The Milky Way's (almost) identical twin

By Phil Plait | January 7, 2011 7:00 am

In my Top 14 Astronomy Pictures of 2010, I started off with a galaxy I called the Milky Way’s fraternal twin; it looks a lot like ours, but has some differences that were worth pointing out.

In one of those coincidences that makes me smile, only a few days later the folks at Hubble Space Telescope released another spiral galaxy image, and this one… well, it’s a beauty:

hst_ugc12158

That’s really something! It’s so pretty I made it my desktop image. Click it to see it in all its 2800 x 2400 pixel galactaliciousness.

The name of this galaxy is UGC 12158. It’s a face-on barred spiral; the bar refers to that rectangular block of stars in the center. Some spirals have a spheroidal central bulge, like Andromeda does, but quite a few have a bar-shaped hub. The Milky Way does, in fact, and observations using radio and infrared telescopes (able to pierce the dust obscuring our view) show that our bar is actually pretty hefty. The small picture here shows an illustration of the Milky Way based on these observations, and we think it’s a pretty accurate representation. The resemblance to UGC 12158 is obvious.

When I first saw this Hubble picture, I was impressed with the beauty of this galaxy I had never seen before. But then I realized something… Y’know, I have a lot of experience looking at Hubble images. I spent years working on them, and after a while you get a feel for them. It’s just practice, and you get what almost feels like instinct about some things. So when I saw this picture and I got that odd (but familiar) feeling in my head, I knew to pursue it. It didn’t take me more than a few seconds to nail it down: this galaxy is big. The size of the star images, the smoothness of the galaxy itself, the way the image feels… I just knew that this was no tiny galaxy.

So I went to the release page for it, and when I saw the distance, I was shocked: that galaxy’s not big, it’s freaking huge. I figured it was part of the Virgo cluster, maybe, 60 million light years away or so. Nope: it’s a whopping 400 million light years distant, which is a long, long haul. That was stunning to me; if it’s that far away the galaxy really has to be a bruiser. So I grabbed a raw image from the Hubble archive and measured its size in pixels, which I could then convert to a spatial size given its distance.

And I can still hardly accept this, but UGC 12158 is 140,000 light years across. I measured it twice, two different ways, to be sure. That’s the biggest spiral I’ve ever heard of! Mind you, the Milky Way is in the top tier of galaxies in the entire Universe when it comes to size, but UGC 12158 whips us by a clean 40%!

When I first saw the galaxy, I figured we might have the Milky Way’s identical twin. Little did I know that it was actually our much, much bigger brother.

The reason this image was taken was as part of a sequence of images of a supernova, a star that exploded in the galaxy. Called SN2004ef, you can see it as the bright blue star just below and to the left of the galaxy’s center. Several images of the supernova and galaxy were taken by Hubble to monitor how the star faded with time; that tells astronomers quite a bit about the physics going on in the churning maelstrom of the explosion.

One of the things I dearly love about astronomy: we get truly important and interesting science at the same time we get outstanding artistry and beauty. That’s true in most fields of science, of course! And sure, maybe I’m biased… but it’s really hard to beat a big, magnificent spiral galaxy.


Related posts:

Setting the bar
Sculpting a barred galaxy
Ten things you don’t know about the Milky Way
Barred for life


CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (50)

  1. Cindy

    That is gorgeous. I think I’ll make it my new wallpaper, too.

  2. Messier Tidy Upper

    Love this superluminous (beyond just brilliant!) image. :-)

    Thankyou, Bad Astronomer, thankyou.

    I presume that Milky Way artwork is to scale with UGC 12158 right?

    I also presume that if a galaxy spanning alien sentience civilisation exist in UGC 12158 then that means the Milky Way’s Big Brother really is watching us .. Spooky! ;-)

  3. Mapnut

    Is the Milky Way really as round as it’s portrayed? (Do we know?) In other words, the outer spiral arms are shown as well-defined and constrained within the disk, but UGC 12158 has two arms that stray off far outside the disk. Is that where the 140,000 light years is measured? In yet other words, it looks like UGC 12158 may be wider but no more massive than the Milky Way.

  4. Messier Tidy Upper

    The reason this image was taken was as part of a sequence of images of a supernova, a star that exploded in the galaxy. Called SN2004ef, you can see it as the bright blue star just below and to the left of the galaxy’s center. Several images of the supernova and galaxy were taken by Hubble to monitor how the star faded with time; that tells astronomers quite a bit about the physics going on in the churning maelstrom of the explosion.

    What variety of supernova – white dwarf (Ia) or supermassive star (type II) or Wolf Rayet star (type Ib?) – can you say please?

