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Interstellar Mission to a Black Hole
- api 1y agoWhat’s be super cool is discovering a! asteroid mass primordial black hole in our solar system. No epic interstellar flight needed. It would be super hard to detect though. We’d have to spot it by gravitational effects or get very lucky and notice lensing. It would emit nothing unless it happened to be nomming on some matter, and even then it’d be so small that the signal would be weak.
- noam_k 1y agoThat would be cool. I read somewhere that a black hole with the mass of the moon will absorb about as much cosmic radiation as it emits Hawking radiation. This is a fine line between "the black hole disappears before we can examine it" and "oops, we got eaten by a black hole".
- MomsAVoxell 1y agoHey, its not like an analog of "Yeah, lets just throw some more mass at the newly-forming black hole in our neighbourhood", said every human that has ever thrown things into the fire, forever ..
- gus_massa 1y agoSorry, but I have to link the "Hole Lotta Trouble" episode of Pocoyo https://www.youtube.com/watch?v=HL_0OL7vZ44 https://www.youtube.com/watch?v=HL_0OL7vZ44
- MomsAVoxell 1y agoYes, you really do.
- api 1y agoBlack holes aren't cosmic vacuum cleaners. They're just super super super compact objects. I've actually posted this a few times: If you suddenly transformed the Moon into a black hole of the same mass, it would continue to orbit the Earth in the same spot. It wouldn't suck up the Earth or anything. The ocean tides would continue as normal under the influence of the black-hole-moon's gravity, which would be the same if it was orbiting at the same distance. You wouldn't see a moon in the sky, but if you focused a good telescope on where it was you'd see gravitational lensing. It would be a little smaller than a BB.
- antonvs 1y agoIf it's in a stable orbit in the solar system, it wouldn't be able to "eat" us. Black holes gravitate exactly the same as any other mass, so it would have the same gravitational effect on Earth as any object if the same mass. What makes black holes special is that you can get much close to their center of mass than you can with normal objects. When you're that close - inside the radius that a normal density object of that mass would have - then you experience gravity at a much higher strength than normal. Put another way, even if our Moon was a black hole with the same mass, very little would change except that it would no longer reflect sunlight. Ocean tides on Earth would remain the same. You wouldn't want to try to land on it though...
- akomtu 1y agoThere was a movie where Moon was a hi-tech 'megastructure' with a white dwarf inside. I wonder if it would be theoretically possible to set up such a mini-dyson sphere around a mini-blackhole.
- api 1y agoIf you set it up at the right radius it would have 1g gravity at the surface, like a little mini-world. It wouldn't be able to hold an atmosphere though, so it would have to have pressurized buildings on it.
- throwaway290 1y agoSomebody write a sci fi with this please, just make sure to describe how trash disposal works
- antonvs 1y agoIf you're interested in black holes and trash disposal, check out the 1978 short story, "The Nothing Spot": https://vintage.failed-dam.org/nothing.htm https://vintage.failed-dam.org/nothing.htm
- antonvs 1y ago
- the8472 1y agoWe do not what such a thing anywhere near Earth though. https://arxiv.org/abs/astro-ph/9911309 https://arxiv.org/abs/astro-ph/9911309
- api 1y agoOnly if it evaporates, which it probably wouldn't do for billions of years.
- the8472 1y agoSomething of asteroid mass would be above the CMB equilibrium temperature, thus already be undergoing runaway evaporation. From the paper: "This implies that M must be less than 0.8% of the mass of the Earth"
- NL807 1y ago>It would be super hard to detect though. Would it? I would've thought there is enough dust in the solar system that it would create constant xray emissions. Even if it's faint, it would stick out like a sore thumb on super sensitive xray telescopes.
- TheOtherHobbes 1y agoAn asteroid-mass black hole is around a micron across. It's not going to be nomming on much because the matter distribution inside the solar system isn't that dense. Any tiny black hole born in the big bang would either have evaporated (if Hawking was right...) or would have grown much larger by now. Even a moon-mass black hole (0.1mm) wouldn't be eating much, although its gravitational effects would be much more obvious.
