12 ms·
Some potentially interesting uses for it: - definitive sink to send all of our nuclear waste (it would be the /dev/null of the Solar System) - gravitational e
by henearkr 7y ago
Some potentially interesting uses for it:
- definitive sink to send all of our nuclear waste
(it would be the /dev/null of the Solar System)
- gravitational energy generator (limitless, until we have no more mass to throw in)
- johndunne 7y agoA /dev/null for the solor system would indeed be an awesome feature :) Though the most dangerous part of this would be the risk of loading the material onto a rocket. Sigh.
- henearkr 7y agoOr maybe very dangerous physics experiments would be arranged to occur in space in a collision trajectory with Devnull, so that it would then be automatically annihilated if it went wrong... Probably the more interesting use is that of an energy source!
- qubex 7y agoLet’s set up a petition to name the (hypothetical) primordial black hole at the nether edges of the Solar System “Devnull”!
- Chris2048 7y agoThere was a story like that called "iHole", but it appears to have disappeared from the 'net..
- henearkr 7y agoIs it related to that? https://www.urbandictionary.com/define.php?term=iHole https://www.urbandictionary.com/define.php?term=iHole
- Chris2048 7y agoI don't think so. It was about a product release by an apple-like corp that was a small personal hole that you could use as a garbage bin.
- xenophonf 7y agoThis is probably what you're thinking of: https://pastebin.com/ateTJxEK https://pastebin.com/ateTJxEK
- fsiefken 7y agohow would this sink differ from using the sun as /dev/null - other then that you might disrupt potential stellar consciousness?
- henearkr 7y agoAgreed. Well, Sol consciousness is already disturbed by occasional comets, isn't it? :) The use as an energy source, however, would even outlast the lifetime of the Sun as a star.
- wtallis 7y agoIt takes substantially more delta V to send a rocket into the sun than to send it out of the solar system entirely. Getting a rocket to a particular object in the outer solar system may take more delta V than either of those options unless you're really patient.
- dr_dshiv 7y agoI don't have an intuition for why it is harder to go to the sun than leave the solar system. How do you think about that?
- RandomGenerated 7y agoSolar winds
- bogcotton 7y agoIn order to get to the Sun rather than just speed past it, you have to decrease your velocity dramatically. When you're in a stable orbit, you are actually spinning around the sun at a huge pace. To gain enough velocity to leave the solar system, you have to increase that pace by an amount that is less than the pace you already have. As a terrible analogy, it takes less energy to overtake a car that is travelling in front of you at a higher speed than it does to slow yourself to a complete stop.
- 7y ago
- pingyong 7y ago>definitive sink to send all of our nuclear waste That seems like a lot of effort when you can just send it to nowhere and it will very, very, very likely never hit anything, ever.
- henearkr 7y agoWell, agreed (or you can throw the trash into Sol). And what do you think about the other use, as an energy source?
- pingyong 7y agoThat makes me wonder how we would get the energy from there back to earth. I mean we already have a for current purposes infinite energy source right at our doorsteps (the sun), we just need to harvest it.
- henearkr 7y agoIt could be used on-place to fill some energy reservoir. Which could be sent anywhere, or also could be used for space travel for example. Yes I agree that currently a Dyson sphere is the most sensible project humanity could ever think of!!
- chronolitus 7y agoI was wondering about the necessary delta-v to do that vs. throwing it into the sun and found this [1] interesting table. Quite informative, it seems like the naive approach of going straight into the sun is much more expensive (dv of 24.0 km/s) than escaping the solar system (dv of 8.8 km/s). But, it seems that there is a trick where you use 8.8km/s to almost escape the solar system, then turn around with very little dv cost and plunge into the sun. [1] https://en.wikipedia.org/wiki/Delta-v_budget#Interplanetary https://en.wikipedia.org/wiki/Delta-v_budget#Interplanetary
- mnw21cam 7y agoYes, that's basic orbital mechanics. It takes longer that way though. There are many examples in orbital mechanics where you can trade efficiency for patience.
- dvdkhlng 7y agoI think the most obvious way to utilize a close-to-earth black hole is for space-flight. By utilizing the Oberth effect [1] it is possible to gain extra kinetic energy when firing engines very deep inside the black hole's gravity-well (while performing a sling-shot). The Penrose Process [2] may also allow for some kinetic energy boost. Unfortunately both effects do not seem to offer the kind of multiple-orders-of-magnitude gain required to make interstellar travel practical. [1] https://en.wikipedia.org/wiki/Oberth_effect https://en.wikipedia.org/wiki/Oberth_effect [2] https://en.wikipedia.org/wiki/Penrose_process https://en.wikipedia.org/wiki/Penrose_process
- beobab 7y agoI'm pretty sure I read a short story about this in an anthology called "Black Holes" by Jerry Pournell back when I was a youngster. In short, the black hole was a "gift" from some advanced race who dropped it into orbit of our star by braking it with Pluto (hence its erratic orbit) for the purpose of interstellar travel.
