[HN Gopher] What if Planet 9 is a Primordial Black Hole? (2019)
___________________________________________________________________
What if Planet 9 is a Primordial Black Hole? (2019)
Author : nequo
Score : 87 points
Date : 2023-09-28 14:53 UTC (8 hours ago)
(HTM) web link (arxiv.org)
(TXT) w3m dump (arxiv.org)
| rishav_sharan wrote:
| I always had a layman pet theory that Planet 9 is a BH, and not
| just any BH one but the one who's supernova remains seeded the
| solar system with heavier elements. Sort of like old grandpa
| blackhole looking after his/her small kid.
| sojuz151 wrote:
| But the normal black holes have a mass greater than the sun
| bell-cot wrote:
| Sorry, but no.
|
| A supernova-born black hole (
| https://en.wikipedia.org/wiki/Stellar_mass_black_hole ) would
| be far more massive than the sun - so the entire solar system
| would obviously revolve around it, not the sun.
|
| Also, the birth of such a black hole _is_ a supernova explosion
| - which would not leave any solar-system-forming remains
| kicking around nearby.
| ballenf wrote:
| Question from ignorance: if the planets are "moons" around
| the sun and the sun rotates around P9, how would we know?
| codesnik wrote:
| relative speed against other stars is very much detectable
| by red and blue shift of light. We would definitely know if
| sun revolves around something, meanining changes its
| direction.
| kadoban wrote:
| I think we'd see the paralax being all weird as well.
| bell-cot wrote:
| Yes, and I suspect the parallax anomalies would have been
| noticed a few decades before the redshift / blueshift
| anomalies:
|
| https://en.wikipedia.org/wiki/Stellar_parallax_method#His
| tor...
|
| https://en.wikipedia.org/wiki/Redshift#History
| whalesalad wrote:
| I read the title as Plan 9 and I think it holds up.
| gigatexal wrote:
| Make it a black hole but very big and the 2001 book gets even
| spookier
| cratermoon wrote:
| Planet 9 is Pluto.
| nameless912 wrote:
| Edit: the original comment I wrote was dumb and needlessly
| critical of an article I barely skimmed while on an airplane at 1
| AM. That's my bad.
| [deleted]
| ryanmcbride wrote:
| dw bud I didn't read the paper either
| seiferteric wrote:
| It's not an article, but a scientific paper exploring the idea.
| titzer wrote:
| It's a research paper, complete with a mathematical analysis.
| Take a gander. It's not "non-journalism."
| TheRealPomax wrote:
| There is nothing weird about this paper, the math works, and
| primordial black holes (which is a astronomical term, not just
| a plain English descriptor) are not the thing you're clearly
| thinking of given your rant.
|
| Checking to see if outer planetary motion can be explained in
| terms of PBH and working out the math as part of that is
| perfectly normal astrophysics, and good science. Read the
| paper, it's perfectly fine =)
| 1970-01-01 wrote:
| Launch a probe already! If the anomaly is a planet, ~you've
| discovered a new planet~ If the anomaly is a black hole, then
| ~you've discovered a local black hole~ If there is literally
| nothing there, use the probe for interstellar science.
| andbberger wrote:
| planet nine is not the eye of the universe
| MaxikCZ wrote:
| Any singular probe would needed to know where to go searching.
| Any scanning instruments it could carry we can build and use
| better at Earth (soon Moon [1], fingers crossed). Your idea
| would require a swarm, an array, with Earth as a centre piece,
| effectively forming search beam rotating outwards.
|
| I agree tho, #LaunchTheProbe #NASA
|
| [1] -
| https://en.wikipedia.org/wiki/Lunar_Crater_Radio_Telescope
| chaps wrote:
| "literally nothing there"
|
| 1. Space is big.
|
| 2. Space is REALLY big!
|
| 3. This thing would be tiny.
|
| 4. This thing would be invisible.
|
| Combine these four together and you'll quickly realize just how
| difficult even scoping out the probe's requirements and such
| would be. Would be cool though.
| codethief wrote:
| You might be interested in Ed Witten's paper about this exact
| problem:
|
| "Searching for a Black Hole in the Outer Solar System",
| https://arxiv.org/abs/2004.14192
| chaps wrote:
| Thanks for sharing! Some interesting things --
|
| "And one would like to launch hundreds of spacecraft (at
| least) in different directions so that some would come
| within dozens of AU of Planet 9, rather than hundreds of
| AU."