    While on with requests; please could we see the other images of that supernova erupting and then fading away and could they make an animation of it? :-)

    @3. Mapnut : Not quite sure but I think I recall reading about a few variations in our models & understanding of the Milky Ways’ structure including extra older outer arms and less significance to some other, formerly thought to be more major, inner arms based mainly, if memory serves, on mapping the distribution of neutral hydrogen and a few other things. Additionally, there’s also the consideration of the amount of mysterious dark matter and energy that may be present in both galaxies too.

  5. dcsohl

    I understand the Milky Way to be 100,000 light-years across. So this new galaxy whips us in diameter by 40%. In volume, it’s at least double. The cross-section area would be 96% larger, and I have to assume it would be thicker as well. 40% thicker? Who knows, but if it were 40% thicker this galaxy would be nearly 3x the volume of ours! Wow!

  6. Lukas

    The fact that our galaxy, the Milky Way, was one of the bigger galaxies in the universe was new to me. Wow! Made me happy, somehow feeling significant! But thinking about it further, that actually just makes me less significant. Hah. Great stuff you got here though. Really pretty picture, thanks Hubble.

  7. Bill Nettles

    Phil,
    Just asking about the process->How do they know the supernova is in that galaxy and not in ours? Before and after comparisons? Parallax?

    What about the bright white star located horizontally to the right of the galaxy center? Supernova in that galaxy or star in ours?

  8. Vernon Balbert

    A wonderful picture and I love looking at them. But at the same time I like looking around these pictures just to see how many other galaxies are in the picture. There are more than 20 other galaxies in that picture. Puts things in perspective, no?

  9. Chris A.

    @Lukas (#6):

    “The fact that our galaxy, the Milky Way, was one of the bigger galaxies in the universe was new to me.”

    Phil’s post should have read:
    “the Milky Way is in the top tier of _spiral_ galaxies in the entire Universe when it comes to size”

    Giant cD ellipticals (like M87, at the heart of the Virgo Cluster) are monsters. The current record holder, I believe, is IC1101 in the middle of the galaxy cluster Abell 2029: It’s 55 times wider than the Milky Way, and possesses around 2000 times more mass.

  10. Absolutely stunning! Thank you for sharing – I think UGC 12158 might be a new favorite.

  11. Bill Nettles

    Okay, answered my own question with a little search. Here’s the summary of the discovery telegrams to IAU:
    “SUPERNOVA 2004ef IN UGC 12158
    T. Boles (cf. IAUC 8397) and M. Armstrong (cf. IAUC 8397)
    independently report their discoveries of an apparent supernova on
    unfiltered CCD images. Boles’ measured position for the new object
    is R.A. = 22h42m10s.02, Decl. = +19o59’40”.4 (equinox 2000.0),
    which is approximately 7″.2 west and 9″.2 south of the center of
    UGC 12158. Approximate magnitudes for SN 2004ef: 2003 Dec. 15 UT,
    [19.0 (Armstrong); 2004 July 16, [19.5 (Boles); Aug. 19, [19.5
    (Boles); Sept. 4.056, 18.5 (Boles); 4.821, 18.5 (Boles); 5.078,
    17.5 (Armstrong); 5.861, 17.5 (Armstrong). Position end figures
    for SN 2004ef by Armstrong are 09s.97, 40″.1; he adds that nothing
    is visible at this location on Palomar Sky Survey images from 1990
    (limiting red mag 20.8) and 1992 (limiting blue mag 22.5).”

    So, nothing was there before, and I guess, with a magnitude around 18, it wouldn’t be a supernova in OUR galaxy. Are the magnitudes in the summary apparent or absolute? Assuming apparent, if this supernova was in our galaxy, say only 50,000 ly away, it would be an apparent magnitude of -1.5! That’s some Sirius brightness :) and it’s only 8.6 ly away. Move this SN to 8.6 ly and it becomes magnitude -20! Sunshine!

  12. Robert

    I love that “mini” S-shaped galaxy on the lower arm of UGC 12158. It’s probably much farther away, but looks just like a baby galaxy hitching a ride.

    May I ask how you knew this was a fuzzy (and therefore big) galaxy, and not a fuzzy picture?

  13. Peter

    These kind of stories always make me wonder whether there is someone out there that is able to look at us the same way we look at, say, the Andromeda galaxy.

    The very thought the answer is “yes” makes me jealous. Since shooting a camera up and take a nice picture of the Milky Way is without our reach, if only the speed of light was not so damn low, I dearly hope there is some cosmic mirror pointed exactly right out there.

  14. dcsohl

    Bill, to further elaborate on your question-and-answer on “where is that supernova”, different types of novae and supernovae have characteristic light curves. Types can be identified by their curve and/or by their spectra. This particular supernova has been identified as Type Ia. Type Ias all seem to have an absolute magnitude of -19.3 (or 5 billion times brighter than the Sun)… so we can tell its distance by the apparent magnitude… which is very very very far away. Way outside our galaxy and almost certainly inside the other galaxy.

