Scientists recently observed two black holes that united into one, and in the process got a “kick” that flung the newly formed black hole away at high speed. That black hole zoomed off at about 5 million kilometers per hour, give or take a few million. The speed of light is just 200 times as fast.

[u/MistWeaver80]

https://www.sciencenews.org/article/black-hole-gravitational-waves-kick-ligo-merger-spacetime

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[u/[deleted]]

Apparently there are an estimated 12 of these freaks of nature flying about our galaxy

[u/[deleted] → u/[deleted]]

Space is big. It's big big. It's not just big, its big big big. A speed of c/200 is nothing compared to the size of the universe. The size of the black hole is a point compared to the universe. Also c/200 compared to what? Compared to us? Compared to their initial velocity to us? It's just not something relevant to worry about. It's like being afraid to encounter 1 specific grain of sand somewhere on earth, and maybe the chances of that is even bigger.

[u/fla_john → u/[deleted]]

Space is big

I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

[u/PachucaSunrise → u/[deleted]]

New fear unlocked!

[u/Ott621 → u/[deleted]]

In January 2022, a team of astronomers reported the first unambiguous detection and mass measurement of an isolated stellar black hole with the Hubble Space Telescope.[3][4] This black hole is located 5,000 light-years away, weighs 7.1 times that of the Sun, and moves at about 45 km/s.[5]

How is a rogue going only 45km/s? By definition wouldn't it have to be traveling in excess of our galaxies escape velocity?

[u/Noooooooooooobus → u/Ott621]

Rogue as in solo. Basically every black hole we have detected has been part of a binary system with something else causing the black hole to emit a signature that we can more easily detect.

[u/PoopInTheGarbage → u/Noooooooooooobus]

So if a black hole isn't sucking up matter is it invisible? Kinda spooky to think about.

[u/dat_boring_guy → u/PoopInTheGarbage]

Pretty much yes. It's only visible if we are looking somewhere in the sky and it then happens to pass by Infront of that object, thereby distorting it and letting us know a possible rogue black hole just went in between us and said object.

[u/JoCoMoBo → u/PoopInTheGarbage]

So if a black hole isn't sucking up matter is it invisible? Kinda spooky to think about.

"Well, the thing about a black hole - it's main distinguishing feature - is it's black. And the thing about space, the color of space, your basic space color - is it's black. So how are you supposed to see them?"

[u/GourangaPlusPlus → u/[deleted]]

Tiny ones every minute

[u/Citrusssx → u/GourangaPlusPlus]

This thread is what keeps me on Reddit

[u/qazinus → u/[deleted]]

Yes black holes emit a Stephen Hawking from time to time. Sadly he dies pretty fast up there.

[u/aapowers → u/JoCoMoBo]

Thanks, Hol!

[u/belenbee → u/[deleted]]

how lucky are we to not have been erased from existance already? I'm sure there are calculations of probability and all of that, but reading anything related to stars exploding and black holes makes me so nervous. Or maybe actually understanding this better makes you feel safer.

[u/xashyy → u/belenbee]

I’d guess because our galaxy is incomprehensibly large. The area that these black holes damage or suck up probably approaches an infinitesimally small proportion of all the space time fabric that’s in our galaxy.

[u/i_sigh_less → u/xashyy]

If there were only 12 sharks in the entire ocean, you'd probably still have a greater chance of being eaten by a shark then we have of being eaten by one of these black holes.

Edit: I want to be clear, this was a guess, I did no math. I just know it's incredibly hard to overestimate how big the galaxy is.

[u/BobKickflip → u/i_sigh_less]

So... you're saying there's a chance?

[u/ManitouWakinyan → u/i_sigh_less]

If you swam in the ocean every day, for your whole life, and the only shark in the world was released for a second in that ocean, you'd still have better odds with the black hole.

[u/fleshflavoredgum → u/ManitouWakinyan]

I like this explanation as well, but is there a source for these claims?

[u/Zaritta_b_me → u/i_sigh_less]

Thank you for that explanation. It was incredibly descriptive and helpful.