|
| Their example of a neat-but-good-luck project could
| actually achieve the goal is [1]. The spec requires ground
| lasers that's powered by a 1GW nuclear power plant for
| propulsion. And, "According to The Economist, at least a
| dozen off-the-shelf technologies will need to improve by
| orders of magnitude." [2]
|
| [1] https://breakthroughinitiatives.org/initiative/3 [2] ht
| tps://en.wikipedia.org/wiki/Breakthrough_Starshot#Technica.
| ..
| ansible wrote:
| I think we would be able to detect it. We can navigate
| spacecraft with high accuracy.
|
| If you can get a spacecraft somewhere in the vicinity of a
| black hole of decent mass (like a 10km asteroid equivalent)
| we could probably detect changes in trajectory of the
| spacecraft from the gravitational attraction.
|
| Or, here's an idea, blow out a tonne of radar chaff in the
| vicinity of the black hole and watch for how it disperses via
| radar.
|
| We could also try detecting Hawking radiation that a BH
| should generate, though that might be pretty faint (I have
| not done the math).
| chaps wrote:
| Friend, let me repeat: Space is BIIIIIIIIIIIIIIG.
| p1mrx wrote:
| What if we create a time loop, launch the spacecraft in a
| random direction, and reset the loop if nothing is found?
| chaps wrote:
| We might just find it after 390.03 years!
| codesnik wrote:
| launch where exactly?
| 1970-01-01 wrote:
| That's the key, you absolutely need to design a probe where
| gravity is the guidance system. My take is a primary probe
| containing hundreds of hyper reflective microprobes, which
| scatter for billions of miles into space. After a few
| decades, the primary probe locates where the majority of
| mircoprobes went, and now you steer the primary probe into
| Planet 9's gravity well.
| smitty1110 wrote:
| I think you're underestimating the area you need to search.
| See the wiki page[1]. There's so much space to look near,
| you need a much better guess before you can send any
| probes. A 9k year orbit, that starts at 340 AU, and has a
| lot of uncertainty in all the parameters, just leaves too
| much volume to check naively. And that doesn't even get
| into the fact that there's not enough light out there to
| feasibly find probes from their reflections.
|
| 1: https://en.wikipedia.org/wiki/Planet_Nine
| [deleted]
| 303uru wrote:
| It would be cool, it would also be insanely hard to pin down. It
| would be about the size of a grapefruit but 5-10x the mass of the
| Earth. And it's way-way-way out there. Oh, and it's basically
| invisible. But, if we could find it, pin it down, and send out a
| probe imagine the science we could do!
| ricardo81 wrote:
| Given that a huge amount of mass in the universe is unaccounted
| for with current models, the idea of masses unaccounted for like
| this surely are still reasonable possibilities.
| didgeoridoo wrote:
| This is called the MaCHO (massive compact halo object)
| hypothesis, and it's pretty close to dead based on the evidence
| we've been able to collect.
| empyrrhicist wrote:
| It wouldn't have to be the main explanation for dark matter
| though to still be a phenomena. I agree that the evidence is
| pretty clear that it's not the main driving factor.
| marcosdumay wrote:
| Yes, and there are different levels of "close to dead" with
| this one being in a very much dead one...
|
| But still, every hypothesis for explaining dark matter is
| close to dead right now. Theoreticians reopening closed cases
| is a good thing.
| jquery wrote:
| Only "dead" in the sense it can't explain all the missing
| matter.
| bashinator wrote:
| I like Occam's razor as much as anyone, but it really is
| starting to seem like there might be more than one cause of
| the phenomenon called dark matter. My understanding is that
| WIMPs (weakly-interacting massive particles) are in trouble
| too, as the LHC has failed to produce them in the expected
| energy regimes.
| chorsestudios wrote:
| Or perhaps it is more evidence that a variant of MOND
| theory is responsible for our observations and there is
| no dark matter.
| slowmovintarget wrote:
| No current MOND theories account for the state of our
| observations of the Cosmic Microwave Background, or the
| ratios of "things" left from nucleogenesis. The biggest
| gotcha for MOND is there's no way to reverse the
| direction of gravity, which would be needed to explain
| large scale structures without dark matter. (With dark
| matter, you see things moving toward where the matter is.
