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94% of the universe’s galaxies are permanently beyond our reach
- Old_Paris 5y agoThis gives me existential dread
- HKH2 5y agoWhy?
- deleted 5y ago[deleted]
- cyberbanjo 5y agoIf this does but life doesn't, you're doing well
- Old_Paris 5y agoYes, I'm doing well with life, kind of. I would attribute it to reading "Metaphysics: Concept and Problems" by Theodor W. Adorno
- rsj_hn 5y ago6% of galaxies ought to be enough for anybody. :)
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- gremlinsinc 5y agoso there's an estimated 200 billion galaxies...still leaves us 12 billion.... I mean how greedy are we?
- cm2012 5y agoThe last enemy to be defeated will be entropy
- post_from_work 5y agoAn interesting written SF series with similar themes: https://en.wikipedia.org/wiki/Xeelee_Sequence https://en.wikipedia.org/wiki/Xeelee_Sequence
- davidhbolton 5y agoWatching this simulated fly through of 400,000 actual galaxies blows my mind. Space is frickin huge... https://www.youtube.com/watch?v=08LBltePDZw&t=31s https://www.youtube.com/watch?v=08LBltePDZw&t=31s
- klyrs 5y agoIf we phrase it "we're permanently beyond the reach of 94% of potentially malicious alien cultures," does that help?
- tehjoker 5y agoI wonder if this is one aspect of The Great Filter that keeps aliens from contacting each other. 6% is still a lot to work with but shaving off 19 out of 20 galaxies sure helps explain a lot.
- awb 5y agoJust to add to it: If you decided to travel to the furthest galaxies you could reach, at some point even they will move beyond the reach of Earth as space expands. To colonize them means to exile yourself from Earth permanently. Traveling through an infinitely expanding universe is like traveling into a permanent headwind in every direction.
- HKH2 5y agoIf you can handle being 'exiled' from the past permanently, what difference does it really make?
- gremlinsinc 5y agoWhat if we're in a simulation, and algorithmically there's a way or method that will drop you in any coordinate at any time in the universe's timeline so that you can indeed explore space, and return home for dinner? I mean it'd require a TARDIS to exist probably lol, but in a sim, why not? Of course if we're in a sim, then that's probably not part of our overall 'goal' for creation, and likely we're the only creatures created so exploration really won't satisfy us, other than total galactic conquest, but then what?
- brundolf 5y agoWeird question I just thought of: if space is always expanding, why aren't the objects around us, even their very atoms, getting slowly torn apart? Are the forces holding them together just constantly pulling them back together? Is it just a very small amount of expansion at a human scale? Does this affect very sensitive measurements of distance?
- c21h30o2 5y ago> Are the forces holding them together just constantly pulling them back together? Is it just a very small amount of expansion at a human scale? Both. Even our galaxy is held together by gravity that's stronger than the expansion of space on that scale.
- ruined 5y agowhy? it was never going to matter to you. any of us here will be outliers if we even make it to orbit
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- Old_Paris 5y agoMy point is, the physics also apply to a smaller scale. According to this image: https://bigthink.com/wp-content/uploads/2021/10/In-enough-Ti https://bigthink.com/wp-content/uploads/2021/10/In-enough-Ti... When you stand next to somebody and you look at this person, through the expansion of the universe and the amount of time the light needs to travel from the surface of that person, to your eyes; means that when you see this person in the original distance, you do not see that person at the actual distance. It's not possible to share a contemporary timeline with other persons, everything is a few nano seconds delayed, you are existing in everybody else's past. Of course practically this doesn't matter.
- Mizza 5y agoSince we can't ever reach most of the universe, that means we'll probably have to simulate it to ever explore it. Which means we're probably being simulated right now. Hm. Let's hope they left `sv_cheats` available.
- gremlinsinc 5y agoIf we're in a simulation...couldn't we learn to reprogram/hack the sim, and just put our spaceships in another galaxy?
- metagame 5y agoThis assumes that we're "truly" sentient, and on top of that, that we have actual free will. Both seem unlikely if things are actually simulated.
- peterburkimsher 5y agoThank you metagame for considering the philosophical and mathematical implications! Here's an (unpublished) proposal for a consistency proof that free will is finite. Conway's Free Will Theorem: "if we have free will ... so must some elementary particles" https://en.wikipedia.org/wiki/Free_will_theorem https://en.wikipedia.org/wiki/Free_will_theorem Infinity cannot be approximated with finite numbers (MIP* = RE "Prior to the new work, mathematicians had wondered whether they could get away with approximating infinite-dimensional matrices by using large finite-dimensional ones instead. Now, because the Connes embedding conjecture is false, they know they can’t.") https://www.quantamagazine.org/landmark-computer-science-proof-cascades-through-physics-and-math-20200304/ https://www.quantamagazine.org/landmark-computer-science-pro... -> Numbers cannot have infinite strings of digits -> The future can never be perfectly preordained (Gisin "If numbers cannot have infinite strings of digits, then the future can never be perfectly preordained.") https://www.quantamagazine.org/does-time-really-flow-new-clues-come-from-a-century-old-approach-to-math-20200407/ https://www.quantamagazine.org/does-time-really-flow-new-clu... Computers can only run recursive simulations, they can never actually reach infinity. The Turing Machine (cellular automaton Rule 110) can only expand to the limit of the tape. Yet we can choose to surrender our free will to the greater good, and be part of the infinite pattern (cellular automaton Rule 90 Sierpinski Triangle). Rather than crystallising in ourselves, we should thank the root node, and thank others and love our neighbour, continuing the growth.
