For now we see through a glass, darkly. (1 Cor. 13:12) The Cosmologist's Tale [starrule.gif] "The reports of my death," Mark Twain once wrote, "Are greatly exaggerated." I quote Mark Twain because of what you may have read. (No, not about Mark Twain, we know he's dead.) "The Big Bang theory's dead," it was reported In 1991. 1 Some cheered, cavorted, Grown men were heard to shout, "Bang, bang, you're dead!" A well-known Christian columnist helped spread The word: the Big Bang theory "has gone bust," Cal Thomas told his readers. 2 You can trust They made a joyful noise unto the Lord. Creationist response across the board Was, "Hallelujah! No explosion! This Means we've been right! It's all in Genesis!" But later findings showed what all along We've known: the Big Bang is alive and strong. 3 It never was near death--that was a hoax From the beginning, put out by such folks As Thomas. Why? To sort this matter out, Let's start with what the Big Bang's all about. The theory says the universe began With the explosion of what science can Describe but vaguely as a hot, dense spot Of matter/energy. 4 We don't know what Existed prior to that. Throughout the past The cosmos has expanded from the blast. What evidence, you well may like to know, First led us to this strange scenario Of all evolving from a superspot? Is this a theory that has really got Predictive power, helping with solution To questions about cosmic evolution, To problems dealt with in the origin And structure of this universe we're in? (The study of such questions is what we Refer to by the term "cosmology.") You bet it has--as any theory should If it's to be considered any good. So let's see just how this hypothesis Developed, what predictions came from this, Then how it weathered its alleged demise. It first of all should come as no surprise That ours is not a static cosmos. We Know well from Newton's law of gravity All bodies in the cosmos will attract Each other. Shouldn't all by now in fact Be clumped together? 5 Yes, they should, of course, Unless there is some counteracting force Or motion that keeps things apart. That's what Had Einstein puzzled once. He said, "I've got This theory I call relativity, That deals with motion, light, and gravity In neat equations by which space is curved And four-dimensional. 6 But I'm unnerved, My neat equations say that space must be Expanding or contracting! What we see, Though, is a static cosmos, stars that stray Not much at all throughout the Milky Way." (He didn't know about the galaxies Beyond our Milky Way, so dim were these, Though soon to be resolved by Edwin Hubble.) "So what expands? My theory is in trouble! I'll have to stick a term in my equations To keep the cosmos static. Aggravations!" Thus Einstein blew the opportunity To make a bold prediction 7 (of course we Have hindsight, that was 1917, Things did look static on the cosmic scene): He could have said, "The universe contracts, Expands, or maybe oscillates!" The facts Observed seemed different, though, and so instead He figured in a constant that he said Would keep the cosmos balanced as somehow It seemed to be. But let's go forward now To 1929. That year may be The greatest ever in cosmology. By that time Hubble, using what was then Earth's largest telescope, had found stars in Great groups beyond our own. And what he saw in '29 is now called Hubble's law: The galaxies or star groups all recede Away from one another, with their speed Proportional to distance. How did he Discover this? There is a shift we see In any moving light, the same effect (It's called a Doppler shift) that we detect In sound: a car horn's higher in its pitch When it's approaching, while a car horn which Is speeding off is lower. A light source Will shift as well; it has no pitch, of course, But color: thus a light approaching you Has spectral lines that shift toward the blue End of the spectrum; if a light instead Is moving off, then it's toward the red The lines will shift. And that's what Hubble saw, All galaxies toward the red. With awe He saw the universe expanding! (Though Poor Einstein couldn't say "I told you so" But kicked himself--he had rejected what His own equations told him--that does not Negate the fact that relativity Predicted an expanding cosmos. He Had but to readjust his calculations: He took the constant out of his equations.) 