Astronomy / Space New ideas for Planet 9

Shadowdancer

Shadowdancer
What if the elusive 9th planet that is screwing with orbits of bodies beyond Neptune was a small primordial black hole? Here's a small paper exploring that hypothesis based on too much lensing happening within our galaxy, and it comes with a full-scale depiction of a black hole of 5 Earth masses: https://arxiv.org/abs/1909.11090

If nothing else, this is dire news for Nibiru conspiracies.
 

Chris Simon

Chris Simon
I'll read the paper later but my first reaction is skeptical.
A black hole the mass of 5-10 Earths would be what? 15cm in diameter? Probably less.

Now this supposes Hawking is right, but no primordial BH this small would survive this long. That is - unless it comes so close to the Sun on its orbit that it manages to "feed" off of it just enough.

If it was a BH, though, I'd be more inclined to believe it a remnant of an ancestor star our solar system is made of. Then again, in that case it would be MUCH bigger than several Earth masses
 

WeComeInPeace

WeComeInPeace
This is actually a very interesting hypothesis. If Planet 9 was a tiny black hole, would we have any chance of proving that?

As far as I know, Neptune was discovered by watching the motion of the outer planets, and by calculating their somewhat mysterious motion, predicting that there had to be another planet out there. Using the same math, people were able to predict it's position, and then it was a question of turning the telescope in the right direction and go "Yep, there it is and it's blue". Have anyone used the motion of Trans Neptunian Objects, and calculated precisely where Planet 9 was supposed to be, and looked for it?

We can't see a black hole with an event horizon the size of a grapefruit or a bowling ball, but from what I've seen in ED recently, even such a tiny black hole causes gravitational lensing that is much larger than the event horizon itself. Would we be able to detect that?

147533


On an even more wildly speculative note: Could dark matter actually be a load of primordial black holes, or can we rule out that explanation?

Edit: I've been fascinated by the idea of rouge supermassive black holes for a while, and tried simulating one passing through the Solar system using Universe Sandbox. I imagined sitting in the garden and watching the tea cups levitate slightly for a few seconds above the table, but if you send a SMBH through the Solar system it causes the planets to go out of their orbit, resulting in a horrible mess resembling the early stages of the Solar system. I never tried with one the size of a grapefruit :unsure:
 
Last edited:

WeComeInPeace

WeComeInPeace
I've never been looking for planets, but I've found a few asteroids IRL (already "Tagged"). Nowadays where you have digital cameras it's not that difficult. You just need to be patient. You take a series of images of a part of the night sky, and look for anything moving slowly through the field. Satelites, planes and UFOs move much faster, so they're easy to filter out.

That got me thinking. A hypothetical small black hole is still in some sort of orbit, meaning it moves. Maybe you could measure lensing of the stars in the field behind it? I honestly don't know, but Neptune was found 1 deg away from the predictions, and that's not a large part of the sky to monitor for a couple of nights. Furthermore, we have better calculators nowadays than Le Verrier had 💻🖲
 

Chris Simon

Chris Simon
WeComeInPeace said:
I've never been looking for planets, but I've found a few asteroids IRL (already "Tagged"). Nowadays where you have digital cameras it's not that difficult. You just need to be patient. You take a series of images of a part of the night sky, and look for anything moving slowly through the field. Satelites, planes and UFOs move much faster, so they're easy to filter out.

That got me thinking. A hypothetical small black hole is still in some sort of orbit, meaning it moves. Maybe you could measure lensing of the stars in the field behind it? I honestly don't know, but Neptune was found 1 deg away from the predictions, and that's not a large part of the sky to monitor for a couple of nights. Furthermore, we have better calculators nowadays than Le Verrier had 💻🖲
Click to expand...
I don't think you can measure lensing of something this small. I mean, it would be a couple centimeters in diameter and WAY past Pluto. Even if it was the size of Pluto, you couldn't measure it's lensing effect.

And to answer your previous question - yes people did try to calculate its position from irregularities of Neptune's orbit. And didn't find anything. Which is probably why the BH hypothesis came to be in the first place.