| Absent dark matter, you see things moving away from where
| matter is, because there is only ordinary matter.)
| SAI_Peregrinus wrote:
| MOND theories _are_ dark matter theories. They posit
| explanations for the observed behaivor, that behavior _is
| dark matter_.
| pndy wrote:
| https://news.ycombinator.com/item?id=21078068 - 4 years ago, 346
| comments
|
| https://news.ycombinator.com/item?id=23993716 - 3 years ago, 119
| comments
|
| https://news.ycombinator.com/item?id=28167058 - 2 years ago, 153
| comments
| sigmoid10 wrote:
| And it's still grasping at straws. The idea of a PBH as planet
| 9 itself is somewhat sound, but this particular paper assumes
| not just a significant population of MACHO dark matter, but
| also an additional WIMP-like particle DM that would produce a
| detectable signal. Is it theoretically possible? Yes. Would it
| be amazing to find evidence for it? Of course. Is it likely to
| happen? No. And we probably won't get a conclusive answer to
| this either way until we can easily send probes outside the
| solar system or at least have enormous telescopes on the moon's
| surface. Until then this topic is mostly an easy path to
| publishing papers to get tenure.
| ToDougie wrote:
| Question for you -- how do we protect enormous telescopes on
| the moon's surface?
| andrewflnr wrote:
| Probably pretty similar to how JWST is protected, which is
| to say not at all, but with enough redundancy to take a
| couple hits.
| PaulHoule wrote:
| Why do you mess around on the surface of the moon when
| something free floating can be much larger with light
| construction?
| huthuthike wrote:
| You can't just make something free floating bigger and
| bigger without introducing new issues. In particular, as
| objects get larger in zero gravity, it becomes harder to
| dampen oscillations. The lighter the object is the more
| problematic these oscillations become. You also run into
| issues with thermal expansion.
| pyinstallwoes wrote:
| Can you expand the oscillations part? I find that
| interesting.
| adhesive_wombat wrote:
| Basically, things that are bolted tightly onto 73 million
| million million tonnes of rock tend not to flop around
| very much. It's a near-perfect "momentum sponge".
|
| Things in virtual freefall that can flex (and everything
| can) do so in response to forces (e.g. thrusting, but
| also heat stresses, say), and will continue to do so if
| they start unless you take care to damp them and dump
| them into heat. There's nowhere for the vibration to "go"
| unless you design one in. Sometimes the structure of the
| craft itself has enough damping for practical purposes,
| especially when you take care to isolate large vibration
| sources (the ISS has a Sorbothane damper for the
| treadmill, for example), but when your big floppy (i.e.
| light) mirror surface has to stay put on a nanometre
| scale, it's not so simple.
|
| It's a bit like the difference between a tuning fork
| glued down flat to a table and one hanging from a string.
| pyinstallwoes wrote:
| By any chance do you know the history of these solutions
| and what what went before understanding this or was it
| already calculated and known far in advance of needing to
| account for it?
|
| In the sense of building things that last in space.
| adhesive_wombat wrote:
| I don't know specifically. I imagine that a lot of the
| concepts came from naval architecture (sloshing of fuel,
| water and cargo has sunk many ships through the ages, for
| example, as well as hull resonances called "springing")
| then aviation (e.g. "flutter", where the wings oscillate,
| has destroyed planes) and space and missiles (again with
| the fuel sloshing, and other modes like pogo oscillation
| where the vibration feeds back into the engines and self-
| reinforces). Some concept of it also in civil
| engineering: the Tacoma Narrows bridge is the canonical
| example.
|
| Fundamentally they're all somewhat similar in that
| there's a flexible and/or sloshing thing that doesn't
| have a huge mass to hand. Spacecraft deployed in space
| usually have smaller forces on them (no air or water and
| the engines are stopped) but are also much flimsier due
| to being ultra-light. Telescopes are even worse as even a
| tiny vibration can ruin the usefulness of the optical
| paths.
| chaps wrote:
| Objects have a resonant frequency and will jiggle in
| strange ways. The larger the object, the larger the
| possible jiggles. The larger the jiggles the larger the
| destruction.
| pyinstallwoes wrote:
| Are you saying any object in space will naturally be
| resonating with itself at some frequency or that by
| proximity and interaction to another object it may cause
| resonance on another and therefore cause it to jiggle in
| strange ways.