- henearkr 7y agoIsn't there some way to stockpile the kinetic energy in several passes, instead of only one slingshot, then finally use all of that for a final throw?
- guelo 7y agoThe limit is the escape velocity of the orbit.
- hinkley 7y agoNot if you have time. And three bodies. If you've achieved escape velocity from the 2nd body (eg, Earth) but not the first body (eg, the Sun) you can keep swinging around the 1st body stealing speed off of the 2nd one each time. Takes some careful orbits and a long time, but NASA does it all the time.
- 7y ago
- dvdkhlng 7y agoAnother idea would be to use the black hole as a gravitational lens to construct a large telecscope. I wonder what the focal length and the effective lense diameter would be. Also the orbital velocity of the image sensor (in orbit around the black hole) might be too high to make this useful. See also [1]. [1] https://physics.stackexchange.com/questions/25498/the-sun-as-a-gravitational-lens https://physics.stackexchange.com/questions/25498/the-sun-as...
- jagger27 7y agoWouldn't you place it at the Sun-IX L1? Edit: never mind, I just remembered there's a specific distance from a massive object you have to be to hit the focal length sweet spot. I wonder if having a smaller radius makes the focal length shorter?
- Enginerrrd 7y agoI can help on this one! In short, it won't work very well. The sun is a much better object to use. Basically, gravitational lenses don't have a "focal length" per se. It's not an exact analogy to a classic glass lens. There is a minimum distance you need to be away from an object to use it as a g-lens. But as you get further away than that, it'll work better. Now, the minimum distance you need to be away from the massive object decreases as the mass of the object increases. So for the sun, you'd have to place a camera about 500AU away to use it. That's too far to be practical at our current technology level. For a smaller object like a planet sized blackhole, you'd have to be orders of magnitude further away. Not very helpful! Now, it's possible I'm mistaken as I'm thinking about some calculations I did on schwarzchild geometry and I didn't consider what would happen very close to the blackhole where curvature is very high, but my intuition says that it won't be very helpful at all. That doesn't mean the blackhole won't be helpful though!!! I think there's an ENORMOUS number of useful experiments we could do. And, I think blackholes can be used as very powerful computers, possibly quantum ones, but I don't know the details.
- ageofwant 7y agoThere is no such thing as nuclear waste, just unprocessed fuel. Things that can't be processed can be dumped under 50cm of sand and you build a kindergarten on top of it. It will be a lower radiation hazard than a one hour plane trip.
- perseusprime11 7y agoIf ever there is a space drive that needs to built for Interstellar travel, can we harvest gravitational energy from this black hole to power it?
- Sir_Cmpwn 7y agoUse as a sink has two issues: - getting nuclear waste out of Earth's gravity well is risky, if the rocket explodes it scatters nuclear waste throughout the atmosphere. And very energetically, given the amount of rocket fuel needed to achieve this kind of flight - getting to planet 9 (black hole 1?) will require loads of fuel or lots (>100 years) of time. Lots of time for something to go wrong, lots of time for errors in orbital calculations to accumulate, small target to hit
- frickinLasers 7y ago> small target to hit Extremely small. The paper has a to-scale illustration of the hypothesized black hole. I wonder what happens to a bus-sized object if you send that black hole through it...
- eloff 7y agoThere are much easier ways to deal with nuclear waste. If you could afford to launch it into space, that's really good enough. You can put it on a collision course with the sun, or just into an out of the way orbit around the sun (or even the Earth as long as it doesn't degrade and fall back while still active.) But really it's easier still to manage it on earth itself. Which is why, even at SpaceX prices nobody does that (that and rockets have a nasty habit of suffering rapid unscheduled dissembly.)
- skykooler 7y ago> You can put it on a collision course with the sun Counterintuitively, this is far more expensive than launching it into said black hole, or just out of the Solar System all together.
- ruffrey 7y agoInteresting- why is that?
- 317070 7y agoThe escape velocity from the sun is 42.1 km/s, while the earth is orbiting at 29.78 km/s. The 29.78 km/s is 3 times closer to the escape velocity than to 0 km/s. This is the first order approximation reason.
- ekimekim 7y agoThe Earth is moving around the sun at ~30km/s. The escape velocity of the sun is ~42km/s. So if you start from Earth, it only takes 12km/s of change in velocity (called "delta-V" by rocket scientists / KSP players) to leave the solar system, but more than twice that (30km/s) to slow down enough to hit the sun.
- thebluehawk 7y agoOrbital mechanics. The earth is orbiting the sun at 30 kilometers per second. So if we launched something into space, since it started on earth, it would have that speed (similar-ish to throwing a ball from a moving car). So that object would now also be orbiting the sun at 30 km/s. We would need to slow it down that much in order to "fall" into the sun. Once something was in earth orbit, it would only take about 12 km/s of delta v (change in velocity) to escape the solar system. More info and math here: https://space.stackexchange.com/questions/3612/calculating-solar-system-escape-and-and-sun-dive-delta-v-from-lower-earth-orbit https://space.stackexchange.com/questions/3612/calculating-s...
