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Rotating Black Holes May Serve as Gentle Portals for Hyperspace Travel
- beefman 8y agoOriginal source: https://theconversation.com/rotating-black-holes-may-serve-as-gentle-portals-for-hyperspace-travel-107062 https://theconversation.com/rotating-black-holes-may-serve-a...
- dang 8y agoOk, changed to that from https://daily.jstor.org/rotating-black-holes-may-serve-as-gentle-portals-for-hyperspace-travel/ https://daily.jstor.org/rotating-black-holes-may-serve-as-ge.... Thanks!
- cletus 8y agoPut me firmly in the camp that believes the speed of light is a hard limit on the universe and I'll use Isaac Arthur dismissal of FTL travel as to why. He contends that there likely isn't a sentient civilization within about a billion light years of us because the signature of Dyson spheres would be unmistabkable and unmissable. Now this isn't to say there isn't one that's say, 600 million light years away that built their first Dyson sphere 500 million years ago although, in practice, this doesn't really change the probabilities that much. If there's FTL then that billion light year practical limit really goes out the window as you can effectively get anywhere in the universe, making the volume of absence be many, many times the size of the observable universe. I'm not sure why the author is talking about gravity ripping you apart in a black hole. It Is Known [tm] that larger black holes have pretty gentle event horizons. I'm not sure why it matters that a black hole would be spinning. You can pretty much assume every significant mass in the universe is spinning to some degree (a state of zero spin being highly unlikely over even small amounts of time). The author talks about the inner event horizon and I guess that's the point. But all of that is highly theoretical. Nothing is known about the inner workings of a black hole. It's all highly theoretical and beyond the ability of general relativity to describe. No other theory has been able to adequately explain or describe gravity let alone extreme gravity so your view on what's within the event horizon probably depends on which unproven theory (eg string theory) you subscribe to. So this is speculation based on speculation.
- felipemnoa 8y ago>>Put me firmly in the camp that believes the speed of light is a hard limit on the universe and I'll use Isaac Arthur dismissal of FTL travel as to why. I would modify your sentence to say that the speed of light is a hard limit through space. Space on the other hand does not seem to have that limitation [1] [1] https://en.wikipedia.org/wiki/Alcubierre_drive https://en.wikipedia.org/wiki/Alcubierre_drive
- ThrowawayR2 8y agoThe Alcubierre drive is a fantasy. It's the equivalent of saying "I can start a business selling unicorn rides if I have a unicorn." The unicorn in this case being "negative mass", there being no way to synthesize such a thing nor even a plausible path by which it might be possible.
- ben_w 8y agoAnd before anyone mentions Casimir cavities, I did a blog post in the style of a paper about that: https://kitsunesoftware.wordpress.com/2017/04/20/can-a-casimir-cavity-be-used-to-construct-true-negative-mass-metamaterials/ https://kitsunesoftware.wordpress.com/2017/04/20/can-a-casim...
- magicalhippo 8y agoAFAIK the Casimir force is due to the van der Waals force between the plates, so doesn't that spoil the negative energy party from the get-go? https://arxiv.org/abs/1605.04143 https://arxiv.org/abs/1605.04143 https://arxiv.org/abs/hep-th/0503158 https://arxiv.org/abs/hep-th/0503158
- sp332 8y agoI'm not an expert, but this paper makes a convincing argument that that's not a problem. https://arxiv.org/abs/1702.03291 https://arxiv.org/abs/1702.03291
- freedman1611 8y agoAs much as I love science fiction. In reality, even making it the nearest star is an impossible feat. Even traveling at the speed of light (which we are not even sure the human body can handle) it would take 100 years to reach our nearest star; let alone the nearest black hole. Even whether black holes exist, and what they really are is hotly debated. I think the idea of interstellar travel is futile, and we should focus on improving our quality of life here (free energy i.e. Telsa tech, transporting goods with electrogravitic vehicles, curing diseases, more scientific agricultural practices, easing access to education/job skills, etc).
- senectus1 8y agoWe might be able to create our own spinning black hole gate :-P What could possibly go wrong with that idea?
- learc83 8y ago>Even traveling at the speed of light...it would take 100 years to reach our nearest star The nearest star is a little over 4 light years away, not 100.
- samplatt 8y ago>Even traveling at the speed of light (which we are not even sure the human body can handle) it would take 100 years to reach our nearest star Er, no. Travelling at c, it would take 4.5 years to get to our nearest star. The nearest (known) black hole is V616, 3,000 years of travel away if travelling @ c.
- rishav_sharan 8y agoA bit pedantic but considering an acceleration and then deceleration of 1g, i can see the 100 year number being valid
- saagarjha 8y agoIt would take just under a year to accelerate to the speed of light at 1g. This doesn’t significantly change the four year number.
- snarfy 8y agoI recall reading somewhere the density at the event horizon of the super massive black hole at the center of our galaxy is about the same as water. The singularity is supposedly infinite, but the event horizon depends on the size of the black hole.
- PopePompus 8y agoThis isn't quite right. If you take the mass of Sgr A* (the black hole in the center of the galaxy) and divide it by the volume of a sphere (let's ignore rotation for simplicity) with the radius of the event horizon, you do get a density value near that of water. But almost all of the mass is concentrated in or near the singularity. If you ignore the small amount of stuff falling into Sgr A* at any given moment, the density at the event horizon is 0.
- soneca 8y agoMy sci-fi plot theory: our universe is what is inside a black hole. The big bang was the formation of a black hole on another universe pulling matter to ours.
- colordrops 8y agoIsn't that just a mainstream physics theory?
