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Space Science

The Universe is Pretty Big 134

Posted by michael from the duh dept.
Psiolent writes "According to a recent article on Space.com, the universe is pretty big (156 billion light years across, to be more precise). Some recent research examining 'primordial radiation imprinted on the cosmos' has led to this conclusion, as well as a few others. This finding is particularly interesting considering the universe is only 13.7 billion years old (which would mean the universe has been expanding faster than light travels), but the article does a good job addressing this seeming paradox."
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The Universe is Pretty Big More

The Universe is Pretty Big

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  • does this not mean, in addition to knowing the size, the correct age is known?..
    i.e. if the universe were 1 light year across, then it would be six months old, as it's expanded in all directions for that long?
    • Um, not quite. If you had RTA, you would understand that the reason the radius of the universe is so large (relative to it's age) is the hubble expansion of the universe. According to current theory, the universe has been expanding since the big bag at an increasing rate. This expansion is not governed by special relativity, and a result of this expansion is that if something travelled 1 light-year in the early universe, it has now travelled something on the order of 1000 light-years. And yes, IAATP (I am a theoretical physicist (in training, at least))
      • Aren't we suppose to be going backward in time if we travel that fast? Or.. at least have time stand still?
        • Well, that would depend on whose frame of reference you're looking at, in an 'ordinary' FTL situation, but this is kinda different because its not that things are moving FTL with respect to each other, its that the space between things is growing on its own. Apparrantly, according to the article, this can happen FTL without violating causality and such.
          • To think, I used to feel that it was a long way down the road to the drug store, but that's just peanuts!

            Appologies to Mr. Adams.
          • Actually, causality isn't violated unless an object is moving FTL in respect to a "fixed" reference point. If two objects are moving at LT light speed away from the "fixed" point. they may be moving FTL in respect to each other. In fact it sorta has to work that way. Just like two cars moving at 60 mph(each) away from a fixed point in opposite directions have a separation speed of 120mph does not mean that one is standing still and the other is moving 120mph. You gotta define the fixed point first.
            • You are using Newtonian velocity addition which is wrong. You have to use relativistic velocity addition. If A and B are both moving away from Q as 0.9c in opposite direction, A is not moving away from B at 1.8 c! They are really travelling at 0.994475c [google.com] with respect to each other.
            • Sorry, for saying you were wrong, without asking you exactly what you meant first. Are you saying that according to the observer in the middle (who sees both cars traveling at 60mph), the separation speed is the distance he sees the car A at plus the distance he sees car B at, divided by the time?

              I guess that you can say that, but it is not a term/measurement used in physics. In physics you only look at one of the cars at a time (if you are using relativity), so you need to be in the other if you want
              • Ok, granted.

                The real answer is since we cannot observe from a point moving anywhere near relativistic speeds, we don't really know.

                And the only "objects" we can observe that are moving anywhere near those speeds are at the limit of our observable radius, and we can't be certain how fast they are in fact moving due to the variability of the speed of light, etc.

                I'm not a physicist, so perhaps I'm stupid, or I dumbed down what has been explained to me, but don't the doppler effect(s) and some of th
                • I don't think the doppler effect can be applied to anything that is FTL. IAAP (by degree) and I am having trouble imagining what the implications would be.

                  I would definitely not want to call anyone here stupid, least of all someone who admits they don't know exactly what might be happening. I screw up in my posts a bit (usually with legal stuff), but I try my best.

                  I like how you point out that since we cannot observe from a point moving anywhere near relativistic speeds, we don't really know. So ma
                  • I was using stupid IRT opening my mouth when I likely should have just read on, but this is slashdot and stuck my foot right in.

                    Thanks

                    I'm reminded of course of many(NOT ALL) scientists and "experts" who claimed that bad things would happen at 762mph. And at 100mph.

                    I'm fascinated by the discussion, and would like to get back to studying some of the more arcane areas of physics, But whenever someone is so dogmatic about a pyramid of theories that cannot(YET I HOPE) be thoroughly tested I get that twi
                    • I remember hearing about when cars were first invented and how a person wouldn't be able to stand going up to 55 mph!

                      <religion>

                      I have managed to reconcile my understanding of physics with my belief in God by realizing that the age of the earth/universe, etc. and my belief in such a thing has no bearing on my eternal soul. I tend to keep the two pretty separate without feeling the need to get philosophical. I married into the

                      Moravian church [moravianchurch.org] (which can actually claim to be older than the Lutheran

            • Don't add at high speeds. If A and B are both moving away from me in opposite directions at 0.6c, they they are NOT moving at 1.2c relative to each other.