8 Now with this cosmological redshift (As it is called), one needs no special gift To see that if the galaxies are moving Away from one another, they are proving They once were closer. Go back far enough In time and they'll be ever denser stuff, Till squeezed into the spot from which they sprang, So dense things must have started with--a bang! Now isn't physics easy? All you do To get the Big Bang theory is put two And two together! Estimate the speed And distances as galaxies recede, And calculate as well the time it must Have taken these star groups to form from dust And gas clouds (although galaxy formation Has been a subject of much speculation-- I'll talk about that later), and you'll know How long the cosmos has been on the go. It's been as long as fourteen billion years By latest estimates. But what appears To have exploded? First, don't think that we Refer to an explosion where debris From something gets blown into space. That's not What we must picture, space itself is what Expands: the blast was everywhere. 9 Okay, But what got this expansion underway, And what was there before? We do not know, To put it simply. When we try to go Back all the way, we find we can't get past What's called the Planck time: we're stopped at the last Instant before the blast itself, because We do not know the physics, all known laws Break down. 10 There's no way mathematically To speak about the "singularity," The term used to denote that superspot Where time reads zero: things are much too hot, The density and curvature of space Are infinite. We can't reach such a place, Time's first split second has already run When we get down to Planck time: that is one Tenth of a thousandth of a millionth of A billionth of, let's see, a trillionth of A trillionth of a second following The Big Bang 11 (as Fred Hoyle dubbed the thing Back in the '40s). 12 That's as close as we Can get. From Planck time, then, what would we see? We'd see at once a great burst of inflation (Were it not far too brief for contemplation) As particles congeal from energy, And four known basic forces--gravity, Electromagnetism, and the pair Called strong and weak--are separated where One superforce had been; inflation through, Expansion will proceed (still not into The second second yet!) more leisurely; The cosmic temperature will steadily Decrease until atomic nuclei (Protons and neutrons) coalesce, this by The time the cosmos is three minutes old; In half a million years it will be cold Enough (three thousand K--still plenty warm!) 13 For the first atoms finally to form (Electrons binding with the nuclei); Decoupling from matter, photons fly Through space: light shines. And atoms ever since Have grouped together. 14 Redshift evidence Exists, then, for our theory. We see how The Big Bang follows from expansion. Now I want to tell of a prediction--not As used by the Biologist, 15 that's what Is better called postdiction 16 (she "predicts" The distant past based on our present fix). No, this prediction came some twenty years Before what was predicted first appears, And this is a prediction that was made Based on the Big Bang. Almost no one paid Attention when in 1948 Alpher and Herman said, "We postulate That an explosion such as the Big Bang Would create radiation that would hang Around today, the 'echo' of it still Should be detectable. This static will Be in the form of microwaves, will come From all directions, and it should be some Five K in temperature." 17 Then ends the story In 1965, Bell Laboratory: There Penzias and Wilson are ecstatic When they conclude that the persistent static Picked up by their antenna has to be That foretold echo, not at five but three K (close!), from all directions. What elation! Now called the cosmic background radiation, It was a lucky find: it brought these guys Not just some static but a Nobel Prize! 18 Now let me tell you something else about The Big Bang. Years ago we figured out The cosmos is three-quarters hydrogen, One-quarter helium, just traces in The cosmos of the other elements. 19 Is there a theory that predicts, makes sense Of just this mix of elements? You bet! According to the Big Bang, what you'd get Is hydrogen three quarters, helium The rest! (The other elements? They come From stars, from the nucleosynthesis The Astronomer spoke of.) 20 On top of this, Earth's age supports the theory too. As I Have said, the estimates now go as high As fourteen billion years since cosmic birth; The radiometric age found for the Earth Is near five billion, which fits right into The larger picture. Everything rings true, It seems: redshift, the background radiation, The elements, the time of Earth's creation, And Albert Einstein's relativity (A theory that's well tested as can be). How is it, then, creationists made merry And published a Big Bang obituary? Well, first of all, the Big Bang is the same As any other theory you can name In that it doesn't give us answers to All questions, something no Einstein can do. Now here's the question that made rumors warm Cal's cockles: how do large-scale structures form? (What, you may ask, are "large-scale structures"? These Are clusters, sheets, great gobs of galaxies.) The cosmos, though it's not all seen by us, Is on the large scale homogeneous-- At least we so assume, because we find The background radiation left behind By the Big Bang to be so smooth. 