[HN Gopher] Three Super-Massive Black Holes Merging Together in ...
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Three Super-Massive Black Holes Merging Together in Our Nearby
Universe
Author : happy-go-lucky
Score : 152 points
Date : 2021-08-29 06:48 UTC (16 hours ago)
(HTM) web link (pib.gov.in)
(TXT) w3m dump (pib.gov.in)
| scott-smith_us wrote:
| "Nearby Universe"?
| GavinMcG wrote:
| ITT: people insist that a term of art is objectively wrong
| because it doesn't match their subjective lay sensibilities.
|
| https://en.wiktionary.org/wiki/term_of_art
| mclightning wrote:
| I didn't understand anything from this sentence.
| wumpus wrote:
| "nearby universe" is astronomy jargon.
| bilinguliar wrote:
| I am wondering if antitrust laws are applicable in this case.
| tannhaeuser wrote:
| Of course they are! It's just that this mass concentration
| appears to be outside a domestic regulated market and NASA/ESA
| are as helpless as the FTC against laws of nature.
| saagarjha wrote:
| There's plenty of competition from smaller mom-and-pop black
| holes in your Local Group.
| 88840-8855 wrote:
| What I just realised - imagine we are living in the future and
| have colonized distant planets. We might need a new tense that
| indicates that an event has already happened on that distant
| planet, but due to speed of light limitations, this information
| has not yet arrived at the observer.
| mike_hock wrote:
| Maybe we could borrow from our distant (or not so distant)
| ancestors, where an event might have happened on the other side
| of this planet, but due to the speed limitations of ships
| sailing the ocean, this information had not yet arrived at the
| observer.
| tzs wrote:
| It is not just the future that needs it. Time travel stories
| are part of our mainstream fiction and so we need to deal with
| time travel tenses when discussing the plots of those stories.
|
| Here's what can happen with our current tenses if you try to
| discuss the popular movie "Back to the Future":
| https://www.youtube.com/watch?v=VLpUlmiVo2k
| smiley1437 wrote:
| https://en.m.wikipedia.org/wiki/Light_cone
| ThalesX wrote:
| We have this in my native language; adapted to English, it
| would sound like <It will have happened>. Three black holes
| will have merged in a nearby galaxy.
| diegoperini wrote:
| Turkish has such flavors of past tenses. They are called
| "observed past" and "learned past" tenses.
|
| As the names imply, one is used when you witness the event. The
| other is used when you forget that you witnessed or you heard
| it from someone else.
| system2 wrote:
| Did anyone say anything about Turkish?
| moab wrote:
| The comment is about turkish tenses that are "similar" to
| the kind of knowledge conveyed in the tenses OP points out.
| It seems relevant to me.
| ehnto wrote:
| The relevancy is obvious. Someone wondered if we will need
| new words for different nuances of tense, and this comment
| described that Turkish has some of those already.
| shsbdncudx wrote:
| We wouldn't know about such events until light reached us
| anyway - light is the speed of causality, so we'd never apply
| this tense you propose.
| Razengan wrote:
| We have words for infinity and shit that would never be
| "applied" but are useful logically.
| foota wrote:
| You might know that something will happen, but it hasn't
| happened yet in your reference frame. I guess this is
| actually just the return of the past, where you wouldn't know
| something had happened yet if it were thousands of miles
| away. I wonder if there's remnants of that time in the
| language used.
| ben_w wrote:
| We might, but Relatively makes it counterintuitive.
|
| In the past/future you find all the stuff within the
| corresponding light cone. The stuff outside the cones can
| flip between being what seems (non-Relativistically) like it
| should be past and future, can be either depending on _your_
| motion relative to it, so an extra tense for spacelike
| separation is something I can imagine a sufficiently advanced
| civilisation using.
| CuriousSkeptic wrote:
| Was just going to say that we should perhaps start with using
| the term "speed of time" instead of "speed of light" to get
| in the right frame of mind.
|
| But then I started to think about it and it doesn't seem
| exactly right either. Causality kind of implies interaction,
| and interaction implies mass (no?), so causality as such must
| necessarily be strictly slower than C. That is, the speed of
| the propagation of the wave function between causally
| connects to events is C but causality as such are the
| interesting things happening at those events.
| dnadler wrote:
| > interaction implies mass (no?)
|
| Not necessarily. Photons, for example, are massless. But
| you're still pretty much correct. Information cannot travel
| faster than C.