- totesraunch 5y agoImagine what's beyond the visible universe! I'm no astrophysicist but it's probably closer to 100%.
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- phenylene 5y agoNo one needs more than 640k galaxies.
- austincheney 5y agoIn case somebody doesn't get the joke: https://news.ycombinator.com/item?id=18120477 https://news.ycombinator.com/item?id=18120477
- RobRivera 5y agolmao bill gates
- nanodeath 5y agoKurzgesagt has a video on this: https://www.youtube.com/watch?v=uzkD5SeuwzM https://www.youtube.com/watch?v=uzkD5SeuwzM
- p2t2p 5y ago* provided that we can't overcome speed of light limit
- awb 5y ago* or time travel / manipulate space-time
- kamaal 5y ago* or physics isn't finished yet and methods exist outside these paradigms.
- otabdeveloper4 5y agoAt this point you're basically hoping for literal magic. It's nice to dream, but, well...
- p2t2p 5y agoLasers are magic for pre-Maxwell physicists
- LinuxBender 5y agoEverything is magic until we understand it. If one took a keychain flashlight back a few hundred years they might be burned as a witch. There are still tiny pockets of humans that believe if you take their picture, you are stealing their soul.
- otabdeveloper4 5y agoI'm not against magic. Just don't pretend like you're above people who believe in magic despite being no different under the skin.
- LinuxBender 5y ago
- ruined 5y agothank god
- bserge 5y agoLike backgrounds in a video game - always visible, never reachable. Perhaps the remaining % are also unreachable and we're just falling for the illusion :D
- ajnin 5y agoIt's mind blowing to imagine that the observable universe is bigger than 90 billion light years, space-time expanding at multiple times the speed of light. If expansion keeps accelerating, then at some point gravity won't be able to keep the local cluster together and even those galaxies will drift away, then star systems, then planets, then matter itself will be torn apart until atoms and particles and quarks are destroyed. A dark future awaits indeed. Something in my mind tells me that there must be more to it, the careful balance of universal constants that allow for matter and stars and life to exist surely would not allow it all to be destroyed forever in the end...
- zrm 5y ago> Something in my mind tells me that there must be more to it, the careful balance of universal constants that allow for matter and stars and life to exist surely would not allow it all to be destroyed forever in the end... Keep in mind that we don't really understand this stuff. "Dark matter" isn't a weird phase of matter, it's the name of the Keleven inserted because our observations of the universe don't match up with the theory. Ditto "dark energy." The expansion of the universe is accelerating and we don't know why. If we don't know why, we don't know it isn't going to stop tomorrow, or reverse, or happen differently based on where you are in the universe. The things we've already observed about relativity and quantum mechanics are very counter-intuitive. But at the same time, "I don't want it to" doesn't mean it's not going to happen. The arrow of time goes in one direction. We don't know how it ends until we get there.
- undersuit 5y ago>Keleven A wonderful use of the word.
- awb 5y ago> the careful balance of universal constants that allow for matter and stars and life to exist surely would not allow it all to be destroyed forever in the end... Imagine a brute-force creation of x^y universes with varying cosmological constants. Surely some universes with the right ingredients for life also include a deep freeze or a Big Crunch. Or, maybe our universe was created in a lab somewhere and they’re trying to figure out how to make a stable universe through experimentation. And we’re iteration #42.
- danielinoa 5y agoIf this fact makes you uneasy just know that 100% of the universe's galaxies, except the one we are currently in, are already unreachable within your lifetime.
- nxpnsv 5y agoPretty much true for all other stars as well… we’re not visiting anywhere soon
- gremlinsinc 5y agoIf this fact makes you uneasy just know that (nearly) 100% of the galaxy's solar systems except the one we're currently in are (likely) unreachable within your lifetime. Though to be fair, I think the original title can't possibly know this, for instance if we live in a simulation, what's to say that some sort of algorithm (assuming we learn to meta-code our own existence) could put us in any galaxy we choose... Or warp drives, worm holes... light speed travel hardly seems worth the trouble, and unfeasable.. but if we can master warp drives, and bending space around us... then is there a limit on max speeds? If we can actually reprogram the universe would there be anything we couldn't do? have any other alien civilizations realized that at all?
- marcosdumay 5y ago> except the one we're currently in You keep repeating that part as if it made any visible difference to the number...
