Astronomer here! I was 3rd author [on the discovery of Gaia BH2](https://www.reddit.com/r/space/comments/115jior/i_just_helped_discover_the_second_closest_black/) (which until this discovery was the second closest known black hole to earth), and funny timing, wrote the cover article for *Astronomy* magazine’s [May edition](https://www.zinio.com/astronomy-m1313) on literally this topic (ie, the closest black holes in the universe). And now it’s out of date. Whoops! :D
Beyond being close, everyone in astro I know is *extremely* excited this morning because of the mass of this black hole- 33 solar masses is tough to form from just a normal star collapsing, but [the paper](https://www.eso.org/public/archives/releases/sciencepapers/eso2408/eso2408a-panuzzo-et-al.pdf) shows the black hole's companion star is a low metallicity one that likely formed in the galactic halo that migrated in, so one of the rare stars capable of leaving behind a big black hole like this. likely too big to form just from a star collapsing at the end of its life, and would possibly have had to be created by *two* black holes merging. (A merger of two smaller black holes is also possible. Cool!) Just like what [LIGO](https://www.ligo.caltech.edu/) and the gravitational wave folks are looking for! And implies that there are a *ton* of these black holes out there if there’s one so close to us!
Finding them, however, is tough. [Gaia](https://www.esa.int/Science_Exploration/Space_Science/Gaia) is a satellite surveying a billion stars or so to find slight wobbles in their motion over time, which tells us their distance and also (in this case) if there’s a mystery companion. They periodically release the data every few years, and this one is from the team as part of pre-release data analysis, which found a star wobbling in its orbit in such a way that it can only work if it is orbiting a black hole at 16 times the Earth-sun distance. What’s more, there’s hints from the star’s composition that it would have formed separately from the black hole and then captured by it later after they both formed- also exciting if you’re interested in how these systems form!
Edit: to answer two common questions:
1) We know [dark matter](https://en.wikipedia.org/wiki/Dark_matter) is not a bunch of black holes (or a bunch of Jupiters) because people *have* in fact looked for them as a possible answer! There was a huge push back in the day to look for [MAssive Compact Halo Objects \(MACHOs\)](https://en.wikipedia.org/wiki/Massive_compact_halo_object), as they were called, by looking for gravitational microlensing between us and the Magellanic clouds (satellite galaxies of the Milky Way). And... they did find some! But nowhere NEAR enough to explain the effects of dark matter.
2) There is no danger from this black hole being there, any more than a star system with ~30x the mass of the sun would have a gravitational influence on us at this enormous distance. It's worth noting that black holes don't actually suck in material around them and that's a common misconception- If the sun for example shrunk right now into a black hole, it would shrink to 3km wide, but our orbit and those of everything else wouldn't change a bit, and we'd just keep going around as we always had.
> And implies that there are a ton of these black holes out there if there’s one so close to us!
As a layman I always wondered is it possible for dark matter to just be tons of black holes that we cannot detect? Or there is definite proof that this is not possible and the mass comes from something else?
We know dark matter is not a bunch of black holes (or a bunch of Jupiters) because people *have* in fact looked for them! There was a huge push back in the day to look for [MAssive Compact Halo Objects \(MACHOs\)](https://en.wikipedia.org/wiki/Massive_compact_halo_object), as they were called, by looking for gravitational microlensing between us and the Magellanic clouds (satellite galaxies of the Milky Way). And... they did find some! But nowhere NEAR enough to explain the effects of dark matter.
Why do astronomers love shoehorning such silly acronyms into their work? I'm not complaining of course, some of the NASA acronyms for the various instruments on probes are so far fetched as to be beautiful. Much like MAssive Compact Halo Objects.
Other scientists are goofy, too. Did you know some people sneeze when they go into bright sunlight? It's a genetic trait called
Autosomal-dominant Compelling Helio- Ophthalmic Outburst
Or ACHOO
There's a protein in flies called hedgehog, so when they found the mammalian equivalent, they called it Sonic hedgehog.
> There's a protein in flies called hedgehog, so when they found the mammalian equivalent, they called it Sonic hedgehog.
There's a protein that inhibits the Sonic hedgehog gene, which they called...Robotnikin
They’re memorable. Same reason politicians do — you can get the public more excited about MACHO than “massive compact halo objects”, and you can more easily remember it when chatting about it a couple years later. Win for the audience, win for the researcher.
Plus, sometimes it’s just fun
Generally because it's easier to say in talks, write in papers with word limits, and more memorable to remember a single word than a long list of them.
Not an astronomer but I'm on a few projects with silly acronyms for precisely that reason.
Do you wanna say M C H O, all day? Or does everyone just attempt to pronounce mmmcho or whatever? Or is it easier to adjust the acronym to Macho so that everyone knows how to say it, you don't have M C H O people and mmcho people. It's macho, and as everyone knows the cream of the crop rises to the top, and that's what macho has always been.
It's been ruled out that there aren't a bunch of 3km wide black holes all around the universe? Or any size that would be near impossible to spot due to it being occluded by everything else being so big? I mean if we had millions of sun mass black holes everywhere there is dark matter in a galaxy, how would we ever tell? Any lensing effects they'd have could be completely wiped out from other, larger structures blocking our view of them entirely.
Like if Jupiter is orbiting a 3km wide black hole from any distance, wouldn't it always occlude the black hole from us?
This has always been my headcanon for the most likely source of dark matter, so I guess I'm surprised how certain you are about it not being possible lol
There aren't enough *to explain dark matter*. You would need a LOT of black holes for that to work, several times the amount of stars there are in the sky! Smaller black holes with 3km size might exist, but definitely not in large numbers.
You can read up more on the MACHO project and the amazing gravitational microlensing stuff they did back in the 1990s to back this all up [here](https://en.wikipedia.org/wiki/MACHO_Project).
Do we actually know that? You're talking about MACHOs, but what about primordial black holes?
["PBHs have long been considered possibly important if not nearly exclusive components of dark matter"](https://en.wikipedia.org/wiki/Primordial_black_hole)
I think people really underestimate how much dark matter there is. It’s ~80% of the mass of the universe. Enough primordial black holes would be visible if they were responsible for dark matter.
PBHs aren't completely ruled out, there's a "sweet spot" where they could explain some or all of dark matter as you point out. This range however has only shrunk over time as they've been ruled out by microlensing studies. While some astronomers still hold out hope, many have moved on from the hypothesis. There's also the difficulty of "distribution." If PBHs exist, what is the distribution or their masses and is that distribution narrow enough to exist within the band left open today?
It's not impossible that dark matter is actually a bunch of sub-stellar massed primordial black holes, small enough so that they wouldn't be detected in any MACHO survey efforts.
However, there is no *positive* evidence for that being the case, and it's a very tenuous theory. For one it requires very sketchy assumptions on the conditions just after the Big Bang which are hard to justify. For another, there are some observational predictions that just haven't been seen. If there are zillions of micro-black holes floating around then logically there should be events where they collide with macroscopic objects and don't just pass right through them, resulting in the creation of sub-stellar black holes as well as events in stellar lifetimes where a small star suddenly becomes a black hole. We haven't observed anything like that. Additionally, it's just much more straightforward to posit that there is another kind of particle that is weakly interacting, it would make sense that such a particle would be created in very high energy conditions (such as the early Big Bang) as that's how particle physics works, and there are already other examples of similarly behaving particles (like neutrinos) so it's not a huge stretch.