              By "fixed point" I assuemt you mean at rest in an inertial frame. There are no fixed points in special relativity.

        • NOTHING is traveling faster than light. The expansion of the universe is not motion, so special relativity does not apply.

          Also, this expansion is not like plate tectonics on earth where there are a couple different areas that are expanding (while there are a couple that are receding). This expansion is happening everywhere at once. So rather than all of the extra space just appearing between New York and London somewhere in the Atlantic, it is as though the earth's diameter started to increase and New
        • Maybe we are, and time would be flowing the other way if space didn't expand so quickly.

    • GO TO YOUR ROOM (Score:2, Informative)

      by Anonymous Coward
      And read the fine article.

      The truth is out there.

    • Re:since light is the FASTEST moving thing (Score:5, Informative)

      by fredrikj ( 629833 ) on Tuesday May 25, 2004 @07:23PM (#9254529) Homepage
      The age of the universe is 13.7 (+/- 0.2) billion years, as established by WMAP a year(?) ago. It is perfectly possible for the universe to have expanded faster than the speed of light since the very spacetime might have been expanding; only particle motion "within" it is constrained by the speed of light. Sort of like having a speed limit for the cars on a road while moving the road itself faster than this speed limit.
  • an atom is very small. More on this story at ten.
    • What kind of lunkheads are modding posts like the two above as redundant.

      A, one wonders, redundant of what? And, B, it's called wit - you lunkheads.

      Lighten up. (cf. Light, speed of. Am too on-subject.)



      Fine. Just give me my minus one and move along.
    • Further, Water is Wet, Eating too much is bad for you, and exercise helps control your weight.

  • That's a minimum.... (Score:5, Informative)

    by Rob Carr ( 780861 ) on Tuesday May 25, 2004 @07:39PM (#9254648) Homepage Journal
    the universe is pretty big (156 billion light years across, to be more precise)

    It's worth pointing out that the156 billion lyrs number is a minimum size for the universe. There's nothing in the data that tells us it's only this large.

    It also doesn't tell us anything about the shape of the universe. Recent studies of the microwave background have proposed that the universe has a soccer ball or even a Picard [newscientist.com] (no relation to the TV character) shape. Neither of these have been ruled out, but the minimum size for either of these shapes in our region of space would be 156 billion lyrs. This new result doesn't even tell us if there is a boundary (no, don't ask me what happens at the edge, I don't know) or if the universe "wraps" like the Asteroids game.

    • One interesting thing in your link about the universe potentially having a Picard geometry was the coment about how near the narrow end two of the three dimensions would be seriously shrunk (you'd be able to see the back of your own head if you went far enough towards the narrow end).
      I read this and remembered that string theory predics several extra dimensions we can't percieve because they're to small.
      Any possible relation here?

      Mycroft
      • string theory predics several extra dimensions we can't percieve because they're to small. Any possible relation here?

        First off, IANAQP. Most of my modern cosmology and quantum physics comes from SciAm, Brian Greene books [slashdot.org], and conversations with Tripoli Rocketry Association member #004. The last time I did tensor calculus was when I looked up Frank Tipler's paper "Rotating Cylinders and the Possibility of Global Causality Violation" [utas.edu.au] twenty years ago. Yes, that is the paper Larry Niven used as the name for

        • What I was thinking was that if a Picard geometry would cause some dimensions to be shrunk to tight circles near it's narrow end, could us being near the narrow end explain why the dimensions predicted by string theory(s) are so tiny.
          I am aware the extra dimension must be very tiny to exist. I'm more looking for the connection, if any, to the potential picard shape for the universe.
          That is do the two descriptions support each other, or possibly one be the consequence of the other, or are they not re
          • What I was thinking was that if a Picard geometry would cause some dimensions to be shrunk to tight circles near it's narrow end, could us being near the narrow end explain why the dimensions predicted by string theory(s) are so tiny.

            One of the important points about the Picard geometry discussed in the "horn of plenty" theory is that the universe would look different depending on where you are.

