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Why is there a normal galaxy sitting at the edge of the Universe?
- tectonic 6y agoNice gravitational lens observation! We're hoping to use the same technique with the Sun to observe exoplanets by launching a fleet of small satellites to 547 AU (80 billion km / ~3 light days). The craft would sample the distorted Einstein ring around our Sun from that vantage point, then combine and reconstruct an image of the disk of an Earth-like exoplanet up to 100 light-years beyond, at a resolution of 25 kilometers / pixel. https://orbitalindex.com/archive/2020-07-08-Issue-72/#more-on-that-solar-gravity-lens-focus-mission https://orbitalindex.com/archive/2020-07-08-Issue-72/#more-o...
- sandworm101 6y agoNot the same technique, but there are similar architectures that could be implemented far sooner. Earth's atmosphere as a refractive telescope: https://www.scientificamerican.com/article/earth-could-be-a-lens-for-a-revolutionary-space-telescope/ https://www.scientificamerican.com/article/earth-could-be-a-...
- tectonic 6y agoNot nearly as powerful, though.
- sandworm101 6y agoThat depends on the planet used. If it works for earth, the next step might be Jupiter or Saturn, something that might be possible by only repositioning the spacecraft. It may even be possible to use the sun's atmosphere, the transparent part, as a lens.
- trimbo 6y ago> it’d still take 25 to 30 years for them to reach a vantage point .... > mission designers would have to pick carefully because they could observe only a single target It will take 30 years to get in position but then we can only look at one target? While it sounds very neat, I'd rather fund something we can use more than once, and sooner.
- freeqaz 6y agoStill valuable as a way to observe a potentially habitable planet in more detail. If we wanted to launch a probe there, it would take a lot more time!
- mrfusion 6y agoWe should build one for each target we want to observe. Starship is going to open so many opportunities.
- augusto-moura 6y agoYou CAN use for more than 1 target, you just need to reposition the telescope a bit. See [1], is a great great video on the subject. I can't recommend enough [1]: https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI
- pas 6y agoThe whole concept is that we should launch a fleet of them every few months. Very lightweight semi-autonomous smart lightsails with some optics. The first fleet helps targeting the second, and all those who come after them. https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI (already linked by a sibling comment, but yes, can't recommend this enough!)
- skykooler 6y ago25 kilometers per pixel is incredible resolution for something that far away!
- biotinker 6y agoThat would be tremendous. Earth is 12700 km in diameter, so such an image would be a bit more than 500px across. Here is a picture of the Earth that is about 500px in diameter: https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg https://cdn.mos.cms.futurecdn.net/3upZx2gxxLpW7MBbnKYQLH.jpg
- andy_ppp 6y agoDo we only get a ring or do we get the whole thing? If we only get a ring why is that? Is the thing we are bending light around in the way?
- aasasd 6y agoYour question seems to be sorta answered in this thread: https://news.ycombinator.com/item?id=24425595 https://news.ycombinator.com/item?id=24425595
- s1dev 6y agoHow do you propose to power a fleet of spacecraft at 550AU? Would you be able to acquire enough RTGs? What about DSN time for the downlink?
- PopeDotNinja 6y agoAnd how would you get them out to, and stop at, 550 AU? Voyager 1 and 2 are nuclear powered with RTGs and they are respectively about 150 AU and 125 AU from the sun, and they are going really fast. The Voyager RTGs are also fairly depleted at this point. I’m guessing these spacecraft would need a faster, more efficient mode of propulsion, like a nuclear thruster or ion drive (or Epstein drive?!). One could also get a lot more fuel for the journey if the the probes didn’t have to launch fully fueled from the Earth’s surface.
- rini17 6y agoNo need to stop at 550AU, the gravitational lens keeps working beyond that(theoretically all the way to infinity). As for how to get there, yes, innovative propulsion is required. My idea is that the probe would dive close to Sun and use solar energy (sail? electric propulsion?) to accelerate itself out to hundreds of km/s.
- 205guy 6y agoI was wondering how fast myself and found this: https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/ Voyager-1 is the fastest at 38,000 mph (61000 km/h) with respect to the Sun, but currently about 90,000 mph (144000 km/h) relative to earth (I guess this fluctuates annually).