|
| Though there may be some special cases that I'm not too
| familiar with. One I'm a little curious about is entangled
| quantum particles, though I'd have to do a little reading
| to be able to say anything further.
| wizzwizz4 wrote:
| Entangled quantum particles cannot transfer information,
| regardless of your interpretation.
| layer8 wrote:
| > has already happened
|
| This isn't well-defined for events outside your light cone. Of
| course we could introduce an outside-one's-light-cone tense.
| snet0 wrote:
| Is this not some kind of sneaky simultaneity? You're imagining
| some absolute "this has happened" where, in your perspective,
| it hasn't yet.
|
| I'm interested if anyone qualified could fix this issue for me.
| When we look into the distance, we see things that we describe
| as "happening X years ago" based on their light-year distance
| to us. We imagine that in the _actual present_ at that
| location, what we 're seeing happened X years ago. Is this not
| implying some absolute time reference that shouldn't really
| exist?
| R0b0t1 wrote:
| It could be possible to go faster than light and preserve
| causality. The problem is we don't know a way to do this --
| all explored ways create contradictions based on the physical
| laws as we know them.
|
| If you can imagine teleporting and still having a consistent
| timeline, then you can imagine going faster than light.
| thethimble wrote:
| "Going faster than light" is impossible. The intuitive
| concept of velocity as something that can be infinitely
| scaled isn't how real relativistic velocity works.
|
| "Teleporting" and "having a consistent timeline" are
| oxymorons.
| api wrote:
| We are pretty sure FTL or "stargate" style teleporting
| would break causality. If anything like this is possible it
| means the universe is far, far stranger than we have
| imagined.
| Jenk wrote:
| Disclaimer: uneducated ignoramus posting.
|
| Does that apply to wormholes, assuming wormholes are a
| thing and we ever develop a method to warp spacetime
| arbitrarily?
| snet0 wrote:
| If you're interested in some simplified-but-still-
| roughly-rigorous discussion about the physics of time
| travel/causality, Sean Carroll did a solo episode of his
| podcast where he talked about a few different ideas in
| this space.
|
| https://www.preposterousuniverse.com/podcast/2020/11/23/1
| 24-...
| grogers wrote:
| Wormholes aren't true FTL travel, they change the
| geometry of space such that there's a new shortest path
| for light to travel from A to B. Setting up a wormhole
| between two points requires slower than light travel to
| extend the wormhole ends. But after initial setup it
| would still be amazing :-)
| gls2ro wrote:
| My understanding is that maximum speed is defined when
| going through space so light speed is maximum speed while
| going through space.
|
| But I think theoretically we can defined travel through
| spacetime (or by transforming space itself) or something
| similar where a distance can seem to be travelled at
| higher speed than light is measured as space. I am
| thinking about this as I heard that when thinking that
| our Universe expands so each two galaxies lets say depart
| from each other will eventually speed up "faster than
| light" in the sense that the space itself expands.
|
| Or I can be very wrong so please correct me.
| snet0 wrote:
| You can certainly _imagine_ going faster than light, but
| that doesn 't mean it's possible. Saying it _could_ be
| possible is basically saying "our understanding of physics
| could be wrong". Technically correct, but at that point we
| aren't having a productive discussion. "Assume everything
| we understand is wrong -> we can now teleport"
| UnpossibleJim wrote:
| Does it even have to be teleporting to break causality,
| to be honest? Given a long enough journey, wouldn't the
| Alcoubiere (sp?) drive accomplish the same thing? By
| making a warp bubble and folding space using
| gravitational forces, none of the laws of physics are
| broken and the user can still move faster than the speed
| of light (though it isn't possible due to the lack of
| anti gravity, which might not exist - so there's that).
|
| Also: https://www.sciencealert.com/pulses-of-light-can-
| break-the-u...
| snet0 wrote:
| It doesn't have to be teleporting. Any superluminal
| travel can break causality. As I linked elsewhere, Sean
| Carroll has a solo podcast episode[0] where he talks
| about a few methods by which time travel could be
| imagined to be possible, given our understanding of the
| limitations. As is the case with the drive you mentioned,
| it's often the case that it's something like "well, if we
| imagine some special case that we don't think is
| forbidden, we can do xyz". I imagine at some point a few
| of these not-technically-forbidden holes will be blocked,
| but also it's not a certainty that all that is true can
| be shown to be so.