21 And that Suggests the early universe was at A high degree of smoothness. How can we Explain, then, all the lumpiness we see Today? It had us stumped. In recent years Research by some of my distinguished peers-- I'll mention Margaret Geller--seemed to show Galactic structures on a scale that's so Humongous they posed quite a mystery; 22 They couldn't be the work of gravity Alone, not in just fourteen billion years, Not when the early universe appears To have been so unlumpy. 23 Furthermore These structures couldn't be accounted for By "cold dark matter." That should be defined, So I'll digress a moment. There's a kind Of matter that's too dark for us to see; We know it's there, effects of gravity Reveal it--over nine-tenths of the mass We know of can't be seen! (Now that's a class Of mass we'd like to know much more about. Black holes, where even light cannot get out; Brown dwarfs, 24 which are failed stars [no starlight glows Without nuclear fusion]; galactic halos; And clouds of gas and dust, these all may be Among the keys to this dark mystery. Theoretical WIMPs--weakly interacting Massive particles--may be impacting The picture too: These particles may be A lot, or all, of mass we wish to see. Neutrinos have some mass, researchers say, A find that also may come into play In solving this dilemma.) 25 For a while The cold dark matter theory was in style ("Cold" means the particles move slowly, "hot" Dark particles move fast); but though a lot Of us had thought it was the best solution To the galactic structures' evolution, The cold dark matter theory seemed to fail In terms of structures on the largest scale. So some said it was dead 26--and when they did, Know-nothings then began to nail a lid On the wrong coffin! What was "dead," you see, Was just a theory about galaxy Formation, not the Big Bang. (By the way, The cold dark matter theory didn't stay Dead long, the cosmic background radiation, We'll see, helped bring about resuscitation.) 27 Newspapers ran headlines that so misled The public, many folks thought they had read About the Big Bang theory dying, not A theory about large-scale structure. What Cal wrote was nonsense! But then what to do About the structure question? Let's review Some data from the COBE satellite (Cosmic Background Explorer), data right From the explosion's afterglow. They show That just three hundred thousand years or so After the blast, the background radiation Had ripples, many a tiny variation In temperature--far less than one degree In difference, and yet enough that we Find here a clue to how large structures were Then to evolve. For what do we infer The ripples are? They're matter, it appears, As it existed all those billion years Ago, in varying densities. Around This stuff more matter clumped together, bound By gravity. These spots or ripples were The "seeds," we think, of galaxies. (A stir Was caused when Smoot, the COBE team's prestigious Chief, said of the data, "If you're religious, It's like seeing God.") 28 But let's move on, There's more we've learned. (Will all someday be known? No, I don't claim we'll ever understand Completely). Will the universe expand Without an end (an "open" universe), Its last stars burning out? Will it reverse Itself as time goes on, with a "big crunch" In store (a universe that's "closed")? Or scrunch Up, then expand, in cycles? If it's flat Instead of curved, with total matter at "Critical density" (that's just enough For gravity at length to stop the stuff), Expansion will be halted--not, however, Before it goes so long it goes forever (If you can picture that). 29 If density Is more than what we need for flatness, we Are in for a big crunch; if it is less, Then gravity can't stop us, we'll progress (If that's the word) forever outward. We Now think (thanks to a probe that lets us see Those early ripples even better) that There'll be no crunch: the universe is flat. 30 More matter, then, exists than what we see, In cold dark form. Mysterious energy Comprises what is left, for studies say Expansion of the cosmos has someway Been speeding up. So-called "dark energy" Is thus proposed--it's antigravity. That's why the constant that Einstein employed To keep the cosmos balanced has enjoyed A comeback--it's in this-and-that equation To try to help explain acceleration. 