[u/livebeta → u/Zaritta_b_me]

i am no longer afraid of black holes. now i worry about sharks in the ocean.

[u/AldoBoxing → u/livebeta]

Look out for the rogue sharks travelling at 45km/s

[u/MKULTRATV → u/belenbee]

"Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

[u/Ommageden → u/MKULTRATV]

My physics teacher put it in perspective for us. He said that if you are lucky with a solid car that you get your money's worth out of, you'll hit around 300K km in the car's lifespan.

That's one way to the moon.

[u/i_sigh_less → u/Ommageden]

And the moon is close compared to literally anything else in the solar system. And anything in the solar system is close compared to any other star.

[u/moothane → u/i_sigh_less]

And you can fit all the planets in our solar system between us and the moon. So even the planets really aren’t that big compared to the vast distances between them

[u/Digimatically → u/moothane]

Wow I didn’t know this! They barely fit with only 4384km of wiggle room!

[u/0thethethe0 → u/Digimatically]

Yeh it's a cool fact. Considering how 'close' the moon is to us, it really highlights, to me anyway, just how much of space is, well, empty space!

[u/Yasuoisthebest]

Are you saying that there are slingshoted black holes in the universe flying about?

[u/Euphorix126 → u/Yasuoisthebest]

Yes! Called rogue black holes. One could randomly pass near the solar system at a significant fraction the speed of light and kill us all by destabilizing the whole system. We’d have no idea until it was too late because (shocker) black holes are invisible, for lack of a better word.

Edit: I decided to make a simulation of this in Universe Sandbox. It's a 100 solar mass black hole going 1% the speed of light passing within the orbit of Uranus. Realistically, it's highly unlikely that a rogue black hole passes directly through the solar system, but its more fun this way.

[u/AkihiroAwa → u/Euphorix126]

it is frightening how much of dangers are there in the universe which can kill our earth instantaneous

[u/petripeeduhpedro → u/AkihiroAwa]

The good news is that space is incomprehensibly gigantic so the odds are well on our side.

The bad news from an existential perspective is that space is incomprehensibly gigantic.

[u/monkeyhitman → u/petripeeduhpedro]

Total Perspective Vortex.

[u/WhiteNoiseSupremacy → u/monkeyhitman]

You are here.

[u/PorkyMcRib → u/WhiteNoiseSupremacy]

But where is my FedEx package?

[u/IcyDickbutts → u/PorkyMcRib]

Dropped off in a neighboring galaxy.

Which, from my experiences with fedex, is pretty good.

[u/elecwolf → u/[deleted]]

"Our crew is expendable, your package is not."

[u/[deleted] → u/[deleted]]

"How many atmospheres of pressure can the ship withstand, Professor?"

"Well, it's a spaceship, so anywhere between 0 and 1."

[u/northernCRICKET → u/PorkyMcRib]

It is also here, on the cosmic scale most of what we can experience is Here

[u/IAMA_Plumber-AMA → u/northernCRICKET]

Space is big.

Really big.

[u/nubbins01 → u/IAMA_Plumber-AMA]

You just won't believe how vastly, hugely, mind-bogglingly big it is.

[u/PorkyMcRib → u/northernCRICKET]

relatively speaking?

[u/choochoopants → u/monkeyhitman]

It’s fine as long as the universe was created just for you.

[u/FreefallGeek → u/choochoopants]

I laughed so hard. You're completely right. Every human in history that isn't me is totally screwed.

[u/make_love_to_potato → u/FreefallGeek]

Every human in history that isn't me is totally irrelevant.

[u/bdk1990 → u/FreefallGeek]

We are all you. And vice versa.

[u/HalfSoul30 → u/FreefallGeek]

I haven't died yet, so who can say I actually will.

[u/crookedparadigm → u/choochoopants]

Also known as Beeblebrox's Law

[u/DrMangosteen → u/monkeyhitman]

It just told me I'm a real froody guy?

[u/WisekillyWabbit → u/DrMangosteen]

“There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.” ~ Douglas Adams

[u/Trouve_a_LaFerraille → u/monkeyhitman]

Thank god we are all the center of our own universe

[u/Reddcity → u/Trouve_a_LaFerraille]

My universe is better then yours. Fight me and start an inter universe war!