  15. Sam H

    Are the dim bluish clumps scattered here and there in the arms the HII star-forming regions? I’ve seen quite a few Hubble images that renders them blue, such as in the fantabulous portrait of M101 that was once my desktop, and the equally stunning portrait of NGC 3370 that is my current one. I know that hydrogen emits pink visible light when ionized (I’ve seen the gas tube in Chem class, so I can also say I’ve SEEN it :)), and the same principle is supposed to be in operation here. This would mean that the above is not really true colour – if so then why would they render them this way? To eliminate colour contrast or something? (dangit colour contrast is what makes space images BEAUTIFUL :)!)

    As for my ID comments yesterday, I didn’t read all the comments but your replies were helpful. I’ll just say that I don’t consider myself with the skeptic movement anymore – in a sense. Global warming is worse than we thought (+6 or 7° by 2100 my guess, hope we don’t repeat the Permian!), Antivax is a fraud, UFOs are explained & YEC is flat-out WRONG. And while I know that ID is ideologically inclined, it doesn’t mean that it isn’t totally false. Yes I’m sympathetic toward them due to my Christian longings and upbringing, but it don’t mean that I can’t attempt to objectively investigate the evidence. ID is by nature a philosophy, but it doesn’t mean it can’t become a scientific theory. If a possible intelligent cause was to be determined in creating an organism, the characteristics of said designed object could be used to produce a theoretical extrapolation of the designer’s own characteristics. But theorizing design is indeed shaky, so the pursuit of naturalism must come first UNLESS unviable by the weight of the observable, hard evidence. I don’t think absolutely strict naturalism should be a rule of science when & where required (emphasis on previous 3 words): when it does it leads to your own “God-of-the-gaps” arguments. As for Occ’s razor, just remember that if the evidence were to suggest an external agent, then that external agent is the simpler hypothesis. It doesn’t matter if some yet-to-be natural explanation possibly exists and so we should bet on it, cuz a designer necessitates it’s own explanation – IT MATTERS WHETHER OR NOT THE HYPOTHESIS WORKS RIGHT HERE, RIGHT NOW. Nothing is simple if it doesn’t work.
    I’m suddenly interested in this issue again, and so will set out to investigate it (even though I dunno crap about technical biology, and dropped my Math class this semester :roll:). Wherever the evidence leads, I hope to follow, WHEREVER THAT MAY BE. I’m going to investigate authors on both sides, and leave aside ad hominem (as several here cannot seem to do), and attempt to dig as deep as I can, leaving aside arguments from authority unlike kuhnigget.
    Now I should be getting back to English :)

  16. Galactaliciousness!! LOL, great commentary. Not a bad big brother to have…

  17. Firemancarl

    Where is that star in the center of the galaxy..just above and to the right of the central bulge? Is that in our galaxy? Are we seeing another galaxy through the center UGC 12158? The igmage is so clear, I don’t think I’ve ever seen a star, or whatever it is, through a galaxy core before. Maybe it’s Coursucant???

  18. tracer

    @ Firemancarl:

    If that point of light is all the way over in UGC 12158, and it’s Coruscant, then Coruscant is brighter than a standard (non-super) Nova.

    I mean, I know the thermal-pollution problems a planet-covering city can cause, but I’d think Coruscant would become uninhabitable LONG before it reached nova temperature!

  19. Messier Tidy Upper

    @19. Firemancarl : Maybe it’s Coursucant???

    & @20. tracer :

    I know the thermal-pollution problems a planet-covering city can cause, but I’d think Coruscant would become uninhabitable LONG before it reached nova temperature!

    Indeed so – if we’ve got global warming issues with our cities now how much worse would a planet-wide city be – even accounting for different power sources! ;-)

    Mind you, the environment, atmosphere and planetary situation generally with Coruscant (& Trantor & other such hypothetical cases too) is clearly very different from Earth’s.

    See :

    http://en.wikipedia.org/wiki/Coruscant

    Incidentally, Coruscant has always struck me as a direct steal from Isaac Asimov’s world of Trantor with its planet-girdling city used mostly in his Foundation series although referred to in a few of his other SF novels as well.

    See : http://en.wikipedia.org/wiki/Trantor

    & http://en.wikipedia.org/wiki/Foundation_series

    @15. dcsohl Says:

    …This particular supernova has been identified as Type Ia. Type Ias all seem to have an absolute magnitude of -19.3 (or 5 billion times brighter than the Sun.) …

    Thanks for that info – I was wondering what type of supernova it was, much appreciated. :-)

  20. Zucchi

    Imagine being on a planet of a rogue star, outside a spiral galaxy, able to see it like that with the naked eye. Will Andromeda look like that from Earth in a couple of billion years, filling half the night sky? (If there’s anybody to see it.)