|
| Your link really doesn't provide any basis for FTL
| travel.
|
| [0] https://www.preposterousuniverse.com/podcast/2020/11/
| 23/124-...
| UnpossibleJim wrote:
| No, I know it doesn't provide any basis for FTL travel.
| It was more a link for the commentors stating that
| nothing can travel faster than light. I should have
| labeled it better =/
| snet0 wrote:
| Well, it doesn't really show something travelling faster
| than light, any more than if you shot a laser at the moon
| and looked at the speed of the dot on the surface as you
| moved it through some angle. The dot can move arbitrarily
| fast, but nothing in the system is actually moving faster
| than light.
| rnd420_69 wrote:
| That concept is indeed meaningless in special relativity. So
| much so that mathematically there is no way to write down an
| absolute point in time, you can only write down time relative
| to another point in space time. Ergo saying something like
| 'that place at [same time as my absolute time]' is not even
| possible.
| rnd420_69 wrote:
| I meant to say general relativity.
| glandium wrote:
| Wasn't there a paragraph or two about making up a tense for
| that in the Hitchhiker's Guide to the Galaxy?
|
| Edit: found it:
| https://sites.google.com/site/h2g2theguide/Index/t/956236 (it
| was about time travel, close enough)
| patall wrote:
| But NASA already has that situation with their Mars rovers
| already. When ever those do something, its always 5-20 minutes
| when you know it has already happened but the signal is not on
| earth yet.
| andy_ppp wrote:
| It's slightly weird to think this will happen at a certain time
| for us but presumably at this point space time will be bent in
| such a way that what does time even mean anymore...
| anonuser123456 wrote:
| For anyone that had the question "How do two black holes merge
| given time dilation?"
|
| http://curious.astro.cornell.edu/about-us/91-the-universe/bl...
| elefanten wrote:
| That was interesting but I'm not sure it answered the question?
| Was the answer that they don't "time freeze" at the threshold
| of event horizons touching each other, but instead "pucker out"
| to meet each other?
| crazydoggers wrote:
| I agree the wording in the article isn't too clear, maybe a
| bit oversimplified.
|
| One thing to keep in mind. What we see as the black hole is
| really the "event horizon". To a local observer there's
| nothing special at that location. You wouldn't notice
| anything crossing it.
|
| So really as the black holes merge, we see their event
| horizons merge. It's not really valid to say one horizon
| falls into the other, as they are simply space time points
| like any other.
|
| What happens to the singularities is probably a whole lot
| more complex and I don't know if it's well defined. In
| addition, there's a lot more typically going on around most
| black holes since many have accretion disks of materials
| accelerated at relativistic speeds and are also rotating
| causing other gravitational complexities.
|
| Where I think the article hits the nail on the head, is we
| need complex simulations and ultimately more data on
| observations to create more accurate models.
| leshokunin wrote:
| "Nearby universe"? Did we just detect another one I'm not aware
| of?
| happy-go-lucky wrote:
| "This is the type of unscripted event in our nearby universe
| ..."
|
| https://www.nasa.gov/mission_pages/swift/bursts/oddball_burs...
|
| "The first stars, called Population III stars (our star is a
| Population I star), were much bigger and brighter than any in
| our nearby universe ..."
|
| https://www.nasa.gov/mission_pages/spitzer/multimedia/timeli...
|
| "In our nearby universe, dust is pumped out by dying stars like
| our sun."
|
| https://www.jpl.nasa.gov/news/10000-earths-worth-of-fresh-du...
|
| "We can't yet directly rule out mysterious sources for this
| light that could be coming from our nearby universe ..."
|
| https://www.jpl.nasa.gov/news/nasas-spitzer-finds-first-obje...
|
| Looks like it is not uncommon for them to say so.
| jhgb wrote:
| Lots of things are "not uncommon" in common speech. That
| doesn't make them paragons of style.
| corobo wrote:
| I think it's more supposed to read as close to us
|
| Casually dropping the discovery of the multiverse as a footnote
| would be fun though
| leshokunin wrote:
| "I found a more comfortable pillow for cryogenically
| suspended space travel!"
| Borrible wrote:
| Well, the universe is everywhere.
|
| Everything else, not.
| VelkaMorava wrote:
| And in a true HN fashion, the award for most autistic and
| pointlessly pedantic comment goes to you.
| dogma1138 wrote:
| Anything within 1 billion light years from us is considered
| "near by universe", it's sometimes also called our local
| universe.