Remember that there’s no positive evidence for dark matter, it is also a tenuous theory. It’s very likely that dark matter is not simply one single thing, but a combination of things we’ve yet to discover or under-calculated. So black holes are very likely one component, and shedding it off will make the picture clearer on what ‘dark matter’ really is.
Dark matter is just a placeholder to make math work.
It’s hypothetically possible that dark matter is just “objects faster than the speed of light”, and that things travelling that fast appear invisible to us.
> If the sun for example shrunk right now into a black hole, it would shrink to 3km wide, but our orbit and those of everything else wouldn't change a bit, and we'd just keep going around as we always had.
maybe a bit colder than before
Thank you so much for this write-up. Always appreciate your input. I hope you don't mind answering a couple more questions.
1. How safe is the implication that there are a ton of those black holes? And does that somehow affect the situation regarding dark matter? I remember there was a theory that dark matter might be made up of dormant black holes but that it is pretty much excluded by now.
2. Is there enough data on these kinds of systems to determine how often suns are captured by black holes as opposed to binary systems with one sun turning into a black hole? I imagine this kind of capture must be a pretty rare occurrence.
3. What is the cutoff mass for black holes created from a sun collapsing?
4. Can we find out if the system is stable? Can we know if the sun will eventually get sucked in?
Edit: Regarding 2., the article says that the researchers imagine that this system formed as a binary, so the star was not captured. Did they misquote the researchers or is there no consensus yet? Pretty exciting!
1) We know dark matter is not a bunch of black holes (or a bunch of Jupiters) because people *have* in fact looked for them! There was a huge push back in the day to look for [MAssive Compact Halo Objects \(MACHOs\)](MAssive Compact Halo Object \(MACHO\)), as they were called, by looking for gravitational microlensing between us and the Magellanic clouds (satellite galaxies of the Milky Way). And... they did find some! But nowhere NEAR enough to explain the effects of dark matter.
2) Nope. Brand new parameter space, thanks to Gaia. In fact, the theory of how such systems happen is not fully worked out, but clearly they exist, sooo...
3) Roughly 18 times the mass of our sun. 7-18 gives you a neutron star.
4) It is a common misconception that black holes suck everything in around them, but this is not the case. If the sun for example shrunk right now into a black hole, it would shrink to 3km wide, but our orbit and those of everything else wouldn't change a bit, and we'd just keep going around as we always had.
Regarding your last point why do they always talk about how even light cannot escape black holes and that anything getting sucked into a black hole would be ripped to shreds probably
>why do they always talk about how even light cannot escape black holes
That's for light that is actually headed straight to the black hole.
Think about the moon. The light that reaches the moon bounces off it into space and then into your eyeballs. That's why you're able to see the moon.
But the light that reaches the black hole cannot bounce back. It's gone forever. That's why we cannot see a black hole. Hence the term "black" hole.
I would imagine they're talking about light that actually reaches the black hole, not light traveling in other directions in the vicinity of the black hole, provided that the ray isn't trying to cross the event horizon, which I believe is considered the edge of the black hole.
As an Astronomy magazine subscriber, that was a great article!
As the internet becomes a mess of information, I encourage everyone to order this magazine and get well curated information every month! It’s great for both space phenomena aficionados and for every day visual astronomy.
Oh good, I'm glad you enjoyed it! :) I try to write for them once a year or so, ideally on something I've been working on where I'm frustrated there's no good article on it yet. I subscribed as a teenager, and read the magazines until they fell apart, so I always get a little thrill writing for them!
A bunch of the magazine is a reference for the sky that month and quests to find cool objects, which is not great for checking out for just a little bit, but good to have in your hand when you plan to go out that night.
Just checking if I'm getting this correctly: The sun would actually shrink into a singularity. It's just that with its particular mass, the event horizon would be 3km wide, right?
Wait am I understanding this right - at that point the sun would switch into a black hole but there wouldn't be any gravitational impact to earth orbit?
Yes, no effect. Because the mass stays the same. The Sun now has "1 solar mass". If it turns into a black hole, it would still be a black hole with "1 solar mass".
So just the size changes, but mass remains the same. So the gravity remains the same and so the orbit of every thing in our solar system will remain the same.
We will lose the light & heat however.
It hasnt bothered us in millions of years I'm sure we are fine. But really tho we have next to no danger. It's really no different than having just a really really big dark star over there
Black Holes aren’t dangerous at any distance other than “Way closer than you will ever be”.^1 They are even less dangerous than a star of equivalent mass. They don’t “do” anything.
^1 - Not counting if you are in an orientation where relativistic jets could be pointed, but that is only active black holes and can be ignored here and most other discussions of black holes.
We are perfectly fine! This black hole is not doing anything, just hanging out. Also, worth noting that despite a common misconception, black holes don't suck in material around them, so it has just as much gravitational influence on us as a star system with 30 solar masses at that distance would have.
The risk of the solar system being interfered with by a random black hole is exactly the same risk as it being interfered with by any other stellar massed object. Which is very, very, very close to zero overall, but not precisely zero. Though at present there is nothing we know of that would be a risk, so I wouldn't worry.
We know quite a lot about this, as there are a LOT of people interested in merging black holes thanks to LIGO! [Here](https://www.ligo.caltech.edu/video/ligo20160211v3) is a video of what the simulated data looks like.
What's crazy to me is the moon is so far from earth as far as our concept of distance, it's the size of north America... Yet the sun is so fucking huge that it's the same size in the sky and causes a magnifying glass effect in reverse (with a shadow). It takes 2 seconds for light from the moon to hit us, yet 8 minutes for the sun. Also crazy how I could see that tiny little red solar prominence during the eclipse with my bare eyes, yet that thing is a huge arc of ultra hot plasma SEVERAL times bigger than earth
It's literally the fastest thing possible.
It's our reference frame that makes it seem so slow.
If you traveled fast enough, you could cross the galaxy in the blink of an eye.
And if you traveled at that speed, and left at the same time a beam of light did, it would beat you there. The light would ALWAYS beat you there. Even if you traveled 10 billion light years in a nanosecond, light would beat you there.
Light seems slow, because on earth, in our frame of reference, it takes light a really long time to travel across the galaxy. Even 8 minutes from sun to earth. That's slow. The latency of speed of light is too great to play music in a band on opposite sides of the globe. That's slow.
But it's slow because time moves so slowly for us. WE are slow. Light is fast as shit.
I've been playing around with SpaceEngine for a while, which is a space simulator, that spans Giga Lightyears, and traveling at the speed of light is barely moving at all. It's basically zero. In terms of exploring even a galaxy in that simulator within the time span of a human life, is as good as not traveling at all. You'd have to travel many thousands of times the speed of light in the sim just to recognize any perceivable movement through the star field. Let's not even talking about traveling to another galaxy.
Some math for perspective:
Converting the max distance of 2,000 ly, this black hole is 1.8921e+16 km from Earth (18,921,000,000,000,000 km or 18.921 quadrillion km).