  21. Nick M

    There are so many awesome things about this image, but for some reason a specific part caught my eye and I was wondering what it is. On the edge of the galaxy, at about 5 o’clock, there’s a peculiar spiral galaxy looking blotch. Is this in fact nothing more than an artifact? Or perhaps a side effect of gravitational lensing? Or could this be something more local, in fact in the foreground of the image? (A nebula or gas cloud of some kind?) Is there even enough information in this single image to hazard an educated guess?

    And good heavens, would you look at all those OTHER galaxies! If only we had the means to travel faster than light without violating causality, or requiring epic amounts of energy!

  22. Joseph G

    @#18 Arch: Yeah! I mean if Andromeda tries to get in our face and steal our lunch money (and it appears it’s thinking about it) we can just point to UCG 12158 and go “Yo! You mess with me, you mess with my big bro over there! Now give me back the Magellanic clouds and we’ll just forget that this whole thing ever happened.”

  23. Joseph G

    Beautiful! Amazing to think that that supernova is a million times more distant then the other big stars in that photo. I sure hope there weren’t any living critters within a few dozen light-years of that beast.

  24. Messier Tidy Upper

    @22. Zucchi Says:

    Imagine being on a planet of a rogue star, outside a spiral galaxy, able to see it like that with the naked eye. Will Andromeda look like that from Earth in a couple of billion years, filling half the night sky? (If there’s anybody to see it.)

    There are a couple of possibilities for worlds having such views :

    1. Stars and accompanying planets in orbits around the Galactic Halo, a vast component of our (& all spiral) galaxies. Stars inthe halo have galactic orbist taking them far above and below the galctic plane. Notable examples include Kapteyn’s Star and possibly also Arcturus although the latter may be part of the thick (or old) disk) stellar population as well as the globular clusters. These tend to be ancient and thus metal-poor stars.

    2. Stars stripped from galactic disks by mergers with other galaxies – the process of galaxies approaching disrupts thedisk and willthrow many stars out into intergalactic space. These stars will include thus younger, metal-richer population I type stars, ones like – and one day perhaps including our Sun.

    3. “Runaway stars” ejected from the galaxy(ies) by gravitational encounters with extremely massive stars or via asymetrical supernovae which often kick pulsars & companion stars out at high velocity. Examples of runaway stars incl. sverela known pulsars plus Mu Columbae, 53 Arietis and AE Aurigae. While, again, this can mean metal-rich (thus likely planet boasting) types of stars are involved, there is a likely problem here in that ejection mechanism would likely destroy or at bets severaly disturb any planets or proto-planetary disks.

    Furthermore while not quite the same thing, it is interesting to imagine what the view from a star on the outskirts of the Galactic bulge might be like. Unless I’m mistaken (& I may be) such stars are more metal-rich than the halo component* but less so than the bright new stars of the galactic disk although there are questions about how the higher radiation levels and rate of supernova, etc ..will affect their potential habitability.

    ————-

    From Ken Croswell’s Alchemy of the heavens (?) book :

    The Main Galactic populations :

    1. galactic Halo – the outer sphere of stars in which the restof tehgalaxy is embedded.

    2. central Galactic Bulge – inner core sphere of stars around the central supermassive Black Hole.

    3. Thick Disk – older disk stars in wider more eccentric orbits, merges with the halo and thin disk & intermediate in metallicity age, etc.

    4. Thin disk – youngest stars & most metal-rich stars making up the spiral arms – divided into two sub-groups – our Sun and most of the stars in our nght sky are of this population.

    (From memory.)

  25. AstroJLE

    Tremendous image and a wonderful galaxy! Looks like in the star forming regions there are many open clusters there. It looks to be a very active galaxy, and one of the things not mentioned that I appreciate about most Hubble images of galaxies are the galaxies captured around the object. I’d almost name it the Superman galaxy because of the S shape that appears in the lower right portion of the galaxy. It is also a good reflection of how powerful a supernova is when you think of how bright it appears in the image. Thanks for sharing this one Phil and for some terrific insight.

  26. Grimbold

    @NickM, #22

    “On the edge of the galaxy, at about 5 o’clock, there’s a peculiar spiral galaxy looking blotch.”

    To me it looks like a combination of two things. The “spiral arms” I think are part of UGC 12158 and the yellowish central bit looks like an edge-on spiral galaxy way in the background.

  27. Joseph G

    Does anyone know if any hypervelocity stars have been directly observed in intergalactic space?