|
| Thanks!
| chaps wrote:
| The latter. Basically [1] but not as exaggerated. Think
| of things like screws shaking loose over time which leads
| to structural failure. Plus, no easy means to release
| that energy like you would when you're attached to a
| planet.
|
| [1] https://www.youtube.com/watch?v=XggxeuFDaDU
| jpollock wrote:
| Look into "Chaos Theory", "Control Theory" and "Damping".
|
| In particular, consider how you would damp an undesired
| movement by a satellite. A naive approach would be to
| apply thrust in the opposite direction. However, the
| control can't be exact, leading to thrust -> thrust <-
| over and over, eventually to the measurement limit of the
| thruster's control.
|
| With a large mass, it's replaced with a spring, and
| converted to heat.
|
| https://en.wikipedia.org/wiki/Damping
| pyinstallwoes wrote:
| Hm, sounds like a fun oscillator algorithm to try for a
| synthesizer!
| giantrobot wrote:
| And torsion effects when trying to move structures or
| reorient the whole structure.
| dividedbyzero wrote:
| Make it very modular and have little robots scurry over
| with a replacement module if one gets hit by a
| micrometeorite or otherwise fails.
| LASR wrote:
| Do you play Factorio? I'm not sure how much of that is
| actually feasible.
| caymanjim wrote:
| Protect them from what? We have enormous telescopes in
| space already. The moon is safer than where Hubble and JWST
| are now.
| dwaltrip wrote:
| Wouldn't the moon's gravity pull in more material,
| putting a telescope at higher risk?
| DrBazza wrote:
| Correct. A large hill/small mountain's worth of debris
| hits the Earth every year. That includes micrometeorites
| that without an atmosphere, would pepper the Earth's
| surface.
|
| It's also the reason why any Moon base would be buried
| under layers of regolith to protect it. Glass domes on
| the moon are sci-fi fantasy.
| OkayPhysicist wrote:
| Since the moon is tidally locked, the side facing Earth
| and its far more massive gravity well would experience
| vastly less debris. It'd be a boring place to build your
| glass domed moon base, but I don't think it would be
| completely infeasible. Especially if it was built in a
| depression in the landscape, the approach angles would be
| greatly limited.
| ceejayoz wrote:
| The ISS gets hit with micrometeorites pretty regularly,
| without any regolith to protect it. Micrometeorites make
| correspondingly micro holes, which in said glass dome are
| patchable.
|
| A 2mm hole in a Soyuz docked to the station was fixed
| with a bit of Kapton tape and some epoxy, and was
| detected by a _very_ small pressure drop in the crew
| spaces.
|
| _Larger_ rocks are more of a problem, but quite rare.
| Your dome is much more likely to get smashed by someone
| mixing up the pedals in a rover.
|
| https://www.livescience.com/how-many-moon-meteorites
|
| > "if you pick a square kilometer patch of ground, it
| will be hit by one of those pingpong-sized meteoroids
| once every thousand years or so"
|
| We've landed in visibly quite smooth areas; for example:
| https://www.flickr.com/photos/nasa2explore/48299974871
| wizzwizz4 wrote:
| That's not really how gravity works. Gravity is time-
| symmetric, so it doesn't have the kind of "sucking"
| behaviour that vacuum cleaners or river valleys on Earth
| have.
| dwaltrip wrote:
| Gravity doesn't suck, but it does exert a force. It's
| called a gravity well for a reason :)
|
| Hence my question.
| psychlops wrote:
| So....the telescopes aren't at higher risk?
| wizzwizz4 wrote:
| Depends where you put it. You have to consider the
| trajectories of the material that could pose a threat.
| Rule of thumb: if the orbital configuration hasn't
| changed for a few thousand years, look at the craters.
| PaulHoule wrote:
| It's the state of physics today.
|
| Einstein was able to predict how light was bent around the
| Sun and Eddington confirmed it right away, it was like Babe
| Ruth pointing to the stands and hitting a home run.
|
| The lag between a phenomenon being predicted or model sped by
| theoreticians and actually observed is getting longer and
| longer in fundamental physics, I mean neutrino oscillations
| were hypothesized in 1957. The fact that you can't get a
| Nobel prize posthumously means a theoretician might never get
| a Nobel in fundamental physics ever again. So they've got to
| do something speculative like this to have a possibility of a
| legacy unless you are Ed Witten and can convince people you
| are a genius without any appeal to experiment whatsoever.