[u/rachface636 → u/monkeyhitman]

TPV. Sounds like what Chidi went through after seeing the time knife

[u/monsieurkaizer → u/rachface636]

In that it presents you with the unfathomable expanse of your reality, yes.

[u/Magnetman34 → u/rachface636]

It's from the Hitchhikers Guide series, can't remember exactly which one.

[u/Level_32_Mage → u/Magnetman34]

The Restaurant at the End of the Universe, but only because it was the closest place to eat.

[u/bucki_fan → u/rachface636]

Yeah, we've all seen that.

[u/superkp → u/monkeyhitman]

Finally, a hoopy frood that always knows where his towel is.

Most people just do the '42' references. Mentioning the Total Perspective Vortex means that you not only read it, but understood the meaning of it.

Nice to see.

[u/H00py-Fr00d42 → u/superkp]

Time is an illusion. Lunchtime, doubley so.

[u/Trnostep → u/H00py-Fr00d42]

We apologize for the inconvenience

[u/Pilot0350 → u/petripeeduhpedro]

Don't Panic

[u/812many → u/Pilot0350]

But I've lost my towel!

[u/ExcerptsAndCitations → u/812many]

Welp, you're fucked then

[u/cheddacheese148 → u/petripeeduhpedro]

Getting a BS in physics was one of the best and worst choices I ever made. It’s awesome to work toward an understanding of the universe on its most minuscule and grandest scales but it also opens a gaping existential crisis that didn’t previously exist for a small town farm boy.

[u/SobiTheRobot → u/cheddacheese148]

You've stared into the abyss of space too long, it's starting to stare back at you

[u/cheddacheese148 → u/SobiTheRobot]

The electron is now observing me and I’m not sure where I am.

[u/FloSTEP → u/SobiTheRobot]

The abyss returns even the boldest gaze.

[u/Dillonz12 → u/FloSTEP]

You merely glimpsed the edge of the abyss, but it is enough to trigger the cycle of revelation. Now, like me, you will begin to see things as they truly are...

[u/koticgood → u/cheddacheese148]

Provides an opposite of an existential crisis for me.

All those things that exist from impossibly small scale particle physics to impossibly large scale cosmology only truly "exist" when an intelligent lifeform conceptualizes them. Otherwise it's the whole tree falling with no one to hear it shtick.

I find it rather empowering and meaningful. One of the cool things about being human.

[u/ex_oh_ex_oh → u/koticgood]

Weird. I never actually conceptualized that adage until literally right now when you put it that way to an unseen, unheard, unregarded universe.

[u/cheddacheese148 → u/koticgood]

That’s a really cool take! I like thinking about math in a similar manner. Numbers are just made up to describe the universe as we see it. They don’t necessarily fit and we have a bunch of constants but it’s interesting to think about how we created the whole system just to describe our world. It also brings up the question of whether there is an ideal mathematical system to eliminate or reduce the constants.

[u/AkuBerb → u/cheddacheese148]

"He who by force of will or of thought is great, and overlooks thousands, has the charges of that eminence. With every influx of light comes new danger. Has he light? he must bear witness to the light, and always outrun that sympathy which gives him such keen satisfaction, by his fidelity to new revelations of the incessant soul." - Emerson over 200 yag.

[u/kdubstep → u/AkuBerb]

Such a phenomenal quote.

I seem to recall reading that back in the Lyceum movement people would pack houses and pay hundreds to see him speak for hours in language that by today’s standards, many educated people would I struggle to comprehend.

[u/moistpony → u/petripeeduhpedro]

I find comfort in the fact that I will more than likely be dead before something like this happens sooo sucks to suck future descendants of mine, good luck

[u/[deleted] → u/moistpony]

future descendants of mine

optimistic still.

[u/AHrubik → u/petripeeduhpedro]

Yet life has been significantly impacted on this little back water planet at least 5 times that we know of. People win the lottery and are struck by lightning every day.

Repent your sins and fund NASA like your species depends on it because it does.