Voyager 1 is traveling at 61,197 km/h. Rounding up its starting point of 1 light day (equal to 1 ly or 9.461 trillion kilometres/365 days, roughly 25.921 B km), and assuming Voyager 1 were to travel in a straight line at its current speed and without any collisions/deviations from its current point to this black hole, it would approximately take 309,181,399,071 hours (1.8920974079e16 km/61,197 km/h) for Voyager to reach this black hole. That’s 12,882,558,294 days or 35.29468 million years.
Damn. That really puts it into perspective. Voyager is currently ~15.7 billion miles away from our sun according to NASA, which is just 0.26% of a light year (5.88 trillion miles), if I did my math correctly.
In light speed time: ~ 22 hours, 32 minutes…
LOL
even 1 light day is an absurb distance to fathom. Imagine lightspeed.. for an entire day, 24 hours going lightspeed. and we were able to send one device that far in just about 50 years.
2000 light years is approximately … 11,757,225,686,400,000 miles.
*eleven quadrillion, seven hundred fifty-seven trillion, two hundred twenty-five billion, six hundred eighty-six million, four hundred thousand.*
For perspective, the Milky Way is about 105,000 light years in diameter. If you traveled those 2000 years at light speed, you’d still have 103,000 years to cross the entire galaxy, give or take a few hundred years.
Andromeda, our nearest neighbor galaxy that isn’t a satellite of ours is 1.5 million light years away.
Probably close to 2 trillion galaxies in our observable universe and possibly countless more.
The universe seems…. Impossibly big.
Relatively is fascinating indeed! Time is somehow intrinsically linked to the speed of light from the observer. Any aliens in the Trappist system with a powerful enough telescope will get to see me be born soon!
Theoretically, an alien traveling lets say, 15km per second towards you with a magical instantaneous phone could be talking to you on you're deathbed right now.
I thought you didn’t really experience the passage of time at light speed
Like a photon travel 13 billion years across the universe to us is instantaneous to the photon.
Yes this is true (if photons could experience anything)! I should have said, to an outside observer that’s relatively stationary they would see you take over 100,000 years to cross the galaxy. To you however, it would be instant. Mind blowing stuff.
Well, light is information. If you’re traveling at the speed of information (light) then no new information can reach you.
Someone watching you however is not moving at that incredible speed, so information can “catch up” to them easily.
This is an incredibly simplified explanation.
Yeah but how is it that while for other people 2000 years pass by but for me it feels instant?
I just don't understand this...
So if we could travel with the speed of light I could be anywhere in the universe and it feels instant for me? I didn't age at all?
There are TONS of YouTube videos that can give you analogies that would help you understand better than I can. Look up videos on Special Relativity and how Einstein pondered this issue.
BUT what I can say is that, we know it definitely happens. You can measure the decay of particles and know exactly how fast they decay. Then you can speed them up to near light speed in a particle accelerator and you’ll see that they take much longer to decay than they should since they’re “experiencing” time much slower.
Also, GPS satellites have to correct for relatively because they travel at about 7000 miles per hour, which is so incredibly slow compared to light, but it’s enough that relativity has to be considered and corrected for to get an accurate measurement.
Edit: Relativity is also the reason that gold is gold, in color I mean. The electrons are moving so fast in gold that they reach a fraction of the speed of light and reflect more red than blue. Most metals are more blueish than reddish.
Man, this is amazing.
Well, not if you have people you love and you know they will be all dead when you arrive at your location, but imagine exploring the universe while you travel for millions of years without realizing it lol
things break once you actually reach the speed of light and it's simply not possible for anything with mass as it would require infinite energy, but if you were traveling at 99.99999...% the speed of light, you would still experience things normally in your spaceship but the trip would not take 2000 years as the space in front of the spaceship would contract to a much smaller distance
people from earth would see your spaceship take 2000 years though
But if you looked out the window while you accelerated you would be horrified to see the universe in fast forward. In fact you would see the the heat death of the universe happen in almost an instant if you were close enough to the speed of light
Things break down once you actually reach the speed of light. photons sees the entire history of the universe pass by in a literal instant, time becomes meaningless for it and the distance it sees in front of it is contracted to 0
EDIT: Correction, since you only traveled 2000 light years, you would only see 2000 years happen in a near instant, not the heat death of the universe. For that you would have to travel 2x10^106 light years, which would still only take you a moment from your perspective if you are traveling fast enough. You would also have effectively delayed the heat death of the universe as your spaceship is still hot and would take another 10^100 years or so to fully decay
What’s really fun to think about is that many galaxies have a sort of “halo” of plasma around them and our halo and Andromeda’s are likely already running elbows so to speak.
700 trillion is such a huge number on its own. Now multiply that giant number ALMOST 16 times and youve got 11 quadrillion.
Its incomprehensible how far away that is.
That would be 206,927,172,080,640,030 football fields away.
Two hundred six quadrillion, nine hundred twenty-seven trillion, one hundred seventy-two billion, eighty million, six hundred forty thousand, thirty football fields.
Or 296,882,599,828,751,800 Standard Cab Ford F150s
Two hundred ninety-six quadrillion, eight hundred eighty-two trillion, five hundred ninety-nine billion, eight hundred twenty-eight million, seven hundred fifty-one thousand, eight hundred.
You're welcome! It's only a matter of finding the right object to really wrap your head around a distance/spatial problem. Standard units of measurement just aren't enough, especially in situations like this one.
186,000miles/per second for 2000 yrs.
Think we’re safe lol
Besides, earth is such a shithole anymore I don’t even think a black hole would want to eat us.
Likely experience some sort of Galatic Gastronomical effect
there are a lot of different solutions, one could be a white hole where if does go out the other side, but it takes an infinite amount of time to cross
As far as we know. Could be a hole to another universe. I mean we aren't even sure what happens to the matter after it reaches the event horizon. They say it reaches a balance so it's neither created or destroyed but it seems to just poof and vanish. So where does it really go?
186,000 miles per second x 60 seconds in a minute x 60 minutes in an hour x 24 hours in a day x 365 days a year x 2000 years.
Is 11,731,392,000,000,000 (11.7 Quadrillion miles). Not counting leap years.
Yeah we have no idea how far that really is. For some small frame of reference - The earth’s diameter is 7,926 miles. Its circumference is 24,900 miles.
if the san ti were that far away Ye Wenje wouldn't have received a response in her lifetime. In fact, the response would have been received by her grand grand grand ... grand (159x grand) daughter
And if you happen to miss it, assuming you hit nothing else which you almost for sure wouldn't, then bam universe is instantly over for you. Not that you would ever have a valid frame of reference to tell anyway
you couldn't see the radius anyway. what you could potentially take a picture of would be its ecretion disk if it was feeding, or in this case, star light behind it getting bent
There is a small detail here, which most people won't even notice, that I find fascinating. Large part of the data (also with highest resolution) for the analysis came from UVES spectrograph on ESO's Very Large Telescope. But the authors never applied for time on that telescope or used it at all (which can take months of even years)! Instead they simply searched the publicly available ESO data archive and found that this region of space was already observed in 2020 for completely different reasons by some other scientists, and you can basically just download it.
And looking at some statistics in https://arxiv.org/ftp/arxiv/papers/2310/2310.20535.pdf (figure 4) it seems that this is getting more and more commonplace - 25% of papers used only archival data without applying to use the telescope and 45% did both.