  28. Messier Tidy Upper

    @ ^ Joseph G. :

    Well there is at least the example of this Expelled Star – HE 0437-5439 – which was formerly an Expelled stellar duo :

    http://www.nasa.gov/mission_pages/hubble/science/expelled-star.html

    Which was originally catapulted out of our Galaxy by an encounter with the Supermassive Black Hole at the core of our Milky Way and has had quite a remarkable odyssey.

    From there :

    … Most of the roughly 16 known hypervelocity stars, all discovered since 2005, are thought to be exiles from the heart of our galaxy. But this Hubble result is the first direct observation linking a high-flying star to a galactic center origin. … [SNIP.] … The stellar outcast [ HE 0437-5439] is rocketing through the Milky Way’s distant outskirts at 1.6 million miles an hour, high above the galaxy’s disk, about 200,000 light-years from the center. The star [ HE 0437-5439] is destined to roam intergalactic space. [Brackets added.]

    Meanwhile the book quoted from in # 26 was indeed Croswell’s ‘The Alchemy of the Heavens’ – an excellent book which I’d highly recommend btw. – and from Croswell’s website this article deals with some known intergalactic wandering stars :

    http://kencroswell.com/VirgoIntergalactic.html

    and this article :

    http://kencroswell.com/MWEdgePlanets.html

    explaining why the outer outskirts of our Galaxy may well be barren probably also applies to the galactic Halo region too.

    Hope these links are enlightening and enjoyable for folks here. :-)

  29. Messier Tidy Upper

    On runaway stars via kaler’s Stars website see :

    http://stars.astro.illinois.edu/sow/mucol.html

    For Mu Columbae & see :

    http://stars.astro.illinois.edu/sow/aeaur.html

    For AE Aurigae whilst this :

    http://en.wikipedia.org/wiki/NGC_2419

    Globular cluster nicknamed “the intergalactic wanderer” and also known as Caldwell 25 would also have a staggeringly great view of our Milky Way Galaxy especially when at its furthest distance and most extreme vantage point. If there are any planets there (which is, alas, probably unlikely), methinks they’d have a unique night sky indeed! :-)

  30. Bjørn Karlsen

    Damn… Would be pretty asm as a wallpaper, hehe. see why you chose it. But the resolution is to low for my screens… Anyone know where I can get Hubble snaps at greater than 3840×1200 res?

    I guess I can use google in a pinch, but you never know what you get with google…

  31. Anchor

    Imagine for a moment that you are an alien in this galaxy UGC 12158 looking back this way at this other spiral galaxy, 400 million light-years away. You’d be seeing a galaxy that very much resembles ‘yours’. But would you guess that amongst that throng is at least one planet, already 4.2 billion years old, on which complex multicellular plant and animal life (including things like jawed fishes and insects) had evolved, and that they had only ‘recently’ survived a major global catastrophe (at the tail end of the Ordivician period, around 420 million years ago)?

    Conceivably, right “now”, super-advanced inhabitants of UGC 12158 with unimaginably ultra-embiggening telescopes are viewing the emergence of plants and animals from the seas to colonize the land…and that one of the evolutionary outcomes of those intrepid amphibious vertebrates would in 400 million years later build telescopes to discover the supernova that excited the astronomers residing in UGC 12158 only last month or last year or anytime within roughly the last 100,000 years, depending on where they are situated in the galaxy with respect to the supernova’s location…if they’re there, they saw it too.

    Our Milky Way is a substantial spiral containing 200 to 400 billion stars, and exoplanet research suggests that most stars possess a family of planets. And if UGC 12158 is as much as 40% larger, it could easily contain a trillion stars. How many planets in this glorious spiral we see right there in this image have been graced with life? Then consider that of the zillions of photons that constantly arrive from the stars of this galaxy to our little planet, some are briefly diverted and must come from the reflected glints of warm ocean-bathed worlds…or even the equivalent of alien tears.

    In other words, for all we CAN discern so far, this might as WELL be a view of our own home galaxy 400 million years ago. Or put it this way: How many other ways does the universe come to look at itself, and how many times has it happened in our own galactic backyard? Aside from the entirely irrelevant issue of size, on this particular metric, our galaxy really ISN’T any different from UGC 12158. Nor is it really any different from all those other spirals sprinkled about in the distant background…

    These are the kind of images that give us our sense of perspective, and ‘quicken the pulse’ (as Sagan would say) to lift us out of our childish conceits and selfish cynicisms. We may be terribly small in the immense scheme of things, but we are no less fantastic for being a part of it all.

    Thanks again Phil! And thanks again HST! Made my weekend!

