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Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

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Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#161

Post by vaxman »

snapetom wrote: post #119
ednite wrote: post #82

Earlier quoted context omitted.

Not sure why the downvotes—if I came off wrong, my apologies. I genuinely meant it in a humoristic way. I'd honestly love to see a probe launched into a black hole.

We don't do humor here, and I'm not kidding. Humor devolves the site into useless one liners. If you want evidence of that, go to reddit and see how useful that site is these days if you want to actually research and learn something. Slashdot knew this back in the day and while funny posts got visibility, they did not add anything to a user's total karma score.

Oh this site does humor great, it's just that the serious participants are so "focused" they don't (or can't) realize how funny their often esoteric comments are.

As far as devolving into useless one liners --there is an emerging tech called the at-proto (not related to modems hahaa) that is poised to disrupt billions of dollars worth of sites like this one. Enjoy this era while it lasts..

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#162

Post by manquer »

nine_k wrote: post #158
AIPedant wrote: post #11

I think “15 times further from the Sun than Pluto” is more meaningful for most readers than “700 times further from the Sun than Earth.” If it exists, it’s way way way out there.

700 AU is way past heliopause, firmly in the interstellar space. Same, 15 times farther than Pluto is definitely away from the Solar system "proper". It's about 100 light-hours away from Sun. I wonder how could this object be counted as a "planet" belonging to the Solar system, even if it were the size of Jupiter. But it's an object "estimated to be 2 to 4 times the radius, and about ten times the mass of the Earth".…

As long it is orbiting the sun, i.e bound by the solar gravitational field then it is in the solar system?

Also depending how elliptical the orbit, is the perigee might be much closer than 700AU, while still being further than Pluto's orbit. For all we know 700 AU is the apogee and say the perigee is 70 AU (1.4x Pluto's apogee ).

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#163

Post by colonial »

TheOtherHobbes wrote: post #16
api wrote: post #7

Earlier quoted context omitted.

I really hope this is true, because it would mean there is a black hole close enough it could be examined and studied. This might allow us to test physics ideas that can’t be tested any other way, and maybe even to “finish” physics. It could also allow gravity and Oberth effect acceleration of small probes to meaningful fractions of the speed of light for interstellar flyby missions. Imagine the Oberth effect boost f…

I really hope it isn't true because if there's one out there, there will be others, and I'd rather not meet one in person. We don't have enough data to see whether there are unexpected instabilities in detected planetary systems. But it would be an interesting project to look for those.

They're no more dangerous than a regular rogue planet, which are pretty common on a galactic scale. The gravitational effects (disruption to planetary orbits) are the same, and Earth would not meaningfully survive a collision with either.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#165

Post by colonial »

K0balt wrote: post #127
jsbisviewtiful wrote: post #47

Earlier quoted context omitted.

Why useful? Considering how hard of a time astronomers are having to simply find it it’s hard to imagine it being easy to study.

Aside from research, it could be used to provoke time dilation, though I’m not sure how much you could get out of a basketball sized black hole.:8

If you're interested in creating time dilation, then a planetary mass black hole unfortunately won't get you any further than, well, a regular planet with the same mass.

(Aside: time dilation already occurs on and around Earth. GPS satellites have to account for the fact that time runs ever so slightly slower on the ground.)

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#166

Post by rkagerer »

NikkiA wrote: post #70
AIPedant wrote: post #11

I think “15 times further from the Sun than Pluto” is more meaningful for most readers than “700 times further from the Sun than Earth.” If it exists, it’s way way way out there.

I dunno, '700 AU' gelled for me instantly, '15 times the distance to pluto' doesn't even make sense given pluto's orbit isn't anywhere near circular.

1 hour at Warp 4

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#167

Post by gonzobonzo »

nonethewiser wrote: post #34
ryao wrote: post #31

Earlier quoted context omitted.

We should add those planets to the official list too. Gauss considered Ceres to be a planet and I believe him over living astronomers. The motivation for this dwarf planet nonsense was to try to keep the official planet list small so children could memorize them with ease, but that is absurd. We do not remove countries from the map to make it easier for children to learn geography and there are over 100 of them.

I mean… there has to be more to it than that right? But im also open to being red pilled on pluto.

That's mostly it. If you want to dive into the details, I recommend this debate[1].

[1] https://www.youtube.com/watch?v=3AFtgZP6Aa8&t=803s

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#169

Post by Dylan16807 »

manwe150 wrote: post #150
tliltocatl wrote: post #77

Earlier quoted context omitted.

Anything that approaches the sun will do so with faster than escape velocity because the gravitational potential energy gets converted into kinetic during the approach. Newtonian mechanics is time-reversible - just like it's impossible for an object in orbit to spontaneously escape without gaining energy from somewhere first, it's impossible to enter orbit without losing energy to another body.

Small nit: this is for objects approaching from infinity in a two body system. Otherwise the object can be in orbit and already be “captured” there. For example, the moon also approaches earth slightly over the month while speeding up, then slows down while moving away. Or it could just be a 3 body system, which is chaotic and can’t be modeled accurately and can have objects spontaneously eject from the stable system…

Your first nitpick only makes sense with a weird definition of "approaches" for the context, so I think it just adds confusion. They're pretty clearly talking about something that is headed in the direction of the sun and not already in orbit.

And the comment you're responding to already mentioned that other bodies can make a capture happen. Nobody was saying capture is impossible.

Re: Evidence of controversial Planet 9 uncovered in sky surveys taken 23 years apart

#170

Post by smolder »

AIPedant wrote: post #11

I think “15 times further from the Sun than Pluto” is more meaningful for most readers than “700 times further from the Sun than Earth.” If it exists, it’s way way way out there.

I think both comparisons together paint a good picture: 15 times further than Pluto, which itself has an orbit ranging from 30 to 49 AU (the distance between Earth and the sun.)
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