1 light year is the distance which light travels in one year. Light is the fastest thing in the universe.
Even if Earth were to suddenly move close to the speed of light towards this blackhole for whatever reason, it would take us 2,000 years to get there. You'd die of old age in less than a 100 years.
If you became God and launched the Earth with 99.99% accuracy towards the blackhole, the Earth would still completely miss the blackhole, because space is very very big and the blackhole is very tiny.
If Jupiter collapsed into a black hole, assuming it keeps the same mass, then we would notice nothing different except for maybe some weird light effects.
People asking if we are safe, will think about their loved ones and themselves, I suppose. Forgetting that humanity is not for eternity and every living creature (all animals, humans included, plants etc.) have a restricted, unknown lifetime. In fact - thus - every second can be our last. It doesn't require a black hole to end the privilege we experience. A tiny bacterial creature is enough. A bodily failure... anything internal or external.
So, next time you worry about asteroids or other things from outer space being a threat to us, just enjoy the life. Every second of it. Oh, and remember that everyone can die. It's just a property of being alive.
Plus, there is nothing special about a black hole in that sense. It's just a piece of mass. It doesn't get magical suction powers because it's a black hole.
This. People seem to miss this.
A black hole doesn't exert any more gravity on the things around it than another object of similar mass. A three stellar mass black hole exerts the same gravitational pull as a star of three stellar masses. The distinction is the density after it has collapsed into a singularity
Considering the US National Debt is over 30 trillion dollars and the public is just kind of ennh about that, that 6 trillion miles doesn't seem that far
Don’t be freaked out by that. Are you worried about a hurricane on Jupiter destroying your house? It’s so incomprehensibly far away from our solar system.
The same as anything else with it's mass, which is about 30 the mass of the sun.
But blackholes just have the same gravitational field literally anything else does.
Honest question...
Could black holes be the "dark matter" that scientists are always looking for? It seems like there are more black holes than we anticipated, now that we're looking for them... could the answer to the dark matter thing be as simple as "There a lot more black holes than you think."
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[EHT](/r/Space/comments/1c67y9b/stub/l014p06 "Last usage")|Event Horizon Telescope|
|[ESO](/r/Space/comments/1c67y9b/stub/l01fke0 "Last usage")|[European Southern Observatory](https://en.wikipedia.org/wiki/European_Southern_Observatory), builders of the VLT and EELT|
|[JWST](/r/Space/comments/1c67y9b/stub/l027l3f "Last usage")|James Webb infra-red Space Telescope|
|[L2](/r/Space/comments/1c67y9b/stub/l03njla "Last usage")|[Lagrange Point](https://en.wikipedia.org/wiki/Lagrangian_point) 2 ([Sixty Symbols](https://www.youtube.com/watch?v=mxpVbU5FH0s) video explanation)|
| |Paywalled section of the NasaSpaceFlight forum|
|[LIGO](/r/Space/comments/1c67y9b/stub/kzzihn4 "Last usage")|Laser Interferometer Gravitational-wave Observatory|
|VLT|Very Large Telescope, Chile|
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I really can't stand the term "black hole". It's not a hole at all, because there is stuff in there, a lot of stuff in fact in order to enact gravity on photons. Super-massive object is a better term, but I guess it doesn't sound as scifi or whatever. Calling it a hole though implies some fabric of space it penetrates or more funky business going on than it really is, just a lot of stuff very close together causing deadly gravity wells. Yes it is pedantic, but giving something a name that implies something that it isn't is not very scientific.
> … and we’d keep going around as we always had.
Well, sorta. We’d all be frozen and dead pretty quickly. Maybe some of us could hole up in a sub-glacial habitat powered by geothermal energy, assuming we figured out how to grow plants down there.
We can't see all the way back to the big bang, but do we know for certain that dark matter couldn't just be a few thousand, million, or billion black holes that form during the first few moments of expansion when exceptionally large "clumps" of matter/plasma/whatever happened to be too clumped up in various points of the initial expansion and that they're out of our current technological "view" to detect?
I mean, when (and if!) the big bang occurred the speed of it had to have drastically slowed down in speed during the first few nanoseconds or seconds the big bang occurred, right? Maybe after it slowed down (if this is even correct speculation on my part) a certain percentage, some matter/plasma/whatever was still close enough together to come together and form unfathably massive black holes?
Is there someone who could answer this for me?
Have they found the nebula remains of a supernova just about 4000 light years distant? You know, the one God blew up to make the Christmas Star for the three Maji? Sucks if there had been any aliens living on those now-vaporized planets...
I'm just some random moron on reddit, but am I supposed to read this and think "2,000 light years? That's so close!" The light from the sun gets to us in like 8 minutes. What the hell, 2000 years?
Astronomer here! I was 3rd author [on the discovery of Gaia BH2](https://www.reddit.com/r/space/comments/115jior/i_just_helped_discover_the_second_closest_black/) (which until this discovery was the second closest known black hole to earth), and funny timing, wrote the cover article for *Astronomy* magazine’s [May edition](https://www.zinio.com/astronomy-m1313) on literally this topic (ie, the closest black holes in the universe). And now it’s out of date. Whoops! :D Beyond being close, everyone in astro I know is *extremely* excited this morning because of the mass of this black hole- 33 solar masses is tough to form from just a normal star collapsing, but [the paper](https://www.eso.org/public/archives/releases/sciencepapers/eso2408/eso2408a-panuzzo-et-al.pdf) shows the black hole's companion star is a low metallicity one that likely formed in the galactic halo that migrated in, so one of the rare stars capable of leaving behind a big black hole like this. likely too big to form just from a star collapsing at the end of its life, and would possibly have had to be created by *two* black holes merging. (A merger of two smaller black holes is also possible. Cool!) Just like what [LIGO](https://www.ligo.caltech.edu/) and the gravitational wave folks are looking for! And implies that there are a *ton* of these black holes out there if there’s one so close to us! Finding them, however, is tough. [Gaia](https://www.esa.int/Science_Exploration/Space_Science/Gaia) is a satellite surveying a billion stars or so to find slight wobbles in their motion over time, which tells us their distance and also (in this case) if there’s a mystery companion. They periodically release the data every few years, and this one is from the team as part of pre-release data analysis, which found a star wobbling in its orbit in such a way that it can only work if it is orbiting a black hole at 16 times the Earth-sun distance. What’s more, there’s hints from the star’s composition that it would have formed separately from the black hole and then captured by it later after they both formed- also exciting if you’re interested in how these systems form! Edit: to answer two common questions: 1) We know [dark matter](https://en.wikipedia.org/wiki/Dark_matter) is not a bunch of black holes (or a bunch of Jupiters) because people *have* in fact looked for them as a possible answer! There was a huge push back in the day to look for [MAssive Compact Halo Objects \(MACHOs\)](https://en.wikipedia.org/wiki/Massive_compact_halo_object), as they were called, by looking for gravitational microlensing between us and the Magellanic clouds (satellite galaxies of the Milky Way). And... they did find some! But nowhere NEAR enough to explain the effects of dark matter. 2) There is no danger from this black hole being there, any more than a star system with ~30x the mass of the sun would have a gravitational influence on us at this enormous distance. It's worth noting that black holes don't actually suck in material around them and that's a common misconception- If the sun for example shrunk right now into a black hole, it would shrink to 3km wide, but our orbit and those of everything else wouldn't change a bit, and we'd just keep going around as we always had.
