here and the particles 'only' going 99.9% of C is 850K
| years back of the napkin.
| umvi wrote:
| > wouldn't it take 8.5 billion [years]?
|
| Yes, if you are assuming the jet was emitted right now. But
| the jet was emitted roughly 8.5 billion years ago. The
| light in front of the jet has already reached us. If the
| jet were also travelling at the speed of light we'd be dead
| right now. But luckily it's travelling slower than light so
| that's why we have 850k more years before the jet reaches
| us.
| 22SAS wrote:
| > If the jet were also travelling at the speed of light
| we'd be dead right now
|
| Does that mean, once the jet reaches us 850K years from
| now, we can say that will be a mass extinction event, or
| even the end of life on Earth? Compared to a billion
| years from now when the Sun's luminosity increases.
| cthalupa wrote:
| No. The matter in these jets isn't like a spaceship where
| the matter is all connected together. It's largely
| individual plasma particles - over billions of light
| years they'll run into other particles, be deflected,
| slow down, etc. There IS friction in space.
|
| Matter decay will have significant impact on the mass of
| matter ejected by the jet, as well, particularly over
| billions of years. As it decays into a lower energy
| state, mass will be turned into photons, and less and
| less of it will be left to impact.
|
| Plus, we won't be in the same spot in 850k years anyway.
| The solar system is moving around the galaxy, and the
| galaxy is moving around the universe, and space in the
| universe is expanding.
| 22SAS wrote:
| Interesting, thank you very much.
| darawk wrote:
| Would we actually? If so, doesn't this imply that the
| probability of earth just having been destroyed by one of
| these things was roughly a coin flip, and therefore gives
| us a (much higher) rough estimate of how likely such an
| event might be?
| twawaaay wrote:
| Not necessarily. Particles will all be charged plasma and it is
| possible that those will be deflected by magnetic fields. But I
| am not astrophysicist so you would want to check on it.
|
| Also, in contrast with the flash where all light has the same
| speed, the particles will have different speed so it will all
| be smeared in time (read -- much smaller in amplitude and hard
| to detect) and arriving much later than the flash.
|
| Then from the point of view of observer on Earth surface,
| charged particles will not be coming exactly from the source
| but at a bit of an angle (due to magnetic fields present).
| Again, I have no knowledge about the magnitude of the effect
| and I also suspect that the people who know this shit have some
| way to account for it...
| baobabKoodaa wrote:
| When they say "pointing straight toward Earth", is that
| hyperbole? Or are they actually saying that by pure random
| chance, out of all the possible directions this thing could have
| taken, it just happens to be pointed directly at earth?
| PKop wrote:
| But there are a lot of black holes yes? Surely some of them
| will point towards us.
| Cpoll wrote:
| Depends on the width of the beam. If it's as wide as a laser
| pointer, the odds of it hitting anything are infinitesimal.
| When something's a light year away, changing the bearing of
| the laser by a degree will cause you to miss it by hundreds
| of thousands of kilometers. Or to rephrase, to hit something
| a light year away you'll have to get the heading accurate to
| many decimal points. (Exercise left to the reader, it's high
| school trigonometry, but I'm rather lazy).
| PKop wrote:
| It's also a statistical question that involves how many
| black holes there are. Do you have a strong sense of that
| number, because I sure don't?
|
| Quick search says there are a very large amount of black
| holes but maybe not so many super-massive that produce
| these beams of light so eh, who knows.
| cogwheel wrote:
| The beam is surely wider than the planet so there's a large
| range of "straight toward"
| dan_mctree wrote:
| It should be at least broad enough to compensate for some
| movement of the earth, considering it was observed for at
| least some days
| cuSetanta wrote:
| Yeah this is pretty much the case.
|
| The important thing is that the light from the beam is
| sufficicently bright that it is not possible to resolve the
| surrounding region of space to see more detail.
| baobabKoodaa wrote:
| If I point a flashlight directly at you, that's different
| from me pointing the flashlight at the person standing next
| to you. Even though in both cases the beam will light you up.
| dotnet00 wrote:
| But that becomes effectively the same thing if the
| flashlight is being pointed in your direction from 10km
| away and it's reasonable to just describe it as pointing at
| you. Coming from 8 billion ly away, the beam is probably
| wide enough that it would appear to be pointed at the Milky
| Way in general.
| bombcar wrote:
| It's 8 billion light years away, even if the beam was _very_
| focused by the time it reached us it is probably tens of
| thousands of lightyears wide.
| ricardo81 wrote:
| I suppose the metric expansion of space over this scale would
| also diffuse the light
| bombcar wrote:
| I tried to find a calculator (you can find ones for "laser
| over meters") that would support supernovas over lightyears
| and came up short.
| umarniz wrote:
| Want to point out how incredibly good the website phys.org is.
|
| I was first introduced to it over 15 years ago and remember
| visiting it using dial-up internet from Pakistan as a teenager to
| learn about the latest developments in physics.
|
| Gem of a resource that is still going strong.
| ourmandave wrote:
| Kurzgesagt just did a vid on black holes and how close they have
| to be before we're f'd.
|
| _The Most Extreme Explosion in the Universe_
|
| https://www.youtube.com/watch?v=q4DF3j4saCE
| jschveibinz wrote:
| "Pointing directly toward earth" ...hmmm. In what possible frame
| of reference could anything be pointed directly toward earth for
| longer than a moment in space and time? We are traveling through
| space and time in multiple frames of reference at a tremendous
| rate. This confuses me.
| ddevault wrote:
| We are incredibly far away from objects like this, so the
| apparent movement is negligible.
| peheje wrote:
| haven't you got this backwards? the further the distance the
| smaller movement an object would need to not be in the
| trajectory?
| winReInstall wrote:
| If you could controll the direction of a black hole, you could
| use it to "disinfect" the neighbourhood or send messages.
| Victerius wrote:
| It's 8.5 billion light years away. It would be like aiming a
| water hose at Mars from low Earth orbit.
| backtoyoujim wrote:
| so given this tool we would either murder or flirt
|
| can there be anything so human ?
| pigtailgirl wrote:
| https://telescope.live/sites/default/files/styles/photo_w102...
|
| very bright ^^
|
| https://telescope.live/blog/transient-flash-identified-dista...
| dustingetz wrote:
| ChatGPT has made contact
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