- pas 6y agoSun slingshot, solar sail https://www.youtube.com/watch?v=NQFqDKRAROI https://www.youtube.com/watch?v=NQFqDKRAROI
- pvarangot 6y agoThat webpage says a tech demo is due 2024, with launch in 2034 and the constellation would reach 550AU by 2064, so probably a lot of how this will work is still WIP.
- z92 6y ago> 547 AU For comparison Voyager-1 is now at a distance of 40 AU only.
- dmead 6y agoIs that number correct? Why not just launch at those starts at that point?
- lpghatguy 6y agoFor comparison, the nearest star to us is 268,770 AU away, or around 491 times further away. It would take quite a bit longer to get there!
- dmead 6y agoi guess i was thinking more about the complexity of arranging a constellation of telescopes around sol versus just sending one much closer to a target star.
- onlyrealcuzzo 6y agoIs Voyager-1 still accelerating?
- saagarjha 6y agoNope, both are slowly decelerating as they leave the solar system: https://upload.wikimedia.org/wikipedia/commons/0/0c/Voyager_speed_and_distance_from_Sun.svg https://upload.wikimedia.org/wikipedia/commons/0/0c/Voyager_...
- hashtagmarkup 6y agoThat is not correct... it is 150 AU away from earth. https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
- cgriswald 6y agoThat is incorrect. It's approximately at 150 AU[0]. For reference, that's about three times the distance of Pluto at aphelion. 547 AU is about 11 times the distance of Pluto at perihelion. [0] - https://voyager.jpl.nasa.gov/mission/status/ https://voyager.jpl.nasa.gov/mission/status/
- networkimprov 6y agoIt's not a new idea... I first heard of it in the intro segment of this Cool Worlds Lab vid https://www.youtube.com/watch?v=jgOTZe07eHA https://www.youtube.com/watch?v=jgOTZe07eHA
- lordnacho 6y agoHow does the lensing work? Why doesn't the galaxy in the middle between us and the faraway galaxy pollute the image with its own light? It it separated by frequency or some trick?
- sp332 6y agoThe light bends around the galaxy. You're right that looking straight at the galaxy wouldn't work, but looking just a tiny bit to the sides does.
- plasticchris 6y agoYour link suggests the satellites word need to be around 2000 AU to avoid the corona, though I suppose the delta v requirements would be pretty small for such a large change so far from the sun (but my only source for the intuition is kerbal so take it with a grain of salt).
- ckosidows 6y ago20 AU per year is a tremendous distance. Pluto is apparently right around 25 AU. Is this speed actually feasible even with solar sails? Big layman here. I only skimmed this link but this stood out to me.
- mensetmanusman 6y agoWow.
- anigbrowl 6y agoThat's really cool. If it's good enough to detect geographic features, will it be possible to photograph the same planet from the night side later in its orbit?
- marsokod 6y agoThat's completely mad! I'd love to be part of that.
- not2b 6y agoThat's four times as far away as Voyager 1 is. I see from the link that it would take 25 to 30 years to reach that distance, and only one target could be observed: we would have to have one particular exoplanet we want to image and go to the right point for the sun to focus the image to.
- interfixus 6y agoIf that can be done, it means the light and the info is there. Meaning here. The lensing and the 550 AU are just ways to catch it. I should be highly surprised if we do not - long before 2064 - have optical and computational trickery to catch such resolution with snapshots from somewhere very close to home.
- sandworm101 6y ago>>> Like this one, it’s not understood how it can exist. I don't like that phrase. It suggests the possibility that this galaxy might not exist, that this could be observational error. I think it does exist. We understand exactly how it exists because we can observe it existing. The more accurate phrasing might be "it's not understood how it could have evolved so quickly".
- CDSlice 6y agoI think the phrase is fine since according to our best models of galaxy formation these galaxies should not be able to exist and yet they do. As such we don't understand how these galaxies can exist and need to do more research to come up with better models that can explain the existence of these galaxies.