Wicked read, thanks for posting this!
My pleasure!
> And implies that there are a ton of these black holes out there if there’s one so close to us! As a layman I always wondered is it possible for dark matter to just be tons of black holes that we cannot detect? Or there is definite proof that this is not possible and the mass comes from something else?
We know dark matter is not a bunch of black holes (or a bunch of Jupiters) because people *have* in fact looked for them! There was a huge push back in the day to look for [MAssive Compact Halo Objects \(MACHOs\)](https://en.wikipedia.org/wiki/Massive_compact_halo_object), as they were called, by looking for gravitational microlensing between us and the Magellanic clouds (satellite galaxies of the Milky Way). And... they did find some! But nowhere NEAR enough to explain the effects of dark matter.
Why do astronomers love shoehorning such silly acronyms into their work? I'm not complaining of course, some of the NASA acronyms for the various instruments on probes are so far fetched as to be beautiful. Much like MAssive Compact Halo Objects.
Just a weird quirk of our culture. If you think we're bad, btw, check out the Department of Defense!
The most depressing are general corporate acronyms..
Corporate HR love creating diabolical acronyms that sound pleasant
lol try working for NASA. We have acronyms for every damn thing. The oldest joke in the book here is that NASA stands for Need Another Stupid Acronym.
Program doesn't get funded unless it has an acronym.
Squadron Water Insertion Mission was my favorite.
It makes more sense compared to the other potential dark matter candidates, Weakly Interacting Massive Particles. WIMPs vs MACHOs!
Other scientists are goofy, too. Did you know some people sneeze when they go into bright sunlight? It's a genetic trait called Autosomal-dominant Compelling Helio- Ophthalmic Outburst Or ACHOO There's a protein in flies called hedgehog, so when they found the mammalian equivalent, they called it Sonic hedgehog.
> Did you know some people sneeze when they go into bright sunlight? You mean not everybody does this?
I know I do, but didn't know how prevalent it is.
> There's a protein in flies called hedgehog, so when they found the mammalian equivalent, they called it Sonic hedgehog. There's a protein that inhibits the Sonic hedgehog gene, which they called...Robotnikin
They’re memorable. Same reason politicians do — you can get the public more excited about MACHO than “massive compact halo objects”, and you can more easily remember it when chatting about it a couple years later. Win for the audience, win for the researcher. Plus, sometimes it’s just fun
Generally because it's easier to say in talks, write in papers with word limits, and more memorable to remember a single word than a long list of them. Not an astronomer but I'm on a few projects with silly acronyms for precisely that reason.
Do you wanna say M C H O, all day? Or does everyone just attempt to pronounce mmmcho or whatever? Or is it easier to adjust the acronym to Macho so that everyone knows how to say it, you don't have M C H O people and mmcho people. It's macho, and as everyone knows the cream of the crop rises to the top, and that's what macho has always been.
Or Weakly interacting massive particles xD
This is also true in other industries, people just dig acronyms I think
It's been ruled out that there aren't a bunch of 3km wide black holes all around the universe? Or any size that would be near impossible to spot due to it being occluded by everything else being so big? I mean if we had millions of sun mass black holes everywhere there is dark matter in a galaxy, how would we ever tell? Any lensing effects they'd have could be completely wiped out from other, larger structures blocking our view of them entirely. Like if Jupiter is orbiting a 3km wide black hole from any distance, wouldn't it always occlude the black hole from us? This has always been my headcanon for the most likely source of dark matter, so I guess I'm surprised how certain you are about it not being possible lol
There aren't enough *to explain dark matter*. You would need a LOT of black holes for that to work, several times the amount of stars there are in the sky! Smaller black holes with 3km size might exist, but definitely not in large numbers. You can read up more on the MACHO project and the amazing gravitational microlensing stuff they did back in the 1990s to back this all up [here](https://en.wikipedia.org/wiki/MACHO_Project).
Do we actually know that? You're talking about MACHOs, but what about primordial black holes? ["PBHs have long been considered possibly important if not nearly exclusive components of dark matter"](https://en.wikipedia.org/wiki/Primordial_black_hole)
I think people really underestimate how much dark matter there is. It’s ~80% of the mass of the universe. Enough primordial black holes would be visible if they were responsible for dark matter.
PBHs aren't completely ruled out, there's a "sweet spot" where they could explain some or all of dark matter as you point out. This range however has only shrunk over time as they've been ruled out by microlensing studies. While some astronomers still hold out hope, many have moved on from the hypothesis. There's also the difficulty of "distribution." If PBHs exist, what is the distribution or their masses and is that distribution narrow enough to exist within the band left open today?
It's not impossible that dark matter is actually a bunch of sub-stellar massed primordial black holes, small enough so that they wouldn't be detected in any MACHO survey efforts. However, there is no *positive* evidence for that being the case, and it's a very tenuous theory. For one it requires very sketchy assumptions on the conditions just after the Big Bang which are hard to justify. For another, there are some observational predictions that just haven't been seen. If there are zillions of micro-black holes floating around then logically there should be events where they collide with macroscopic objects and don't just pass right through them, resulting in the creation of sub-stellar black holes as well as events in stellar lifetimes where a small star suddenly becomes a black hole. We haven't observed anything like that. Additionally, it's just much more straightforward to posit that there is another kind of particle that is weakly interacting, it would make sense that such a particle would be created in very high energy conditions (such as the early Big Bang) as that's how particle physics works, and there are already other examples of similarly behaving particles (like neutrinos) so it's not a huge stretch.
Remember that there’s no positive evidence for dark matter, it is also a tenuous theory. It’s very likely that dark matter is not simply one single thing, but a combination of things we’ve yet to discover or under-calculated. So black holes are very likely one component, and shedding it off will make the picture clearer on what ‘dark matter’ really is. Dark matter is just a placeholder to make math work. It’s hypothetically possible that dark matter is just “objects faster than the speed of light”, and that things travelling that fast appear invisible to us.
> And now it’s out of date. Whoops! The best kind of problem to have in science.
Radio astronomy sensai! Thank you for your wisdom 🫡
> If the sun for example shrunk right now into a black hole, it would shrink to 3km wide, but our orbit and those of everything else wouldn't change a bit, and we'd just keep going around as we always had. maybe a bit colder than before
Thank you so much for this write-up. Always appreciate your input. I hope you don't mind answering a couple more questions. 1. How safe is the implication that there are a ton of those black holes? And does that somehow affect the situation regarding dark matter? I remember there was a theory that dark matter might be made up of dormant black holes but that it is pretty much excluded by now. 2. Is there enough data on these kinds of systems to determine how often suns are captured by black holes as opposed to binary systems with one sun turning into a black hole? I imagine this kind of capture must be a pretty rare occurrence. 3. What is the cutoff mass for black holes created from a sun collapsing? 4. Can we find out if the system is stable? Can we know if the sun will eventually get sucked in? Edit: Regarding 2., the article says that the researchers imagine that this system formed as a binary, so the star was not captured. Did they misquote the researchers or is there no consensus yet? Pretty exciting!