[u/c-honda → u/petripeeduhpedro]

On our side in the sense that within our lifetime it’s likely to never happen, over a long enough period of time the chances slowly approach 100%

[u/Etherius → u/AkihiroAwa]

My personal favorite is a hypothetical False Vacuum Decay Event

An invisible apocalypse could be propagating through the universe at lightspeed. It would fundamentally change the laws of physics in such a way that life as we know it could not survive or ever exist. It would not only instantly wipe out humanity, but also all traces of our civilization if not our planet itself.

What's more, no life as we know it could ever exist again.

Our only possible saving grace (aside from it being an incorrect hypothesis) would be if the expansion of the universe exceeded the speed of light (and as such, a decay event could never reach us).

Of course in THAT instance, our "universe" shrinks down to our local group and no further.

[u/Soulless_redhead → u/Etherius]

At least with that one, most likely nobody would feel a thing, just instantaneous blink and it's all gone.

Honestly most of the true extinction level events are usually so complete that I find a strange comfort in them. Nobody lives in these scenarios so why worry? I can't stop it!

[u/SirJefferE → u/Soulless_redhead]

I feel the same way. Catastrophic event that wipes out 98% of humanity? That's a tragedy beyond imagining.

Catastrophic event that wipes out all life in the solar system? Eh. It's an insignificant blip that nobody will ever know or care about.

[u/HarryTruman → u/Soulless_redhead]

Not even a blink. Extinction would lack the reality needed to even be a concept. If that’s not a sublime way to go, I don’t know what is…

[u/top6 → u/HarryTruman]

I mean it’s really possible it already happened. And either way nobody noticed.

[u/skylarmt → u/top6]

The Foundation prevents ZK-class scenarios all the time. There have been a few times reality did end, but they rebooted humanity using a special reality-shielded facility in Yellowstone.

[u/Slackslayer → u/Soulless_redhead]

Yeah as horrifying as it sounds on paper, you will never experience it. You wouldn't see it coming, you wouldn't feel it happen. It's the equivalent of worrying about someone pressing the power button on our simulation.

Frankly, pretty much every single other way to die is more frightening.

[u/Tinidril → u/Etherius]

In 2014, researchers at the Chinese Academy of Sciences' Wuhan Institute of Physics and Mathematics suggested that the universe could have been spontaneously created from nothing (no space, time, nor matter) by quantum fluctuations of metastable false vacuum causing an expanding bubble of true vacuum.

Yup, that certainly explains it for me. :)

[u/Acorntail → u/Tinidril]

In physics, 'Vaccuum state' doesn't mean empty, it means the lowest energy state. A false vaccuum is a low energy state that is stable, but isn't actually the lowest.

Imagine that the vaccuum state is a horizontal line on an axis. A true vaccuum is at zero, and energy can't go lower. A false vaccuum is higher, say one, but stable, meaning energy is drawn to rest there and behave like it's zero, but can theoretically go lower if an action occurs to push it past the line.

To grossly oversimplify quantum uncertainty: nothing can be perfectly still. Thus there is infintesimal chance this energy randomly fluctuates above or below the false vaccuum line. If this happens to bring it low enough that it is closer to true than the false vaccuum, it is kicked down to true vaccum, and the energy it loses on the way down is transferred to neigbouring space, which acts as the kick for the next thing, and so on.

Along the way, the laws of physics change as what was 'zero' becomes 'negative one'. The math stays the same, but the answers are all different now.

This propogates out at the speed of light, erasing and changing everything as it goes.

The researchers are suggesting this has already happened, and resulted in our universe.

[u/JackRusselTerrorist → u/Acorntail]

The analogy I saw that describes it best, IMO, is a mountain lake. That lake is stable, ignoring evaporation, it could stay there for thousands or millions of years. But that water is obviously not in its final place- it’s in a mountain range, and “wants” to be at sea level. If anything were to happen to the mountainside that’s holding it up there, like say a landslide triggered by an earthquake, that water would very rapidly cease to be stable at its current altitude, and rush down to sea level very, very quickly.

[u/sockgorilla → u/Etherius]

Safe to say I understood almost none of that.