- antonvs 1y agoWe wouldn't have to get lucky if it was on the last stages of evaporating. If it has reached a mass of about a billion kg it would be shining plenty bright to detect, and would only have a few thousand years to live before destroying most life on Earth with gamma radiation.
- terminalshort 1y agoAccording to this calculator https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator https://www.vttoth.com/CMS/physics-notes/311-hawking-radiati..., the luminosity would only exceed that of the sun for 46.7 nanoseconds, so unless it's much less than 1 AU away we would probably be fine.
- terminalshort 1y agoCould you find it by Hawking radiation?
- pavel_lishin 1y agoI remember reading somewhere that it's possible for such a black hole to get captured by an asteroid (or vice versa, I guess), and happily live inside a rock, slowly orbiting inside the asteroid, sucking up atoms here and there. It would be detectable as an asteroid that's twice as dense as it should be.
- Cthulhu_ 1y agoIf it was asteroid mass, wouldn't it have the same gravitational effect of an asteroid itself? Plus, someone else mentioned it'd be like a micron across, which if my pop-sci understanding of these things is correct, it'd disappear in a poof of hawking radiation.
- api 1y agoIt would have the same mass, and it would be tiny -- like the size of a hydrogen or helium atom. AFAIK an asteroid mass black hole wouldn't evaporate yet since the CMB is still warmer than its Hawking temperature. Very tiny black holes would have evaporated earlier in the universe. A black hole evaporates when its Hawking temperature exceeds the ambient temperature.
- hansmayer 1y agoSuch a fantastic overview. And here we are, instead of building the infrastructure for accelerating solar sails, we're investing the money in AI-pornbots instead :/
- einrealist 1y agoAt least the AI-pornbots will operate from space. /s
- radu_floricica 1y agoConsidering AI-pornbots are increasing the derivate of the function, they might actually be the right move.
- deleted 1y ago[deleted]
- TheOtherHobbes 1y agoWhat are the odds the first alien probe to visit the solar system will be a pornbot or some form of marketing droid?
- Cthulhu_ 1y agoAI porn sells, solar sails are a research project at best. There is no money to be made from space flight, only discovery, and unfortunately capitalist forces far outweigh curiosity. Even the space race wasn't for science but for politically one-upping the others, doubly so because being able to bring a payload into space also demonstrates they can bring a payload anywhere on the world.
- Mistletoe 1y agoHow do you stop if your solar sail has you going near light speed? Or does it strand you halfway between stars in the doldrums where the force on both sides of your sail equals out from two stars?
- hvb2 1y agoYou would fold the sail?
- hansmayer 1y agoThat would not stop the probe from continuing to glide further. He's making a good point here.
- ceejayoz 1y agoGliding is fine. We whizzed past Pluto with New Horizons. Never stopped, just a photo flyby.
- voidUpdate 1y agoThat only stops you accelerating, it doesn't put the brakes on
- jordanb 1y agoDeceleration is the same as acceleration. You use the light of the star you're approaching to slow down.
- Cthulhu_ 1y agoBut if you're going near light speed, the light / particles would be too faint to have any significant effect until you get very close. You'd basically just fly backwards straight into it. Unless your sail is very large and/or the total mass is very small.
- SiempreViernes 1y ago
- wartywhoa23 1y agoIt is stated multiple times across the article that the probe would need a means of changing is trajectory, but not even a hint of idea how that could possibly be done is given. So the most important and blocking aspect of the mission is simply skimmed over, and the rest of it is built upon this omission as if it was something trivial to come up with. Does anyone have an idea how to equip a 1g spacecraft with any means to steer itself at 1/3 speed of light? The kinetic energy at that speed would seem to require something very incompatible with the weight constraint, to my understanding.