- undersuit 6y agoThe article also states that a galaxy making stars at the rate of this new one shouldn't be a disc galaxy. >the theoretical models are wrong, or at least (and more likely) incomplete.
- newacct583 6y ago> that this could be observational error This could absolutely be observation error. Messups in science happen all the time. You never take a single data point at face value without question, in any field. The spectrum might be polluted by another more distant object, the line matching might have been faked by some other intervening medium, the modelling for the lensing galaxy could be wrong. I agree, it looks good. But it could totally be a mistake.
- Avamander 6y agoYou can never sum up an entire paper in one sentence with all the nuance.
- crusso 6y agoObservational error is always a good speculation. It seems to be at the heart of most of these "impossible physics" stories. Remember not long ago when neutrinos were thought to have been observed moving faster than the speed of light? Cold fusion? Before people jump on the idea of re-evaluating Einstein's theories, it's always good to get more people looking at the data, independently verifying it, thinking about it. In a few months, it's likely that this blip will disappear like most others.
- excalibur 6y ago> Why is there a normal galaxy sitting at the edge of the universe? To facilitate the restaurant?
- cheschire 6y agoOne must ponder which came first, the universe or the restaurant.
- djsumdog 6y agoWe'd know if we only listened to the dolphins.
- KarimDaghari 6y agoDon't forget about the ants!
- logotype 6y agoSounds like Vogon poetry.
- dddw 6y agoDon't forget your towel!
- disown 6y agoNot that anyone cares what I say, but the Restaurant is on the other end of the universe.
- jahnu 6y agoGive it a rest, Marvin
- AnimalMuppet 6y agoRight! This galaxy is there for the Big Bang Burger Bar.
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- BurningFrog 6y agoFirst thought is that it can be a small blob galaxy in front of a bigger one.
- giantrobot 6y agoBut the odds of that happening are astronomical!
- Randor 6y agoI found an interesting paper on the subject over on the European southern observatory website: https://www.eso.org/public/archives/releases/sciencepapers/eso2013/eso2013a.pdf https://www.eso.org/public/archives/releases/sciencepapers/e...
- SloopJon 6y agoI find it funny when scientific articles (esp. pop astronomy) describe something as weird, bizarre, or extremely unlikely. We're reversing the effects of gravitational lensing on a galaxy at a distance that's a significant fraction of the radius of the observable universe. Are astronomers that confident in their models that the inferred shape of this galaxy is bizarre? I'd love to have that level confidence in software.
- freeqaz 6y agoWe can more readily validate gravitational lensing than any early universe physics. So my guess would be that modeling the lensing is the easy part to validate :)
- slg 6y agoThat is the premise of the article. It is bizarre in relation to our models of the universe. We don't know if it is unusual in relation to the universe itself. As the article states: >Clearly, the theoretical models are wrong, or at least (and more likely) incomplete. Obviously, there’s more to learn about galaxies that exist at the edge of the observable Universe. I am reminded of that tale about how "Eureka!" is not exclamation of good science but instead "That's odd.". This article is saying "That's odd." in a way that signals we are on the verge of new scientific discovery.
- aasasd 6y ago> I'd love to have that level confidence in software Well, I mean, if you spend years mathematically validating your programs...
- djsumdog 6y agoI've always been puzzled by the estimated age of the universe at being 13 billion years. That's just the size of the observable universe, correct? Isn't there a future horizon beyond which light will not currently reach us?
- vkou 6y agoNo, 13 billion years is the age of the universe. The observable universe is a sphere with a diameter of ~93 billion light years (And is likely to only be a subset of the entire universe).
- skykooler 6y agoHow can we observe things over 40 billion light years away if they've only been around to emit light for 13 billion years?
- wffurr 6y agohttps://en.m.wikipedia.org/wiki/Observable_universe#Misconceptions_about_its_size https://en.m.wikipedia.org/wiki/Observable_universe#Misconce...
- function_seven 6y agoThe universe has been expanding ever since the Big Bang. Things that are very far away are moving away from us at speeds "faster" than light. No, they're not violating the cosmic speed limit. The fabric of spacetime itself is expanding everywhere, and that makes objects at very large distances apart get even further apart faster than a lightspeed traveler could move them. https://www.space.com/33306-how-does-the-universe-expand-faster-than-light.html https://www.space.com/33306-how-does-the-universe-expand-fas...