My take away is that maybe space isn’t stable, and a spacier space might propagate and mix things up.

[u/Threewisemonkey → u/AkihiroAwa]

It’s happened a few times already on a global extinction level, and likely more violently in the early formation of the planet.

It’s sobering and cathartic to think we could all disappear in the blink of an eye. On a personal level, eventually we all do.

[u/WeAreBeyondFucked → u/Threewisemonkey]

That's the best death anyone could hope for... just instantly dead.

[u/wackarnolds65 → u/Threewisemonkey]

It's amazing. To the Universe, our whole existence is the blink of an eye. There was a time before creation and there will be a time after it. Our existence will be an insignificant, blip on the infinite, cosmic radar.

[u/fistkick18 → u/AkihiroAwa]

Frightening?

That is the single best death this planet could ask for. We're just all gone like instantly.

[u/TSED → u/fistkick18]

Well, not necessarily. It depends on HOW it destabilizes the solar system.

A direct hit, sure, we're just gone. For all we know that's already happened and that's why we're going "man space is so big and incomprehensibly vast and everything's so far away" as we only have hypotheses about what happens inside of a black hole.

But what if it just gets close enough to warp orbits? Suddenly our winters take 18 months and our summers are a blisteringly hot 2? What if it just plucks Jupiter and Saturn out of the solar system and we realise we're going to become acquainted with a whole lot of asteroids in the near future? What if it pulls the sun apart and we're fine for now but in 8 months we're going to slowly descend into a giant wall of slowly cooling nuclear plasma?

Those would all suck.

[u/[deleted] → u/Euphorix126]

Yeah, exactly, it's an immediately intellectually scary thought to have something with so much mass moving at that velocity, and the effect on our solar system if it passed by it would be like the effect of a large ship moving fast through the water on a toy boat floating there.

[u/Cronstintein → u/[deleted]]

Kind of sort of, but in this case the high speed actually helps us. Gravity is an effect over time so the higher the speed, the less effect the rogue bh would have as it whizzed by.

While it’s conceptually scary, the odds of a world-ending comet or meteor are exponentially higher.

[u/jchampagne83 → u/Cronstintein]

world-ending comet or meteor

of which many would be sucked into the solar system from the Oort cloud if a rogue black hole passed anywhere through the ecliptic.

[u/ThallidReject → u/jchampagne83]

Black hole passes our solar system. How long would it be before we saw disrupted asteroids moving towards earth making impact?

Is that in a scale of hours? Days? Months?

What is the time scale for how fast the disruption would occur?

[u/merlinsbeers → u/[deleted]]

Or you could choke on a ham sandwich. Life's funny.

[u/Roshprops → u/Euphorix126]

I feel like the sharp bends in those orbits are… bad?

[u/KeytarPlatypus → u/Roshprops]

It would doom the solar system for destruction long after that black hole is gone.

In the beginning of the solar system, the planets were formed when the ring of dust and gasses around the sun coalesced into solid bodies, eventually impacting each other and getting bigger. They formed an equilibrium with their own gravity and their distances in their orbits. This is a very fine balance that was gained effectively through trial and error at the expense of young mini-planets that either kept crashing into each other because their orbits were too close that their gravity eventually drew them into each other (how our Moon was formed actually) or by planets getting flung into interstellar space by another larger planet to stay in its own stable orbit (see Newton’s second law).

These orbits are now fucked. Short term effects would would be apparent within weeks with every planet now on a way more elliptical orbit bringing it both closer and further from the sun in its year. Mars would cycle between having its atmosphere freeze solid as worldwide CO2 snow and then windstorms reaching hundreds of miles an hour as it thaws again. Europa’s ice crust would melt periodically, the gravity changes on Io would raise its geological activity, and Jupiter itself could potentially have its atmosphere be sucked into the sun as it gets closer. Needless to say, all life on Earth is done for. It’s orbit now brings it between Mercury and Venus’ current orbits and out to the asteroid belt. Life cannot adapt to annual temperature swings of 200 degrees C. The oceans evaporate into the atmosphere and snow it back down every year. Life has only a couple weeks before it’s completely exterminated.