|
| It does point to a programme of observations to try to catch
| P9 in a gravitational snare and look really hard in that area
| with all kinds of telescopes and has the double prize of
| possibly finding non gravitational evidence for DM.
|
| Personally I think interstellar travelers would use FFPs as a
| resource but the question of how a civilization that lives on
| an FFP (imagine something like Pluto cut up into small
| (5000km) ringworlds) finds the next one seems pretty tough to
| me.
| irrational wrote:
| Except, I've never heard of Ed Witten and I'm pretty sure
| people had heard of Einstein during his lifetime.
| nonameiguess wrote:
| I didn't recognize the name but figured he was the guy
| who came up with M-theory, and sure enough, that's him. I
| believe the point here is achieving a legacy within the
| academy, not being known in pop culture. I think there's
| a lot of ambivalence about his influence, but it's
| definitely been large. His papers revealing how the whole
| superstring thing can be constructed in a way that
| doesn't blatantly contradict observed reality diverted at
| least a generation of theorists into the search for the
| holy grail of a theory of everything, but because we have
| no means of experiementally probing anything at the
| scales involved, it has also turned a generation of
| physicists into algebraic topologists largely divorced
| from experimental practice.
|
| You can think of him maybe like the Velvet Underground of
| physicists. They never achieved much popularity
| themselves, but virtually every rock band of the past 40
| years that has gotten popular cites them as an influence,
| and many artists would rather have that as a legacy than
| popularity. Similarity, I think a lot of physicists would
| rather be well known and influential to other physicists
| rather than becoming the next Michio Kaku or someone else
| who shows up on television a lot.
| PaulHoule wrote:
| In fundamental physics there are few very hard problems
| that are unambiguously real problems of which I would
| name: (1) what is dark matter? (2) what is the mass of
| the neutrino? (3) why is there so much matter in the
| universe and not so much antimatter? (4) Quite a few
| strange things about very high energy cosmic rays
| (Notably 2 is not "physics beyond the standard model", it
| is "a missing piece of the standard model")
|
| A lot of other questions might not really be "real" in
| various senses like: it's interesting to speculate that
| the interior of a quantum black hole is entirely unlike a
| classical black hole but you're not going to have anyone
| take a look and come back and tell us and we can just
| speculate if something kills you at the apparent horizon
| or not (so many bad ideas including the idea there is an
| "information paradox" come out believing the classical
| picture of the black hole interior which is probably just
| wrong), the "hierarchy problem" and various allergies to
| fine tuning are really human preferences or things like
|
| https://en.wikipedia.org/wiki/Anomalous_magnetic_dipole_m
| ome...
|
| where between the experimental errors and the possibility
| that theorists aren't quite doing the math right and that
| the answers to 1-4 might account for any difference (I
| wouldn't be surprised it is if 1-4 _have the same answer_
| )
|
| The experiments for (1) and (2) are devilishly hard,
| there are accelerator observations of CP violations that
| are a line on (3), but the cosmic scale of (3) and (4)
| imposes its own difficulties.
|
| Really there are a lot of grad students chasing a
| moderate number of postdocs who hope to get one of very
| few permanent positions and out of it all there is a tiny
| amount of glory to be had.
|
| Condensed matter physics lacks the cosmic difficulties
| but it isn't dramatically better. How superconductivity
| works in cuprates
|
| https://en.wikipedia.org/wiki/High-
| temperature_superconducti...
|
| is still quite mysterious after 35 years. I would name
| check Mark Newman as a standout in the "complex systems"
| area but the real accomplishment he made in my mind
| wasn't finding an explanation for "universal" power laws
| in complex systems but instead proving we didn't know
| what we were doing when we plotted our statistics on log-
| log paper and drew a line... And he published about that
| _in a statistics journal_ not a physics journal but it 's
| OK because the paper is in arXiv anyway.
| codethief wrote:
| > I didn't recognize the name but figured he was the guy
| who came up with M-theory
|
| As it so happens, he's also the guy behind this paper:
| "Searching for a Black Hole in the Outer Solar System",
| https://arxiv.org/abs/2004.14192
|
| :-)
| philipov wrote:
| Wow, really? You've never heard of Ed Witten?
