Could Evidence of Primordial Black Holes Be Hiding in Plain Sight? (universetoday.com) 62
"Are Primordial Black Holes real...?" asks Universe Today. "If they do exist, a "new paper suggests they may be hiding in places so unlikely that nobody ever thought to look there..." — in planets, in asteroids, and here on earth.
Physicists hypothesize that Primordial Black Holes (PBHs) formed in the early Universe from extremely dense pockets of sub-atomic matter that collapsed directly into black holes. They could form part or all of what we call dark matter. However, they remain hypothetical because none have been observed... The authors claim that evidence for PBHs could be found in objects as large as hollowed out planetoids or asteroids and objects as small as rocks here on Earth. "Small primordial black holes could be captured by rocky planets or asteroids, consume their liquid cores from inside and leave hollow structures," the authors write. "Alternatively, a fast black hole can leave a narrow tunnel in a solid object while passing through it."
"We could look for such micro-tunnels here on Earth in very old rocks," the authors claim, explaining that the search wouldn't involve specialized, expensive equipment... "The chances of finding these signatures are small, but searching for them would not require much resources and the potential payoff, the first evidence of a primordial black hole, would be immense," said Dejan Stojkovic [the paper's co-author from the State University of New York]. "We have to think outside of the box because what has been done to find primordial black holes previously hasn't worked...." Cosmology is kind of at a standstill while we wrestle with the idea of dark matter. Could PBHs be dark matter? Could they behave like the authors suggest, and be detected in this manner?
"The smartest people on the planet have been working on these problems for 80 years and have not solved them yet," Stojkovic said. "We don't need a straightforward extension of the existing models. We probably need a completely new framework altogether."
"We could look for such micro-tunnels here on Earth in very old rocks," the authors claim, explaining that the search wouldn't involve specialized, expensive equipment... "The chances of finding these signatures are small, but searching for them would not require much resources and the potential payoff, the first evidence of a primordial black hole, would be immense," said Dejan Stojkovic [the paper's co-author from the State University of New York]. "We have to think outside of the box because what has been done to find primordial black holes previously hasn't worked...." Cosmology is kind of at a standstill while we wrestle with the idea of dark matter. Could PBHs be dark matter? Could they behave like the authors suggest, and be detected in this manner?
"The smartest people on the planet have been working on these problems for 80 years and have not solved them yet," Stojkovic said. "We don't need a straightforward extension of the existing models. We probably need a completely new framework altogether."
Found 'em (Score:3)
Primordial black holes in Comice pears (Score:3)
The forum participants at growingfruit.org may have answers.
A narrow tunnel of destruction sounds like larvae of the codling moth, a pest of apple and pear that is the proverbial "worm in the apple."
The go-to chemical-free protection for backyard fruit growers is to put plastic zip-lock sandwich bags around the fruit as they form, before the codling moth larvae hatch and start looking for fruit to tunnel into. My go-to low-risk-to-humans chemical is acetamiprid, a so called neonicotinoid that binds to
I'm skeptic (Score:4, Interesting)
While in the scifi black holes are usually depicted as just that... black... holes, it should usually have, if they remain in a place with mass, an accretion disk.
Atmost everything rotates. Asteriods, planets, stars... they rotate. When some object cross paths with a BH at slow speed (if it's fast enough, the object could just cross from side to side) all that mass will enter the BH not directly, but rotating. So... in other words, it will create an accretion disk.
And that disk can endure for a significant time, turning into a very bright object we should be able to detect. It doesn't seeming the case.
Or... maybe I'm overestimating the lifetime of an accretion disk on a small black hole. I'm not sure about the supposed real duration of it.
Re:I'm skeptic (Score:5, Informative)
They are talking about microscopic black holes. These things will have a radius of 1nm ( I.e. you'd need a microscope to see the track through a rock ).
Something this size would have the mass of a very large mountain ( 10^15kg) , and take 10^20 years ( universe is 10^10 years old ) to evaporate.
Calculator is here: https://www.vttoth.com/CMS/phy... [vttoth.com]
I'm skeptical because if these things are kicking about in any appreciable numbers, they would fall into stars and completely eat them.
Still worth looking for, would be a simple job for a team of students.
Re: (Score:2)
Re:I'm skeptic (Score:4)
I'm skeptical because if these things are kicking about in any appreciable numbers, they would fall into stars and completely eat them.