The sad fact is, if it really is a black hole and it's this small, we will never find it unless it collides with something.
 

WeComeInPeace

WeComeInPeace
Chris Simon said:
...unless it collides with something.
Click to expand...
Like a T-9 loaded with biowaste? As long as I get the coordinates I'm pretty sure I can make that happen :)

Edit: If we could confirm the existence of PBHs, it could potentially solve the "dark matter" issue, and honestly, that's a bit of a embarrassment. Nothing is showing up at the LHC to the best of my knowledge. If it should hypothetically turn out that all the dark matter is black holes, that would change our view on the Universe considerably, but I guess any explanation would.
 
Last edited:

Chris Simon

Chris Simon
WeComeInPeace said:
Like a T-9 loaded with biowaste? As long as I get the coordinates I'm pretty sure I can make that happen :)

Edit: If we could confirm the existence of PBHs, it could potentially solve the "dark matter" issue, and honestly, that's a bit of a embarrassment. Nothing is showing up at the LHC to the best of my knowledge. If it should hypothetically turn out that all the dark matter is black holes, that would change our view on the Universe considerably, but I guess any explanation would.
Click to expand...
Well, PBHs being "dark matter" is definitely one of the explanations I could get behind. Unlike the prominent "It's a completely different type of matter that doesn't interact with anything", because the chance that there is yet another particle type that we don't know about is becoming highly unlikely.
Plus it collides with most of the theories that proved to be otherwise very good. On the other hand the PBHs already ARE in our theories, we just haven't found one.

So the whole argument boils down to "We know what it does but we don't know what it is" vs. "We know what it is and how it works, we just can't find it yet" of which I'm definitely inclined towards the latter. :)
 

WeComeInPeace

WeComeInPeace
Chris Simon said:
Well, PBHs being "dark matter" is definitely one of the explanations I could get behind. Unlike the prominent "It's a completely different type of matter that doesn't interact with anything", because the chance that there is yet another particle type that we don't know about is becoming highly unlikely.
Plus it collides with most of the theories that proved to be otherwise very good. On the other hand the PBHs already ARE in our theories, we just haven't found one.

So the whole argument boils down to "We know what it does but we don't know what it is" vs. "We know what it is and how it works, we just can't find it yet" of which I'm definitely inclined towards the latter. :)
Click to expand...
Science can be "interesting" because it can tell you about reality, but where science is "exciting" is at the fuzzy edges of our "web of knowledge". That is the area where imagination is somewhat accepted. I've always liked Feynman's description of the scientific method, where he starts by saying "First we guess...". I think it's also why I think science in general has become a little too hostile against metaphysics. Empiricism and Logical Positivism is fine, but I'm sort of a Feyerabend guy when it comes to philosophy of science:

en.wikipedia.org

Paul Feyerabend - Wikipedia

en.wikipedia.org en.wikipedia.org

Many misunderstood him, and he was a provoking son of a gun, but even Popper accepted Feyerabend's theories at the end.
 
Last edited:

WeComeInPeace

WeComeInPeace
There's an experiment called the Optical Gravitational Lensing Experiment (OGLE) in Poland. It scans the sky for evidence of gravitational "microlensing," places in space where a planet or some other object's gravity has bent the path of a ray of light, causing it to hit Earth. In the cases of the stars studied by OGLE, this light-bending just looks like the star momentarily brightening.

But OGLE has reported something strange, they said. Six times, it has spotted very brief microlensing events, less than 0.3 days long, suggestive of very fast-moving objects between 0.5 Earth masses and 20 Earth masses zipping past stars. This isn't how planets look to OGLE, Unwin said, and there's good reason to suspect that the six objects might be primordial black holes. (Another possibility is very-fast-moving "free floating planets" moving around outside star systems, but current planetary models wouldn't predict that many such planets zooming around the universe.)

www.livescience.com

Is Our Solar System's Mysterious 'Planet 9' Really a Grapefruit-Size Black Hole?

It probably isn't a black hole, if it exists at all. But two physicists think we should check to see if it's a black hole anyway.
www.livescience.com www.livescience.com
 
You must log in or register to reply here.
Back
Top Bottom