| irrational wrote:
| I have never read or heard the name in my 50+ years of
| life. I haven't googled him, so I still have no idea who
| he is.
| nyssos wrote:
| One of the most significant living physicists, and the
| only one to have won a Fields Medal (arguably the most
| prestigious award in mathematics). Known for Chern-Simons
| theory, contributions to AdS/CFT, and of course M-theory,
| among many other things. Physicists breaking out into
| mainstream culture for anything other than popsci is not
| really a thing that happens anymore, but he's extremely
| well-known among academics.
| david-gpu wrote:
| Has he predicted anything that has ever been observed?
| Because in my layperson's eyes that's the difference
| between math and theoretical physics.
| whatshisface wrote:
| Predicting a truly novel observation is rare, and has
| always been rare. Mostly what physicists do is clarify
| our understanding of things we've already observed, and
| extend techniques to handle cases that are more difficult
| to calculate than the cases that are presently considered
| tractable. For every one coulomb's law or socks-cling-to-
| stuff-after-drying effect there are a million papers
| about figuring out how to calculate the electrostatic
| fields of various configurations.
|
| The vast majority of what theoretical physicists do is
| "just math" except that unlike math, it's aimed at a
| problem posed by nature rather than a problem imagined up
| on the basis of what seems most interesting.
| thehappypm wrote:
| I haven't either.
| swader999 wrote:
| And yet we can't escape debating this. Each time this is posted
| we get sucked in.
| pyinstallwoes wrote:
| Do thoughts/ideas have inertia?
| swader999 wrote:
| They create reality.
| pyinstallwoes wrote:
| That contemplation definitely has layers to it.
| A_D_E_P_T wrote:
| For what it's worth, a primordial black hole Planet 9 is the plot
| of Stephen Baxter's new book, "Creation Node," which was released
| about a week ago. (Well, it's the seed of the plot, and then
| things take a few turns. It's an interesting book!)
|
| As an aside, it takes the first visitors about 30 years to reach
| it, and they've got better tech than what's available to us
| today. It's pretty far out.
| wawwow wrote:
| [flagged]
| readyplayernull wrote:
| Shouldn't this imply that many star systems also have small
| blackholes orbiting them, even in between other planets? Just
| like we found that there are many other earths. If something is
| possible it will happen again and again in the vast Universe.
| lyind wrote:
| Every inhabited system should have a stellar trash can nearby.
| :D
| perihelions wrote:
| This is a very "dense" paper. So: if dark matter is something
| that annihilates itself, that's a two-particle interaction, so
| its macroscopic rate scales as density squared r2. If there's a
| black hole in the solar system, the dark matter halo immediately
| surrounding it would be compressed far denser than around a
| normal object, so it'd have a much brighter annihilation signal.
| Nothing's known about dark matter annihilation. They speculate,
| if its cross section is large enough, this annihilation could be
| observable by gamma-ray telescopes like Fermi or the upcoming
| CTA. And that would distinguish a black hole from something else.
| That's all I could understand. It'd be a discovery of a solar
| system black hole, and new dark matter physics, two-for-one.
|
| I'm curious what math led to that funny exponent in eq.(5): r(r)
| ~ r^{-9/4}.
| dmix wrote:
| > or the upcoming CTA
|
| I'm guessing this refers to
| https://en.wikipedia.org/wiki/Cherenkov_Telescope_Array ?
| kurthr wrote:
| Just a thought, if a black hole that close were discovered
| there would be another space race to get there. It just sounds
| so cool to the politicians (who've seen the movies) that any
| scientist would have no problem convincing them to loosen the
| purse strings.
| cgriswald wrote:
| For reference, if it exists, it's _closest_ approach to the
| sun is more than six times farther than Pluto's furthest
| approach and it took New Horizons nearly a decade of travel
| time to reach Pluto. A probe would be a decades long project.
| Sending humans would be effectively impossible.
| pierat wrote:
| > Sending humans would be effectively impossible.
|
| I can think of PLENTY of billionaires to send :)
| kzrdude wrote:
| Do we even have a guess where it is right now? The orbit is
| huge, so the search area is ginormous, even if we would
| know approximately where in its orbit it would currently
| be.