|
| Tt's the region of space around us in which cosmic evolution
| doesn't play a major factor for observations unlike something
| that say is 10 billion light years away.
|
| Basically it's a anything close enough to us that when we
| observe it we can assume that at least as far as the galactic
| evolution goes it's in a current or "developed" state, as in
| mature and fully formed galaxies.
| jhgb wrote:
| That's usually called "space", not "universe". The universe
| is the _entirety_ of space around us. By virtue of
| countability, the phrase "nearby universe" is problematic
| since it suggests contrast with other, "far" universes (which
| don't include the space around us).
| rrrrrrrrrrrryan wrote:
| "Hot singles in your area" is a bit different than "Hot
| singles in your nearby area."
|
| The term "nearby universe" is perfectly fine, as far as the
| English language goes.
| jhgb wrote:
| > "Hot singles in your area" is a bit different than "Hot
| singles in your nearby area."
|
| I wasn't using the word "area", though.
|
| > The term "nearby universe" is perfectly fine, as far as
| the English language goes.
|
| Not according to my language sensibility at the very
| least. Just like sibling comment's remark about "nearby
| house" when talking about the very house you're currently
| in.
| _jal wrote:
| "Inheritance" means very different things to programmers
| and normal people. You can't expect domain use to follow
| your sensibilities.
| userulluipeste wrote:
| One is class1 inheritance, the other one is (most likely
| about) wealth inheritance. They do, however, both respect
| the notion of inheritance, I don't see why anyone's
| sensibilities would be affected. But then comes "local
| universe", which although refers to the local _part of
| THE_ universe, it drops the definitive article, only
| because coining a new (albeit controversial) term in
| astronomy is more rewarding for someone looking to leave
| a mark on the domain than to respect logic to a more
| sensible result.
|
| 1 Let's leave for now what "class" means for programmers
| vs. other kinds of people.
| dogma1138 wrote:
| You are more than welcome to become a prominent
| cosmologist and advocate for the term change.
| garbagetime wrote:
| > "Hot singles in your nearby area."
|
| This doesn't sound like standard English either, though.
| rrrrrrrrrrrryan wrote:
| If it's good enough for the New York Times, it's good
| enough for me:
|
| https://ludwig.guru/s/nearby+area
| pndy wrote:
| While it does sound weird, it is a term that scientists are
| using to distinguish between the universe as a whole of
| existence that was, is including us and will be, and what
| we can observe within our capabilities from our position on
| Earth, in the Sol system, travelling in the Orion Arm of
| Milky Way galaxy. The universe _and_ the observable
| universe.
|
| This of course has nothing to do with the popular scifi
| concept of parallel universes.
| userulluipeste wrote:
| A better call would have been "nearby _part of the_
| universe ", with "the" being the most important word that
| should not have been left out. It may not have been as
| terse/catchy as "nearby universe", but it would not have
| strayed into controversy (the kind of which we see here).
| dogma1138 wrote:
| It's very much called the local universe not local space
| http://www.astro.wisc.edu/our-science/research-
| areas/extraga...
|
| Space or outer space isn't a term commonly used in
| cosmology which is the field of study of the chronology and
| evolution of the universe.
|
| And in this context it makes perfect sense within 1b light
| years we can observe the universe as it is more or less in
| its current state, so looking at something 100 light years
| away or 1b isn't that different. Once you go past that line
| you begin to go further and further in time so different
| stages within the evolution of the universe take precedence
| over local phenomena.
|
| It doesn't indicate that there are other universes out
| there just due to the speed of light what we can observe
| can be drastically different than what is around us as well
| as what is actually going anywhere else at the current age
| of the universe.
| jhgb wrote:
| You do realize at the very least the significant
| difference between "local" and "nearby"?
| GavinMcG wrote:
| You do realize at the very least that different academic
| fields have developed different lingo, and that words
| therefore mean different things in different settings?
| dogma1138 wrote:
| Can you read the definition? "Local Universe - Studies of
| the nearby universe encompass a region of approximately 1
| billion light years in radius, over which the effects of
| cosmic evolution are small."
| [deleted]
| lmilcin wrote:
| I was about to comment the same.
|
| No, they mean our universe.
|
| Sadly. If title was true it would be much more exciting.
| xvilka wrote:
| Just a weird wording. I believe they meant "in our
| neighborhood".
| bradrn wrote:
| Or possibly 'nearby in our universe'.