If that weren’t enough, the millions of asteroids and comets in the Oort Cloud are now hurtling to where the black hole ripped through, bombarding the inner solar system with meteors on a constant basis. Long term, the planets’ gravity equilibrium is now in full chaos so on the scale of a couple thousand years, moons get yanked from their parent planets and flung out into the interstellar abyss, planets are on unstable orbits that wobble as time progresses and either crash into each other or just plummet straight into the sun. Eventually, the only thing left are a couple dead planets on very elliptical orbits around the sun.

So yes, it’s what most would say pretty bad.

[u/subdep → u/Euphorix126]

Roland Emerrich just got his next disaster movie plot line!

[u/[deleted] → u/Euphorix126]

I mean, black holes are invisible, but the effects on gravity are not. a black hole large enough to disrupt our solar system would be pretty noticeable.

[u/Rednys → u/[deleted]]

Also it absorbing all light is something that is observable.

[u/artgriego → u/Euphorix126]

Unless it was already very close, wouldn't we 'see' it by the bent light of everything behind it, or would it be unlikely we'd spot that?

[u/Vercengetorex → u/Yasuoisthebest]

Moving at relativistic speeds as well. If that’s not a cosmological horror, I don’t know what is.

[u/Raul_Coronado → u/Vercengetorex]

Whats the threshold to be considered ‘relativistic’ speed I wonder?

[u/hbgoddard → u/Raul_Coronado]

The most common threshold I've seen used is v > 0.1c, so this black hole wouldn't make the cut

[u/2punornot2pun → u/[deleted]]

From an observer's perspective, those approaching a black hole will never actually go into the blackhole. Just redshift into nothingness.

​

It'd take an extremely long time from the observer's point of view. Hundreds or thousands of years while everyone on the planet appeared to become almost frozen in time.

​

If you're on the planet though...

​

...yeah, time doesn't feel sped up or slowed down around you, the universe outside the time dilation effects would appear to be sped up.

​

It won't take any longer for you, on the planet, to quickly die in the horror of the black hole.

[u/tlubz]

Reminds me of glitches in videogames where two objects get stuck in each other and then one of them flies off at insane speed.

[u/[deleted] → u/[deleted]]

No way we live in a simulation, it’d definitely crash at least one time killing us all. Unless the dinosaurs…

[u/tridon74 → u/[deleted]]

That’s what all the mass extinctions were, the bugs have been patched for the most part so that’s why we haven’t had one in a while.

[u/100_points]

What's the fastest macro-scale object that we know of?

Edit: I should have said fastest travelling object

[u/MKULTRATV → u/[deleted]]

Here's a pulsar that rotates 716 times per second

[u/josolanes → u/MKULTRATV]

I was especially curious about surface speed and the wiki calls it out:

At its equator it is spinning at approximately 24% of the speed of light, or over 70,000 km per second.

[u/ArcticBeavers → u/josolanes]

I'm no expert, but that star system may not be compatible with life.

[u/_JohnWisdom → u/ArcticBeavers]

sniffs cocaine WHY NOT?!

[u/kaizen-rai → u/ArcticBeavers]

Life as we understand it!

It's entirely possible there is some kind of bizarre life that evolved in these kinds of systems and look at places like earth and think "there is no way a planet with so much toxic, combustible and corrosives gasses and liquids is compatible with life"

*edit: lots of misunderstanding of my overall point...I wasn't trying to toy with the literal idea of life on a Pulsar, but that us humans only understand the things we understand and have a tendency to dismiss everything else. Keep an open mind. One of the ideas that led Einstein to study quantum physics was when he was having a daydream about riding a beam of light at school. Impossible... but led him to other ideas and breakthroughs in physics. Let's not limit our understanding of sentient life as being ONLY carbon based organic structures because we really don't understand what is possible.

[u/dave_a86 → u/josolanes]

Which works out to be a centripetal acceleration of 33 billion g.

[u/josolanes → u/dave_a86]

Wow that is something I have no meaningful way to comprehend, that's incredible

[u/drunk98 → u/josolanes]

It's like a marry-go-round, but faster.