- vkou 6y agoThey were closer to us when they emitted that light. They've since moved further away.
- wffurr 6y ago
- natch 6y agoI never understand why articles like this use present tense to talk about past events. It was churning out a lot of new stars.. not is. I guess the “as seen from our current vantage point” is understood, but to me the needless emphasis of that perspective just muddies things, no? Anyone of you downvoters care to enlighten me?
- erulabs 6y agoStrictly speaking our observations are not continuous. We pointed a large array at it and then the array probably went on to other work and looked elsewhere - so technically “was” is more correct, since we do not know what it “is” doing, rather only what it appeared to be doing. Either way it’s a pretty uninteresting difference in tense.
- natch 6y agoI find it a very interesting difference, because it and other fuzzy writing like it has a devastating impact on science literacy, leading to lack of comprehension of concepts. Weak thinking on science in turn contributes to many of the problems we face as societies today.
- svachalek 6y agoOur language tenses weren't really designed for distant space phenomena. Should we say Betelgeuse is a red supergiant or was a red supergiant? When we look at the sky it exists "now" for us and there's no way to know if it's exploded since the light that we're seeing now left its surface. And even if we talk about the light that's leaving it in our "now" that's kind of vague since there's no real universal common clock.
- rcarmo 6y agoIt's likely to be the parking lot for The Restaurant At The End Of The Universe, no? (I can't help but wonder what Douglas Adams would make of this sort of thing - or the present time, for that matter.)
- macawfish 6y agoThe only reasonable explanation is aliens
- adventured 6y ago> The thing is, where they found it is not normal: The light we see from it left the galaxy 12.4 billion years ago, meaning we’re seeing it as it was when the Universe itself was only 1.4 billion years old! It's not confusing at all. It's because the long-worshipped, conventional big bang theory is wrong. The universe doesn't have a beginning or end. It's eternal. The original sin of that theory is that it's tainted with forced space for a deity belief at the center and always has been. The universe cycles unevenly through phases of motion, it doesn't magically start from nothing and then 'die.' The conventional big bang theory is as bad as any other children's tale going, it's up there with Santa Claus. We're going to find a lot more supposed abnormalities like this over time. They're not abnormalities, it's the entrenched incorrect theories that are the problem. The universe (everything that exists) is drastically larger than we already think it is. Humans are arrogant, we didn't realize the extent of the micro world, and the same exact mistake is being made at the macro scale. What they think is a singular ~14-15 billion year old universe, is nothing more than one collection of galaxies, there are many more like it nearby (many as in trillions and trillions). The micro world was far smaller than we imagined; the macro world is far larger than we're imagining. It's the same mental mistake playing out, caused by the same arrogance. What's beyond the 'universe' that we can see so far? More massive collections of galaxies, similar to the one we inhabit that we mistakenly call the universe.
- xwdv 6y agoWouldn’t a universe with no beginning or end begin to exist only when the first sentient being is able to observe it?
- depressedpanda 6y agoStrong claims, but can you back them up? How do you explain the apparent accelerating expansion of the universe, i.e. that the farther away something is, the more redshifted it gets? How do you explain the cosmic microwave background radiation enveloping us in all directions?
- outworlder 6y agoOf course they can't back this up. What the universe really is, is a simulation. We are trapped in it. "Lightspeed limit": this is because the simulation has a finite computing power. You can either move in time normally, or you can move in space. If you go to the max allowed speed, there's no processing left over to simulate time, therefore time stops for that entity. At intermediate speeds, slow down time accordingly. "Planck length": resolution of the simulation. It's discrete, and you can't go any smaller. "Heisenberg uncertainty principle": another simulation optimization. Instead of simulating all particles, just use a probabilistic function. You actually don't have to simulate it, just the macroscopic effects, unless there's an observation. In which case you can compute either the position or speed of the particle. See also: atom orbitals "Superluminal" expansion: it's just so we don't try to get to other galaxies, which are only being simulated in a macro scale. This was left by the developer to turn the 'lightspeed bug' into a feature. Also closes bug UNIVERSE-001 where the background radiation was still visible, but other galaxies visibility was off due to performance concerns. Now they can be enabled. "Dark matter": other civilization experiments that we don't have permissions to see. Still there and interacting with matter. Bug is still in the backlog. See, anyone can come up with whacky stuff.