Its easy to see how microscopic black holes can’t eat stars though, at least not easily. Look at the total watts for that 1nm diameter object, 350W or half a horsepower. Thats like an atom powering a horse. The surface temperature needed to pass that heat flux is 1E8 C or a very similar temperature to the center of a star. Growing microscopic black holes is literally taking the most forceful explosion possible under physical laws and forcing it backwards with gravitation, only when the curvature reaches a low (large) size does it get easy to feed by increasing the target size while decreasing the radiation pressure outward which is why it can take long periods of time and very low mass ones emit so strongly that they simply evaporate inside the core of a star. That is unless it’s huge and collapsing under its own mass after most of its nuclear fuel is spent.
Re: (Score:2)
Could you please explain the 350W of power? Is that just the Hawking radiation that comes out automatically from a 10^15 kg black hole? If they are so bright, wouldn't they be a bad candidate for black matter because they would be visible in space? Doesn't that mean that most of the black holes would have to be bigger - probably less than 100W so that they could hide more easily?
For those that understand a bit and want more this paper seems interesting [arxiv.org]
Re: (Score:2)
Could you please explain the 350W of power? Is that just the Hawking radiation that comes out automatically from a 10^15 kg black hole?
Yep, it’s the radiated power due to hawking radiation and for the most part is mostly photons but as the power increases anything can start popping out
If they are so bright, wouldn't they be a bad candidate for black matter because they would be visible in space? Doesn't that mean that most of the black holes would have to be bigger - probably less than 100W so that they could hide more easily?
Yes, well they aren’t that visible because of distance. Near earth sunlight has about 1000W/m^2 so while the color will be different the brightness is about the same as a fully reflective rock with 1/3 sq meters area or a few square meters of actual space rock profile. Possible to see with our best telescopes but only close by earth. Then as yo
Stars that just up and disappear (Score:2)
There was a news item (yeah, yeah and yeah) recently about astronomers being baffled with stars that just disappear from survey images without being noticed as supernova explosions or otherwise leaving a nebular or neutron star pulsar remnant.
Apparently this really is "a thing" among astronomers doing these survey, but the high frequency of the claimed occurrence makes being swallowed by a black hole unlikely.
Until now . . .
Re: (Score:2)
Something related to this? https://www.savvydime.com/astr... [savvydime.com]
Interesting.
Re: (Score:2)
Pretty much.
Interesting yes, but extraordinary claims require extraordinary proof and all of that. That the disappeared stars that were once not-so-disappeared stars on archival photographic plates weren't defects in emulsions to begin with and so on.
Now if there were a plausible theory giving bounds on the prevalence of the nano black holes in TFA, and if there was some estimate of the rate at which these black hole would eat stars, one could think there is something to these disappearances. But the
Re: (Score:3)
It actually turns out that a black hole inside a star would be very stable. [science.org] And it should be possible to detect it, based on subtle features of the star's radiation. That seems like a much better approach than looking for holes in rocks. Our best estimates are that a primordial black hole should hit the earth about once every billion years at most. It might have happened a few times in the history of the planet.
Re: (Score:3)
No, 1 nanometer is orders of magnitude too high an estimate. Observed data constrains primordial black hole masses to about 10^13kg, which gives a Rsch of about .0001 nanometers. That's only a couple of orders larger than a proton, it is *not* easy to feed them and one is not going to fall into a star and completely eat it. In the unlikely event it collides with a star, it will absorb scarcely any of it as it passes through.
Re: (Score:2)
A 10^-15 kg black hole has an event horizon radius of a thousandth of a nanometre and a "surface" gravity of ~ a third of a g.
There are lots of ways of putting limits on primordial black holes, eating stars (actually neutron stars) being just one of them. If they're small enough they can happily sit inside a star, or Earth, without any problems. They probably wouldn't very often because they wouldn't interact enough to slow down.
There's a range of primordial black holes in the 10^-15 to 10^-10 g (smallest a
Re: (Score:3)
Agreeing with ErroneousBee, I think these things are too small to have a proper accretion disk. Gravity is weak so even things that are a few thousand atoms away would not get sucked in and just wouldn't be affected. Particles either collide with the black hole and disappear or they more or less ignore it. To be honest, based on what I understood before (and IANAP and more specifically IANYP) I don't see how they would get captured by an asteroid at all. What slows them down to match the asteroid's speed i
Re: (Score:3)
Agreeing with ErroneousBee, I think these things are too small to have a proper accretion disk. Gravity is weak so even things that are a few thousand atoms away would not get sucked in and just wouldn't be affected. Particles either collide with the black hole and disappear or they more or less ignore it. To be honest, based on what I understood before (and IANAP and more specifically IANYP) I don't see how they would get captured by an asteroid at all. What slows them down to match the asteroid's speed in the first case?