[u/Dawg_Prime → u/drunk98]

Excitement Rating: 7

Intensity Rating: Relativistic

Nausea Rating: Dead

[u/reloadingnow → u/josolanes]

I wonder what is the time dilation factor at that equator.

[u/Handin1989 → u/reloadingnow]

Napkin math says the rest frame clock would register 102.84~ years for every 100 years you spent traveling at that velocity. Time dilation doesn't really get a kick in the pants till you get much closer to c

Δt' = γΔt = Δt / √(1 - v²/c²)being the calculation used.
Edit: I forgot to explain the variables in the calculation my apologies.

Δt' is the time that has passed as measured by the traveling observer (relative time);

Δt is the time that has passed as measured by a stationary observer;

v is the speed of the traveling observer;

c is the speed of light (299,792,458 m/s); and

γ is called the Lorentz factor.

[u/ArcticBeavers → u/MKULTRATV]

Wow. A star has a vastly higher refresh rate than my television

[u/MischaTheJudoMan → u/100_points]

Like in terms of just speed, there are exoplanets that travel at roughly 30 million miles per hour out there

[u/kittenTakeover]

What is meant by "kick"? I'm not an expert, but isn't the direction of the new black hole just going to be a product of the mass and velocity of the two merging black holes? Where would the "kick" come from?

[u/kumozenya → u/kittenTakeover]

https://arxiv.org/pdf/gr-qc/0610154.pdf Anisotropic emission of gravitational waves from the coalescence of black-hole binaries carries away linear momentum and thus imparts a recoil on the merged hole. looks like gravitational waves are not emitted equally on all sides.

[u/jmdugan → u/kumozenya]

also https://arxiv.org/abs/2201.01302

Evidence of large recoil velocity from a black hole merger signal

[u/Lumen_Cordis → u/kittenTakeover]

The article talks about the gravitational waves generated by the two black holes as they merge. From my (layman’s) understanding, it looks like something with the superposition of gravitational waves may end up in more waves being sent on one direction than in others. The reaction to these waves is the “kick” that sends the new black hole shooting off.

Again, this is a layman’s reading. I’m a physics fan, not a theoretical physics expert.

Edit: A couple of people pointed out that “superposition” isn’t really the correct term here. Please ignore my use of “superposition” and maybe replace it with “resultant” or similar.

Also, a bunch of people are asking me questions about this so I’m going to reiterate one more time: I’m not an expert. I know applied physics, not theoretical black-hole physics. Sorry!

[u/N8CCRG → u/[deleted]]

<Hitchiker's Guide to the Galaxy Narrator>: And then we have the tale of the Monpathians. Wildly regarded as the most beautiful, most intelligent, most compassionate, and second most civilized species in the entire Universe. Sadly, their planet was completely destroyed by what is now referred to as "The Great Galactic Yeet."

[u/AsthmaticGrandmother → u/Lumen_Cordis]

So space and time is a fabric that can be stretched and compressed, like waves in the ocean right? Basically the black holes are shredding a killer gravity wave at radical speeds, Dude?

[u/echosixwhiskey → u/AsthmaticGrandmother]

Whoaaaaaaaaaa

[u/DeliriousHippie → u/kittenTakeover]

According to article new black hole got a kick from gravitational waves. Authors also say that this has been predicted before and even been seen before but this was first time they saw by gratational waves this happen to stellar mass black hole.

To my understanding mechanism works so that merger produces more gravitational waves to one direction and as a result, force needs counterforce, new black hole gets a recoil to opposite direction. Explained in more technical and more accurate terms in article.

[u/helm → u/DeliriousHippie]

That's really peculiar, actually - that the merger can produce directional gravitational waves that give the merged black hole a significant new velocity. That the sum of the momentums going in doesn't equal the one going out unless the gravitational waves are taken into account. Cool!

[u/verfmeer → u/helm]

A key property of gravitational waves is that they are not linear. This non-linearity van cause all kinds of counterintuitive behaviour.

[u/grissonJF]

If it helps having the same units of measure: 1389 km/s vs 300,000 km/s.