            As we look around, the universe appears to be pretty much the same in any direction we look. The fine structur

            • What I was trying to find out is if a picard topology could be the reason why 6(or 7) diminsions was so small.
              I think just about everyones' understanding is a bit primitive compared to the likes of Hawking,Michou(sp?),Greene,Thorn, and a few others.
              I'll have to look for Greene's books, I rather liked Hawkings books and few others I've read.
              Most of the basic stuff I can follow about as well as anyone can w/o the math/physics skills needed to study the actuall theory. But I hadn't heard much about
            • As an aside, an implentation of Conway's Life was the first non-trivial program I ever wrote.
              Would have been 84 or 85 while I was still in highschool.
              It was writing in basic on a commodore64. ahhh fond memories.
              Eventually the birth and death rules as well as the graphics for cells could be user set as well as patterns saved and loaded.

              Mycroft
      • You should also check out Brane theory which is one of the top 3 cosmology theories of the day. Interestingly, the Brane theory and string theory are not mutually exclusive. Here [popsci.com]'s a simplified take on cosmology from the Popular Science web site.
        • I've read a fair amount of the laymans explanations of the various theories. And brane theory (a 'fork' of string as I understand it) is certainly interesting. I think I've read that artical, but I'll check it later thanks.
          The problem is I don't really have the background a REAL theoretical physicist has to know whether the feature of a picard space that curls some dimensions down tight has any significance wrt string theories shrunken dimensions or if I'm totaly of base or out at 90 to the whole thing.

  • obligitory Douglas Adams Quote (Score:4, Insightful)

    by Adrick42 ( 694038 ) on Tuesday May 25, 2004 @08:14PM (#9254905) Homepage

    Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the drug store, but that's just peanuts to space.

    Douglas Adams

  • Er, yes (Score:5, Informative)

    by Wylfing ( 144940 ) <brian@wy l f i ng.net> on Tuesday May 25, 2004 @08:41PM (#9255077) Homepage Journal
    This finding is particularly interesting considering the universe is only 13.7 billion years old (which would mean the universe has been expanding faster than light travels)

    Sure. There is no restriction to the rate at which spacetime can expand. Relativity only applies to the acceleration of matter.

    • Would this work on cops? (Score:5, Funny)

      by serutan ( 259622 ) <snoopdougNO@SPAMgeekazon.com> on Wednesday May 26, 2004 @02:33AM (#9256719) Homepage
      No, officer, I wasn't actually going 90 miles an hour. It just seems like it because the spot in the road where I was a minute ago is a mile and a half away now.
    • get off your elitist pipehorse please, the guy making that comment is just stating that as observation (which is entirely interesting). not asserting that is impossible.

      but given this was modded up so strongly, when exactly do people these days get introduced into the theories of relativity? a 100 year old solution too i might add. i guess that's rhetorical. it does disappoint me to some extent. it seems all it takes is a free saturday night from the brew and tele. but wait, i'm throwing oxymorons he
  • from the article:

    A hall of mirrors could mean the universe is finite but tricks us into thinking it is infinite.

    Think of it as a video game in which an object disappearing on the right side of the screen reappears on the left.

    Well, shoot... thank god I tought it was just me being obtuse. I mean... at least now I know why altho it is finite, I won't hit a wall if I were to travel (or try to) 156 Billion Light Years +1 inch. Turn's out I'll just warp to the other edge... like pacman.
  • On the one hand the article says that the univers is 156 billion light years across, but on the other hand, it says that the universe is probably not finite. Whats up with that? Am I correct in translating to "The universe is at least 156 billion light years across?"
    • Am I correct in translating to "The universe is at least 156 billion light years across?"

      Perfectly! What we can see of the universe is pretty uniform, suggesting that it just keeps on going in the same way presumably forever in all spatial directions, making it infinite. On the other hand, if there is a change or boundary outside the range of what we can see, how would we know?

    • If somehow you could be at the 'edge' of the observable universe 156 billion light years away as postulated from Earth right 'now' the universe would still appear to be 156 billion light years wide from there. That's what it means for everywhere to be the 'center' of the universe. It's infinite yet bounded like the surface of a sphere.

      • Re:finite? (Score:4, Informative)

        by Tango42 ( 662363 ) on Wednesday May 26, 2004 @05:58AM (#9257291)
        You've got that the wrong way round. A sphere is finite yet unbounded. In other words the surface area of a sphere has a finite value, but there is no edge.