You simply need to use a gravitation of two mass calculator [omnicalculator.com] to see how that’s wrong. Use the op example of 1E8 kg mass and the other as the mass of a proton or so, at 1cm you experience 1g as a free proton. This rapidly increases to infinity at the horizon and wouldn’t have an accretion disk so much as emitting light like a 350 watt bulb and ripping apart all matter within only a few micrometers or less and exploding it in a superheated gaseous cloud of continuous explosion.
Re: (Score:2)
1g doesn't sound like enough to much affect a solid. E.g. if I put a 1cm radius hole with a vacuum inside a rock and placed the black hole perfectly in the middle, surely nothing would happen? If the black hole was surrounded by fluid, that would be different on the other hand.
Re: (Score:2)
In the hypothetical scenario any matter getting close is going to be moving extr
Re: (Score:2)
Use the calculator..
I tried; when I put in exponents it seems to break. I'll keep trying to work out what goes wrong.
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Primordial black holes are sub-microscopic. They would be orders of magnitude smaller than a hydrogen molecule. They will not be accreting anything.
Re: (Score:3, Insightful)
The antidote is to disrespect the liars and punish them early on the small stuff.
Re: (Score:3)
There really isn't an antidote to psychopathic manipulators. Other than ignoring them. If one con fails, they try another. Rinse, repeat. These people are very predictable, actually. Just toxic to anyone who stays in close proximity or listens to them. Self-care requires boundaries excluding them.
Re: (Score:2)
There really isn't an antidote to psychopathic manipulators. Other than ignoring them. If one con fails, they try another. Rinse, repeat. These people are very predictable, actually. Just toxic to anyone who stays in close proximity or listens to them. Self-care requires boundaries excluding them.
Black holes (Score:3)
Re: (Score:3, Informative)
Well, the thing about a black hole - its main distinguishing feature - is it's black. And the thing about space, the colour of space, your basic space colour, is black. So how are you supposed to see them?
Because that isn't their main distinguishing feature at all. That would be their extreme mass.
Hugely massive objects tend to trap less massive objects in unstable orbits, which eventually spiral into the highly massive object, and at a very high speed.
Those objects (particles) at such a high speed interact and heat up.
Heating up is another term for emitting light.
We just so happen to be fairly well equipped to see things that emit light.
Re: (Score:1)
It wouldn't leave a hollow structure (Score:2)
Unless a planet was spinning at impossible speed the core and then the rest of the planet would simply collapse into the black hole as there would nothing to prevent it and even solid rock doesn't have nearly the strength on that scale to resist it. So any planets that did have black holes hiding inside wouldn't remain planets for long.
Re: (Score:2)
The problem is there would be no support for the rock above once the rock below has been swallowed up and at the centre the pressure is so high even though its zero G any liquid rock would immediately fill any voids and in turn get eaten. Rinse and repeat.
Re: (Score:1)
If an atom sized black hole is eating a billion atoms a second at the center of the earth, it will still take 300M years to consume 1kg of mass (assuming liquid iron.) The sun will die and become a white dwarf before any appreciable amount of matter is consumed by such a black hole.
Re: (Score:2)
Would be a hell of a lot more than a billion and it wouldn't stay atom sized for very long, but yeah, other than that. great analysis.
Re: (Score:2)
Highly Unlikely (Score:2)
Indeed, rather that these somewhat unlikely notions, the best way to detect PBH
Re: (Score:2)
Re: (Score:2)
You won’t be able to detect primordial black holes nor interactions from them with the actual LIGO experiment
You can definitely search for them [arxiv.org] in certain ranges of masses and number densities. Whether or not you detect them depends on whether they are there to be found. The talks I have seen suggest that LIGO will be able to cover a lot of the available mass/density phase space that remains unchecked under the assumption the dark matter is primarily black holes of a uniform mass. At the low end of the mass space PBHs would be extremely numerous and we'd have seen signs of their gravitational anomalies as they pa
Re: (Score:2)
You won’t be able to detect primordial black holes nor interactions from them with the actual LIGO experiment
You can definitely search for them [arxiv.org] in certain ranges of masses and number densities. Whether or not you detect them depends on whether they are there to be found. The talks I have seen suggest that LIGO will be able to cover a lot of the available mass/density phase space that remains unchecked under the assumption the dark matter is primarily black holes of a uniform mass. At the low end of the mass space PBHs would be extremely numerous and we'd have seen signs of their gravitational anomalies as they pass through the Earth etc. This new paper is suggesting ways they could hide but it seems very implausible.