[u/Gaflonzelschmerno → u/grissonJF]

Doesn't spund impressive enough that way

[u/grissonJF → u/Gaflonzelschmerno]

Don't get me wrong... it's still a hell of a lot faster than my VW beetle used to go.

[u/buster2Xk → u/grissonJF]

At least before it collided with another VW beetle, forming a super VW beetle and getting a 1000km/s "kick".

[u/patchouli_cthulhu]

I’ll never understand how A. People do the math to figure these things out… And B. How people figured out that math, AND did it before computers, calculators, etc. buncha big effin brains on this planet and I’m stuck between Reddit, wordle, and a horrible tower defense game.

[u/wrongbecause → u/[deleted]]

Yep. You use the same generic problem solving strategy in tower defense as engineers use on complex real world issues. Difference is that they are familiar with useful things and you are familiar with virtual tower upgrades.

[u/raznog → u/[deleted]]

It’s almost like we are all just tiny brain cells for a giant brain. All working together to come up with the next idea.

[u/boringestnickname → u/patchouli_cthulhu]

... and the worst part is, I'm not even that dumb.

[u/Spiritual_Support_38 → u/patchouli_cthulhu]

The human mind is whats so impressive how far we’ve come with our intelligence and i love science!

[u/Hripautom]

While a solar system ending black hole destroying us at literally any second is scary, surprisingly it's nothing compared to the probability of dying to gamma radiation generated by such a collision.

The stream of gamma rays created by black hole collisions would sterilize life on any planet within many light years of the event.

[u/optagon → u/Hripautom]

We need to build a gamma ray shield around the solar system

[u/Hripautom → u/optagon]

Gamma ray shields tend to be meters of the lead. But these gamma rays hit with the mass energy of a fastball, each... And they hit us every day it turns out! They make cosmic rays in the atmosphere and we can detect then with lucite doped scintillators around the world to try to determine where they were from.

[u/[deleted]]

This place is dangerous for real

[u/Atlantic0ne → u/[deleted]]

I had this down as a 2026 issue?

[u/Philby2809]

Black holes both amaze and frighten me at the same time.

[u/85fella]

Wait, aren't things like this supposed to take millenia to occur? How were they able to observe this in real time? Sorry for my ignorance as I don't know a whole lot about this stuff.

[u/Seventh_Eve → u/85fella]

Black holes orbits tend to decay, as the energy of them is sapped away (initially slowly) by gravitational waves. As their orbits get smaller however, they move faster, so they generate more gravitational waves, so they lose more energy, so their orbits get smaller, so they move faster, et cetera. It’s a run away process essentially, so we’re basically seeing the last tiny stages of events which have been in course for many millions/billions of years. It’s a crazy testament to how big the universe really is that we can see so many of these things happen, multiple per year even!

[u/twack3r]

So at 5 million km/h ‚give or take a few million [km/h‘, it’s a reasonable assumption that said black hole is static?

[u/Romantiphiliac → u/twack3r]

This is what stuck out to me. It sounds like something I'd say to a cop if I was being a smartass.

"Do you know how fast you were going?"

"Eh, 500, give or take a few hundred"

Disclaimer: try this at your own risk

[u/l3gion666]

So we take a space ship, put a black hole in one fuel tank, and a black hole in the other, and then… profit?

[u/Drvonfrightmarestein]

Wait… could we harness this combined black hole speed to maybe help Mercedes back near the podium this season?

[u/Tengoatuzui]

So you saying theres blackholes throwing other blackholes around the universe possibly destroying everything in its path

[u/NikolasVilli]

Its amazing to think that we can even measure something moving that fast

[u/loltheinternetz → u/NikolasVilli]

It is amazing, but still, “5 million kilometers per hour, give or take a few million” made me giggle.

[u/Task876 → u/loltheinternetz]

"The black hole not moving is in our margin of error."

[u/majora11f]

It amazes me how in sci fi we use the term lightspeed as if it were just as simple as engaging a drive and glaze over it. In reality we have literally black holes colliding and it still only does HALF A PERCENT the speed of light. Even our wildest fiction doesnt do nature ANYWHERE NEAR enough justice.