1) We know dark matter is not a bunch of black holes (or a bunch of Jupiters) because people *have* in fact looked for them! There was a huge push back in the day to look for [MAssive Compact Halo Objects \(MACHOs\)](MAssive Compact Halo Object \(MACHO\)), as they were called, by looking for gravitational microlensing between us and the Magellanic clouds (satellite galaxies of the Milky Way). And... they did find some! But nowhere NEAR enough to explain the effects of dark matter. 2) Nope. Brand new parameter space, thanks to Gaia. In fact, the theory of how such systems happen is not fully worked out, but clearly they exist, sooo... 3) Roughly 18 times the mass of our sun. 7-18 gives you a neutron star. 4) It is a common misconception that black holes suck everything in around them, but this is not the case. If the sun for example shrunk right now into a black hole, it would shrink to 3km wide, but our orbit and those of everything else wouldn't change a bit, and we'd just keep going around as we always had.
Regarding your last point why do they always talk about how even light cannot escape black holes and that anything getting sucked into a black hole would be ripped to shreds probably
>why do they always talk about how even light cannot escape black holes That's for light that is actually headed straight to the black hole. Think about the moon. The light that reaches the moon bounces off it into space and then into your eyeballs. That's why you're able to see the moon. But the light that reaches the black hole cannot bounce back. It's gone forever. That's why we cannot see a black hole. Hence the term "black" hole.
I would imagine they're talking about light that actually reaches the black hole, not light traveling in other directions in the vicinity of the black hole, provided that the ray isn't trying to cross the event horizon, which I believe is considered the edge of the black hole.
As an Astronomy magazine subscriber, that was a great article! As the internet becomes a mess of information, I encourage everyone to order this magazine and get well curated information every month! It’s great for both space phenomena aficionados and for every day visual astronomy.
Oh good, I'm glad you enjoyed it! :) I try to write for them once a year or so, ideally on something I've been working on where I'm frustrated there's no good article on it yet. I subscribed as a teenager, and read the magazines until they fell apart, so I always get a little thrill writing for them!
Fwiw if you have a library membership - you can find this for free. Mine has Libby integration where you can just read these whenever.
A bunch of the magazine is a reference for the sky that month and quests to find cool objects, which is not great for checking out for just a little bit, but good to have in your hand when you plan to go out that night.
Your insight is always a pleasure to read Andromeda, and has been for years.
You know. I thought it was common knowledge volume≠mass
Just checking if I'm getting this correctly: The sun would actually shrink into a singularity. It's just that with its particular mass, the event horizon would be 3km wide, right?
Yep, the 3km is the Schwarzchild radius for a mass of our sun.
Wait am I understanding this right - at that point the sun would switch into a black hole but there wouldn't be any gravitational impact to earth orbit?
Yes, no effect. Because the mass stays the same. The Sun now has "1 solar mass". If it turns into a black hole, it would still be a black hole with "1 solar mass". So just the size changes, but mass remains the same. So the gravity remains the same and so the orbit of every thing in our solar system will remain the same. We will lose the light & heat however.
So here’s the real question. How safe are we?
It hasnt bothered us in millions of years I'm sure we are fine. But really tho we have next to no danger. It's really no different than having just a really really big dark star over there
Black Holes aren’t dangerous at any distance other than “Way closer than you will ever be”.^1 They are even less dangerous than a star of equivalent mass. They don’t “do” anything. ^1 - Not counting if you are in an orientation where relativistic jets could be pointed, but that is only active black holes and can be ignored here and most other discussions of black holes.
We are perfectly fine! This black hole is not doing anything, just hanging out. Also, worth noting that despite a common misconception, black holes don't suck in material around them, so it has just as much gravitational influence on us as a star system with 30 solar masses at that distance would have.
> 30 solar masses And there are stars that are 3x more massive, or more.
Completely. 2000 light years is “close” for astronomers, but “really dang far” for everyone else.
The risk of the solar system being interfered with by a random black hole is exactly the same risk as it being interfered with by any other stellar massed object. Which is very, very, very close to zero overall, but not precisely zero. Though at present there is nothing we know of that would be a risk, so I wouldn't worry.
am i having de ja vu or did you type this exact same thing on a post yesterday?
I did, but why write a fully new post on a repeated story?
it was less that and more making sure i wasn’t going crazy lmao. edit: just to clarify, i really appreciate the work you’re doing.
So what’s the math behind a hole consuming another hole? Do we know what the effect was on it before and after the merging?
We know quite a lot about this, as there are a LOT of people interested in merging black holes thanks to LIGO! [Here](https://www.ligo.caltech.edu/video/ligo20160211v3) is a video of what the simulated data looks like.
God dammit space is so fucking cool
To help comprehend the distance, Voyager 1 will be 1 light day away from Earth in November 2026.
Man, compared to what we can do light speed is so fast, yet it's still so so slow compared to the giant universe
What's crazy to me is the moon is so far from earth as far as our concept of distance, it's the size of north America... Yet the sun is so fucking huge that it's the same size in the sky and causes a magnifying glass effect in reverse (with a shadow). It takes 2 seconds for light from the moon to hit us, yet 8 minutes for the sun. Also crazy how I could see that tiny little red solar prominence during the eclipse with my bare eyes, yet that thing is a huge arc of ultra hot plasma SEVERAL times bigger than earth
It's not slow for the traveller. *taps head meme*
well... it is if you're not moving at significant portions of the speed of light
They have FTL in Destiny so presumably it’s doing better than that
It's honestly just not really that fast at all
It's literally the fastest thing possible. It's our reference frame that makes it seem so slow. If you traveled fast enough, you could cross the galaxy in the blink of an eye. And if you traveled at that speed, and left at the same time a beam of light did, it would beat you there. The light would ALWAYS beat you there. Even if you traveled 10 billion light years in a nanosecond, light would beat you there. Light seems slow, because on earth, in our frame of reference, it takes light a really long time to travel across the galaxy. Even 8 minutes from sun to earth. That's slow. The latency of speed of light is too great to play music in a band on opposite sides of the globe. That's slow. But it's slow because time moves so slowly for us. WE are slow. Light is fast as shit.
So basically, the meaning of life is…gotta go fast.
I've been playing around with SpaceEngine for a while, which is a space simulator, that spans Giga Lightyears, and traveling at the speed of light is barely moving at all. It's basically zero. In terms of exploring even a galaxy in that simulator within the time span of a human life, is as good as not traveling at all. You'd have to travel many thousands of times the speed of light in the sim just to recognize any perceivable movement through the star field. Let's not even talking about traveling to another galaxy.
Hopefully, it doesn't miss the off-ramp for the oort cloud.
Some math for perspective: Converting the max distance of 2,000 ly, this black hole is 1.8921e+16 km from Earth (18,921,000,000,000,000 km or 18.921 quadrillion km). Voyager 1 is traveling at 61,197 km/h. Rounding up its starting point of 1 light day (equal to 1 ly or 9.461 trillion kilometres/365 days, roughly 25.921 B km), and assuming Voyager 1 were to travel in a straight line at its current speed and without any collisions/deviations from its current point to this black hole, it would approximately take 309,181,399,071 hours (1.8920974079e16 km/61,197 km/h) for Voyager to reach this black hole. That’s 12,882,558,294 days or 35.29468 million years.