        To clarify, when we talk about spheres in this context we mean the surface, not the inside - hence a sphere is 2D, not 3D.
        • Actually his/her interpretation is correct. They were specifying a minimum size.
          • The universe could be:
          • Finite
          • Infinite with a closed topology (would this actually be a special case under finite?)
          • Infinite with an open topology
          Sorry if I massacred the distinctions between what is still plausible based on this discovery.
          • I'm having trouble visualising an infinite, closed space... if it's closed it has to be finite, surely? (and I don't think it's a special case because most finite models of the universe involved a closed topology, rather than an absolute boundary)

  • Universe potentially older (Score:4, Informative)

    by ipoverscsi ( 523760 ) on Tuesday May 25, 2004 @10:43PM (#9255819)
    According to a recent Science News article [sciencenews.org] (subscribers only), the universe may actually be older than the aforementioned 13.7 billion years.

    The evidence comes from the fact that older stars must fuse carbon, nitrogen and oxygen into helium, unlike their younger bretheren that fuse pure hydrogen. The slowest part of the carbon-nitrogen-oygen reaction comes during the collision of a proton with a nitrogen-14 nucleus. Using particle accelerators to mimic the interior of older stars they have determined that the reaction occurs half as fast as estimated.

    Two research teams, one from the National Institute for Nuclear Physics in Padova, Italy, and the other from the University of North Carolina at Chapel Hill, have performed nearly identical experiments and their prelimiary results agree, although their findings have not yet been published.

    • I'm not sure exactly which reaction you're talking about in older stars (ie: fusion or fission) but fusing carbon, nitrogen and/or oxygen into helium is quite impossible. This comes from the fact you should have learned in chemistry that all three aforementioned elements are heavier than helium.

    • Re:Universe potentially older (Score:5, Interesting)

      by drudd ( 43032 ) on Tuesday May 25, 2004 @11:50PM (#9256109)
      As the previous answer noted, you're a little confused about the Carbon-Nitrogen-Oxygen (CNO) cycle. In these set of reactions, the carbon is only used as a catalyst for making helium (so you're still turning H -> He, but you're doing it by repeatedly capturing protons (H) and then beta-decaying). See this article [wikipedia.org] for more information on CNO.

      Now the argument that the referenced article is using is that less massive stars will stay on the main sequence longer, due to the reduction in CNO efficiency. Thus older globular clusters will have a bluer turnoff than previously expected.

      While this will cause a systematic underestimation of the age of globulars by ~0.7-1.0 Gyr, the uncertainties are so large (+/- 1-1.5 Gyr or so), that they are still consistent with the age of the universe derived from CMB observations.

      Doug
    • As other have mentioned, the CNO cycle is just a catalyst larger stars use to fuse Helium (basically 4p + C12 = He4 + C12 instead of the "normal" method). However since heavier elements are used in the reaction, higher temperatures (core temp >18M kelvin) are needed to initiate the reaction due to a strong positive repulsion force within the nucleus, only larger stars (> ~1.2 solar mass) have core temps high enough to initiate the reactions. Our sun gets about 2% of its energy from CNO, but a 1.2 so

  • Only space expanding? (Score:3, Interesting)

    by DerWulf ( 782458 ) on Wednesday May 26, 2004 @02:42AM (#9256749)
    I am no scientist, so please forgive. How come the distances between objects seem to be increasing ( space time expansion or so they say) but not their size? What makes matter so special that the space time between molecules is not expanding as well? What makes our perception so special that only the distances between objects we like to observe ( galaxies, stars) increases but not the distances within them?
    • I'm guessing it has somthing to do with gravity, but I'd like someone who knows what current theory says to answer.
      So anyone cluefull enough who chooses to post has at least two people who would appretiate the effort.

      Mycroft
    • My guess is that objects do expand, but since even the biggest objects are infinitesimally small compared to the massive distances between them, we are not going to be talking about objects expanding in the same way we talk about space expanding, since the detectable expansion of objects is likely to be fairly negligible.

      I'm not a scientist either, so I'm just making a complete stab-in-the-dark guess, and I'm very happy to be corrected by anyone with a more researched answer. :)

    • It's because the attractive forces overpower the expansion. At a short enough range, even gravity is strong enough to hold a galaxy in one piece and keep its stars from Hubble-expanding away from each other. It's only at the vast distances of intergalactic space that the expansion can finally overpower the fundamental forces.

      • wouldn't this imply that gravitational force would become greater if the expansion slows down or stops?

        • Yup, over large enough scales. Which is why everyone was concerned (up until a few years ago) about whether or not there might be a "Big Crunch". If the universe ever stops expanding, it must then proceed to collapse -- excepting the unlikely possibility that dark energy weakens but thereafter remains constantly balanced at the equilibrum, as Einstein originally envisioned when he proposed the Cosmological Constant.