- Scapeghost 7y ago> - definitive sink to send all of our nuclear waste (it would be the /dev/null of the Solar System) Now, black holes probably aren't known to be gateways to other locations, but that comment made me wonder what if they are, and dumping our hazardous waste in them has far reaching consequences somewhere else, then that in turn made me think of what other cosmic-scale consequences of alien technology might be out there. I mean, if a civilization has planet-spanning tech, their "waste products" could be on the scale of planets too. Somewhere, a species must be burning through solar systems like we're burning the Amazon.
- xurias 7y agoMight as well throw it into the sun if you have that much trash. Maybe they got around to building space elevators.
- Scapeghost 7y agoI don't mean just literal garbage, but more like side-effects of "exotic" technology that messes with the fabric of space and stuff like that. Like was it The Three Body Problem or some other story where an alien species’ faster-than-light travel tech causes the universe to expand faster and faster, making it harder and harder for younger species to produce enough energy for FTL.
- sandworm101 7y ago>> definitive sink to send all of our nuclear waste That depends on the orientation of this thing. If it is spinning in just the right way, dumping anything into it would be like activating the death star. Even a week astrophysical jet pointed at earth would be a very bad thing. The last place you want to be standing when feeding a black hole is above/below it.
- henearkr 7y agoSo first things to know when we find it: - how is the axis (like finding the head of a fluffy shitzu dog) - how much is it spinning?
- daveslash 7y agoGetting nuclear waste off the surface is extremely risky & challenging. Rockets occasionally explode and scatter their payload. Even a 0.01% (1 out of 10,000) failure rate might be considered too high a risk. I think that a lot of people would not take the risk that 1 out of every 10,000 rockets with nuclear waste will explode and scatter the contents into the upper atmosphere.
- MertsA 7y agoEspecially high level radioactive waste which is some of the only stuff you might care enough about to worry about a "permanent" solution. The existing nuclear payloads are either RTGs or occasionally fresh fuel that is only lightly radioactive compared to high level waste.
- EricE 7y agoWhy would you want to throw away "nuclear waste" - we should be burning it! It's only viewed as waste because of politics and ignorance. Instead of stupidly burying it we should be building the various reactors that will easily burn our existing waste - dramatically reducing the overall radioactivity and producing energy at the same time! All the fear mongering around nuclear power is beyond hysterical at this point :(
- labawi 7y agoPersonally, I'm also concerned with magnitudes of "low-level" waste, which I believe is not really burnable. Not that it would be reasonable to launch entire reactors and ancillaries.
- sandworm101 7y agoIf it is still radioactive, it can almost certainly be reprocessed and shoved back into a reactor.
- beefman 7y agoParent is talking about stuff like tyvek suits. Also, steel components like reactor vessels and steam generators. Also, fission products are extremely radioactive and non-burnable. None of it is the least cause for "concern", of course.
- emilfihlman 7y ago100% this. Sending nuclear waste to a black hole? Now that's the epitome of stupid.
- hackerpacker 7y agoyou must have missed the second bullet point.
- jorge-d 7y ago"Nuclear waste" is a term that is used to describe the byproduct, but also all the equipments that came in contact with radioactive material (cf [0]). So while we can indeed reuse some of the waste on other future nuclear facilities, there will still always be some kind of waste. [0] https://en.wikipedia.org/wiki/Radioactive_waste#Low-level_waste https://en.wikipedia.org/wiki/Radioactive_waste#Low-level_wa...
- lliamander 7y agoYou want to feed the beast?
- henearkr 7y agoHow could you not feed such an adorable tiny creature?
- lliamander 7y agoThat's the thing - if you get too close, you can't not feed it!
- henearkr 7y agoHe's so irresistible!
- nobrains 7y ago"definitive sink to send all of our nuclear waste" ... where it would slingshot and return back to earth like a nuclear waste comet
- ropiwqefjnpoa 7y agoI feel that once we have a method to deliver all that nuclear waste to the black hole, we'll then have a process to utilize it instead.
- deleted 7y ago[deleted]
- ryan_j_naughton 7y agoThe concept of waste is a very narrow view of the world and one trapped in our 20th century concepts. Waste implies we have no use for it any further. This concept views the world on very limited time scales (wherein we can continue to take from the world and turn things into waste that we have no use for any longer). Instead we should always be thinking about reuse of materials. Waste should never be a terminal state so much as the waste products of one process should be converted into a useful input to something else. Ultimately with limited materials on planet earth, virtually everything needs to exist in a cycle (water cycle, carbon cycle, etc). The problem with the blackhole idea is that all atoms / baryonic matter could be used for something. When you send them to a blackhole, they literally cease to exist as baryonic matter (or at a minimum are never usable again). Thus, you are literally taking that material out of use (technically they will eventually be converted into energy as hawking radiation).
- m4rtink 7y agoExactly - in our universe on a fundamental level all waste is just atoms and elementary particles in the end. With enough clean & cheap energy nothing really prevents you from reassembling those particles into something useful.
- kamaal 7y ago- That's Jupiter already. - That's Sun.