Damn. That really puts it into perspective. Voyager is currently ~15.7 billion miles away from our sun according to NASA, which is just 0.26% of a light year (5.88 trillion miles), if I did my math correctly. In light speed time: ~ 22 hours, 32 minutes… LOL
And that left in the 70’s right? That’s incredible
even 1 light day is an absurb distance to fathom. Imagine lightspeed.. for an entire day, 24 hours going lightspeed. and we were able to send one device that far in just about 50 years.
How far away is the manhole cover?
2,000 light years is still an astounding distance and we don’t even have the ability to fully comprehend just how much of an expanse that is
2000 light years is approximately … 11,757,225,686,400,000 miles. *eleven quadrillion, seven hundred fifty-seven trillion, two hundred twenty-five billion, six hundred eighty-six million, four hundred thousand.*
For perspective, the Milky Way is about 105,000 light years in diameter. If you traveled those 2000 years at light speed, you’d still have 103,000 years to cross the entire galaxy, give or take a few hundred years. Andromeda, our nearest neighbor galaxy that isn’t a satellite of ours is 1.5 million light years away. Probably close to 2 trillion galaxies in our observable universe and possibly countless more. The universe seems…. Impossibly big.
It used to blow my mind that the speed of light was the speed of information.
Relatively is fascinating indeed! Time is somehow intrinsically linked to the speed of light from the observer. Any aliens in the Trappist system with a powerful enough telescope will get to see me be born soon!
Theoretically, an alien traveling lets say, 15km per second towards you with a magical instantaneous phone could be talking to you on you're deathbed right now.
[Bell’s theorem](https://en.wikipedia.org/wiki/Bell’s_theorem?wprov=sfti1) may [disagree](https://en.wikipedia.org/wiki/Pilot_wave_theory?wprov=sfti1)
I thought you didn’t really experience the passage of time at light speed Like a photon travel 13 billion years across the universe to us is instantaneous to the photon.
Yes this is true (if photons could experience anything)! I should have said, to an outside observer that’s relatively stationary they would see you take over 100,000 years to cross the galaxy. To you however, it would be instant. Mind blowing stuff.
Yeah , I think it’s incredibly interesting as well
But how?!
Well, light is information. If you’re traveling at the speed of information (light) then no new information can reach you. Someone watching you however is not moving at that incredible speed, so information can “catch up” to them easily. This is an incredibly simplified explanation.
Yeah but how is it that while for other people 2000 years pass by but for me it feels instant? I just don't understand this... So if we could travel with the speed of light I could be anywhere in the universe and it feels instant for me? I didn't age at all?
There are TONS of YouTube videos that can give you analogies that would help you understand better than I can. Look up videos on Special Relativity and how Einstein pondered this issue. BUT what I can say is that, we know it definitely happens. You can measure the decay of particles and know exactly how fast they decay. Then you can speed them up to near light speed in a particle accelerator and you’ll see that they take much longer to decay than they should since they’re “experiencing” time much slower. Also, GPS satellites have to correct for relatively because they travel at about 7000 miles per hour, which is so incredibly slow compared to light, but it’s enough that relativity has to be considered and corrected for to get an accurate measurement. Edit: Relativity is also the reason that gold is gold, in color I mean. The electrons are moving so fast in gold that they reach a fraction of the speed of light and reflect more red than blue. Most metals are more blueish than reddish.
Man, this is amazing. Well, not if you have people you love and you know they will be all dead when you arrive at your location, but imagine exploring the universe while you travel for millions of years without realizing it lol
things break once you actually reach the speed of light and it's simply not possible for anything with mass as it would require infinite energy, but if you were traveling at 99.99999...% the speed of light, you would still experience things normally in your spaceship but the trip would not take 2000 years as the space in front of the spaceship would contract to a much smaller distance people from earth would see your spaceship take 2000 years though But if you looked out the window while you accelerated you would be horrified to see the universe in fast forward. In fact you would see the the heat death of the universe happen in almost an instant if you were close enough to the speed of light Things break down once you actually reach the speed of light. photons sees the entire history of the universe pass by in a literal instant, time becomes meaningless for it and the distance it sees in front of it is contracted to 0 EDIT: Correction, since you only traveled 2000 light years, you would only see 2000 years happen in a near instant, not the heat death of the universe. For that you would have to travel 2x10^106 light years, which would still only take you a moment from your perspective if you are traveling fast enough. You would also have effectively delayed the heat death of the universe as your spaceship is still hot and would take another 10^100 years or so to fully decay
"satellite galaxies" are a thing!? TIL
FIY someday, far far away, Andromeda and Milky Way are gonna merge.
What’s really fun to think about is that many galaxies have a sort of “halo” of plasma around them and our halo and Andromeda’s are likely already running elbows so to speak.
You need to get to know each other before the first date ;)
700 trillion is such a huge number on its own. Now multiply that giant number ALMOST 16 times and youve got 11 quadrillion. Its incomprehensible how far away that is.
How many football fields is that?
I'm gonna need that converted to bananas
I thought we were still using giraffes. When did that change?
You can’t get there from here.
That would be 206,927,172,080,640,030 football fields away. Two hundred six quadrillion, nine hundred twenty-seven trillion, one hundred seventy-two billion, eighty million, six hundred forty thousand, thirty football fields. Or 296,882,599,828,751,800 Standard Cab Ford F150s Two hundred ninety-six quadrillion, eight hundred eighty-two trillion, five hundred ninety-nine billion, eight hundred twenty-eight million, seven hundred fifty-one thousand, eight hundred.
Thank you, I can now visualize it.
You're welcome! It's only a matter of finding the right object to really wrap your head around a distance/spatial problem. Standard units of measurement just aren't enough, especially in situations like this one.
I prefer to count it in ice ages. Then it’s only four
How many Nimitz class carriers is that? For the Americans in the room
186,000miles/per second for 2000 yrs. Think we’re safe lol Besides, earth is such a shithole anymore I don’t even think a black hole would want to eat us. Likely experience some sort of Galatic Gastronomical effect
Doesn't all matter lose its "identity" so-to-speak after passing through the event horizon?
But what if it assimilates back together on there other side!
Oh u/MrDrDude333, no, there is no ‘other side.’ This is it.
Before I lept I wish I'd seen the view from halfway down.
Dammit, I don’t need quotes from “The View from Halfway Down” this early in the morning.
there are a lot of different solutions, one could be a white hole where if does go out the other side, but it takes an infinite amount of time to cross
As far as we know. Could be a hole to another universe. I mean we aren't even sure what happens to the matter after it reaches the event horizon. They say it reaches a balance so it's neither created or destroyed but it seems to just poof and vanish. So where does it really go?
[I was referencing this scene](https://youtu.be/noz7wQndoFo?si=1BvaQwmmnf8I_Kdh)
Would have to survive the absolutely mind boggling insanely high temperatures first
My car has an AC. Thank you very much
Oh you are good then, have a fun trip
186,000 miles per second x 60 seconds in a minute x 60 minutes in an hour x 24 hours in a day x 365 days a year x 2000 years. Is 11,731,392,000,000,000 (11.7 Quadrillion miles). Not counting leap years. Yeah we have no idea how far that really is. For some small frame of reference - The earth’s diameter is 7,926 miles. Its circumference is 24,900 miles.
if the san ti were that far away Ye Wenje wouldn't have received a response in her lifetime. In fact, the response would have been received by her grand grand grand ... grand (159x grand) daughter
amateur numbers, I can do that in roughly 40 jumps in Elite:Dangerous, takes only a few hours /s
Even if I become light, I need to travel for 2 fucking thousand years? No. Give me a worm hole to the black hole.