- pier25 6y agoIsn't it possible that the galaxy is much younger and it actually moved faster than light? I seem to remember reading that "islands" of spacetime could do that.
- dylan604 6y agoWhich sci-fi author wrote that? That might make for interesting reading if you find it and share with the rest of the class.
- pier25 6y agohttps://phys.org/news/2015-10-galaxies-faster.html https://phys.org/news/2015-10-galaxies-faster.html
- SahAssar 6y agoThat article explains that the galaxies are only moving faster than light from our perspective since every part of space between us and it is expanding. So, no it's not moving faster than light. The space between it and everything else is expanding.
- deleted 6y ago[deleted]
- iwonderwhy 6y agoAll right hackernews. Genuine question, not sure where else to ask. If galaxies and stars at the other “end” formed out of matter resulting from the big bang, just as the matter we are made of, how did we get here at the same time that that matter got there? Is it because speeds faster than light are possible, and around the big bang all matter was spread near instantly at that speed? I don't understand how matter of the same “kind” was spread throughout the universe all at the same time without traveling at speeds greater than the speed of light. Because if we watch the ”opposite” direction from where the big bang occurred we don't really observe matter in a state closer to its original state, or parts of the universe in radically different states - which should result from that matter traveling further than the matter we are made of, as for us to now catchup with light that is “younger” than that towards the core of the universe. Am i missing something?
- zemnmez 6y agothis is because things aren’t ‘moving apart’— space itself is expanding (into what? nobody knows). it’s not that the galaxies are being propelled apart from a force in a particular place either; everything is expanding away from everything else. On the traditional balloon model, the surface of the balloon represents space itself. Those dots on the surface of an expanding balloon are not moving relative to space (the surface of the balloon), and so despite the distance increasing between us, the rate of increase of that distance is not bound by the speed of light, which only limits passage through spacetime. The wikipedia page on redshift describes well how redshift applies to objects which are in space that is expanding: https://en.wikipedia.org/wiki/Redshift#Expansion_of_space https://en.wikipedia.org/wiki/Redshift#Expansion_of_space
- dumpsterdiver 6y ago>"space itself is expanding (into what? nobody knows)" I have a terrifying theory on this (granted, the Earth will be long gone). What if the universe is not actually expanding in the sense that it is being propelled by an initial explosion, but instead falling towards a much greater mass - the end of time so to speak, where all mass ends. Considering that gravity is a "weak force", the scale of such a mass makes me uncomfortable to think about. Perhaps what we observe as the fabric of space-time itself "stretching" is actually a similar process to what happens to matter as it enters a black hole?
- brian_herman__ 6y agosyfy really good science information for being a entertainment channel I wish more places would do this like the history channel.
- rinze 6y agoThey're looking at us, wondering exactly the same thing.
- DoctorOetker 6y agoperhaps they look less chaotic because the rays at each point of the the ring when reconstituted was not emitted at the same time, so the picture we computed is a reconstitution of a large spread of time during which movement of the stars in the galaxy blurred substantially giving the impression of a more homogenous and orderly galaxy (a chaotic galaxy at astronomical shutter times might look orderly)
- bitwize 6y agoThey had to build Milliways somewhere...
- sktguha 6y agoI wonder if any intelligent civilisation was there on that galaxy,how incredibly advanced it must be by now , assuming it has survived till now.
- tresCommatoso 6y agoWhen i was a kid, we used to dream about the "ping-pong" machine of light. Basically- the light bending of the black holes allowed for images of the sky to be stored, distorted and bounced around to almost noise - of skys objects in diffrent times.. Drive it through a simulation, and you could see a nova light up, reflected back from the ping-pong machine over the aeons.. There was this nasa book, "Cycles of fire" we sat and daydreamed about..