| MaxikCZ wrote:
| Given such a scientifically interesting object so close to
| us, I can't imagine any other reality than massive world-
| scale spending to not just "get there first", but first to
| perform other low-hanging publicity stuns (think first
| space walk, first moon landing). The fact you _can't_ even
| land there is a massive accessibility boost. The thought is
| so exciting. The understanding of physics would be destined
| to leapfrog, distinctively changing humanity, and nature.
|
| Can anyone imagine something concrete?
| dpe82 wrote:
| Related; it's instructive to learn that a significant
| motivation behind the Apollo program was its national
| defense implications: https://youtu.be/xZFnTBSRKcg?t=137
| ClumsyPilot wrote:
| First man to die by black hole?
| yellowapple wrote:
| "First human to experience spaghettification firsthand"
| would be quite the honor, I suppose.
| [deleted]
| peteradio wrote:
| > I'm curious what math led to that funny exponent in eq.(5):
| r(r) ~ r^{-9/4}.
|
| Renormalization.
| autokad wrote:
| planet 9 is Pluto
| naikrovek wrote:
| aren't papers supposed to advance scientific knowledge?
|
| this seems to be a paper describing something that could be true,
| probably isn't, and doesn't advance science as a whole at all.
| mxkopy wrote:
| it's arxiv chill
| nequo wrote:
| The paper got published in Physical Review Letters in 2020:
|
| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12.
| ..
|
| It advances scientific knowledge by providing a testable
| prediction. The prediction can be used to collect data and
| determine whether there indeed is a black hole orbiting the
| Sun beyond Neptune.
| bifftastic wrote:
| It would suck
| TheRealPomax wrote:
| "clever joke" aside: why? Primordial black holes are a rather
| completely different category from super-massive black holes,
| with masses theorized as small as a single plank mass. Not a
| lot of sucking happens when PBH are involved.
| NoMoreNicksLeft wrote:
| Wouldn't a Planck mass black hole have evaporated
| immediately?
| aldousd666 wrote:
| Yes it would have. Planck mass black holes aren't even
| mentioned in this paper, I'm confused as to where this came
| from. PBH = 'primordial black hole' meaning formed at the
| beginning of the universe, not Planck Mass Black Hole,
| which, you're right, would have evaporated instantly.
| TheRealPomax wrote:
| Things are weird when dealing with Planck quantities, so
| "almost certainly", but only almost. The main point was
| that PBH are generally small and look nothing like what
| people think of if they've only heard of black holes from
| popular science and sci-fi.
| short_sells_poo wrote:
| I suppose given the enormous force gradients around even
| a basketball sized black hole, it could potentially be
| turned into one of the most efficient ways to convert
| matter into energy by building an accretion disk around
| it?
| NoMoreNicksLeft wrote:
| If you get the timing right, you could just shoot those
| at the enemy near the speed of light, and they would
| explosively decay right as they arrived. If the mass was
| low enough, they'd be effectively invisible, wouldn't
| they? Screw antimatter bombs, these would be pretty
| horrific. Instead of kilograms' worth of matter-to-energy
| conversion, you could have hundreds of tons worth. Wonder
| what that would be in megatonnage?
| horsellama wrote:
| Fig1 in the paper shows the exact size of the PBH: > FIG. 1.
| Exact scale (1:1) illustration of a 5M[?] PBH. Note that a
| 10M[?] PBH is roughly the size of a ten pin bowling ball.
| harha_ wrote:
| Yes it's a joke, but in fact it would be like winning in
| lottery, once again, to have a black hole this "close" to
| earth.
| nashashmi wrote:
| I am convinced it is not a planet.
|
| It is the gravitational drag of a moving solar system moving
| around in a spiraling milky way galaxy around a theoretical black
| hole in the center.
| ToDougie wrote:
| https://binaryresearchinstitute.org/bri/ We're in a binary star
| relationship with
| https://en.wikipedia.org/wiki/Barnard%27s_Star
| nashashmi wrote:
| "The alternative explanation advanced by the Binary Research
| Institute is that most of the observable is due to solar
| system motion, causing a reorientation of the earth relative
| to the fixed stars as the solar system gradually curves
| through space (the binary theory or model)."
|
| Glad to know there is a similar theory being proposed.
| Apocryphon wrote:
| I love precession and ancient knowledge, thank you for that
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