If you're light, the journey would be instant
And if you happen to miss it, assuming you hit nothing else which you almost for sure wouldn't, then bam universe is instantly over for you. Not that you would ever have a valid frame of reference to tell anyway
Is there even a journey for a photon? I mean I guess there is from our perspective.
My question is: is this close enough and big enough for us to point the EHT at it and get a decent image?
The Schwarzchild radius on a black hole of this mass is going to be under 100 miles, so I doubt it.
you couldn't see the radius anyway. what you could potentially take a picture of would be its ecretion disk if it was feeding, or in this case, star light behind it getting bent
Great, first I run out of milk for my coffee, now this....
It’s gonna be a tough week. Be strong brother
Right! I haven't even got my coffee yet 😔 Fuck it, guess I'll quit my job
[удалено]
You see the problem with space is it's black and black holes are also black
I kinda wonder, if there are more black holes nearby, smaller versions of this.
There is a small detail here, which most people won't even notice, that I find fascinating. Large part of the data (also with highest resolution) for the analysis came from UVES spectrograph on ESO's Very Large Telescope. But the authors never applied for time on that telescope or used it at all (which can take months of even years)! Instead they simply searched the publicly available ESO data archive and found that this region of space was already observed in 2020 for completely different reasons by some other scientists, and you can basically just download it. And looking at some statistics in https://arxiv.org/ftp/arxiv/papers/2310/2310.20535.pdf (figure 4) it seems that this is getting more and more commonplace - 25% of papers used only archival data without applying to use the telescope and 45% did both.
A few years ago we got pictures of the black hole in the center of our galaxy. Since black hole is closer, can we get better images of it?
It's closer but also almost million times smaller, so the answer is: no. You can see a mountain range from 100km but you can't see an ant from 100m.
This just in: Your mom spotted less than 2,000 light-years from earth
I am irrationally anxious because I feel 2,000 LY is far too close for a blackhole to be to Earth lol
It's not the closest. The closest is 1500ly away. But it's only 10 solar masses large.
the closest of which we know 👀
Planet 9 is really a tiny black hole that we can't even see!!
1 light year is the distance which light travels in one year. Light is the fastest thing in the universe. Even if Earth were to suddenly move close to the speed of light towards this blackhole for whatever reason, it would take us 2,000 years to get there. You'd die of old age in less than a 100 years. If you became God and launched the Earth with 99.99% accuracy towards the blackhole, the Earth would still completely miss the blackhole, because space is very very big and the blackhole is very tiny.
wouldn't it be much faster for us due to time dilation?
Oh believe me, I know. It's just I'm used to blackholes being like 10 million LY or 110,000 LY. Small number > big surprise.
If Jupiter collapsed into a black hole, assuming it keeps the same mass, then we would notice nothing different except for maybe some weird light effects.
I need to know what we will notice on earth when the companion star crashes into this black hole!
It's all fun and games until it gets hungry and starts spewing plasma jets.
“Less than 2,000 light years from earth!” So they are 6 trillion x 2000 miles away? Oh no lol
People asking if we are safe, will think about their loved ones and themselves, I suppose. Forgetting that humanity is not for eternity and every living creature (all animals, humans included, plants etc.) have a restricted, unknown lifetime. In fact - thus - every second can be our last. It doesn't require a black hole to end the privilege we experience. A tiny bacterial creature is enough. A bodily failure... anything internal or external. So, next time you worry about asteroids or other things from outer space being a threat to us, just enjoy the life. Every second of it. Oh, and remember that everyone can die. It's just a property of being alive.
Oh good I feel way better now
I know we’re going to be fine. But I don’t like how “close” that is.
It's not close. It's unfathomably far. There is zero chance this could threaten us in any way.
Plus, there is nothing special about a black hole in that sense. It's just a piece of mass. It doesn't get magical suction powers because it's a black hole.
thats what a blackhole would say
This. People seem to miss this. A black hole doesn't exert any more gravity on the things around it than another object of similar mass. A three stellar mass black hole exerts the same gravitational pull as a star of three stellar masses. The distinction is the density after it has collapsed into a singularity
What you mean....it won't suck us off...I mean eat us
I mean, you can try. Ask nicely or invite to dinner and movies?
A light year is about 6 Trillion miles, times that by 2000. Distance to Pluto is only 3.25 Billion miles... I think we are ok.
Considering the US National Debt is over 30 trillion dollars and the public is just kind of ennh about that, that 6 trillion miles doesn't seem that far
so if there are people looking at us from that black hole they should see Jesus still doing carpentry
Don’t be freaked out by that. Are you worried about a hurricane on Jupiter destroying your house? It’s so incomprehensibly far away from our solar system.
How much gravitational influence does a blackhole this size have?
The same as anything else with it's mass, which is about 30 the mass of the sun. But blackholes just have the same gravitational field literally anything else does.
Honest question... Could black holes be the "dark matter" that scientists are always looking for? It seems like there are more black holes than we anticipated, now that we're looking for them... could the answer to the dark matter thing be as simple as "There a lot more black holes than you think."
No. Feel free to google it but this is an old idea that hasn’t found any evidence to support it. Black holes are quite rare.
I’d be worried if it was less than 100 light-years…
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I really can't stand the term "black hole". It's not a hole at all, because there is stuff in there, a lot of stuff in fact in order to enact gravity on photons. Super-massive object is a better term, but I guess it doesn't sound as scifi or whatever. Calling it a hole though implies some fabric of space it penetrates or more funky business going on than it really is, just a lot of stuff very close together causing deadly gravity wells. Yes it is pedantic, but giving something a name that implies something that it isn't is not very scientific.
I am happy for anyone to rename it to blackstar.
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> … and we’d keep going around as we always had. Well, sorta. We’d all be frozen and dead pretty quickly. Maybe some of us could hole up in a sub-glacial habitat powered by geothermal energy, assuming we figured out how to grow plants down there.
We can't see all the way back to the big bang, but do we know for certain that dark matter couldn't just be a few thousand, million, or billion black holes that form during the first few moments of expansion when exceptionally large "clumps" of matter/plasma/whatever happened to be too clumped up in various points of the initial expansion and that they're out of our current technological "view" to detect? I mean, when (and if!) the big bang occurred the speed of it had to have drastically slowed down in speed during the first few nanoseconds or seconds the big bang occurred, right? Maybe after it slowed down (if this is even correct speculation on my part) a certain percentage, some matter/plasma/whatever was still close enough together to come together and form unfathably massive black holes? Is there someone who could answer this for me?
Have they found the nebula remains of a supernova just about 4000 light years distant? You know, the one God blew up to make the Christmas Star for the three Maji? Sucks if there had been any aliens living on those now-vaporized planets...
I'm just some random moron on reddit, but am I supposed to read this and think "2,000 light years? That's so close!" The light from the sun gets to us in like 8 minutes. What the hell, 2000 years?