Here is the thing, the frequency is wrong for the type considered in the article cited originally which are microscopic and the weight of 10,000,000 kg on up to maybe a planet mass. It would be far to high frequency and the ripples of rather the derivative of the quadruple moment would lack enough amplitude in any merger or interaction. They are looking for regular old large black holes that just exceed the expected solar mass range black holes so maybe 50 to 100 solar mass and up to it’s detectio
Re: (Score:2)
current theory is wrong (Score:2)
Re:current theory is wrong (Score:5, Insightful)
> You need a new theory it's been almost a century of stagnation.
You misunderstand.
The universe is expanding - and that expansion is accelerating, where we'd expect it to be constant. We don't know what is causing that acceleration, but we want to give the thing doing it a name - so we call it "dark energy" or "dark matter". It's because there's a phenomenon we can't explain - not that there's a theorised particle and we're out to try and prove it (like we did with the Higgs Bosun, for example).
There is no _theory_ here as such - there is a space for one, which hasn't yet been formed to any decent degree yet. If/when someone comes up with a plausible theory for why the universe expands as it does, then the words you quoted would read "the smartest people on the planet have been working on this for 80 years, and Joe Bloggs solved it".
Once the theory has been formed, then people can spend another 80 years trying to prove it - but that's another problem.
Re: current theory is wrong (Score:2)
The universe is expanding - and that expansion is accelerating, where we'd expect it to be constant.
Why would we expect that? Because our theories of gravitation assume "flat" space-time curvature as distances from masses increase?
Perhaps we are deluding ourselves by expecting that a theory tested and supported by local observations doesn't need an extra term or two at larger distsnces.
Two ideas come to mind:
Space-time is like a water bed. Curved downwards by the presence of local mass, it bulges up farther away. To conserve the total volume. We see the acceleration of distant masses as the downward s
Re: (Score:2)
> Two ideas come to mind:
There are proposed theories along these lines. Try f(R) gravity, TEVES, Galileon Gravity, Brans-Dicke theory, and Quintessence. Disclaimer: GPT-4o told me about these. So if one of them turns out to be a theory about the operation of toilets bowls, I apologize. Looks legit though.
Re: (Score:2)
Space-time has been measured to be flat on the largest scales to an incredible degree of precision. The method I've read about involves measuring angles between regions of disparate temperatures in the CMB.
But I do like your water bed theory; it needs some modification, though. Rather than curving down and bulging up it would probably be better to say it compresses in one place and it must conserve itself by expanding elsewhere.
Unfortunately, it is my understanding that we've never seen evidence that spa
Re: (Score:2)
There is no dark matter. You need a new theory it's been almost a century of stagnation.
Here's one that shows some promise. [wikipedia.org]
Asteroid with liquid core? (Score:2)
You must be joking. Also, not a physicist, but, if "micro" holes were formed 12 billion years ago wouldn't they have evaporated yet?
There are no gravity anomalies in the asteroid belt wtf
Re: (Score:2)
You must be joking. Also, not a physicist, but, if "micro" holes were formed 12 billion years ago wouldn't they have evaporated yet?
There are no gravity anomalies in the asteroid belt wtf
The paper I linked to above [arxiv.org] says that some of them probably have and you could detect them with that. Depending on their starting mass you'd get occasional explosions from their final evaporation happening somewhere "close" (10 parsecs?) to Earth that you could detect.
Fission Track Dating (Score:2)
Geologists use a technique called Fission Track Dating in certain Uranium bearing minerals. It's not the best radiometric dating technique because the tracks "heal" if the sample gets heated. The same process would impact any search for a PBH track in a rock.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Smart People (Score:3)
"The smartest people on the planet have been working on these problems for 80 years and have not solved them yet"
Time to call in the stupid people.
Our motto: "Non Impediti Ratione Cogitationis".
Don't black holes (Score:2)
gobble up anything that goes into their event horizon? What is to prevent anything from stopping this process once it gets to the center of a planet or star? I'm pretty sure everything would turn into a black hole if there were many of these things around.
Re: (Score:2)
Don't black holes / gobble up anything that goes into their event horizon? What is to prevent anything from stopping this process once it gets to the center of a planet or star? I'm pretty sure everything would turn into a black hole if there were many of these things around.
Sure, but the idea with them is that they're really small, so almost nothing does fall into them and on the other hand they are evaporating all the time via hawking radiation so, if they start off small enough then, on average, they are getting smaller almost all the time.
Diblert (Score:3)
Re: (Score:2)
That's just what I thought. Sadly a few of them have previously made me think of different sort of "dark matter" too :)
Not enough rapidly spinning asteroids (Score:2)