- soneca 8y agoIs it? Gotta change my plot now then :)
- db48x 8y agoThe problem with that plot is that even if it's true, it doesn't change anything. You can't leave the black hole (because space-time at the edge is expanding faster than the speed of light), so there's nowhere else to go.
- soneca 8y agoThere is where the "-fi" part enters (I'm ok with "soft" sci-fi).
- anonytrary 8y agoholography? https://en.wikipedia.org/wiki/Holographic_principle https://en.wikipedia.org/wiki/Holographic_principle
- beautifulfreak 8y agoStanford physicist Leonard Susskind gave a great talk on it. https://www.youtube.com/watch?v=2DIl3Hfh9tY https://www.youtube.com/watch?v=2DIl3Hfh9tY
- steanne 8y agohttps://phys.org/news/2012-05-black-hole-universe-physicist-solution.html https://phys.org/news/2012-05-black-hole-universe-physicist-...
- dev_dull 8y agoJohn Titor is that you?
- vertline3 8y agoI'm just confused, I thought a black hole was where gravity was so strong light could not escape it just starts looping back on itself like a coin in a large funnel, then how could we escape? We would just spiral down the drain? Why would there be a portal?
- YayamiOmate 8y agoIf your drain analogy holds beyond the point of you losing the sightof probe, the matter that goes into drain does not cease to exists, even if for all your practical purposes it does. On the contrary, you can be sure it does reappear somewhere. Also, it's pretty much certain that wherever there appears infinity in physical model you can be sure it's a limitation of the model, not actual physics of the object. We do not observe infiities, even though pretty much every of our models has some. Those would be two basic hunches against stuffing matter into infinity without consequences. Some kind of exit seems natural, the question is how destructive it would be.
- vertline3 8y agoPredicting portals is still far from that though. Like I would be ejected to the other side? And gravity would stop pulling me in? I could see a burst of energy somehow.
- sliken 8y agoIf there were an exit to a blackhole, they would stop gaining mass. If that was true they would all be the same size.
- rhn_mk1 8y agoIs it just me, or does the article not attempt to explain what this has to do with "hyperspace travel"? The only thing new here is that you can plunge into oblivion without getting torn apart in the process.
- unparagoned 8y agoNope, your not missing anything. The whole hyperspace stuff sounds like clickbait. You need exotic matter stuff with negative mass/energy stop stop a wormhole from collapsing, otherwise it would destabilise as soon as a photon enters it. This article is showing that in theory if you could keep the bridge open somehow, you could send a ship through. That's a big if
- julius_set 8y agoI do wonder though if you travel at the speed of light wouldn't your ship break apart even if you accidentally hit a tiny rock in space? Maybe even dust?
- deleted 8y ago[deleted]
- virgakwolfw 8y agoYes, they might. And then again they might not. Probably not. In fact, there’s not a snowflakes chance in hell they will. This is the scientific equivalent of wondering how many angels can dance on the head of a pin. Oh, except now they have a computer model. Plus ça change, plus c'est la même chose
- justanegg 8y agowe're more likely to cure death than hyperspace travel
- Roark66 8y agoI'm not quite sure how do we start with a "probability to survive trip to the event horizon" and end up with a possibility to travel faster than light? What is that hyperspace the article talks about? How falling down the black hole would transport the object anywhere spatially? The only thing such a trip could be used for is to see the end of the universe. As every object getting near the event horizon experiences the time slowing down compared with the outside a person on board a ship could probably see stars going out etc as billions of years passed. The time slows down so much one could never "pass through" a black hole as reaching the singularity would require the time to stop. So as the ship approaches the singularity the black hole would get smaller and smaller as it evaporated during those billions of years until it eventually disappeared. However, a ship wouldn't survive the disappearance as when the black hole is getting smaller the tidal forces increase eventually ripping the ship to shreds.
- mirimir 8y agoYes, TFA says nothing about what happens after surviving the fall. But from Burko and Khanna (2019) I get this: > The fate of an astronaut who falls into a black hole depends not just on the latter’s properties (such as the intrinsic parameters, i.e., the mass and spin angular momentum, and the external perturbation fields) but also on the former’s worldline. ... However, astronauts with positive energy and low angular momentum (including counterrotating ones) arrive at the outgoing leg of the black hole’s inner horizon ("outgoing inner horizon", henceforth, OIH). > The properties of spacetime at the OIH have been proposed to be those of an effective shock wave singularity. Specifically, it was proposed in [2] that daughters of a family of free-falling astronauts whose geodesics intersect with the OIH, and who are separated only by time translations (and labeled by the advanced time values at which they cross the event horizon (EH) [symbols]) experience a change of order unity in typical metric perturbations, and that these changes occur over a lapse of proper time that drops like [symbols] with increasing [symbols], where [symbols] is the surface gravity of the OIH. Sufficiently late-falling daughters therefore experience an effective shock wave singularity, the Marolf-Ori singularity ("outflying singularity"). I have no clue what that means. Anyone? 0) Burko and Khanna (2019) The Marolf-Ori singularity inside fast spinning black holes, https://arxiv.org/pdf/1901.03413.pdf https://arxiv.org/pdf/1901.03413.pdf
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- UncleSlacky 8y agoThis looks a lot like what was proposed back in the 70s by Adrian Berry in his book "The Iron Sun: Crossing the Universe through black holes": https://www.goodreads.com/book/show/1091779.The_Iron_Sun https://www.goodreads.com/book/show/1091779.The_Iron_Sun
- reagle 8y agoA halo drive sends light, instead of people, slingshotting around binary black holes and harvests the energy (via solar sales) in the blue-shifted life. Much safer!