| snet0 wrote:
| I know it's a joke but it means nearby universe as distinct
| from distant universe, if anyone is actually confused.
| scott-smith_us wrote:
| ...but then wouldn't it make sense to say something like
| "nearby region of the universe"?
|
| Somehow the word "universe" in the phrase "nearby universe"
| seems redundant (e.g. where ELSE would it be?)
| dghughes wrote:
| Yes the phrasing threw me off too. It's like saying there's a
| room in a "nearby house" when you mean your own house.
| amelius wrote:
| No, "another universe" is a contradiction since if we found
| one, our universe would simply be bigger than previously
| thought and cosmological physics would need an overhaul.
| zzt123 wrote:
| Wouldn't it be fair to consider a causally disconnected
| (relative to us) place to be another universe, at least in
| layman terms? After all, it is expected in a couple trillion
| years that nothing outside the local group will be
| observable.
|
| Who knows how much "disconnected universe" there is. Unless
| that is somehow known, which seems difficult since it is by
| definition causally disconnected.
| flancian wrote:
| Max Tegmark covers this in Our Mathematical Universe.
|
| It's a question of definitions. He makes the argument that
| defining "universe" to mean "our visible universe", that is,
| a radius of around 140B ly, is the most useful; if you assume
| infinite space and infinite matter (which seem to follow from
| the theory of inflation, which has provided explanations and
| predictions elsewhere), there are likely infinitely many
| universes all around following this definition (for other
| visibility scopes).
| flancian wrote:
| Max Tegmark covers this in Our Mathematical Universe.
|
| It's a question of definitions. He makes the argument that
| defining "universe" to mean "our visible universe", that is,
| a radius of around 14B ly, is the most useful; if you assume
| infinite space and infinite matter (which seem to follow from
| the theory of inflation, which has provided explanations and
| predictions elsewhere), there are likely infinitely many
| universes all around following this definition (for other
| visibility scopes).
| stan_rogers wrote:
| Just an unnecessarily pendantic note: the visible
| (observable) universe would be defined as anything that
| emitted radiation that would have reached us, and in an
| expanding universe that means it's considerably larger than
| 14-ish billion light years radius. Conveniently, it works
| out to about 14 billion _parsecs_ , so nobody needs to
| remember another number, they just need to do the
| conversion.
| scott-smith_us wrote:
| This was certainly true when I was a kid, and "universe"
| meant "all existing matter and space (observable or not)".
|
| As a youtube-couch expert on astrophysics, I hear "universe"
| redefined as something like "a bubble of matter and spacetime
| that is 'quarantined' and can never communicate with the rest
| of the cosmos" whenever multiverse theory is discussed.
| ncmncm wrote:
| These are still tens if not hundreds of thousands of light-years
| apart.
|
| It will take how long, a billion years?, for dynamical friction
| to bring them together?
|
| How close do they need to be before gravitational radiation
| begins to carry away enough energy that merging can proceed
| without depending on external mass?
| chasil wrote:
| The article mentions the "final parsec problem," which implies
| that a binary pair will never merge. A three-body arrangement
| is one scenario where a merger can take place.
|
| "Gravitational waves can cause significant loss of orbital
| energy, but not until the separation shrinks to a much smaller
| value, roughly 0.01-0.001 parsec."
|
| https://en.wikipedia.org/wiki/Binary_black_hole#Final_parsec...
| [deleted]
| wirthjason wrote:
| I know this has nothing to do with the article but there's been
| too many global warming news headlines recently and it's making
| me depressed. I read this one and imagined the opening to be...
| > The effects of global warming have produced wildfires,
| hurricanes, drought, and other extreme events at an alarming
| pace. The situation has gone from bad to worse as scientists
| recently discovered three super massive black holes merging
| together in our nearby universe.
| drclau wrote:
| I think it's important we all become aware of the reality of
| the climate crisis. The fact that we aren't yet is one of the
| reasons we have failed to deal with it better.
|
| I was very surprised to find out that some people around me,
| which are software engineers and reasonably well informed
| people, were oblivious to the dangers the climate crisis poses.
|
| To this end, maybe it's important to repeat it many times,
| until it hits everyone.
| zanethomas wrote:
| omg, the universe is going to be sucked into one gigantic black
| hole!
| yashasolutions wrote:
| Three Super-Massive Black Holes get into a bar...
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(page generated 2021-08-29 23:03 UTC)