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An unlikely example of a rather unusual megastructure is in the manga/anime Aria: https://en.m.wikipedia.org/wiki/Aria_(manga) https://en.m.wikipedia.org/wiki/
by m4rtink 6y ago
An unlikely example of a rather unusual megastructure is in the manga/anime Aria:
https://en.m.wikipedia.org/wiki/Aria_(manga) https://en.m.wikipedia.org/wiki/Aria_(manga)
It is a slice of life story about a grouo of gonodoli riding turist guides in a replica Venice on terraformed Mars. You can see terraformed mars quite often in SF, that's not what I'm talking about. Not even the flying islands that hist the power sources keeping the planet warm.
You see in tgis story, there is one thing kinda hiding in plain sight - it's terraformed Mars with Earth strength gravity.
Yes, not 1/3 g but full 1 g and they did it during the terraforming, it's not a mistake by the author.
So how exactly do you triplicate planets gravity withou importing 2 times of it's mass in the proccess ?
By buikding a Mars spanning series of particle accelerators that accelerate dense macroscale objects to near lightspeed under the surface.
Thanks to the theory of relativity things behave as they had much more mass as they approach lightspeed, which is exactly what you need to simulate two more Marses of mass needed to achieve 1 g like on Earth - bam, artificial gravity using known physics! :-)
Just don't thing about the insane amount of energy requured to accelerate so much muss in your accelerator racetracks to lightspeed. Or what would happen if even just one of these superlaminar dense capsules anaged to collide with the accelerator wall, making all other crash as well. Very close supernova might seem like a firecracker in comparison.
- elihu 6y agoHuh, that's clever and terrifying.
- ars 6y agoYou would need to capture the ENTIRE energy output of the sun for about 5 years to generate that much energy. If you can do that, terraforming Mars is nothing, you could just grab a bunch of nearby asteroids or a planet or two and combine. And just think about how much material you need in order to build a collector large enough to entirely encompass the sun - it's WAY WAY WAY larger than your added Mars mass. Also you would need a magical strength material just to hold those lightspeed objects in place (think of the huge centrifugal force they are generating). There's nothing in the world that could hold them in place. I assume they are charged - or how are they keeping them in their "track"? No physical material could handle it. So they have to be charged, well the Synchrotron radiation generated would be enough to sterilize anything nearby. So "known physics" is a bit of a stretch.......... :)
- eloff 6y agoNot practical at all, but an unusual idea for sure.
- m4rtink 6y agoStory whise there is a caste of underground dwelling engineers who rarely venture to the surface who are taking care of that - via a giant pipe organ like musical instrument/control console! They effectively play the whole planet using their inner understanding of the system and perfect musical hearing, keeping everything in perfect balance and harmony. (There are actually some other "engineer castes" such as the Salamanders that live on the floating islands and keep the ppanet warm. They are much less baddass but still rather hot blooded for some reason.)
- kiki_jiki 6y agoBLAME! Could be an example of megastructures gone haywire.
- m4rtink 6y agoI still remeber that one episode when the main character goes up a stairwell for quite a while (possibly weeks+) then finally reaches the top, opens a manhole cover basically, enetering a huge room - for one he can't see the ceiling and it goes in all directions and seems flat. After wandering around for an unspecified while he encounters a cyborg scientist looking through some sort of instrument. He tells him this "room" in the megastructure is a spehrical empty space and has the inner diameter of Jupiter. So if you ever wondered where to Von Neumann construction bots that got a little haywire got all the raw materials...
- freeone3000 6y agoMy favorite thing about this is that it's completely irrelevant to the show. It's a healing-type show about the daily life of a gondola driver. It could have taken place in actual Venice with no real changes.
- deleted 6y ago[deleted]
- Retric 6y agoOuch, that’s one of those painfully bad ideas that makes it obvious most people lack a basic understanding of physics. Creating enough mass from energy to hit ~2/3 earths total mass is several orders of magnitude larger than the Death Stars main weapon. And as you point out if basically anything fails all that energy gets released on Mars.
- elihu 6y agoIt's a minor detail of the setting of a story. I doesn't matter if it's practical in real life, it just has to be not be in contradiction with the fictional world of the story. Kind of like Star Trek allowing faster-than-light travel due to imagined discoveries in the fields of physics. I like hard science fiction that's based in known physics, but I can still enjoy science fiction that's not totally realistic as long as it's at least consistent with itself and doesn't contradict known physics out of pure laziness or ignorance. I think it's a better solution than just saying "Mars is at full gravity because of magic we won't explain."