- antonvs 1y agoEasy fix: change the description to "Interstellar Mission to the General Galactic Vicinity of a Black Hole"
- dvh 1y agoSimply. You do Monte Carlo with the probes. You fire 1000 and one or two will have perfect trajectory so that no correction is needed.
- magnat 1y agoDid you, by any chance, play Outer Wilds recently?
- gus_massa 1y agoI don't think 1000, or even 1000000 are enough if you use random directions. Space is <huge>huge</huge>. This has been posted here afew times https://joshworth.com/dev/pixelspace/pixelspace_solarsystem.html https://joshworth.com/dev/pixelspace/pixelspace_solarsystem....
- estimator7292 1y agoSolar sails. You can fire a shit ton of lasers from the planet (or orbit) at the probes and very,very slowly boost them up to the desired velocity.
- marcellus23 1y ago
- vee-kay 1y agoRelated: "Project Solar Sail" by Arthur-Clarke and others, is a good anthology (stories, essays and illustrations) about the new Age of Sailing (Sailing in Space)via lightships and solar sails.
- ck2 1y agoThe most aggressive yet most realistic project we could reasonably do is the SGL Telescope Won't happen under this administration and really might take a planet-wide effort but it would be incredible https://www.centauri-dreams.org/2022/07/22/solar-gravitational-lens-sailcraft-and-in-flight-assembly/ https://www.centauri-dreams.org/2022/07/22/solar-gravitation... https://www.nasa.gov/general/direct-multipixel-imaging-and-spectroscopy-of-an-exoplanet-with-a-solar-gravitational-lens-mission/ https://www.nasa.gov/general/direct-multipixel-imaging-and-s... https://www.universetoday.com/articles/a-mission-to-reach-the-solar-gravitational-lens-in-30-years https://www.universetoday.com/articles/a-mission-to-reach-th...
- deleted 1y ago[deleted]
- amai 1y agoWhat is the point of such a mission? There is literally nothing to see there.
- Cthulhu_ 1y agoA black hole may be invisible but its accretion disk and the effects on the light being deflected around it are anything but.
- hunterpayne 1y agoIsn't Relativistic time dilation a problem for this idea? To the probe, the trip is only a few centuries but to us on Earth, millions of years. Maybe 0.1c isn't enough to cause this to be a huge problem but I think it is. Perhaps one of you Einstein enjoyers can tell us for certain.
- kakacik 1y agoNo need to be snarky and especially not here re basic science. Time dilation happens exponentially, ie with 0.5c you don't have time going 1/2 slower, rather a miniscule amount. Once you keep approaching speed of light closer and closer, all things go extreme (time, energy required, mass and so on).
- turtletontine 1y agoTime dilation is 1/sqrt(1 - (v/c)^2). So at 0.1c that’s 0.5%. Certainly much higher than any human has ever experienced! But not exactly gonna change 100y to 100,000,000y.
- prerok 1y agoTime dilation is exponential. At 0.1c it's definitely measureable but not a practical problem.
- optimalsolver 1y agoHaving read Michael Crichton's Sphere, I think I know how this ends.
- LogicFailsMe 1y agoSeems like first we need to get out of the gravity well... Then we need to cure ageing to give people skin in these games... Then we need to crack FTL or find a way to cryo-sleep or we end up with dystopian science fiction ships of the damned... Not in my lifetime I suspect...
- deleted 1y ago[deleted]
- dlasud 1y agoSied
- metalman 1y agobuild very large optical interometric telescopes, put the in geosycrenous orbit or L², and point them at various gravitational lenses in the universe till something interesting shows up, like the well lit event horison of a black hole surrounded by bright stars. given starships load carrying capacity, previos mass restrictions, are gone, with cost guaranteed to be dramaticaly less, and time frames that will get public interest, plus the same instrument can be used to image exoplanets surface's at high resolutions et say cheese
- AlessandroF6587 1y agoHow a nanoprobe (required by the propulsion solution) can send data back to us from >10 ly away?
- sliken 1y agosend 1 a day, that way you only have to communicate to the nearest probe.