[HN Gopher] Map of the observable universe
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Map of the observable universe
Author : xd
Score : 227 points
Date : 2022-11-18 14:49 UTC (8 hours ago)
(HTM) web link (mapoftheuniverse.net)
(TXT) w3m dump (mapoftheuniverse.net)
| noradina wrote:
| COOOOOOOOL!
| u1tron wrote:
| noradina wrote:
| wow very interesting
| revskill wrote:
| Hope there's similar map of universe of all algebraic structures.
| lgas wrote:
| https://ncatlab.org/nlab/show/HomePage maybe?
| bookofjoe wrote:
| Where is the dark matter?
| rodamaral wrote:
| According to the main view, dark matter floats throughout the
| galaxy (and outside) but is much more concentrated near the
| center. A tiny amount is probably crossing your body right now,
| but there's no way to feel it except for the minuscule
| gravitational force coming out of nowhere.
| svachalek wrote:
| As I understand it, dark matter is loosely clumped around the
| bright matter, held by gravity but otherwise not interacting
| with it.
| [deleted]
| CyborgCabbage wrote:
| Why only 90 degrees?
| pixl97 wrote:
| Well, we can't get a full 360 degrees because of the zone of
| avoidance caused by the center of the milky way.
|
| Also after a particular number of degrees it doesn't matter
| quite so much, the universe is isotropic enough that looking in
| any direction pretty much gives the same results.
| glitcher wrote:
| I suppose we only have one point of reference to make
| observations from, but it feels a little strange how the
| graphics tend to give a false sense of us being at the center
| of the universe.
|
| Would this graph essentially look the same if the
| observations were made elsewhere, like way over near the
| redshifted elliptical galaxies? Sometimes it's difficult to
| wrap my mind around the combination of distance _and_ time
| represented at these scales.
| svachalek wrote:
| Not a physicist but that's how I understand it, anywhere
| you go in the visible universe should have a perspective
| that looks more or less just like ours, as if they were at
| the center. We can only see so far though, so someone a
| billion light years from here would have a visible universe
| that overlaps with ours like a Venn diagram, but would be
| seeing things we can't. Who knows, maybe there's something
| really interesting they could see that we cannot, like an
| edge of the actual universe with nothing beyond?
| Kaibeezy wrote:
| I think it said right on the map that it's not only
| essentially the same in all directions, it's pretty much
| the same from any vantage point, since the distance makes
| most of the difference in what would be seen.
| rodamaral wrote:
| We are the center of the Universe. Of our observable
| universe, at least, by definition. And the total Universe
| might be much bigger, potentially infinite [or even smaller
| than the visible universe!]. Even if finite, the Universe
| would have no center. It's different from a finite amount
| of matter forming a sphere within an infinite grid, but
| much like a spherical surface that has no center (the
| sphere does, the surface does not).
|
| > Would this graph essentially look the same if the
| observations were made elsewhere
|
| Yes, an alien in a very far away galaxy would see a similar
| picture. If they are within a few billion light-years, they
| would see a younger red-shifted Milky Way.
| frankosaurus wrote:
| > This map shows a slice of our Universe. It was created from
| astronomical data taken night after night over a period of 15
| years using a telescope in New Mexico, USA.
|
| So, this is the slice that the telescope was observing.
| brink wrote:
| How complete is it?
| dylan604 wrote:
| according to the map itself, about 90deg
| nuccy wrote:
| Actually we cannot see far (other galaxies, early galaxies,
| quasars) in some parts of the sky because we are in our own
| galaxy plane [1], so stars, but mostly gas and dust between
| them obscure significant portion of our field of view [2]. So
| it is not flat 90 degrees, but roughly two cones with 90
| degrees openings in Milky way's plane perpendicular
| directions.
|
| 1. https://scitechdaily.com/gaia-spacecraft-discovers-parts-
| of-...
|
| 2. https://www.darkenergysurvey.org/supporting-science/large-
| sc...
| dylan604 wrote:
| In a few more millennia, our arm of the Milky Way will spin
| around so that we are able to the other side. We should be
| able to get some decent parallax measurements to distant
| objects at that time as well.
| dmbche wrote:
| Neat! Does someone know why there is a band of white/blue
| galaxies between the redshifted ones and the edge of the
| universe? I would've assumed it kept getting redder!
| nonfamous wrote:
| Those are quasars (which are why they are bluer). Beyond a
| certain distance galaxies become undetectable, but quasars
| are much brighter.
| cvak wrote:
| Is there an actual 3d map like this?
| markild wrote:
| Reminds me of
| https://hitchhikers.fandom.com/wiki/Total_Perspective_Vortex
| brunoqc wrote:
| I don't understand. Is that thing from fiction, real or both?
| w4ffl35 wrote:
| You should start here:
|
| https://www.amazon.com/Complete-Hitchhikers-Guide-Galaxy-
| Box...
| [deleted]
| dcwardell wrote:
| I always appreciate content like this which is easy to digest but
| still inspires awe in the universe around us.
|
| Scrolling around the map and looking further and further back in
| time reminded me of this Kurzgesagt video [0]. It's crazy to
| think how much of the universe is lost to and unreachable by us.
|
| Kurzgesagt has a lot of great content (even if it's a bit
| cartoonish). I'm sure they get things wrong, but I feel like they
| make an effort to research the topic first.
|
| [0] https://youtu.be/uzkD5SeuwzM
| boringg wrote:
| I am a bit disappointed that they didn't mark where the alien
| civilizations are currently living.
|
| Also add-on feature would be nice to find some tribes on the map
| that have either "scrolls of ancient wisdom" or a good chance of
| a "an advanced tribe" I'm less interested in the "valuable metal
| deposits worth 50" but that's far better than "unleashed a horde
| of barbarians!" but I guess it's a gamble for every tribe you
| find.
| Mockapapella wrote:
| I know I should be amazed by this, but whenever something like
| this pops up I get just a little bit sombre. With everything
| humans have accomplished, it still seems absolutely miniscule
| when looking at the scale of everything out there. More so,
| there's a sense of loneliness. Yes we have each other, but beyond
| that? We're all we've got for now, maybe ever. I just wish I
| could live long enough to know.
| layer8 wrote:
| Potentially adding some somberness:
|
| Feelings like somberness and loneliness only exist in your
| mind, as a result of how evolution formed how our brains work.
| It doesn't have any real meaning outside of our current
| restraints. In fact, meaningfulness itself is a concept that
| only exists within our minds.
|
| That set aside, what I find more disappointing is how the speed
| of light, the accelerating expansion of the universe, and the
| inescapable increase of entropy place serious constraints on
| anyone's future.
| Ptchd wrote:
| When I click the arrow to go down, it does nothing.
| [deleted]
| fallingknife wrote:
| > Beyond this distance, galaxies are harder to see. However, we
| can still see quasars. They are much brighter and bluer.
|
| But don't we have pictures of galaxies going back to the earliest
| universe? I thought that JWST is specifically made to image them.
| aizyuval wrote:
| Awesome! Loved it! Simple and so fascinating.
| sigmoid10 wrote:
| Nice visualisation, but the explanations contain a bunch of
| mistakes. The cosmic microwave background is not "the first flash
| of radiation" after the big bang (which would've been much
| earlier), it is the "wall" of _last_ scattering before the
| universe became transparent enough. And its distance is also not
| limited by light travel distance within the age of the universe
| (13.7Gly) but by its rate of expansion, resulting in an actual
| distance closer to 40Gly.
| DiogenesKynikos wrote:
| Indeed, the Cosmic Microwave Background is the light that's
| still left over from a time when the Universe was much hotter
| and filled with plasma. At a certain point, the Universe cooled
| down enough to become neutral, which made it mostly
| transparent, and allowed the photons that had been bouncing
| around in the plasma to travel indefinitely.
|
| > its distance is also not limited by light travel distance
|
| At cosmological scales, there is no single, correct definition
| of "distance." There is coordinate distance, light travel
| distance, angular diameter distance, luminosity distance, and
| other measures.[0] All these distances are the same at very
| small scales, but when you start looking at larger scales,
| General Relativity starts to matter and the geometry of the
| Universe is no longer Euclidean.
|
| 0. https://en.wikipedia.org/wiki/Distance_measure
| dimator wrote:
| wow, your last paragraph filled a little empty gap in my
| brain, thank you!
| sigmoid10 wrote:
| On a global scale, the universe as a whole is actually
| remarkably close to euclidean [1] (which is a mystery of its
| own). So it's not curvature that's the problem, but
| expansion. To account for this, people usually quote the
| _comoving_ distance [2] (which factors out expansion) when
| talking about very distant things like the microwave
| background. I.e. the distance light would have to travel
| today if you could freeze the evolution of the universe for
| the duration of the journey.
|
| [1] https://en.wikipedia.org/wiki/Shape_of_the_universe
|
| [2] see your own source
| wrycoder wrote:
| And it's not an "actual photograph" LOL.
| xbryanx wrote:
| Explain it to me like I'm five:
|
| Why can we only see 90deg of the sky?
|
| I look at the map at the bottom of the page and wonder why it
| isn't a circle. I'm obviously missing a key concept.
| tremon wrote:
| Not sure if this answers your question, but from the
| description tab, under "What is this map?"
|
| _The full map is actually a sphere. This visualization shows a
| thin slice of the Universe. Its thickness is about 10 degrees.
| More astronomical data is available but it is not possible to
| show all of it at once on a 2D map. The image would be
| completely saturated with dots._
|
| It actually visualizes the slice depicted on the main page as a
| 3D rotation. I would struggle to explain the concept of arc
| slicing to a five-year-old though.
| legohead wrote:
| > Its thickness is about 10 degrees.
|
| Does that mean their slice is only 1/36th of the whole
| picture?
| tremon wrote:
| It's 1/72nd of the celestial sphere I think, since a single
| rotation gives you the east and west views in full, but due
| to the 90deg field of view, you need to repeat that
| rotation in the north-south direction to cover the entire
| sphere.
| lagrange77 wrote:
| Wonderful
| TheRealPomax wrote:
| "Map of the Observable Universe" (big difference, and the actual
| title on the page itself)
| pseidemann wrote:
| The biggest difference in existence.
| dang wrote:
| Ok, we've made the universe observable in the title above.
| Thanks!
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(page generated 2022-11-18 23:00 UTC)