- throwawaylinux 5y ago100% of this solar system's other planets and moons are (likely) unreachable by you within your lifetime.
- kamaal 5y agoNearly 100% of the countries on this very earth are unreachable to most poor humans within their lifetime. And for a sizeable chunk of humans even reaching the very neighbourhood of their country, geography involves putting their lives on risk on a near sure to sink boat only to be shot/sent/sunk back by border police. Humans are horrible at working together for their own good.
- joering2 5y agoBeyond OUR reach. I am sure extreme advanced civilization are capable of traveling 3-dimensional space without considering 4th dimension (time). Just like we can use video-recorder to record 3D world and put it on a 2D film to watch on a 2D screen, if advanced ET figured out ways to travel without consideration for time, then then switch from one point to another happens instantaneously. Whether its going from one room to another, or from one place in Universe to another, far far away. To them Einstein theories or articles like this one are just "thing of being a human-being".
- cm2012 5y agoIf it's possible for the galaxy to expand faster than light it's likely possible that we can also go faster than light eventually.
- kakkan 5y agoif the universe is expanding faster than the speed of light why can't we harness that power and travel that fast?
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- kgilpin 5y agoThe expansion of space itself is not subject to the same constraints as travel through space. Put another way: Nothing can travel through space faster than light. But the expansion of space itself isn’t a form of travel, and so it’s not subject to this limitation.
- milleramp 5y agoIs there a galaxy on the boundary that is half disappeared (to us) and half visible?
- c1ccccc1 5y agoThis is a really great question that embodies the hacker spirit of trying to find loopholes and edge cases. I'm not an expert, but I think the answer is that there are no half-reachable galaxies. If there is a galaxy that is only partially reachable, then it must eventually be torn apart by the expansion of the universe. We could theoretically send a ship to the reachable half, and if the galaxy was still in one piece, we could then take a quick jaunt from the reachable half to the unreachable half. So for the unreachable half to be actually unreachable, it would have to be far away from the reachable half. I'm guessing that all galaxies have strong enough gravity that they won't be torn apart by the expansion of the universe. Reachable and visible are different things. There are plenty of galaxies that are visible, but not reachable. But I think a similar argument would apply to show that there are no half-visible galaxies. Light can certainly make it from one side of a galaxy to the other. If we can see the light emitted by the near side of the galaxy, then we can see light that originated on the far side of the galaxy and passed through the near side on its way to us. Both sets of photons will reach us, and both will have about the same redshift. The only difference will be that the the photons from the far side of the galaxy will be a few thousand years older than the near ones. (This is all ignoring the fact that we can see all the way back to the cosmic microwave background, which comes from a time in the universe's history when there were no galaxies at all. Anything we can see that looks like a galaxy isn't even on the visible/not-visible boundary!)
- garmaine 5y agoNo. The proper boundaries are between galaxy clusters, which remain gravitationally bound to each other. If you can reach a cluster such that its gravity is strong than the expansion of the universe, then you can reach every part of that cluster.
- lostmsu 5y agoDoes the mean, that the cluster, that is going to become unreachable next is going to "become" unreachable in its entirety in a single unit of time (like maybe Plank time)?
- koonsolo 5y ago"most of the universe's galaxies are already receding faster than the speed of light" Relativity theory: "It's impossible to go faster than the speed of light" WTF?
- goatlover 5y agoThe expansion of space doesn’t fall under that limitation. Spacetime isn’t a particle or collection of particles. It’s the gravitational field.
- mrphoebs 5y agoSpace-time isn't a gravitational field. Gravitational fields curve space-time.
- goatlover 5y agoWell, that might be a matter of interpretation: "I point out that the often voiced claim that in the general theory of relativity (GR) geometry and gravity are ‘associated’ with each other can be understood in three different ways. The geometric interpretation asserts that gravity can be reduced to spacetime geometry, the field interpretation claims that the geometry of spacetime can be reduced to the behaviour of gravitational fields, and the egalitarian interpretation affirms that gravity and spacetime geometry are conceptually identified." https://www.sciencedirect.com/science/article/abs/pii/S1871177408000053#:~:text=as%20the%20discovery%20that%20spacetime,positions%20rather%20than%20single%20positions https://www.sciencedirect.com/science/article/abs/pii/S18711....
- zamadatix 5y agoExpansion isn't objects in space moving farther apart through space it's the change in the geometry of space itself. A poor analogy might be a continuous zoom of a map map on your phone while something always moves less than a constant speed limit of pixels per second on the screen. It is easy to see this object can move around locations on the map but may not be able to reach most of the map if it is zooming in fast enough that far away portions !at get farther away faster than it can travel to them at the constant pixels per second.
- lazyeye 5y agoInterstellar travel is ripe for disruption.
- ram_rar 5y agoI'll be more than happy if people are successfully able to reach mars in my lifetime.
- asplake 5y ago94% of the _visible_ universe's galaxies