Revealing the Universe: the Hubble Extreme Deep Field

By Phil Plait | September 25, 2012 12:13 pm

Astronomers using the Hubble Space Telescope have created the deepest multi-color* image of the Universe ever taken: the Hubble Extreme Deep Field, a mind-blowing glimpse into the vast stretches of our cosmos.

Check. This. Out.

Yegads. [Click to cosmosenate, or grab the bigger 2400 x 2100 pixel version.]

This image is the combined total of over 2000 separate images, and the total exposure is a whopping two million seconds, or 23 days! It’s based on the original Hubble Ultra Deep Field, with new observations added in since the originals were done. It shows over 5500 galaxies – nearly everything you see in the picture is a galaxy, an island universe of billions of stars. Only a handful of individual stars in the foreground of our own galaxy can be seen.

Here’s some detail from the image:

The variety of galaxies is amazing. Some look like relatively normal spirals and ellipticals, but you can see some that are clearly distorted due to interactions – collisions on a galactic scale! – and others that look like galaxy fragments. These may very well be baby galaxies caught in the act of forming, growing. The most distant objects here are over 13 billion light years away, and we see them when they were only 500 million years old.

In case your head is not asplodey from all this, I’ll note that the faintest objects in this picture are at 31st magnitude: the faintest star you can see with your naked eye is ten billion times brighter.

So, yeah.

I’ll note that the purpose of this and the other deep field images is to look as far away and as far back in time as we can to see what the Universe was like when it was young. The wealth of data and scientific knowledge here cannot be overstated.

But I suspect, in the long run, the importance of this and the other pictures will be their impact on the public consciousness. We humans, our planet, our Sun, our galaxy, are so small as to be impossible to describe on this sort of scale, and that’s a good perspective to have.

But never forget: we figured this out. Our curiosity led us to build bigger and better telescopes, to design computers and mathematics to analyze the images from those devices, and to better understand the Universe we live in.

And it all started with simply looking up. Always look up, every chance you get. There’s a whole Universe out there waiting to be explored.


The folks at Hubble will be holding a public interactive discussion of the HXDF image on Google+ at 13:00 Eastern (US) time on September 27th, where you can ask astronomers questions. Tune in and learn more!

Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team


* In 1998 a single-color image was taken with the STIS camera on Hubble, and reached similar depth. It would take some serious analysis to know which image sees fainter objects!


Related Posts:

- Astronomers have found when and how the cosmic fog was lifted (a brief history of the young Universe)
- Another record breaker: ultra-deep image reveals ultra-distant galaxy
- Record-breaking galaxy found at the edge of the Universe
- Hubble digs deep to see baby galaxies

CATEGORIZED UNDER: Astronomy, Pretty pictures

Comments (105)

  1. This is why I think life on another planet isn’t just a possibility but a statistical certainty. There are 5,500 galaxies in this tiny segment of the sky. (IIRC, the original Deep Field took up about the size of the moon in the sky.) There are 5,500 galaxies there. This means there must be tens of thousands (if not hundreds of galaxies), each with millions (if not billions) of stars. Even if only a tiny fraction of those stars had planets which could support life, there would be a huge number of life-sustaining planets out there. For this to be the only planet where life arose would be extremely unlikely.

    Mind you, this doesn’t mean we can reach that life nor does it mean that life can reach us. It doesn’t do us any good right now if a billion light years away Zorax is looking up at the stars from Xelex Prime wondering if there’s any life out in the Universe. The Universe might be teeming with civilizations, each so far apart that not only are communication/travel impossible, but that merely being able to detect another civilization’s existence might be a rarity. Imagine a Universe full of lonely civilizations wondering “Is anyone out there?”

  2. Nathan

    Thanks, Phil. I’ve always enjoyed your enthusiasm, insight, and relentless debunking of pseudoscience. You’re the Carl Sagan of our time!

    The earlier comment about the statistical certainty of life being present somewhere else in the universe is great philosophy. Unfortunately, this argument doesn’t hold water in the realm of statistics. Using statistics, we cannot answer the question of intelligent life at the present time. We currently have a sample of one; we are aware of life on a single planet. Until we find another civilization or rule out another civilization’s existence in our own galaxy, this question will not be answered.

  3. Steve D

    There seem to be quite a few spiral galaxies in the image that are peppered with what look like large bluish spheres. Are those star-forming regions?

  4. TechyDad, there are on the order of 100 billion galaxies in the observable universe. The total number of stars whose light now reaches us is somewhere around 10^22. Feel free to up your confidence :-)

  5. Ted

    So to a non boffin like me I look and think lovely pic and article then I think:

    Is there even a theoretical mode of transport that has a sufficient speed that might make these (or even out closest star) possible to visit?

    Obviously Voyager might get there one day even at its current speed but that is a plane journey that would definitely cramp your legs.

    So in a nutshell – just how “out there” do you have to be before you can talk about visiting say another galaxy? Is it total SciFi at present?

  6. Pete Jackson

    The Hubble Deep Field is only 2.5 arcminutes across, or 150 arcseconds. If we concentrate on the detail of the image given above, it is about 1/4 of the Hubble Deep Field, or about 38 arcseconds across.

    So lots of the galaxies, upon which we can see so much detail, are only about one arcsecond in angular size! And which would look just like a blob from a ground-based telescope (unless they have adaptive optics).

    Using simple geometry, our Galaxy (70,000 light years across) would subtend one arcsecond from a distance of 14 billion light years. But way back then, in the early universe, galaxies had not grown as large as ours yet.

  7. Barber of Civility

    Almost smack dab (a highly technical term) in the middle of the picture is an orangy galacticky object that appears to be rectangular (looks sort of like a cheese grater). Can anyone tell me if we know anything about it?

  8. Menyambal

    So please to clarify: How much of the sky is in that first image? The size of the moon? One one-zillionth?

    Thanks.

  9. The Bobs

    It would be interesting if an annotated version of the picture was produced with estimated distances for selected galaxies in the photo. It would give people good idea if the depth of the field.

  10. carbonUnit

    I presume the two bright objects in the upper half of the detail image are foreground stars. It looks as if Hubble has resolved solar disks, not just bright points. Is that an artifact, or is it actually possible to resolve disks now? (Can’t wait to view these pics on the 55″ screen when I get home…)

  11. Brian

    Obviously Voyager might get there one day even at its current speed

    Actually …. Given the acceleration of the expanding universe, I doubt Voyager could ever visit anything outside of our Local Group, even in theory. The other galaxies are moving away — not fast, but faster than Voyager.

    Come to think of it, does Voyager even have enough speed to escape the Milky Way galaxy? What is the galaxy’s escape velocity, anyway? I don’t have the foggiest notion.