31 Exciting times! The Big Bang theory lives, And will until such time as someone gives A better explanation of the facts. Creation? What does that explain? It lacks Predictive power. Listen, I don't claim That the Big Bang is gospel, it's my aim To show it's still the best idea we've got Based on what we observe. And it does not Rule out creation. Could the Big Bang be A firework set off by some He or She? There's no way to confirm or to deny That He or She was there. (I'll say that I Would much prefer, though, that it be a She. But I'm not chauvinistic, that's just me.) Paul Steinhardt has a theory that explains The Big Bang as what happened when two branes Collided ("branes" are short for membranes), that There was no superspot but a Big Splat Or a Big Bump instead. Won't say I doubt it, So far I haven't wracked my brains about it. 32 One last thing and I'll close. You may have heard About this fellow Alan Guth. The word That he put out is that the universe Is a "free lunch," it came from "nothing." 33 Worse Than that, creationists will say--they too Promote creation out of nothing, 34 through God's work--is Guth's and Linde's view that we Live in but one of an infinity Of universes, little bubbles, 35 and Someday, says Guth, someone might understand It all so well she'll have the tools--perverse As it may sound--to start a universe In her own basement. 36 Edward Tryon, there's Another one: "Perhaps," Tryon declares One day (it was a sudden inspiration), "The cosmos is a vacuum fluctuation!" 37 What did he mean by that? Could there be truth In this? Well, let me say that Linde, Guth, And Tryon surely are not nuts or manics. A branch of physics called quantum mechanics Is weird indeed compared to everyday Perceptions; but it helps us see the way Things happen in the subatomic realm-- And I would say the devil's at the helm If I were a creationist (they blame The devil for about all you can name). The quantum vacuum actually is full Of particles that we call "virtual"; These particles appear and disappear Through vacuum fluctuations. Thus we hear It said that they come out of "nothing." Guys Like Guth and Tryon then hypothesize The universe itself began that way-- "One of those things," as Tryon likes to say, "That happen from time to time." 38 Tryon's funny And Alan Guth has made a lot of money (Guth first proposed inflation 39--not the sort That keeps the rest of us all running short Of money, but the rapid early stage Of the expansion). Who, though, is so sage That he can ever say, "I know"? Can we Hope to unveil that singularity We say exploded? It may in the end Be more than we can ever comprehend. Epilogue to the Cosmologist's Tale At this point, a predictable mishap: The Biochemist spilled Coke on the lap Of the Cosmologist. She held her temper, Accepting his apologetic whimper As he awoke. The man had slept right through The whole Big Bang--except for coming to Whenever the Cosmologist had said The word "creationists." "You go ahead," She said to the Geologist, "I'm through." "Your tale was nicely told, expansive too," Said the Astronomer. "We should at least Speak also of Lemaitre, both a priest And an astronomer. 40 For it was he Who, having heard of relativity, Then of redshift, was actually the first To theorize about an ancient burst Of 'fireworks,' a 'primeval atom' that Exploded. 41 It was not just some fiat Of God--Lemaitre, though he was ordained, Felt science and religion best remained Completely separate fields. 'The Bible,' he Once stated, 'doesn't teach astronomy Nor was it ever meant to, any more Than the binomial theorem's good for Teaching religion.' 42 Too bad that today Creationists can't see things in the way Lemaitre did." The Scholar said, "And, look, That same position's one John Calvin took: 'The Holy Ghost did not intend to teach Astronomy.' 43 But they're beyond the reach Of even Calvin, these creationists. Try reasoning with fundamentalists." 44 "What?" said the Biochemist. "It's not worth One's time!" "Geologist, discuss the Earth," Said the Cosmologist. "Include a quake Or something. That might keep this man awake." [starrule.gif] Top | Notes | Geologist | Contents | Bibliography | Index | Home | Book Order FREE counter and Web statistics from sitetracker.com [img]