    • The objects are expanding as well. All of spacetime is expanding. Maybe this will help. If you read up on the cosmic background radiation [wikipedia.org], you will see that before it was discovered [uoregon.edu], physicists were correctly predicting its temperature. They accounted for the fact that the expanding universe would redshift this radiation [that has been around since the Big Bang]. Unlike the Doppler effect [wikipedia.org], this isn't caused by a velocity difference of the object and observer, but because the wavelength of the radiation
    • Think of it this way... You put 2 magnets on a rubber sheet, stuck together, then you stretch the sheet. The sheet will expand underneath them, putting some force on them, but the magnetic force between them is much stronger and will keep them together.

      Now on the scale of molecules, planets, solar systems, even galaxies, expansion is tiny still. The intermolecular forces, electric, magnetic, gravity, whatever will all overpower the expansion by many many orders of magnitude. IIRC the estimates for expa
    • I believe the answer is that space is expanding, pushing the electron away from the nucleus, and the proton away from the neutron. Now, factor the small rate of expansion versus the attraction of the nuclear forces, and the particles will move back towards one another (which you can argue you can't really tell because of the uncertainty princible). The net is that is looks like the space OUTSIDE of the atom is expanding while the atomic particles remain the same distance from one another.

      Take this one le
    • What makes matter so special that the space time between molecules is not expanding as well?
      Matter is held together by electromagnetic forces that are much stronger than the local repulsion due to cosmological expansion.

    • Re:Only space expanding? (Score:3, Informative)

      by ggwood ( 70369 )
      Expansion is severely reduced near massive objects - thus massive bodies do not expand with the rest of the universe, but at a tiny (or perhaps zero) fraction of the Hubble rate.

      My source? I asked this in the context of the distance from the Sun to Pluto increasing over time of John C. Baez [ucr.edu], who works on gravity and has written books on it, so I would say he is a good authority.

      His response was that space does not expand (much) near massive objects - meaning even between the Sun and Pluto the expansion w

    • This is actually a really great question. Don't let the flurry of responses fool you, the answer to something like this is not so easy or cut-and-dry.

      The truth is, no one is completely sure. The replies you've gotten aren't too far off from nice, accepted answers that you might get from a physicist, but it's one of those things where no one really knows.

      First, consider the statement "space is expanding". Sounds simple enough, but lets start with the simple: What is space? I mean, what is it that's exp

    • OK, I'll write more, because in my last post I wanted to show people how confusing this really is, but now I'll make an attempt at an understandable explanation. It's not really a perfect explanation, but it should be understandable.

      The problem with the explanation of electromagnetic and gravitational forces holding the molecules together is that it already assumes some funny things about space and matter, which isn't entirely clear. Let's say space was expanding uniformly, and space is flat. Why isn't

  • WTF? (Score:2, Interesting)

    by wafwot ( 739342 )
    I'm surprised no one has brought this up yet, and I apologize if this seems out of context for me to be commenting, since I'm a musician and a composer, but has anyone read the article and felt that all of this information "makes sense" only if Earth is the center of the creation of universe?

    We can measure the distances to far off galaxies to get a "radius", but a "radius" implies a center, primarily the Earth. I have some serious problems with us, because it implies that the "Big Bang" occurred right he
    • In the article 156 billion light years is given as minimum estimate.

    • WTF back at you (Score:2, Informative)

      by PatrickThomson ( 712694 )
      The big bang did indeed ocurr right where earth is. it also ocurred where alpha centauri is, and where the Andromeda galaxy is. the big bang *was* the universe. Trying to pin it down is like trying to draw on a balloon with a pen the exact location of the unblown balloon.

    • Re:WTF? (Score:4, Informative)

      by Anonymous Coward on Wednesday May 26, 2004 @06:30AM (#9257388)
      I think your question is a fair one, coming from someone with no scientific background and it seems three points need to be cleared:

      a) the concept of "radius", or "coordinate system".
      b) the concept of "isotropy"
      c) the concept of 4D surfaces

      a) Radius here is indeed taken as distance to the earth. Cosmologists like to use a spherical coordinate system where the earth sits at the centre, simply because it is *convenient*. Let me first explain isotropy and hopefully it will become clear why this, in this case, doesn't matter:

      b) Isotropy says that the *visible* universe is pretty much the same everywhere we go. Cosmologists reached this conclusion based on *observational* evidence. This means (among other things) that the universe is expanding *at the same rate* everywhere in space. This has huge implications.