  32. Joseph G

    @Messier Tidy Upper: They are indeed enjoyable and enlightening. I dunno what we’d do without you sometimes :D

    Also, I was pleasantly surprised to see that Ken Croswell link. His book “The Life of Stars” is at this local cafe I frequent (they have all sorts of assorted books in there). I’ve spent hours flipping through it while having coffee :)

  33. Joseph G

    @34 Anchor: Heh, alien tears :) I’ve often wondered what it’d be like to ride a solar photon – to follow it up through the radiative zone and the convective zone, absorbed and re-emitted, zooming out of the photosphere, bouncing off a water droplet in a cloud on earth, and out into interstellar space to who-knows-where.

    So true, though! As vast as the universe is, and as incredibly tiny a part of it as we are, we can still remember that we are a part of it. And to be a part of something so huge and beautiful makes one feel rather special in its own way.

  34. Rob R.

    Dumb question:

    How do we know that some of these things aren’t reflections? By that I mean, for example, how do we know that this UGC 12158 isn’t the actual Milky Way from ~400 million years ago or its reflection? That make any sense?

    . . . told ya it was a dumb question.

  35. Messier Tidy Upper

    @ ^ Rob R. : Not a dumb question – rather quite an imaginative one actually methinks. ;-)

    I think we know UGC 12158 is not a reflection of our Milky Way because of various differences in the galaxies such as the size and spiral arm structure & perhaps via UGC 12158’s spectrum versus the calculated spectrum our Milky Way would show – & also because we’re pretty sure the universe doesn’t work that way and doesn’t mirror objects like that without distorting them – eg. Einstein rings and galactic lensing.

    For instance, to have a reflection of the Milky Way we’d need the light to be reflecting off some other larger object or material-like giant mirror or sheet of water / ice / metal which we have no evidence for and no reason to think exists. So nice idea but almost certainly not the case.

    @35. Joseph G : Thanks – that’s great to hear & much appreciated. :-)

  36. Messier Tidy Upper

    @ Rob R : If you’d like more info and feedback on this idea, might I suggest putting it on the BAUT forum :

    http://www.bautforum.com/

    or searching for similar notions on there assuming you haven’t already done so.

    You may be interested in checking out these wikipedia entries on :

    http://en.wikipedia.org/wiki/Einstein_ring

    Einstein rings & on :

    http://en.wikipedia.org/wiki/Gravitational_lens

    gravitational lensing. I’ll also just add to that that gravitational microlensing has been used to detect certain planets around distant stars and also “MACHO” objects in our Galaxies outer Halo region. :-)

  37. icemith

    Truly inspirational, (in a good sense, not a Good sense, if you get my drift), shot of our “Big Brother Galaxy”. And for all those involved in obtaining it and processing it.

    But one thing that bothers me. A photo, for want of a better name, (maybe it is very appropriate as we are talking about photons from a distant past), of this galaxy, being perpendicular to the trajectory of those photons that terminate their life in our sensors, are arriving at about the same time. True those from the central bulge will arrive somewhat sooner, (we’ve already missed them), as the “top” of the bulge is slightly closer, maybe by quite a few thousand light years. So we actually get an updated view of that bulge, or at least the peak of it.

    This brings me to my central question. It concerns the “Bar” and the “Globular” bulge shapes. I wonder if some so-called globular bulges could actually be barred bulges viewed end-on? That is of course only with those galaxies that share our Milky Way’s plane and/or point of view. It would present a rounded globe (bulge) that we are familiar with. How could we be sure otherwise? Maybe in some considerable time we could determine it from rotational views, but that is going to take quite a few (thousand) years.

    Conversely, maybe the barred version is actually depicted by the same mechanism, ie, the distortion of the “photo”, not unlike the distortion we see everyday in movies where the wagon wheels of speeding wagons go oval, when we know that they have to be circular, (excluding Mac Sennett police cars which DID have eccentric wheels!), and it is a function of “time” and not a common “now”.

    Any other thoughts out there?

    Ivan.

  38. What always gets me about pictures like this, is the feeling of just how SMALL we are. I just stare at the pictures and feel both amazing and insignificant at the same time.

  39. reidh

    so its around 4 times its diameter in distance from us? Thats close. Good thing the universe is expanding instead of contracting.

  40. Anchor

    #40 icemith Says: “But one thing that bothers me. A photo, for want of a better name, (maybe it is very appropriate as we are talking about photons from a distant past), of this galaxy, being perpendicular to the trajectory of those photons that terminate their life in our sensors, are arriving at about the same time. True those from the central bulge will arrive somewhat sooner, (we’ve already missed them), as the “top” of the bulge is slightly closer, maybe by quite a few thousand light years. So we actually get an updated view of that bulge, or at least the peak of it.”