- Retric 6y agoThe advantage of saying magic we can’t explain is you have fewer uses of other magic we can’t explain. Having that much mass moving near light speed requires absurdly strong materials etc. You need a silly energy source, etc etc. Similarly, you get a lot of knock on effects from the other hand waves.
- forgotmypw17 6y agoit's ok, the engineers learned enough from the previous 3 failures to make sure it really doesn't happen again with this one :)
- deleted 6y ago[deleted]
- croon 6y ago> Ouch, that’s one of those painfully bad ideas that makes it obvious most people lack a basic understanding of physics. I disagree. That's the fun thing about scifi. As long as your idea could theoretically work (which you seem to agree), you can decide whether the theoretical risks manifest or not, or handwave uninvented solutions to those. Scifi is about dreaming within our universe beyond our current knowledge or limitations. At least that's my two cents. Edit: Not familiar with this specific book, but just in general terms.
- mrec 6y agoFirefly also included gravity in terraforming: All those moons - just like the central planets, they're as close to Earth-That-Was as we could make 'em: gravity, atmosphere, and such but never provided any explanation. In that medium (live-action TV) it's just handwaving around the production difficulties of showing low-G; Joss by his own admission will cry if you ask him science questions.
- ansible 6y agoWhile I loved the show, the science was particularly bad. For example, in the pilot episode, they pass by a Reaver ship while enroute to another planet. The encounter occurs slowly enough for the crew to get a long look at the Reaver ship as it passes. The closing speed seemed to be about 100mph at best. Whereas with the Apollo mission to the moon, the capsule was traveling 25,000 mph, or ten times the speed of a bullet. And even then it took three days to get to the moon. And even 25k mph is slow if we're talking about crossing actual interplanetary distances.
- mrec 6y agoYeah, Joss 'fesses up to that one in the episode commentary. I don't know if it's "particularly bad" by the standards of screen SF. No shows do it well, and the vast majority don't even try.
- albatruss 6y agoWhat about The Expanse?
- mrec 6y agoFrom the little I've seen of it, much better than most but still not great.
- ansible 6y agoThere are things like the Epstein drive that is nearly "magic". It is as if you had some device that could do direct matter-energy conversion with 99.999999999999999999999% efficiency. Beyond that, they do treat maneuvering in space with greater realism that most shows.
- deleted 6y ago[deleted]
- saberdancer 6y agoIs this really how objects interact with the environment? I am aware of what it means to speed up such an object, as you approach c you need more and more energy, it "feels" as your mass is increasing. What surprises me is that this effect would extend to objects outside? This seems surprising to me. By the same logic, if an object moved at speed of light it would have infinite mass and unless gravity is not proportional to mass, you would have infinite gravity.
- hirple 6y agoHence it is impossible for an object (with mass) to reach c. Only progressively closer - 0.99c, 0.999c, 0.9999c etc.
- saberdancer 6y agoIt's impossible yes, but does it generate a gravitational field?
- carapace 6y agoThere's no "generating" gravity. Energy is Mass. They didn't pack atoms, they packed energy, but it is the same stuff.
- ars 6y agoYes it does! Gravity is generated by energy, and mass is just one type of energy. For example photons produce a gravitational field of their own, and are influenced by gravitational fields. So yes, energy in the form of velocity does produce gravity. It can get complicated to calculate though, because velocity in the same direction as the observer doesn't exist, only in other directions (including perpendicular). A thought experiment: Two huge identical masses are traveling toward each other, and perpendicular to an observer. They collide and "stick" to each other. All their velocity is now rest energy, which obviously has gravity. But this means that even before they collided they also had gravity (since you can never create or destroy gravity, only move it). Now rotate the experiment - one mass is traveling toward the observer, and the other is traveling with the observer. This time when they collide part of it is rest energy, and the rest is kinetic (since the observer is still moving, while the two objects stopped each other dead still at a point in space). But this time, the mass that was with the observer had zero gravity (from the POV of the observer), but the mass traveling toward the observer had more gravity. But it means that gravity is not a "global" phenomenon, it depends on your POV. And that makes for some difficult calculations if you must account for multiple objects all moving. (For example in cosmology. From my understanding the calculations are so complicated that they are mostly just ignored because few objects are moving fast enough for it to matter.)
- Rexxar 6y agoSo the energy they need to bring is the energy equivalent of the matter they would have needed to bring to get the same result. Or an other way to see it : they have to annihilate two Mars planet to get enough energy to create gravity on the third one.
- m4rtink 6y agoYep, pretty much - but tourist from Earth will feel gravity just as at himo and gondola rides will be 100% authentic! ;-) No wonder Aria is a perfect slice of life / healing series - any aggressive aliens or other evildoers don't stand a chance agains their rather low profile yet insanely high tech level! :)