    Hmm … quick check of online sources shows that the Milky Way’s escape velocity isn’t well known, but it has to be more than 500 km/s, since there are captured stars with that velocity. Voyager 1′s velocity relative to the solar system is about 17 km/s. So it probably isn’t going to be leaving the galaxy anytime soon.

  12. Carey

    @7. Menyambal: It’s about 2 millionths of the whole sky (or one 500,000th if you prefer).

    Someone please check my math. There are 360×360 square degrees in the entire sky, or 129,600. The moon is 0.5×0.5 square degrees, or 0.25.

    0.25 / 129600 = 0.000001929 or 2 millionths.

    Although I don’t see where Phil said this new image covers the same amount of sky as the moon.

  13. I would also hugely appreciate an accurate description of what proportion or percentage of the sky this image covers. Degrees, most people can figure out, but when it comes to viewing angles described in arcseconds, it gets tricky to visualize for a layperson like myself. Thanks! :)

  14. Unsettled Scientist

    Carey, incorrect. From the spacetelescope website:

    “The image covers an area less than a tenth of the width of the full Moon, making it just a 30 millionth of the whole sky. Yet even in this tiny fraction of the sky, the long exposure reveals about 5500 galaxies, some of them so distant we see them when the Universe was less than 5% of its current age.”

    TheBobs, there is an annotated version:
    http://www.spacetelescope.org/images/heic1214b/

  15. Nickster

    “It’ll have to go.” – Krikkit

  16. MJP

    Actually, the whole sky only has just over 41,000 square degrees, not 129,600. Still, your point is well taken.

  17. Jay

    Even at Voyager’s speed, it will take 73,000 years to reach our closest star (Proxima Centauri). Since we are around half-way out on an arm of the Milky Way (which is 100,000 light years across), if Voyager was heading straight out toward the edge (and it’s not), it would take around 424,349,000 years to get there.

    So, no time soon… !

    The bright points are stars, but those aren’t their disks. They’re just that bright relative to these galaxies that they’ve blown out their centers.

    Short of science fiction, it’s very unlikely we’ll ever visit another star, much less another galaxy.

  18. Ted

    10) Brian
    Yeah but when those galaxies hit the edge of the universe they are going to bounce back so Voyager can meet them on the way back during The Big Crunch !

    OK your explanation makes more sense :)

  19. guest

    The size of the Hubble field was originally stated as being the deadest part of the sky, about the size of a grain of sand held at arms length. If that’s the case, WOW!

  20. bungle

    TechyDad:
    “Imagine a Universe full of lonely civilizations wondering “Is anyone out there?””

    And imagine that all those civilizations are parting away at accelerated speed. At some point we would need a Hubble to even see another star (well, of course at that point, earth is no more, but still). Or maybe instead of exploding we start to implode.

  21. Paul

    Is there even a theoretical mode of transport that has a sufficient speed that might make these [...] possible to visit?

    If the cosmological constant is nonzero, as the evidence seems to suggest, these galaxies are lost to us. Even traveling extremely close to the speed of light we would never reach them — the expansion of the universe would pull them away even faster. They and we are now causally disconnected.

  22. truthspeaker

    Is this an old photo, or did they take new photos of a previously photographed slice of sky?

  23. Paul

    There are 360×360 square degrees in the entire sky,

    You have incorrectly computed the surface area of a sphere.

  24. Ivan

    Here’s the size of the Hubble extreme deep field as seen from the ground: http://www.spacetelescope.org/images/heic1214d/

  25. MikeS

    The angular size of the Extreme Deep Field is nicely illustrated by this image:
    http://www.spacetelescope.org/static/archives/images/screen/heic1214d.jpg

  26. Michael Weir

    As far away as those are, and factoring in the speed of light, these galaxies could look totally different today, right now. *mind blown*

  27. This is truly incredible. It appears there are galaxy “types” that resemble one another. There are the blue and red ones that seem to show up twice in the picture and then there are the red “sun like” ones which show up many many times in the picture, and then there are the spirals which seem to be the most common… fascinating. I wonder what is going on in each one of them!

  28. Kenneth J. Hendrickson

    If your world-view is materialism (nothing exists except matter and energy, and the result of interactions between that matter and energy), then the vast size of the universe guarantees other life, based upon the fact that there is life here.

    But materialism is provably false — not by science, but by philosophy. It is not hard to demonstrate. It is pretty much impossible to talk about a universe without teleology — goals. Even Darwinian evolutionists talk as if “nature” itself had goals. It is impossible to explain our behavior, and other animal behavior, without reference to goals. But goals cannot arise from nothing, and being non-material entities, they must arise from (be caused by) other non-material entities. Indeed, there must be a chain of such “final” (goal-directed) causation leading to the current behavior of all goal-seeking entities we currently observe, including ourselves.

    Not only is materialism provably false by reference to teleology, it is also provably false by reference to Aristotealian (or Platonic) “forms”. Triangles certainly exist. And yet no actual triangles perfectly instantiate the perfect triangular form. Their lines are not perfectly straight, for example. And yet, we all know what triangles are. Furthermore, triangle-ness exists outside of us. Even if there were no humans, triangle-ness would still exist. It existed before we did. All of mathematics is the same. The “form” of triangle-ness — what makes triangles triangles — is non-material.

    Ideas, likewise, are non-material entities. They can be encoded in material, such as voltages in a computer memory, ink splotches on a page, pressure variations in air due to speech, etc. But the idea itself is not the encoding of the idea. The idea itself is non-material, even if it is encoded in a material medium. Some ideas have always existed (at least as long as the universe itself has existed), waiting for us humans to discover them; theories of mathematics are examples.

    All of this, with a bit more argumentation, can be used to show that a First Unmoved Mover, must exist — that an Uncaused Cause must exist. In short, God must exist. He can’t not exist, given what we see in the material universe, and given what we humans see in ourselves. (Read “The Last Superstition”.)

    If Forms exist (either Platonic, or Aristotelian, or Thomistic), and if Final Causation (goal-directed behavior) exists at all, then it is a lot more questionable whether or not life exists elsewhere in the universe. If life was not created by mindless purpose-less natural processes here, then it would likely require a Mind, and Purpose, elsewhere also. The argument for life existing elsewhere would therefore be a philosophical argument, based upon logical necessity, rather than an empirical scientific argument based upon statistics. Nobody has ever made such an argument yet.

  29. Shawhan

    Surface area of a sphere formula. 4 pi r ^2

    Isn’t this just an approximation anyway? didn’t think the universe was very spherical.

    Truthspeaker, they have taken several deep field photos, this one is Extreme!! Not just deep:)

  30. Peter

    @11- Carey, math check, as requested.

    Since the sky is a sphere, there are much less than 360*360 square degrees in the sky. The number comes out to about 41,253 square degrees. The formula is 4*PI*r^2, where r (radius of sphere) is (180/PI).

    I didn’t find an explicit statement about the Extreme Deep Field (XDF), but the Ultra Deep Field, which is the same field, I believe, is about 3.4 arcminutes on a side). Let’s assume that the XDF is essentially square, so its area is 1/300th of a square degree.

    So the XDF is (1 / 41253) * (1/300), which is about 1/12,700,000 of the whole sky, or, if you prefer, about 80 billionths.

  31. Robin

    A sphere subtends 4π steradians, with a steradian being a square radian, which is [(180/π)^2]°. So a sphere subtends 4π[(180/π)^2] sq. degrees=41,252.88 sq. degrees.

  32. digital_dreamer

    15) truthspeaker,
    Yes, they are new photos from a previously photographed slice.

    The article says: “It’s based on the original Hubble Ultra Deep Field, with new observations added in since the originals were done.”

    MAJ

  33. moT

    The link at the very top of the article (http://www.spacetelescope.org/news/heic1214/) helps put the size of this view in perspective.

  34. John

    Does anyone see any gravitational lensing going on in this picture?

  35. Dutch Railroader

    @10 – Concerning the paths of the Voyager (and Pioneer) spacecraft: they escape our solar system with a relative velocity of only a few km/s, which is trivial compared to the 220 km/s orbital velocity of the sun around the MW. The Voyagers will go in orbit around the MW in a path only slightly different from that followed by the sun. Genuine escape from the MW would require Delta V >> 500 km/s, or more than two orders of magnitude greater than what the probes are carrying.

  36. danadam

    @Nikola and others
    > … of what proportion or percentage of the sky this image covers
    It’s all there in the first link. With the Moon to scale: http://www.spacetelescope.org/static/archives/images/screen/heic1214d.jpg

  37. Chris

    Kind of makes you wonder if there is anybody looking back at us

  38. Steve D

    Ever want something as a kid and years later get it as an adult? That happened to me when I found that Life magazine classic from the 1950′s “The World We Live In” in a used bookstore. Words cannot describe the awesomeness. Did I mention the Chesley Bonestell art? It has a photo of tiny fuzzy specks two billion light years away, the most distant galaxies ever seen, or about 15% of the way to the limits of this field. At that time, telescopes had penetrated to magnitude 23. Magnitude 31 was so far out of the question it was absurd.

    And yet there’s something about some of those old black and white photos that presents an air of tantalizing mystery that I don’t get from these glorious modern images.

    As for the angular area of a sphere, an easy way to picture it is the circumference C = 2pi r. The area of a sphere is 4pi r^r = C^2/pi. This gives us the area in terms of the circumference and neatly avoids dealing with the radius of the Universe. Since C = 360 degrees, A = 360*360/pi = the same result as Robin.

    By the way, I’m not the same Steve D as #2. Gotta come up with a better handle.

  39. BobKC

    According to Wikipedia, the Hubble Ultra-Deep Field image is a little over 3 arcminutes across, or about 0.05 degrees. The full moon is about 0.5 degrees across, so it covers about 1/10 the angle of a full moon. Or, to visualize it another way, if you tape a dime to a wall and back up 67 feet, the image above would cover an area of the sky about equal to the dime. (someone please check my math)

  40. Menyambal

    If you click on the link above the picture, http://www.spacetelescope.org/news/heic1214/, there’s a page with all the info we’ve been asking for.

    “The image covers an area less than a tenth of the width of the full Moon, making it just a 30 millionth of the whole sky.”

    There’s even a picture showing that the image is less than the size of most of the maria on the moon.

    Wow.

    Thanks.

  41. Menyambal

    If you click on the link above the picture, http://www.spacetelescope.org/news/heic1214/, there’s a page with all the info we’ve been asking for.

    “The image covers an area less than a tenth of the width of the full Moon, making it just a 30 millionth of the whole sky.”

    There’s even a picture showing that the image is less than the size of most of the maria on the moon.

    Wow.

    Thanks.

    (Sorry if this double posts.)

  42. Scott

    I wonder if they used the panorama camera from the new iPhone for this…;)

  43. Headzero

    1/2 way down the picture approximately 1/4 of the way in from the left – there is a green object. Is this ‘Hanny’s Voorwerp’ or something similar?

  44. Entropy

    The image is actually more like ~1/10 of a moon ~ .05 degrees on a side (my own estimation from http://www.spacetelescope.org/images/heic1214d/). That makes it 61 billionths of the sky, meaning there are 5500/61 * 10^9 = 91 billion galaxies in the observable Universe, call it 10^11. This is where the “100 billion galaxies” claim comes from. With about 10^11 stars per galaxy, there are about as many stars in the observable Universe as molecules in a human brain. Of course, we can’t see the vast majority of the Universe yet, as implied by it being nearly flat from WMAP etc., meaning at the very least the Universe is “nearly infinite” in true size.

  45. Gene Homme

    I believe the bright object with diffraction spikes is a foreground star, everything else a galaxy.

  46. Chris

    “This is where the “100 billion galaxies” claim comes from.”

    I hope that’s not where it comes from, or it would surely be wrong. There is not the same amount of stars equally distributed in every direction. The deep field images are captured by looking specifically in the direction from where the big bang happened. This image might be a big chunk of the universe.

  47. scgvlmike

    TechyDad, I love your turn of phrase, ‘Imagine a Universe full of lonely civilizations wondering “Is anyone out there?”’ Such elegant despair!

    It also sounds like a marvelous starting point for a speculative fiction story, a la’ Niven or Flynn.

  48. Soggy

    I understand how people look at a photo like this and think ” with so many planets around so many stars in so many galaxies, there must be life out there somewhere.” And maybe there is…but I enjoy a little simple math now and again so I got out the old graphing calculator (because nothing else would handle the number this big) and did a little math. And this math is crude but I’ll share it anyway

    The original Hubble deep field covers about 1 24millionth of the sky and contains about 3000 galaxies 24million X 3000 = 72billion galaxies x 200billion average stars per galaxy = 1.44e+22 stars (A). we’ll give each star a goldilocks planet for simplicity, I know that’s way to many but I don’t want to do the math on that. Now lets say that each planet has all the amino acids that are needed to form life. A protein used by a living organism is only made from left handed acids, to get a string of left handed acids to randomly form a simple protein 100 acids long in primordial soup is 1.267650600228229e+30 (B)

    The odds of a protein 100 acids long forming around a star are (B)/(A)= 88031291.68, actually not bad odds. But that’s just a chain of 100 random left handed acids. there are 20 different acids used in life and each has 2 sides when you factor that in the odds become 1 in 1.1159291974020763e+139. and that’s only a chain of 100, many acids are many hundreds if not thousands longer which causes these numbers to grow exponentially.

    So really, Even with the mind numbing vastness of the universe, The math still says no.

  49. Unsettled Scientist

    Chris wrote > “There is not the same amount of stars equally distributed in every direction. The deep field images are captured by looking specifically in the direction from where the big bang happened.”

    Nonsense. You’re comparing the distribution of stars in our galaxy to the distribution of galaxies in the universe. These are not the same thing. There is the Hubble Deep Field, and the Hubble Deep Field South looking in the opposite direction basically. Their similarity very much supports the cosmological principle that the large scale structure of the universe is homogeneous. That is to say, the same in every direction. Finally, there is no direction from which the big bang happened.

  50. Menyambal

    Chris @ 47, the Big Bang happened in every direction. Anywhere we look, we are looking back in time, and that is when the Big Bang was. There are slight variations in what we see, but they are slight, so an assumption that galaxies are distributed evenly in not wrong.

    Stars, on the other hand, vary in amount toward and away from our galactic plane.

  51. Shayne O

    @Nathan sure the “sample of 1″ thing is true. But it seems like its almost every other week we learn new things that tell us that the chemistry we once assumed unique in the triggering of earths life is rather common, and we learn new things about just how hardy life can be and just how easy some of the early reactions are.

    Its almost certain that the universe is teeming with life. But not only that, its also very likely that some of that is complicated and multicellular.

    The only reservation I have about whether sapient life is common, is whether there exists a dynamic wherein a species becomes truly intelligent human styles, they promptly learn to nuke themselves or destroy their ecosystem before gaining the wisdom to realise what a truly bad idea it might be.

    Perhaps in the final analysis humans ARE alone, because like a million civilizations before us and another million to come, just as we stand on the precipice of touching the stars , we allowed ourselves to be eliminated, not by unseen monstery enemies, but by our own greed and arrogance.

    I hope I’m wrong. Perhaps we’re a few years from the NASA boffins announcing the warp-drive things real and we can finally spread off the planet and not leave our eggs in one basket. Perhaps we might even realise that demonizing our climate scientists as a vast left wing conspiracy is foolish and dangerous, and we avert a catastrophe. Perhaps we finally get around to finally dismantling our nuclear weapon capacity and sparing our children the threat of a terrible terrible mistake.

    Or perhaps in 1000 years the vorlons will land and look across the ruined cities that held humanity like a grave and wonder how the cockaroaches that now dominate the ecosystem ever managed to send those strange black and white television images that their radio telescopes had picked up a few years earlier depicting an anthropod species marcing about in some strange nameless forgotten war.

  52. wilson

    with respect to travel, distance measures and the effect of an expanding space; yes, it we assume that the red-shift can only be attributed to an expansion of space. If we assume the red-shift is related to the ‘mean-free-path’ of the wave like properties of photons; we get the same metric for distance, but don’t have to contemplate the idea of the ‘expansion of space’.
    I think it is a ‘hoot’ that folks talk about the expansion of space. I don’t know where the notion comes from. The basic principle of entropy seem pretty measurable, the Lorentz-Fitzgerald contraction seems pretty measurable (both in ‘Lorentzian’ and ‘Einsteinian’ spaces). But the ‘expansion of space’? Really? Really…?

  53. amphiox

    Voyager may not be leaving the Milky Way, but other galaxies are coming to it. Eventually every galaxy in the Local Group will be part of one mega galaxy, so Voyager will have a chance to visit stars born in Andromeda. Other galaxies not so much, assuming expansion is constant and the nonzero value of the cosmological constant really is constant and will not flip sign. But we don’t know that for certain.

  54. Mike

    You realize, of course, that all of this is a result of a conscious universe contemplating itself…

  55. User

    The first paragraph needs to be modified, it should read: “Astronomers using the Hubble Space Telescope have created the deepest multi-color* image of the Universe ever taken^H^H^H^H^H released to the public.”

    Source: http://www.popsci.com/technology/article/2012-06/nasa-adopts-two-spare-spy-telescopes-each-maybe-more-powerful-hubble

  56. Nathan

    @21 ” Even traveling extremely close to the speed of light we would never reach them — the expansion of the universe would pull them away even faster. They and we are now causally disconnected.”

    You’re forgetting about the Alcubierre drive! All we need is some exotic matter and more mass than is present in the observable universe and we’ll go there. Of course, upon entry, we’ll annihilate our destination with gamma rays, but still.

  57. bjdcha226

    So I gaze at this image and observe the background “between” the galaxies and protogalaxies and there is a fuzzy graininess instead of a velvet black; i’m wondering if those grains are borne of galaxy light, or just a compression artifact of the picture.

    Could it be that the background is as saturated with early light as it appears?

    The “light problem” notwithstanding, at some point if you look far enough back you may get a gradually more and more homogeneous, undifferentiated wall of light, or am i just talking layperson’s smack…

  58. Summer

    These pics are awesome. Always firmly believed in life on other worlds, not only in our own Galaxy, but also in others.
    Surely we are not all at rudimentary stages of Space travel. Build ships, get out there and explore. A first contact within 40 Earth years would be great.

  59. truthspeaker

    Ri Caragol Says:
    September 25th, 2012 at 3:10 pm

    This is truly incredible. It appears there are galaxy “types” that resemble one another

    Indeed there are: http://en.wikipedia.org/wiki/Galaxy#Types_and_morphology

  60. bullsballs

    A beutiful picture!

    I have always wondered, are we looking out to older and older data, or is our vision being distorted by gravity and we are seeing around the inside of a sphere rather than out to the edge of the sphere?
    Could it be the universe is larger and older than we predicted? Or are we being tricked by ‘mirage’?
    If the universe is larger and older than we thought, could it preclude a ‘big bang’ beginning? Or is it more likely?

  61. Ken

    Has there ever been a counter-factual-type story where an intelligent species evolved on a cloud enshrouded planet? I have wondered how we humans would have evolved, in terms of our development of science and math, had our planet been as cloudy as Venus……

  62. I like the Digital Cuttlefish’es take on this – see link in my name here to his post “Hubble Does It Again” posted on 25th September, 2012 at 9:46 pm.

    Which has inspired my own bit of contemplative doggrel on this as follows :

    Truth in rhyme.
    Looking back in time.
    The starstuff that is us
    Sees so far
    Beyond ourselves
    Through a looking glass into darkness.
    With eyes of glass and metal.
    Eyes of science
    Unfogged by superstition now,
    Well mostly. ;-)

  63. Kenneth J Hendrickson @ #28 said: “All of this, with a bit more argumentation, can be used to show that a First Unmoved Mover, must exist — that an Uncaused Cause must exist. In short, God must exist. He can’t not exist, given what we see in the material universe, and given what we humans see in ourselves. (Read “The Last Superstition”.)”

    I’m a complete philosophy numpty, so I’ll take your arguments at face value. However having said that, I assume that the arguments don’t allow us to draw any conclusions about the nature of God, nor do they provide any basis for worshipping It.

    “If Forms exist (either Platonic, or Aristotelian, or Thomistic), and if Final Causation (goal-directed behavior) exists at all, then it is a lot more questionable whether or not life exists elsewhere in the universe. If life was not created by mindless purpose-less natural processes here, then it would likely require a Mind, and Purpose, elsewhere also. The argument for life existing elsewhere would therefore be a philosophical argument, based upon logical necessity, rather than an empirical scientific argument based upon statistics. Nobody has ever made such an argument yet.”

    Forgive me, but could you please explain what part of the physical process of life coming into existence is necessarily impossible without the intervention of God?

  64. Robin

    @Kenneth J (#28):

    Fortunately, philosophy is not required and not relevant to science and specifically, the scientific method, so philosophic proof is actually no proof of anything real. By real, I mean physical phenomena, the laws and theories associated with such phenomena, including the origins of the Universe.

    @Wilson (#53):

    The expansion (or contraction) of space is the result of an exact solution of Albert E’s general relativistic field equations. Given the age of the universe, expansion of space has to be the case if the speed of light is a fundamental limit of speed because bodies more than about 4 or 5 x10^9 parsecs away would be moving apart at speeds greater than c. Since the expansion of space isn’t limited by the speed of light, we’re in luck ‘cuz now we don’t have to explain how each of those bodies would have acquired infinite energy to go the speed of light. We also conveniently don’t have worry about how those superluminal bodies acquired infinite mass, and we wouldn’t to pull out our hair trying to reconcile our observed universe with one that has infinite mass.

  65. SpaceSon

    Space is freakin’ awesome.

  66. If you listen to the egg head biologist we (meaning) humans and other species came from the primordial sea where virus and chemicals made cells which eventually became us crawling out of the sea. The question is could this be duplicated on other planets. Not likely. They fail to take in thousands of variables none of which point to life as we know it. But here is an interesting hypothesis, if we do find life like ours on another planet, was it by accident or by design. I think I go with Mr. Peter B. The universe is to well organized and chaotic at the same time. For what reason? I always questioned where the “first” atom came from for the “Big Bang” to be a “Big Bang.”

  67. Tara Li

    @67 SMichael – Oh, so many problems there. Could the chain of chemical reactions that resulted in us be duplicated *EXACTLY* on another planet? Not real likely. Could *A* chain of chemical reactions resulting in life “like” us occur? That is a completely different question – one I’m fairly convinced is “yes”. Of course, then one must ask how much “like” us you’re talking about. Does it have to be genetically compatible humanoids to the point of mutual fertility? Or just generally humaniform? Does it have to be carbon based? There’s been some theorizing of chemical systems using silicon & fluorine, which might apply to Venus and hot Super-Earths. How about some kind of hydrocarbon cycle that might have evolved on Titan? For that matter – how about semi-stable complexes of magnetic fields & plasma? What might we find down in the Sun? And just how complex does it need to be to qualify? Bacteria? Vertebrate animals? Sapient/Sentient, like us?

    As for the “first atom” and the “big bang” – what if there is no discontinuity? When one is walking straight north – there’s no magic spot that forces you to stop walking, just because you’re at the North Pole. It’s just a semi-arbitrary point on the globe, and you can just keep walking across the ice without ever knowing you’ve hit it (for that matter, unless you have some fairly sophisticated equipment, you likely *WILL* cross it without knowing exactly when you’ve hit it – and no, the big pole erected on the ice won’t help, as the North Pole, both the magnetic & rotational poles, drift a bit.)

  68. Yuri

    @Kenneth (#28):

    Firstly, understanding teleology, Platonic Idealism, and similar philosophical constructs is important in understanding the way we categorise concepts and communicate them, and how we use language. However, it’s even more important to understand that “the map is not the territory” (or, “the description is not the described”). Furthermore, various philosophical constructs we use to describe things do not limit or affect the reality of the object(s) being described, and defining a ‘class’ of objects (e.g. ‘triangles’) only serves as a conceptual construct useful to our understanding, and does not in fact affect real things that fit our definition of triangles, either individually or as a group. As you say, these are immaterial ideas, but you neglect the important consequence of this, which is that such concepts only ‘exist’ inasmuch as they can be defined and understood, but do not have the properties of existence as normally understood (e.g. ‘this chair exists’ and ‘the concept of Chair exists’ are *not* statements of the same order) – philosophical Forms (of any school) have no more claim to objective existence than any other concept or mental construct. The very most that can be inferred from their ‘existence’ is that we, as a species and society/ies, have the ability to isolate and categorise individual parts of our subjective experience, form a generalised concept to describe them, and communicate that concept to others. Any further inferences are necessarily based on a confusion of concept with object (Platonic Idealism being the shining example of this kind of confusion).

    Secondly, you state “It is pretty much impossible to talk about a universe without teleology — goals. Even Darwinian evolutionists talk as if “nature” itself had goals.”. This isn’t quite right – Darwinian evolutionists do often speak teleologically, but this is simply shorthand for a concept which (at this time) is more cumbersome to express to the general public – it’s a real problem, because listeners often confuse the shorthand statement with the actual concept (the “map is not the territory” problem again, in a different form). However, reformulating such statements without teleology is trivial; for example, (a) is an inaccurate, teleological statement, but the general public will get the gist of it, (b) is accurate, but the general public is, sadly, to poorly educated on average to understand what it means, and (c) is accurate and the general public *could* in theory understand it, but would probably be asleep a short way in…
    (a) “Species A developed trait B in order to take advantage of environmental condition C”
    (b) “Natural selection favoured trait B in species A under environmental conditions C”
    (c) “Random variations within species A included individuals with a larger measure of trait B relative to the general population. Under environmental conditions C, individuals with a higher measure of trait B were more likely to survive and reproduce than individuals with a lower measure of trait B. Over time, lower survival and reproduction rates led to individuals without a high degree of trait B becoming an progressively smaller proportion of the population of species A, until no individuals of species A existed that did not have a very high measure of trait B.”

    (with apologies to the general public, and apologies to commenters for feeding the teleologist…)

    To various others: Thanks for providing a scale for the image!

  69. Regner Trampedach

    My God, – it is full of galaxies!
    carbonUnit @ 10: Sorry to burst your bubble, but those two are not stars, they are galaxies like pretty much everything else there. There is one star in that detail image (recognized by the blue/magenta difraction spikes). A cursory scan of the whole image, revealed only three(!) stars. And I assure you, they are nowhere resolved. And remember – even though it has been up there for a while, it is still the same Hubble telescope – it is still a 2.4m reflector, and that diameter of the light-bucket is what determines the resolving power. At a wavelength of 500nm (green) Hubble can resolve features down to 0.052 arc seconds, which in turns means a solar-sized star would have to be closer than 0.09 parsec = 0.29 light years from us, to actually be resolved. So far, the closest star (Proxima Centauri) is still 3.6 light years away…
    Cheers, Regner

  70. Menyambal

    I’m not sure I can explain this right …

    If we are looking out in every direction at the Big Bang, and the universe was smaller all the way down to it, the deep field photo is not really the size it seems to be. Everything in it looks bigger than it “really” is—it is really a photo of a lot of small galaxies in a small universe. It just looks bigger because we are looking at it from several directions, so to speak.

    It’s like seeing the little-bitty dot of the Big Bang all over the sky. We are seeing that part of the old, small universe over a bigger part of the sky than we should.

    … I need to work on this more.

  71. Heli

    Wow! The picture is amazing! I feel pretty small now.

    @Regner Trampedach (#70): What exactly causes the foreground stars to have diffraction spikes with such distinctive colors?

  72. B

    Must get my hands on a TARDIS.

  73. bassmanpete

    a mind-blowing glimpse into the vast stretches of our cosmos.

    OUR cosmos, Earthling?

  74. iuniverse
  75. Nicola

    This picture just takes my breath away, especially while watching Tony Darnell’s video ( http://www.youtube.com/watch?v=oAVjF_7ensg )

    Another great way to watch it, is to look around with an iPad: http://vissee.ch/phos4rise/example/deep-space/

    Just amazing what we can do.

  76. SMichael @ #67 said: “But here is an interesting hypothesis, if we do find life like ours on another planet, was it by accident or by design. I think I go with Mr. Peter B. The universe is to well organized and chaotic at the same time. For what reason? I always questioned where the “first” atom came from for the “Big Bang” to be a “Big Bang.””

    Eh? What do you think I said? Read my comment again. I was questioning Kenneth J Hendrickson’s conclusions.

    Personally I think Hendrickson’s claims are wrong, but given I’m a philosophy numpty I don’t have the skill to challenge them (thanks Yuri @ #69).

    And I don’t have a problem with the concept of the Big Bang either.

  77. kpyke

    According to the wikipedia, the hubble deep field “covers an area 2.5 arcminutes across, about one 24-millionth of the whole sky, which is equivalent in angular size to a 65 mm tennis ball at a distance of 100 metres.” (http://en.wikipedia.org/wiki/Hubble_Deep_Field)

  78. chasd00

    “But never forget: we figured this out. ”

    “we”? what do you mean “we” ? The vast majority of humanity was busy either killing each other, starving, or toiling away to keep clothes on their backs when this was done. A very very very few people are fortunate enough to have the intellect and resources to do this. There’s no “we”.

  79. Unsettled Scientist

    > What exactly causes the foreground stars to have diffraction spikes with such distinctive colors?

    The diffraction spikes are caused by the metal support structure holding one of Hubble’s mirrors in place as the light passes by them. The colors in this image are false as the light was recorded outside of the human-visible spectrum.

  80. How many of these galaxies belong to the Virgo Cluster, if any?

  81. Regner Trampedach

    Heli @ 73: The diffraction spikes are due to the object being unresolved, which is why you see them for stars but not for galaxies, and the colors are due to the different colors being from different exposures. I am not quite sure how much the spikes follow the telescope, but it looks like the exposures with blue and red filters were taken at different times, with the telescope having rotated 45 degrees in between. It looks to me like the green exposure is rotated just slightly clock-wise with respect to the red one. As Unsettled Scientist @ 79 says, the exposures range from 435nm blue light, to 1.6microm infrared light, so I am just talking about the colors assigned (in the image) to those actual filters.
    I also found another star, just to the left of the one in the detail image (and outside it). It seems to have one or two galaxies smack-dab behind it, which is my excuse for not noticing it before. But it reveals itself by its red diffraction spikes.
    Cheers, Regner

  82. Paul

    How many of these galaxies belong to the Virgo Cluster, if any?

    Probably none? I don’t believe this deep field is anywhere near Virgo.

  83. Unsettled Scientist

    > The diffraction spikes are due to the object being unresolved, which is why you see them for stars but not for galaxies

    Actually, you do see them for galaxies. Phil pointed this out a few years ago in one of the posts he links in this one. In this image you can see a bright star in the upper right with diffraction spikes, and to its right is a galaxy with diffraction spikes.

    http://blogs.discovermagazine.com/badastronomy/2009/12/08/hubble-digs-deep-to-see-baby-galaxies/

  84. Dr Who

    I have always wondered about pictures like these. What I wonder about is how do we know that the telescope is directed at the center of the universe and not in a direction that is away from the center of the universe. If we had a camera sitting over the earth which way is the center of the universe, up, down, left, maybe right? Since we are in a spiral galaxy it could be possible that the direct line to the center of the universe my be through the center of our galaxy inwhich would basically block our view. I love the pictures but I have always wondered if what you see is always what it is.

  85. Sandy

    Beautiful picture, and a testament to all the physicists, engineers, and general public who built the foundations, created the instruments, and funded it.

    I think it would be there whether we were here or not. All that philosophy seems to me to have been developed before physics. Now that we understand so much of the universe (not all by any means), do we still need to argue whether material things vs. idealizations “exist?” Isn’t it clear that material things do exist, regardless of what we experience? Am I missing something here?

    As for the statistical nature of DNA (not protein!) evolution, the probability that a *particular* strand of DNA would spontaneously evolve is low. The probability that some kind of DNA (or possibly some other mode of information storage, replication, and mutation) would evolve under the right conditions (a Goldilocks planet) seems to me to be very favorable, given that particular chemical reactions will occur if the reactants are present.

    Finally, assuming we need a god of some sort to start everything out assumes that cause and effect is necessary “before” a universe can be made. Maybe cause and effect have no meaning without a universe, so that the universe can come into being without particular cause. Once it got going, physics (>chemistry, >biology) proceeded on course.

  86. @Ken,

    Not about a planet shrouded in clouds, but Nightfall by Isaac Asimov took place on a planet that was in perpetual daylight. It’s many suns kept the sky lit every hour of every day… until one day when all stars but one set and the one that didn’t was blocked by a solar eclipse. Then the people were able to see the stars – and all hell broke loose.

    There’s the short story by Asimov and a novel that Robert Silverberg adapted from the short story. I recommend reading both.

  87. bjdcha226

    @ Dr Who

    Keep in mind you are looking back in time, every direction you could look is the center of the universe. It’s relative. You’re seeing an earlier younger smaller universe, but against a tableau that surrounds us. That is a mind blowing paradox, but it’s true. The “out there” is “in there”; the center of the universe is everywhere and nowhere. The universe is not like a big room filled with galaxies. Keep in mind the further out you look the further back in time you see into earlier epochs of galaxy formation.

  88. Dr Who @ #86 asked: “What I wonder about is how do we know that the telescope is directed at the center of the universe and not in a direction that is away from the center of the universe.”

    Centre of the universe? I didn’t know the universe has a centre, any more than the [i]surface[/i] of the Earth has a centre.

    And even if the universe [i]has[/i] a centre, what makes you think this is an attempt to image it?

    “If we had a camera sitting over the earth which way is the center of the universe, up, down, left, maybe right?”

    If the universe has a centre, its direction would depend on what part of the Earth the camera was over.

    “I love the pictures but I have always wondered if what you see is always what it is.”

    What do you mean? As far as we can tell, light (or electromagnetic radiation) operates the same way throughout the universe, both in space and time. The only differences we see are those involving physical changes in the universe over time. As the BA says in his comment, the purpose of these images is to look “…as far away and as far back in time as we can to see what the Universe was like when it was young…” So what we’re looking at is what galaxies looked like when the universe was much younger than it is now.

  89. Clive DuPort

    Surely if we look in any direction & predict that the universe is 13.7 billion years old because of the observable distance among other things, then the Earth must be at the centre. Unlikely.
    I presume the Big Bang started from a single point and spread out relatively evenly over time so that if we’re not at the centre, which seems far more likely, then it could have occurred billions of years earlier but we can only observe so far back. That may explain why those distant galaxys are so well formed and mature looking at only 500 million years old.
    Just a thought.

  90. #86 Dr. Who, #91 Clive DuPort:
    The Earth is not “at the centre of the Universe”; nor is anywhere else, because the Universe doesn’t have a centre! Just as, as has already been pointed out ( both in this thread and 1000 times before ), the Big Bang didn’t happen at any place or in any direction; it happened everywhere!
    Space itself ( or more accurately, space-time itself ) came into existence with the Big Bang. The Universe is not expanding into, or within, some previously existing space; it’s space itself which is expanding, and carrying the galaxies and everything else with it.
    From our point of view, all galaxies ( except those within our Local Group, which are gravitationally bound ) appear to be moving away from us – but from the point of view of any other galaxy, it would appear the same. They are not all moving away from us, or from any point in space; everything is moving away from everything else.
    To visualise it, draw some dots on the surface of a balloon, then inflate the balloon. All the dots move away from each other, and all the distances between them increase; there is no single dot which remains stationary or occupies any privileged position.

  91. Clive DuPort

    #92. Neil Haggath

    Thanks Neil, that makes sense & helped me to understand the concept. I had been thinking too three dimensionally.

    Kind regards,

    Clive

  92. Hello John, I’m not sure that there is any gravitational lensing. Would you see?

  93. Nigel Depledge

    Kenneth J Hendricksen (28) said:

    If your world-view is materialism (nothing exists except matter and energy, and the result of interactions between that matter and energy),

    Where does information fit into your definition of materialism?

    then the vast size of the universe guarantees other life, based upon the fact that there is life here.

    Only if the universe is genuinely infinite. But the observable universe is quite obviously not infinite, so what really matters to us is whether or not life exists elsewhere in the observable universe. And materialism does not guarantee this.

    But materialism is provably false — not by science, but by philosophy. It is not hard to demonstrate. It is pretty much impossible to talk about a universe without teleology — goals. Even Darwinian evolutionists talk as if “nature” itself had goals.

    Only casually, in the firm knowledge that such talk is an approximation to reality. There is no evidence of any teleology in nature. Therefore, there is no basis to assume the existence of teleology.

    It is impossible to explain our behavior, and other animal behavior, without reference to goals.

    Well, true, but so what? Those goals do not exist independently of the behaviours exhibited by animals and plants. They are merely abstract concepts invented by humans to explain nature in a way that is comprehensible to us.

    But goals cannot arise from nothing, and being non-material entities, they must arise from (be caused by) other non-material entities.

    Nonsense.

    Goals are intrinsically connected to – in your example – the organisms that strive to attain them. And, depending on your frame of reference, they are intrinsically connected to the scientist using the concept of goals to explain animal or plant behaviour.

    Indeed, there must be a chain of such “final” (goal-directed) causation leading to the current behavior of all goal-seeking entities we currently observe, including ourselves.

    You have not shown this. You simply state it and expect everyone else to accept it.

    Not only is materialism provably false by reference to teleology,

    You did not do this.

    it is also provably false by reference to Aristotealian (or Platonic) “forms”. Triangles certainly exist.

    Prove it.

    If you cannot prove that triangles exist independent of human thought then they are potentially nothing more than a component of human thought.

    And yet no actual triangles perfectly instantiate the perfect triangular form. Their lines are not perfectly straight, for example.

    Again, so what?

    You have not shown that the concept of the triangle exists independently of human thought.

    And yet, we all know what triangles are.

    We have all been taught what triangles are.

    Furthermore, triangle-ness exists outside of us. Even if there were no humans, triangle-ness would still exist. It existed before we did.

    Maybe so, but you are merely claiming this to be the case. You have not shown it to be so. Did the concept of the triangle exist before humans started scratching lines in the dirt? I don’t know, but neither do you.

    All of mathematics is the same. The “form” of triangle-ness — what makes triangles triangles — is non-material.

    But it could be intrinsically linked to human thought, and might not exist independent of humans.

    Ideas, likewise, are non-material entities. They can be encoded in material, such as voltages in a computer memory, ink splotches on a page, pressure variations in air due to speech, etc. But the idea itself is not the encoding of the idea. The idea itself is non-material, even if it is encoded in a material medium.

    You might find it easier to discuss this if you use the word “information”. Ideas are information. And there is a whole branch of mathematics that deals with information. But ideas as information do not exist independently. For example, marks on paper are only ideas within the context of a written language. Without that context, they are merely pretty patterns or meaningless scribbles.

    Some ideas have always existed (at least as long as the universe itself has existed), waiting for us humans to discover them; theories of mathematics are examples.

    This is random speculation. You have not shown that mathematical theories exist independently, and I suspect you do not actually know it. You are assuming that the existence of these abstract concepts implies their independence from human thought. This may indeed be the case, but your argument assumes it as self-evident, yet it is not so.

    All of this, with a bit more argumentation, can be used to show that a First Unmoved Mover, must exist — that an Uncaused Cause must exist. In short, God must exist. He can’t not exist, given what we see in the material universe, and given what we humans see in ourselves. (Read “The Last Superstition”.)

    Following from your previous specious argument, this, too, is specious.

    If Forms exist (either Platonic, or Aristotelian, or Thomistic), and if Final Causation (goal-directed behavior) exists at all, then it is a lot more questionable whether or not life exists elsewhere in the universe. If life was not created by mindless purpose-less natural processes here, then it would likely require a Mind, and Purpose, elsewhere also.

    You ignore here the possibility of a natural process that is mindless but not purposeless. After all, a dandelion plant is certainly mindless, yet it possesses a purpose. The existence of mindless purpose – or at least the convincing illusion of purpose in the mindless – is all around us.

    At the end of the day, your entire argument rests on your definition of the word “exist”. What does it mean for an abstract concept to exist? Can an abstract concept exist at all without a mind to ponder it?

    The argument for life existing elsewhere would therefore be a philosophical argument, based upon logical necessity, rather than an empirical scientific argument based upon statistics. Nobody has ever made such an argument yet.

    I’m not in the slightest bit surprised. Such an argument would likely be torn to shreds. It was not hard to find holes in your own argument here.

  94. Unsettled Scientist

    > I presume the Big Bang started from a single point and spread out relatively evenly over time

    The presumption is incorrect, it didn’t start from a single point. A singularity is not a point in space or time, it’s more of a pathology of the maths, and incomplete path, a divide by zero, a breakdown of the geometry. It is not a singular point in that geometry.

    http://plato.stanford.edu/entries/cosmological-argument/#5.3

    “It is not that the universe arose out of some prior state, for there was no prior state. Since time too comes to be, one cannot ask what happened before the initial event. Neither should one think that the universe expanded from some initial ‘point’ into space. Since the Big Bang initiates the very laws of physics, one cannot expect any physical explanation of this singularity; physical laws used to explain the expansion of the universe no longer hold at any time before t>0.”

  95. wilson

    @robin (#65)
    Yes, it is a consequence of looking at the universe in a relativistic manner. However, this is not the only point of view. For instance, the idea that the speed of light is a fundamental limit is certainly true within the perspective of relativistic physics (relativistic geometry).
    This does not change the idea that the speed of light is not a limit from a Lorentzian view point. Even a child can understand that if an object travels in one direction at 2/3 times the speed of light and another object travels in the other direction at the same speed, an independent observer would have little trouble deducing that the two objects are traveling away from each other at 4/3 times the speed of light.
    True, the travelers as well as the observer have not technology that can signals faster then the speed of light.
    So, by premise offered, “…if the speed of light is a fundamental limit of speed …” (where, as we say in the logic game ‘ “if” implies “not” ‘ ;-) , as is obvious that it is not that the speed of light limits the flight of an object, it is difficult to conclude that space is expanding.
    All the results still work out nicely on the ‘mean-free path’ hypothesis without the goofy ‘magic’ of expanding space (tough to argue against the expanding space argument when physics hasn’t come up with a more measurable definition of ‘space’ other than ‘that expanding stuff’.
    I don’t have a problem with fanciful theories, just not sure why that one is so popular. I even work with engineers who think you would need an infinite amount of energy/mass to ‘go faster than the speed of light’, when the simpler conclusion is ‘it makes no sense to think you can receive signals faster than the speed of light ‘(see: mass, space, geodesics, none of that are needed to explain the evidence you already have!)
    The speed of light is fundamental to understanding relativistic physics. Please don’t make into more than it is.

  96. Nigel Depledge

    WIlson (100) said:

    So, by premise offered, “…if the speed of light is a fundamental limit of speed …” (where, as we say in the logic game ‘ “if” implies “not” ‘ , as is obvious that it is not that the speed of light limits the flight of an object, it is difficult to conclude that space is expanding.

    Erm, easy enough, when you see the relationship between redshift and distance.

    Unless you start to postulate “tired light” scenarios . . .

    All the results still work out nicely on the ‘mean-free path’ hypothesis without the goofy ‘magic’ of expanding space (tough to argue against the expanding space argument when physics hasn’t come up with a more measurable definition of ‘space’ other than ‘that expanding stuff’.

    Experimental results are such a drag, aren’t they?

    As far as anyone can tell, SR is correct, and c is an absolute limit.

    Any competing theory in which c is not an absolute limit has to explain how come SR has passed every test we have thrown at it.

    I don’t have a problem with fanciful theories, just not sure why that one is so popular.

    Observational data.

    I even work with engineers who think you would need an infinite amount of energy/mass to ‘go faster than the speed of light’, when the simpler conclusion is ‘it makes no sense to think you can receive signals faster than the speed of light ‘(see: mass, space, geodesics, none of that are needed to explain the evidence you already have!)

    You seem to think that distant objects (those with high redshift and hence high recession velocities) are moving away from us relative to their local space. If this were truly the case, you would indeed require infinite energy to arrange such a scenario.

    However, those distant objects are moving no faster relative to local space than is our galaxy moving within its local space. Space itself is expanding, carrying galaxies along with it.

    AFAICT, no-one really knows why, other than that it seems to be a fundamental property of the universe.

    The speed of light is fundamental to understanding relativistic physics. Please don’t make into more than it is.

    Having gone back and re-read Robin’s comment #65, I have to agree with it, and your argument doesn’t touch the point made in #65.

    SR, including c being a fundamental speed limit, is correct as far as anyone can tell. If it is in some way wrong or incomplete, it is at the very least a good approximation to the truth. Your postulated alternative, about which you say very little other than that c is not a speed limit except for the transmission of data, appears to be little more than a steaming pile of bovine faecal matter. How, for instance, do all those distant galaxies know to move away from ours? Why does none of them have motion that is perpendicular to our line of sight (and thus neither recedes from nor approaches our galaxy)? Why does none of them have motion towards our galaxy? If c is nothing special and matter can travel faster than c, how come data cannot? Your alternative only explains observations if you place Earth at a special place in the universe, and you provide no reason so to do.

    The parsimonious explanation, and therefore the only reasonable conclusion on current information, is that space is indeed expanding as GR implies. Incidentally, GR is another theory that has so far passed every test we have conceived for it and is therefore either correct or a good approximation.

  97. Nigel Depledge

    Chris (47) said:

    The deep field images are captured by looking specifically in the direction from where the big bang happened.

    The BB happened everywhere, so every direction is the direction in which the BB happened.

    The deep field, ultra deep field etc. images are captured by finding and photographing a patch of sky that has no (or very very few) other objects in it.

  98. wilson

    for Depledge (#102), ‘c’ is a fundamental limit of measurement.

    It is granted that SR holds up well. I believe that SR has not held up to every experiment; “grand unified theory(s)” and much work with “strings” is happening because SR doesn’t explain everything.

    There are devices being used today where objects (packets, wave-bundles…) met with instantaneous velocities far greater than ‘c’. The ability to measure what is happening to those objects is fascinating: trying to measure/characterize and event where instantaneous acceleration is faster than ‘c’ are technically difficult to do. Yet, these experiments are now considered ‘common’ (if not done everyday).

    So, we already know that SR is based on the idea of measurement and that ‘c’ is a fundamental limit within the domain of SR. We also know that ‘c’ is not a physical limit as we have machines causing reactions between objects where acceleration and instantaneous velocities are close to twice ‘c’.

    I don’t think I’m saying anything odd.

    As to the comments about #65, I chose not to address those as the content did not relate to my comment. If that was impolite, I apologies.

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