    The actuality is we never see what we habitually think of as a “snapshot” confined to a particular instant of time that “preserves the moment” for galaxies, or anything else for that matter. Whenever we look at images of galaxies we are only recording all the photons that arrive within the span of the cameras’s exposure. Galaxies are huge and so we are compelled to see features within them that are considerably displaced in time.

    Suppose, for example, that UGC 12158 happened to be oriented nearly edge-on to our line-of-sight: we’d be viewing photons that launched off of its background arms up to 140,000 years EARLIER than those that sprung from its foreground arms. All galaxy ‘snapshot’ images are necessarily ‘distorted’ in this way – they are ‘smeared out in time’. Considering that a galaxy like this probably gives forth a supernova at rate of perhaps a few times per century (say), the number of these relatively extremely brief events over the course of 140,000 years can exceed a quarter of a million such blasts! But because we can only sample each part of the galaxy at a time, we must still wait about a half century, on average, to witness them.

    But even a camera taking a SUFFICIENTLY SHORT exposure of a friend is similarly smeared out in time, albeit to a far lesser extent: an image recording a portrait of your friend shows her ears to be slightly ‘younger’ (from the point of view of your friend) than the tip of her nose (if she is facing you), by the time it takes light to travel those several inches that separate them. Instead of a displacement on the order of 100,000 years, as with edge-on galaxies, the time displacement between the background ears and foreground tip of the nose (say, a depth-distance of roughly 10 centimeters) in your friend’s image would amount to only about 30 billionths of a second.

    Of course, ordinary cameras operate with exposures that last a great deal longer than that, typically with exposures lasting around a relatively humongous hundredth of a second. So what you get is an image that records your friend’s ears and nose smeared over the course of that 1/100 second exposure, with all of those overlapping photons, whenever they leap from distant ears to nearby nose, contributing to the image.

    With a typical shot of a distant galaxy, however, an hour-long exposure (say) is only about one part in 876.6 million of a hundred thousand years. But if the 100,000 light-years of depth-distance with typical edge-on spiral galaxies the size of our Milky Way were equated with the ten centimeter depth-distance between the ears and nose of your friend, and you scaled up the 1/100 of a second exposure time typical of ordinary point-and-shoot photography in typical human portraits accordingly to match, astronomers would have to keep their telescopic camera shutters open and scrupulously trained and focused on the target galaxy for roughly 100,000 years. (That’s the crude order-of-magnitude figure I come up with…you are free to check the math for yourselves).

    It’s a good thing that stars in distant galaxies are bright and that cameras have been developed that come equipped with photo-sensitive means to record light over a modest amount of time that doesn’t unduly press the patience of beings who live, typically on average, about 660,000 times longer than an hour-long exposure. (And some exposures, such as the Hubble Ultra Deep Fields, have been constructed out of exposures totaling DAYS). If circumstances had dictated either that our lifespans were significantly shorter and/or we had evolved a lesser visual capacity as well as engineering dexterity than we have, our ability to eke out information about a universe filled with a froth of galaxy clusters might never have entered our ken…and we would then by now be even more ignorant than we are. ;)

  41. Nigel Depledge

    Sorry to encourage OT talk but . . .

    Sam H (17) said:

    And while I know that ID is ideologically inclined, it doesn’t mean that it isn’t totally false.

    Every claim made by the ID authors that we can objectively detect design has been shown to be false. This is not to say that we might be able to detect it at some undertermined point in the future, but none of the methods proposed by e.g. Bill Dembski are real – all of them are arguments from analogy (which rely on extraneous information that we already possess), false dichotomy or some other fallacy of reasoning. Dembski’s “deductive filter” explicitly excludes the set of all hypotheses no-one has thought of yet for no justifiable reason. Furthermore, he constrains his range of hypotheses in such a way that any combination of chance and natural law is excluded as a possible answer.

    What we can detect is manufacture. And there’s no sign of that in biology.

    Yes I’m sympathetic toward them due to my Christian longings and upbringing, but it don’t mean that I can’t attempt to objectively investigate the evidence.

    But why do you not accept that this process has already occurred, and the answer is – overwhelmingly – that ID is a load of rubbish?

    All of the arguments made to support ID have been shown to be wrong. All of them, without exception.

    ID is by nature a philosophy,

    What makes you think this, when the Discovery Institute went to such lengths to tell people like you that it was genuine science?

    If you consider ID as a philosophy, then you can find plenty of aspects that simply cannot be refuted, but that are – pretty much by the same token – intellectually sterile. I.e., they result in mere navel-gazing, not any actual progress towards anything.

    but it doesn’t mean it can’t become a scientific theory.

    As expounded by Behe, Wells, Dembski et al., no, it cannot ever become a scientific theory. Perhaps a form of ID that looks a lot more like Theistic Evolution (TE) may eventually have some scientific basis, but this is mere idle speculation.