      Try this: Find a piece of paper and draw a series of black dots, in a grid, equally spaced. Make one of your dots red. That's the earth. Now imagine your paper is elastic and you take its four corners and pull, so that your paper gets bigger (you'd pull exactly the same amount horizontally and vertically). You'd see that the distance from the red dot to the nearest black dots had increased by a given amount, say D.
      If you repeated this exercise having coloured ANY of the other dots red, you'd find the same thing. Meaning, expansion (and measured distances DUE TO EXPANSION are the SAME no matter where you sit in the Universe.
      So it doesnt really matter that we're measuring distances due to expansion with a radius relative to the earth. You'd get the same answer if you were sitting on the galaxy M31, measuring distances relative to it.

      c) So where is the centre of expansion? Look at your fictitional piece of paper and you'll be able to tell that it's nowhere in the piece of paper. In fact it seems to be everywhere. The right answer gets complicated due to the fact that we live on a curved 3d space. But the answer is again nowhere in our 3d space, and again it seems to be everywhere. We'd have to get into higher dimensions to explain this but the point that I would really like to get across is that there is NO centre of expansion. Not that we can visit

      I hope this helped.
      --r

    • Re:WTF? (Score:2)

      by CXI ( 46706 )
      has anyone read the article and felt that all of this information "makes sense" only if Earth is the center of the creation of universe?

      Yep, and it only makes sense if the rest of the universe is also the center. Cosmology is weird, don't try to apply common sense to it.
    • I have some serious problems with us, because it implies that the "Big Bang" occurred right here, where we are now in the universe. Absolute and utter bull.

      I think that by definition the Big Bang occurred everywhere. Either that or everywhere occurred at the the Big Bang. Take your pick.
    • We can measure the distances to far off galaxies to get a "radius", but a "radius" implies a center, primarily the Earth.

      Not really. It's more analogous to the statement "the earth's circumference is at least 20,000 miles" - no matter where you are, you can go at least 20,000 miles in a straight line before you get back to where you started. That statement doesn't imply that you're at the center of the earth, just that you can treat it as the center for the purpose of describing your observations.

    • Well, if you can measure accurately from another point in the universe, please do,

      We can't identify an edge, so since we can measure in every direction from us, and light appears to move at the same speed in all directions, we OBSERVE a spherical universe surrounding us.

      It doesn't mean anything other than that is what we observe and thusly how we speak. Just like sunrise... It looks like it comes up so thats how we talk.
  • Space is big
    Space is dark
    It's hard to find
    A place to park

    Burma Shave

  • Oh come on /.'rs I can't be the only one.... (Score:3, Informative)

    by Bitsy Boffin ( 110334 ) on Wednesday May 26, 2004 @11:42AM (#9259815) Homepage
    who immediatly thought of....

    Whenever life get you down, Mrs. Brown,
    And things seem hard or tough.
    And people are stupid, obnoxious or daft,
    And you feel that you've had quite enu-hu-hu-huuuuff!
    Just - re-member that you're standing on a planet that's evolving
    and revolving at 900 miles an hour,
    It's orbiting at 19 miles a second, so it's reckoned,
    the sun that is the source of all our power.
    The Sun and you and me, and all the stars that we can see,
    are moving at a million miles a day,
    In the outer spiral arm, at 40,000 miles an hour,
    of the Galaxy we call the Milky Way.
    Our Galaxy itself contains 100 billion stars,
    it's 100,000 light-years side-to-side,
    It bulges in the middle, 16,000 light-years thick,
    but out by us it's just 3000 light-years wide.
    We're 30,000 light-years from galactic central point,
    we go round every 200 million years,
    And our galaxy is only one of millions of billions
    in this amazing and expanding universe.
    The universe itself keeps on expanding and expanding,
    in all of the directions it can whizz,
    As fast as it can go, at the speed of light you know,
    twelve million miles a minute, and that's the fastest speed there is.
    So remember, when you're feeling very small and insecure,
    how amazingly unlikely is your birth,
    And pray that there's intelligent life somewhere up in space,
    because there's bugger all down here on Earth.

  • Here's the problem I have with this guy's "explanation" on how the universe can be bigger than it is old. From the article:

    Imagine the universe just a million years after it was born, Cornish suggests. A batch of light travels for a year, covering one light-year. "At that time, the universe was about 1,000 times smaller than it is today," he said. "Thus, that one light-year has now stretched to become 1,000 light-years."

    I understand the concept that everything is getting further from everything else, no

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