    If a possible intelligent cause was to be determined in creating an organism,

    How? How can you – in principle – detect “design” without requiring information that tells you “artificial manufacture”?

    the characteristics of said designed object could be used to produce a theoretical extrapolation of the designer’s own characteristics.

    I agree in principle, but this is again mere speculation.

    But theorizing design is indeed shaky,

    That’s putting it mildly.

    so the pursuit of naturalism must come first UNLESS unviable by the weight of the observable, hard evidence.

    If evidence for biological design were ever to come to light, then biological design would be known to be a part of nature. End of.

    “Naturalism” is merely a vaguely scary and bugbear-ish label applied by the creationists to investigations that deal with facts rather than fantasy. Reality is the only reliable arbiter of truth when it comes to our ideas about how the world functions.

    I don’t think absolutely strict naturalism should be a rule of science when & where required (emphasis on previous 3 words):

    Again, it sounds like you’ve fallen for the propaganda. What exactly do you mean by “naturalism” and how can a set of investigations that demand real evidence in order to draw conclusions ever seriously consider the supernatural? Surely “we don’t know yet” is a far more honest answer than “god did it” when you have no evidence to indicate the god even exists? How can the not-natural (if you’ll pardon a rather clumsy expression) ever have a serious place in improving our understanding of the world?

    when it does it leads to your own “God-of-the-gaps” arguments.

    I’m not sure I see what you’re trying to say here. How does “naturalism” ever lead to GOTG arguments?

    IIUC, GOTG is the insistence that god operates in the areas that science has yet to elucidate. And, as science advances, those gaps get smaller. At heart, it is an argument from ignorance: for instance “evolution cannot explain X, therefore god did it”. This is a fallacy, because it assumes that science will never explain X. It also rejects “we don’t know yet” as a valid answer.

    As for Occ’s razor, just remember that if the evidence were to suggest an external agent, then that external agent is the simpler hypothesis.

    To some extent, and provided it is not in clear conflict with well-established laws of nature. So what?

    Thus far, all of the millions of pieces of evidence that support evolutionary theory point to a purely natural – indeed an inevitable – process.

    It doesn’t matter if some yet-to-be natural explanation possibly exists and so we should bet on it, cuz a designer necessitates it’s own explanation – IT MATTERS WHETHER OR NOT THE HYPOTHESIS WORKS RIGHT HERE, RIGHT NOW. Nothing is simple if it doesn’t work.

    If I have understood you correctly, then you are missing two key points:
    1. If evolutionary theory were wrong in any substantial or gross way, we would already know it by now. The core of the theory has been around for 150 years, and has been tested very thoroughly. Therefore, we can conclude that this core of evolution is at the very least a good approximation to how biology really works.
    2. ID does not work right here, right now. If you parse through all of the fallacies amd strawman attacks on evolution, ID boils down to nothing more than “someone somewhere designed some stuff in biology, somehow”. ID has no ideas about when it happened, how it happened, or (officially at least) who did it. It was designed to be sufficiently vague that it could include YEC, OEC, TE and everything in between.

    To expand slightly, if evidence were ever to come to light indicating that biological organisms on Earth were deliberately designed, we would already know that evolution was that designer’s toolkit.

    Furthermore, consider this: if one accepts ID with all its vaguenesses, the concept of multiple designers makes a damn sight more sense than the idea of a single solitary designer. How else, for instance, to explain the platypus? Or the Ichneumonidae? Or the diversity of eyes? Or the human pelvis? Additionally, the competing theory of Incompetent Design is also a better fit for what we know of biology than the ID that is expressed by the luminaries of the Dscovery Institute.

  42. Nigel Depledge

    Sam H (17) said:

    I’m going to investigate authors on both sides, and leave aside ad hominem (as several here cannot seem to do), and attempt to dig as deep as I can, leaving aside arguments from authority unlike kuhnigget.

    So, you reject the expertise of the world’s leading biologists, right? What is your basis for this radical approach?

    Good luck with understanding Dembski’s writing, BTW, as he has specifically tossed his word-salad to confound the lay reader into thinking he might have a point. Particularly his “complex specified information” concept. See if you can work out what that means without having to resort to an analogy.

    Also BTW, if you are going to go throwing accusations around (ad hominems and arguments from authority), how about you back up those claims with specific examples, huh?

  43. Nigel Depledge

    reidh (42) said:

    so its around 4 times its diameter in distance from us? Thats close. Good thing the universe is expanding instead of contracting.

    Er … no.

    It’s about 4,000 times its diameter away from us.

  44. Wissydig

    Spirals are sooo tweesty i loveeit. thanku

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »