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What If Dark Matter Really Doesn't Exist? 1063

Posted by Hemos
from the what-then dept.
sonar67 writes "According to The Economist: 'It was beautiful, complex and wrong. In 150AD, Ptolemy of Alexandria published his theory of epicycles--the idea that the moon, the sun and the planets moved in circles which were moving in circles which were moving in circles around the Earth. This theory explained the motion of celestial objects to an astonishing degree of precision. It was, however, what computer programmers call a kludge: a dirty, inelegant solution. Some 1,500 years later, Johannes Kepler, a German astronomer, replaced the whole complex edifice with three simple laws. Some people think modern astronomy is based on a kludge similar to Ptolemy's. At the moment, the received wisdom is that the obvious stuff in the universe--stars, planets, gas clouds and so on--is actually only 4% of its total content. About another quarter is so-called cold, dark matter, which is made of different particles from the familiar sort of matter, and can interact with the latter only via gravity. The remaining 70% is even stranger. It is known as dark energy, and acts to push the universe apart. However, the existence of cold, dark matter and dark energy has to be inferred from their effects on the visible, familiar stuff. If something else is actually causing those effects, the whole theoretical edifice would come crashing down.'"
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What If Dark Matter Really Doesn't Exist?

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  • by garcia (6573) * on Monday February 09, 2004 @05:07PM (#8229942) Homepage
    So what if it doesn't really exist? We know very little about anything anyway. Trying to find a unified explanation via "String Theory" is spotty at best but at least it "helps".

    What's the difference if dark-matter is really just another false theory? In the long run it's not going to make a whole heck of a lot of difference.
  • No dark matter ? (Score:2, Interesting)

    by (463614) on Monday February 09, 2004 @05:09PM (#8229973) Homepage
    Then we're screwed. Life is doomed to die out with the heat death of the universe. We won't go with a bang, but with a whimper...
  • Relativity (Score:5, Interesting)

    by mozumder (178398) on Monday February 09, 2004 @05:09PM (#8229984)
    Actually, with Einstein's relativity, doesn't Ptolemy's theories hold true? Everything is relative to a point of view?

    Sorry I didn't ask this question in Modern Physics's class. It was a morning class, and I was sleeping.
  • Brief History... (Score:2, Interesting)

    by mwheeler01 (625017) <(moc.liamg) (ta) (releehw.l.wehttam)> on Monday February 09, 2004 @05:10PM (#8229987)
    Anyone who's read a Brief History of Time would know that any theory that describes something accurately is pretty valid. Whether or not it's elegant is another matter. Most Physicists believe that God created the laws of physics to be elegant and try to iron our the complexities of their theories. If dark matter doesn't exist it pokes a rather large hole in things but going under such an assumption may lead to a more elegant picture of how the universe began, and the nature of matter etc...
  • by AKAImBatman (238306) <> on Monday February 09, 2004 @05:10PM (#8229991) Homepage Journal
    ...but doesn't String Theory tend to suggest that "dark matter" isn't actually dark matter, but instead is gravitation bleeding from other universes? The same theory also explains why gravity in this universe is so weak. Because most of it bleeds of into other universes via the higher dimensions, it's weak enough for you and I to move our limbs.

  • What does it matter? (Score:3, Interesting)

    by MrPCsGhost (148392) on Monday February 09, 2004 @05:10PM (#8229999) Homepage
    Are planes going to drop from the sky? Will we be thrown out of orbit? This sounds like the Bugs Bunny cartoon where Bugs floats on air because he never studied the laws of gravity (I know I've probably got the reference wrong, but you get the idea).

    Your experiment fits the model, or it doesn't. If it doesn't then one or both need to be tweaked, or scrapped.
  • Dark matter? (Score:0, Interesting)

    by dustmote (572761) <fleck55&hotmail,com> on Monday February 09, 2004 @05:12PM (#8230031) Homepage Journal
    A friend of mine is doing his master's thesis on a theory that rather more elegantly explains the phenomenon without having to resort to dark matter, but unfortunately I don't understand enough of physics to know if he's right or not. Something about gravity. (I know, I physics, that really narrows it down, since there's so little about gravity out there...) In any event, I suspect we will find something a little more elegant, just like the article said, because dark matter sounds......well, silly.
  • by MoonBuggy (611105) on Monday February 09, 2004 @05:13PM (#8230054) Journal
    Indeed - as the summary says, it's not so much a parse error as a dirty hack, so to speak. Our current theory does the job without breaking anything, and in time we will work out a more elegant way to describe the same concept.
  • by Tablizer (95088) on Monday February 09, 2004 @05:14PM (#8230068) Homepage Journal
    There seem to be growing "hints" that something is wrong with current theories about the very nature and behavior of gravity. This includes alleged dark matter that cannot be identitied, planetary space probes with slight deviations from expected sun "pull" [1], and the fact that there is no identifiable "negative" gravity while the other forces do have negative values or particles.

    [1] It was originally thought that heat generated from nuclear fuel cells was "pushing" the probes, but this was mostly ruled out because the heat lessens over time, but the pull was constant.
  • I hope its a kludge (Score:5, Interesting)

    by mnmn (145599) on Monday February 09, 2004 @05:17PM (#8230108) Homepage
    Science has been progressing on the basis of constantly proving theories as kludges and bringing about something newer and more real. Imagine if our currently held view was true (before Standard Model), we will never be able to travel faster than light, we'll never harness energy bigger than a hydrogen bomb, we'll never really travel far beyond the Solar system, travel back in time etc.

    Before the cannon was invented everyone thought the arrow was the greatest weapon, and few could really predict the power of "Little Boy" on Hiroshima. Quantum Mechanics has given us so much hope, of unknown and unexplainable realities, and that far more is possible than we first thought. It means the road before us is much longer, but far more interesting. I'd prefer it that way.
  • by Daniel_Staal (609844) <> on Monday February 09, 2004 @05:17PM (#8230110)
    Sure, in the long run it doesn't matter.

    That is, of course, if we keep testing it and trying to see if it is true. (Or the closest approximation of 'true' we have been able to come up with.)

    It matters now if it is not true because then we know we need a better theory. And that means we either didn't understand something we thought we understood, or that we hadn't explored our understanding fully. Either way, there is likely something else that will be affected...
  • quantum matter (Score:2, Interesting)

    by planckscale (579258) on Monday February 09, 2004 @05:19PM (#8230132) Journal
    Perhaps scientists are looking at dark matter and the universe incorrectly. Looking for 'matter' in 3-4 dimensions (light, heat, matter) when judging the weight of all matter and its relevance to the size of the universe. I think until we grasp that all that's seen and measured as a way quantifying a 10-20 dimentional universe, we'll be stuck at a dead end. Perhaps the 'matter' in the universe is a small portion of it's quantum octuplets in different dimensions, parallel universes, and infinate possiblities all rolled up in a 11 dimensional quantum state. Empty space may be just and 'place' in a super string soup that isn't actually empty but an infinately wide probablity of being any possible particle at any point in time. Seems like this could provide a little extra 'weight' to dark matter.

  • Re:No dark matter ? (Score:4, Interesting)

    by Daniel_Staal (609844) <> on Monday February 09, 2004 @05:20PM (#8230144)
    Hey, all the better!

    If the end of the universe is a heat death it might be possible to live forever, in smaller increments of time/energy. If the universe crunches, everyone and everything dies...
  • Re:Relativity (Score:3, Interesting)

    by crow (16139) on Monday February 09, 2004 @05:20PM (#8230148) Homepage Journal
    I would have to look more closely at Ptolemy's theory to be sure, but you might be right.

    With Relativity, you can pick your reference point, and we normally use the sun for the solar system. However, you could say that the sun orbits the Earth and the other planets orbit the sun. If you then look at the path of the other planets relative to the Earth, they may well be traveling in something close to what Ptolemy described.

    I've long thought that Rennaisance astronmers would have gotten in a lot less trouble with the Church if they had left the Earth fixed and said that the other planets orbited the sun, which orbited the Earth--all mathematically equivalent, but politically safer.
  • dark matter evidence (Score:4, Interesting)

    by dpa (579262) on Monday February 09, 2004 @05:22PM (#8230181) Homepage
    There is some intriguing evidence [] of the existence of strange quark matter, a dark matter candidate, which we've recently published in the Bulletine of the Seismological Society of America []. as previously discussed on /.
  • by zx75 (304335) on Monday February 09, 2004 @05:25PM (#8230221) Homepage
    The term 'Dark Matter' refers to all celestial matter that does not radiate to a significant degree rendering it 'invisible' from this distance at which we view it.

    The existence of dark matter should be obvious, since we know of the existance of numerous asteroids in our own solar system, there should be many throughout the universe, but since they don't radiate energy we are unable to see them and thus cannot account for how much mass they contribute. Astronomers, by examining the change in the rate of expansion of the universe (a tricky prospect, prone to errors that I do not completely understand) it is believed that such 'dark matter' makes up roughly 70% of all mass in the universe. Which means that we cannot account for 70% of mass because we cannot see it.

    Even stars fall into the category of dark matter, old dead stars, halo stars in other galaxies (those in a sphere around galaxies which we have only recently confirmed exist around our own galaxy) and likely many other astronomical bodies exist that we simply have not observed.

    Dark matter has too many connotations in lay-man's speech that are overly misleading. I'm sorry, but Star Trek did not 'get it right' by any stretch.
  • by PineHall (206441) on Monday February 09, 2004 @05:25PM (#8230222)
    I don't think what Dr. Shanks is proposing is as big of a change as that article makes it out to be. Dark energy has always been a kludge of sorts. He is proposing a theory to define this dark energy factor/constant. It does not radically change the Big Bang Theory, rather it adds to it.
  • by peter303 (12292) on Monday February 09, 2004 @05:25PM (#8230235)
    The keynote speaker [] at the 2003 SIGGRAPH conference in San Diego was the British astrophysicist Anthony Lasenby. He claimed that a new kind of unified Euclidean and hyperbolic geometry could explain acceleration and deceleration in the Big Bang. He was talking at SIGGRAPH because his new unification of geometry is supposed to be more elegant for computer graphics modeling than the current homogeneous coordinates now used. He wrote a book [] about the geometry. But I have been unable to find a paper relating to the cosmological application on the web.

    This is not the first time geometry has been used to unify and simplify physics. Previous examples are Galilean coordinates, special relativity, and general relativity.
  • by DesScorp (410532) <> on Monday February 09, 2004 @05:25PM (#8230244) Homepage Journal
    Entire careers in physics are going straight down the shitter because of dark matter, because it doesn't exist. From the very first time I read about it, I thought "Geez, this sounds like a 3 year old trying to cover up the fact that he doesn't KNOW the reason why". I really think that's what it comes down to. Very smart people not wanting to admit that they have no idea why they can't explain the lack of visible matter in relation to the effects of gravity.

    It's one thing to predict a phenomena without being able to immiedietly prove it. Proof is usually found pretty soon. But kludge's are the black eye of science, and even really bright people can make them (remember Einstein and his cosmological constant?). I think Dark Matter will join that same heap, right on top of Steady State Theory, and it'll happen in my lifetime.
  • by bob the Martian (113876) on Monday February 09, 2004 @05:27PM (#8230273)

    There are current astrophysical models which postulate that the Universe is a hyperplane embedded in higher dimensional space, called Randall-Sundrum models. In which case gravity can propagate trasverse to this plane, hence there can be matter outside the Universe which can still interact with it. There is also the idea that this 'brane' (as it is called - nothing to do with zombies) has a small extra dimension (less than 1mm in size) so the current gravitational law needs to be changed to r^{-4} or so at very short distances.

    String theory as such tends not to comment on dark matter (could be D0-particles, could be fish) as no-one knows how to compactify it down from 10D and break supersymmetry in a useful way.

  • M.O.N.D. (Score:5, Interesting)

    by bokmann (323771) on Monday February 09, 2004 @05:28PM (#8230289) Homepage

    Bringing this up without mentioning M.O.N.D. is irresponsible journalism. MOND (Modification of Newtonian Dymanics) is a theory that simply says that gravity 'decays' at a slightly different rate than expected over astronomical distances. The effects predicted by this theory are spot on to the observed effects that dark energy and matter try to explain.

    I googled about found this link [], but I first read about it in New Scientist about a year ago.

  • by Anonymous Coward on Monday February 09, 2004 @05:31PM (#8230334)
    as predicted by John Titor [], a Time Traveller from 2036. The Universe is apparently composed of Infinite Universes...a Multiverse of sorts as the MWI (Multi World Interpretation) states.

    If he's right, we're in for a bad time starting later this year.

  • Re:quantum matter (Score:2, Interesting)

    by EvilTwinSkippy (112490) <yoda&etoyoc,com> on Monday February 09, 2004 @05:32PM (#8230363) Homepage Journal
    I like the idea that what we view as the universe is actually an interference pattern. Thus, what we try to describe with physical models of the universe is describing an effect, not the underlying cause. Like those psuedo science studies that prove mice exposed to flourescent light die, or taking this strange herb cures some dread disease based on anecdotal evidence from a self-selecting population.

    Now, forget about superstrings. Science has to work out a few more forces in nature first. There is no decent explaination of why life actually works. It has this habit of taking disorder and generating order out of it. There are some pretty wild things this does to thermodynamics.

    Next, Physics needs to study emergent intelligence. There are too many self-regulating systems out there for every one of them to be a fluke. And I'm not just talking about organisms. Tides, climate, the orbits of stellar bodies. Yes it sounds wacko. But it may explain why things can be completely random at a quantum mechanical level, but balance out in larger systems.

    Investing a whole lot of time tryign to invent new maths to solve problems that are only caused by the last new math you invented is pointless. There are too many life-and-death questions of immediate importance that require serious work.

  • Re:Theory. (Score:5, Interesting)

    by nacturation (646836) <<moc.liamg> <ta> <noitarutcan>> on Monday February 09, 2004 @05:33PM (#8230371) Journal
    Just like the Theory of Evolution.

    Yes, exactly. That evolution occurs is a fact which can be demonstrated. On the other hand, the theory, which tries to explain how evolution works, could be inaccurate/wrong. The theory itself may change many times and might be completely overhauled for some new radical explanation. However, regardless of whether or not we understand the mechanisms behind it, nothing can change the fact that evolution exists.

    See: Evolution is a Fact and a Theory []
  • by peter303 (12292) on Monday February 09, 2004 @05:37PM (#8230425)
    I may be showing a few gray hairs here, but revolutions in the sciences have occurred in my lifetime with scientists adapting fairly well. The first was the acceptance of Big bang in the late 1950s. Between 1927 and 1955 the Big Bang was just one of several "equally attractive alternative theories" which included the eternal-infinite universe and continuous creation of matter. The microwave background and the abundance of helium brought the big bang into the fore front.

    In the 1960s the quark unification of subatomic particle became the predominate theory. Plus quantum electrodyanamics was verfied in high energy experiments to extremely high precision.

    Also in the 1960s plate tectonics replaced an up-and-down explanation of geologic forces.

    If the evidence suggests a more powerful theory, then physicists will revise their theories again. Science does not stay attached to incorrect theories (though block-headed individuals do).
  • Pardon my naivete (Score:5, Interesting)

    by El (94934) on Monday February 09, 2004 @05:38PM (#8230451)
    I may be incredibly naive, but it has always bothered me that we insist on believing there are only 4 types of force in the Universe, each operating on widely different scales. Why can't there be other forces that operate on too large a scale or too small a scale for us to observe? Is the postulate of "dark force" effectively a theory about a fifth type of force?
  • Re:In 100 years... (Score:3, Interesting)

    by pla (258480) on Monday February 09, 2004 @05:41PM (#8230489) Journal
    Dark Matter will be taught to school children as the Aether of 21st century science.

    ...Of course, experimental verification of the Casimir effect has proven that an Aether does in fact exist, just not the same one that Michaelson and Morley tested for and disproved.
  • by i_should_be_working (720372) on Monday February 09, 2004 @05:41PM (#8230496)
    there are several types of dark matter that have been proposed. some are pretty exotic (rare, hard to observe particles) and some is pretty straight forward.

    one type we know to exist merely from looking at the rotational velocity of galaxies. looking at the visible matter (stars) of a galaxy allows one to calculate it's visible mass. stuff on the outer rim of galaxies is moving far too fast to be held in place by the gravitational attraction of the visible matter alone. therefore there must be more mass in the galaxy than we can see. we can't see it so it's called dark matter. nothing exciting, no CMB measurements involved.

    on a side note, the existence of anything we observe is inferred from it's effects on other things. when i see something, i infer that it exists from the photons that have bounced off of it and into my eye. gravity is just a valid observational tool as light is.
  • Re:Theory. (Score:3, Interesting)

    by cperciva (102828) on Monday February 09, 2004 @05:42PM (#8230508) Homepage
    Please demonstrate one species evolving from another.

  • Re:Brief History... (Score:5, Interesting)

    by Brandybuck (704397) on Monday February 09, 2004 @05:47PM (#8230590) Homepage Journal
    From your article: "60% responded...", "half replied...". In other words, a self-selecting survey. Demonstrates nothing.
  • by benj_e (614605) <> on Monday February 09, 2004 @05:49PM (#8230618) Journal
    Kludges are not "the black eye of science". They are initial attempts to explain observations. They may look foolish down the road, but early theories are, in fact, a starting point for further study.

    As far as the cosmological constant is concerned, it seems to have new life [].
  • by Avian visitor (257765) on Monday February 09, 2004 @05:52PM (#8230659) Homepage
    I don't know about dark energy, but there is more direct proof for the existance of dark matter than background radiation and galaxy clusters.

    Take a few neighbouring galaxies for example. We can measure the velocity of stars orbiting the center using Doppler effect, which is pretty accurate. The problem is that all stars circle the center in approximately same time while gravitational therory predicts that those stars that are on the rim of the galaxy should take longer to make one orbit. That can only be explained with a large halo of dark matter that sourunds the galaxy and holds more mass than the visible (light-emitting) matter in the galaxy.

    Compton scattering can't explain that.
  • by peter303 (12292) on Monday February 09, 2004 @05:53PM (#8230690)
    My recollection of the talk is bit fuzzy, by Lasenby defines an extension to Cartesian analytical geometry consisting of the linear combinations of perpendicular, parallel and infinite unit vectors. Zeroing the the latter two gives conventional analytical geometry. Another choice of coefficients gives the hyperbolic geometry, best illustrated by some of Escher's olizard paintings. Lasenby claims if you give the cosmos this mixed geometric basis, with a slight non-Cartesian component, then that will explain the change in the Big Bang expansion rates.

    On the other hand, some physicists claim "Geometry Equals Force", so augmenting geometry is creating new forces, and we are back to dark energy again.

    On the other hand, my brain may have blown a fuse hearing these new ideas and I restated them incorrectly.
  • by tgibbs (83782) on Monday February 09, 2004 @05:55PM (#8230723)
    But kludge's are the black eye of science, and even really bright people can make them (remember Einstein and his cosmological constant?).

    To be fair, the cosmological constant was a constant that emerged naturally from the derivation of General Relativity, with no indication of what its value should be. To apply it to reality, some value had to be assumed or determined. The simplest thing to do would have been to arbitrarily give it a value of zero, but that would have implied an expanding universe. In the absence of evidence for expansion, Einstein chose to give it a value that made the universe static.
  • by GammaRay Rob (452271) on Monday February 09, 2004 @05:55PM (#8230726)
    The original article makes the parallel argument that theory keeps adding cruft to fit the current observations, just as adding epicycles on epicycles was required to account for the Earth-centered theory. So far, so good. However, cosmology has now fairly completely accounted for the observations at this point, and has no more tooth fairies to fall back on; that is, no more epicycles are waiting in the wings, nor are more required.
  • by sdedeo (683762) on Monday February 09, 2004 @05:55PM (#8230729) Homepage Journal
    It is doubtful that the entire theoretical edifice of dark matter and dark energy will collapse all at once (in the way it might more reasonably have been said to have happened for the electromagnetic aether.)

    In particular, dark matter, though incredibly mysterious, is probably on firm enough ground that it will withstand a series of challenges. Galactic rotation curves and measurements of cluster temperatures both give very strong evidence for dark matter on vastly different scales; in addition, it is difficult (OK, fine: downright impossible in standard Einsteinian gravity) to get any kind of structure to form *at all* in the universe if one is only allowed to use the visible matter. The precise ratio of dark to visible is definitely up in the air; and, of course, there are competing models that modify gravity -- if these matured enough (they may already have -- I haven't kept up) to make predictions on a wider range of scales, they might work as well.

    Indeed, a lot of gravity modifications (extra dimensions, etc.) behave *phenomenologically* as if there was dark matter -- so all the effort we've put into simulating dark matter may not be in vain after all, even if Einsteinian four dimensional spacetime is not the name of the game.

    In contrast, indeed, is the exact count of the "baryons" (ordinary matter.) I would be very surprised if we were off by a factor of (lets be ultra-conservative here) five in the baryon number, which is constrained very well by big bang nucleosynthesis, whose predictions remain in the "ordinary" realm of nuclear explosions. Something we know a little about.

    The real mystery is "dark energy." There, the evidence is a lot shakier. It rests on a few pillars. There is a theoretical bias that wants the universe to be flat (so that the missing mass-energy is made up for by some dark energy component that doesn't cluster and affect our galactic rotation curves.) There are some really excellent (but difficult) measurements of universe acceleration, a signature of dark energy, from people who observe distant supernovae (these provide "standard candles" that allow you to measure distance given an apparent brightness.)

    Finally, there are the CMB measurements, which provide a similar kind of distance measurement, but are open to alternative interpretations (instead of measuring apparent brightness, they measure apparent angular size -- but it is perhaps possible, if you squeezed around, to construct a different model where the apparent angular size is squished in odd ways.)

    And then there are a host of other measurements that one might call more "marginal" (without prejudice to the people who work very hard to do them -- I aspire to be one of them.) They rely on a few more astrophysical assumptions, and perhaps would not convince the slashdot skeptic. (My profound apologies if I've missed out someone's awesome measurement.)

    One big "trouble" is that we haven't seen good evidence for a very particular signal that one would associate with the simplest model of dark energy. (This is the "low quadrupole" -- the news stories you read about finite universes are from people who, in part, are motivated by the desire to explain this low quadrupole signal by other means.) Of course, it is entirely possible to make more exotic dark energy models that don't show this signal (I've coauthored a paper on one such model), but that missing signal, gosh, damn.

    The Economist is usually good with science articles, but it really kind of missed the point on this one. Shanks et al. are not "bringing down the whole edifice"; they are pointing out what they see as a possibly problematic signal in the CMB data. This may inspire in some a little additional -- and very healthy -- skepticism about the dominant models. But it is important to mention that there really is no "dark energy mafia"; nearly any astrophysicist worth his or her salt would drop dark energy like a stone if the evidence started piling up, and many, many astrophysicists keep a hand in alternate models that don't rely on dark energy because, hey, what a scoop that would be.

  • Dark Charge (Score:2, Interesting)

    by centauri (217890) on Monday February 09, 2004 @06:03PM (#8230865) Homepage
    I've looked at it this way for years: Say there happened to be a race of creatures that lived on the nucleus of an atom, held to their home by, say electromagnetism. Electromagnetism is their dominant force. They know about the strong and weak forces, but they know nothing about gravity. This race has developed the ability to look out into "space" and they can see lots of other atoms, all of which obey the laws with which they are familiar. Looking out further, they see huge groups of atoms (electrically neutral objects, such as, say rocks) that behave in ways that are contrary to the laws of electromagnetism. If they followed our path, they might be forced to posit the existance of invisible charges or Dark Charges that are responsible for the movement of these objects.

    Now, we happen to know that electrically neutral objects obey gravity, but when we look out and see large groups of objects acting contrary to gravity, it never occurs to us to theorize the existence of a force that we don't experience in our regime.

    Maybe there are forces "above" gravity, just as gravity is above electromagnetism.
  • by xestrel (306192) on Monday February 09, 2004 @06:07PM (#8230934)
    I disagree with the statement that careers are being wasted on dark matter studies.

    Without some sort of hypothesis to explain a phenomena, no progress would be made whatsover. Okay - so maybe dark matter will not be the ultimate explanation to the question of why universe is apparently lacking mass, but careers spent studying the possible existance of dark matter and ways one would detect said matter if it did exist does ultimately yield information about the nature of the world.

    After all, without the Michaelson-Morley experiment, we may have continued laboring under the idea that we exist in an ether. And without a testable hypothesis for the ether, there would have been no experiment.
  • by Graff (532189) on Monday February 09, 2004 @06:15PM (#8231045)
    I imagioned what life would be like for a process on a Linux box. In some respects, the system never changes. In other respects, as chunks of the system are refined an upgraded, previously famliar systems take on more complex, and at times, incomprehesible behavior.

    An interesting concept indeed. However, what that is really doing is just moving the rules up a level. Suppose that the
    "rules" of the immediate universe are changing on some level, whether caused by "intelligence" or by some sort of natural process. In the end that modifying factor is either itself governed by a set of rules or is fundamentally rule-less.

    If the modifying factor is rule-less then there is no hope for ever truly understanding the nature of the universe, although we may still be able to get a grasp on some fundamental concepts that don't change often. On the other hand if the modifying factor does so according to some set of meta-rules then we still have the chance to figure out both our immediate rules and the meta-rules that govern how the modifying force works.

    All of that is still pretty out there for us, what we do know is that the "rules" of our observable universe change extremely slowly, if they change at all. It is slow enough for us to treat the "rules" as being constant for reasonably large time periods on the order of billions of years.
  • Re:Theory. (Score:5, Interesting)

    by EvilTwinSkippy (112490) <yoda&etoyoc,com> on Monday February 09, 2004 @06:15PM (#8231048) Homepage Journal
    What do you mean absence. Look at dogs. We took wolves and turned them into a wide variety of shapes and colors from Great Danes to Chiwawa's all within the last 40,000 years.

    The same is true with almost any domesticated animal. For pete's sake the entire science of animal husbandry is application of Evolution, just under our control.

    Of course, our efforts in domesticating animals show that one force seems to be required to really make evolution work properly: a regulator. Someone who reviews what's good, what's bad, and what is really cool, though unexpected.

    Next time some god-boy goes on a rant about how evolution doesn't exist, quote the parable of the Wheat and the Tares. In it Jesus talks about how God can't really tell what is useful and what is not until it has had a chance to develop. Once it is clear what is good, and what is not, someone comes by and clears the crap out.

    Evolution by any other name to me.

  • by rknop (240417) on Monday February 09, 2004 @06:20PM (#8231109) Homepage

    Entire careers in physics are going straight down the shitter because of dark matter, because it doesn't exist. From the very first time I read about it, I thought "Geez, this sounds like a 3 year old trying to cover up the fact that he doesn't KNOW the reason why".


    The primary evidence for dark matter is that if you look at how galaxies move and how clusters of galaxies move, they should all be flying apart. They are moving too fast for the amount of gravity we calculate by adding up all the mass of the stars and the gas that we can see. Since galaxies and clusters are around all over the place, we know they're not falling apart. Ergo, there must be more gravity than can be accounted for from the material we can see.

    The simplest, easiest, and most direct explanation is that there is more there than we can see. Matter not emitting light, thus called dark matter. There's nothing kludgy or ad-hoc about this, it's the most natural conclusion to make. The alternative is that Newtonian Gravity (or General Relativity, which has Newtonian Gravity as a limit in the relevant case)-- that theory which perfectly predicts the motions of planets, spacecraft, apples, and other things that we have lots of experience with-- must be wrong. There are people who believe this over Dark Matter, in fact, but to me, "stuff there that we haven't found yet" seems to be a much more likely and plausible explanation.

    The evidence for why the dark matter can't all be baryonic (i.e. made up of "normal" stuff) is more indirect, but it comes out of other theories for the construction of the elements in the hot early Universe-- and this other theory itself has made predictions that match well what was observed.


  • by Barlo_Mung_42 (411228) on Monday February 09, 2004 @06:23PM (#8231156) Homepage
    "Do you really have to prove God exists before you'll believe?"

    As a matter of fact, yes. ;)
    Some people get by fine on faith and that works for them. I've known many happy faithful people and I sometimes even envy that quality in them.
    But that just isn't how I work. I look at the world with an innate need to figure it out. This makes it impossible for me to take any religion literally.
    I suspect this is common with many geeks.
  • by Anonymous Coward on Monday February 09, 2004 @06:27PM (#8231211)
    This is some good reading if you want to go on this tangent: tm l

    (that is a .html - not sure why it's not coming throught correctly in this preview)
  • by EvilTwinSkippy (112490) <yoda&etoyoc,com> on Monday February 09, 2004 @06:28PM (#8231229) Homepage Journal
    what we do know is that the "rules" of our observable universe change extremely slowly, if they change at all.

    Well, if have learned anything from geology and climatology, it's that what previously looked like a steady constant system today has in fact been subjected to sudden and violent changes in the past. Continental "drift" is not a gradual process. It occurs one violent event at a time. Ocean currents don't gradually fade. They abruptly stop and then change direction.

    No one has bothered to even look to see if the rules by which our universe exists today are the same as a few million years ago, or a few billion years ago. How would you be able to tell that, say, the gravitational constant of the universe has been constant all along?

    We can't. We don't have any observations before about 3000 years ago. That's not even a clock pulse to the universe. Heck, even in our own systems we continually tear down and rebuild the rules. Look at building codes. Look at military tactics. What used to work no longer does. And these are far simpler systems than the inner workings of the Universe.

  • Re:Theory. (Score:5, Interesting)

    by Noren (605012) on Monday February 09, 2004 @06:32PM (#8231275)
    In Britain, there are two types of gull which appear to be different species, a white herring gull and a lesser black-backed gull. They are quite different in appearance and do not (directly) interbreed. They are currently considered one species, though, because they share genetic material indirectly. The white gulls breed with the North American gulls and the black-backed breed with the northern European gulls... which, as you go around the world's northern edge, gradually change characteristics to become the other. Each local population occasionally breeds with its adjacent areas' slightly different gulls, and these small changes add up, until around the Alaska/Siberia area the gulls are roughly intermediate between the two types of gulls as found in Britain. There's no clear place to draw the line separating the spectrum between the two ends of the ring to separate those ends into two species.

    If all the herring gulls in North America and/or Asia were to die due to some natural disaster (or to human interference), the white herring gull and lesser black-backed gull in Britain would become different species. In a sense this is a situation where the gulls have in most ways already evolved into two species, and could readily become two species given particular natural events. This type of species is called a ring species. []

  • by Coulson (146956) on Monday February 09, 2004 @06:35PM (#8231323) Homepage
    Optimism about the continued accumulation of human knowledge is pretty well-founded. All you need is the scientific method and written language (or some semi-permanent way of passing information on to the next generation). Over time, the body of human knowledge will continue to grow.

    The only pitfalls are destruction of information (collapse of civilization, burning of the Great Library of Alexandria, etc.), or knowledge saturation (more data exists than any one person can master in a lifetime of study).

    The second danger is interesting, but is helped by the fact that (a) information stored on physical media decays, (b) it can be combatted by increased specialization (which appears to be the dominant trend). Also, the scientific method is valuable for weeding out invalid theories, thus reducing the overhead of useless information (phlogiston).

    Ergo, historians are justified.
  • by SlowGenius (231663) on Monday February 09, 2004 @06:41PM (#8231409) Homepage
    Alexander Shulgin's writeup of the "Infinitely Old Universe" [] idea (in place of the Big Bang) seems more poignant than ever....

  • by Black Parrot (19622) on Monday February 09, 2004 @06:42PM (#8231433)

    > Evolution, OTOH, has never been demonstrated or shown in an experiment. To demonstrate evolution would require watching a planet from start to finish, which we have not yet done.

    Sorry to inform you, but science allows indirect evidence as well.

    > Something not taught in school that should be is that evolution is dependent upon natural selection, but not the other way around. The earth could have been populated by God/Aliens/someone creating species in a test tube somewhere and populating the earth. Natural selection would just as easily occur with this hypothesis.

    You seem to be confused about the subject matter. It is correct to say that it doesn't matter whether gods/aliens/naturalforces/blindchance created life, because evolution could operate on the result regardless of the origin. All evolution requires is imperfect self-replicators.

    > BTW, I'm a scientist

    You certainly don't talk like a scientist. What is your field, and where can we find a list of your publications?

    > WRONG. There is no such thing as proving a theory right (i.e. as truth).

    And a real scientist would know that scientists don't spend their time trying to "prove" theories right. Rather, scientists look for explanations for observed phenomena, and theories are the product of that endeavor.

    > Evolution is so mathematically improbable that I'm surprised that most scientists just accept it.

    Can you show us the math on that?

    > It's a great theory to explain things right now (which is why we use it), but there's a good chance it will probably be proven false someday.

    Can you show us the math on that, too? (I'll gladly accept "it may be proven false someday", but you are asserting more than that, even with your double qualification. What are the chances that the theory of evolution will be proven to be false some day?)

  • by barawn (25691) on Monday February 09, 2004 @06:50PM (#8231546) Homepage
    On the other hand, some physicists claim "Geometry Equals Force", so augmenting geometry is creating new forces, and we are back to dark energy again.

    This is not a claim. It is a definition. The best example of it is the Coriolis and centrifugal "forces".

    This comes about because we define motion under no forces as motion in a Cartesian reference frame. Therefore any deviation from that motion is a force.

    I guess you could make the statement that "well, maybe that definition is wrong", but physicists would invoke one of the Fundamental Rights of Physicists and say that if motion under no forces is "very very close to but not quite" motion in a Cartesian reference frame, then it is, and the deviation is caused by another effect, which we will term a "force".

    So, yup, back to dark energy.
  • by egomaniac (105476) on Monday February 09, 2004 @07:20PM (#8231904) Homepage
    I always thought this was an interesting an odd part of modern science and cosmology. Why should we assume occam's razor, that simpler explanations are better? Why should the universe be simple and elegant?

    You have misunderstood Occam's razor. It doesn't say that at all.

    Occam's razor, in its original form, translates to "Do not multiply entities unnecessarily". That has been modernized to "The simplest explanation is usually correct", which is close, but not exactly the same.

    What Occam's razor really means is: given two (or more) possible explanations of a phenomenon, with no evidence favoring one over the other, assume that the simplest one is correct.

    For instance, if I find a pinecone lying on the ground under a pine tree, the simplest explanation is that it fell off of the pine tree. Sure, it might have been planted there by invisible space aliens in conjunction with the Illuminati acting in strict accordance with the Masonic doctrine of the Coming of the Pine Cone King, but since there is no evidence to favor one explanation over the other, I should assume that it fell off of the pine tree.

    That doesn't mean that it did fall off the pine tree, and it doesn't mean that I might not change my mind as more evidence is found. It also doesn't mean that I shouldn't look for more evidence and try to determine the origin of the pine cone with greater accuracy. That isn't what it says at all. It just means that until such evidence arises which would cause me to revise my view of things, I should assume the simplest explanation that fits the facts. The explanation should only change when the known facts do, or a better explanation is found.
  • by renard (94190) on Monday February 09, 2004 @07:35PM (#8232097)
    What scientists do is try to disprove a hypothesis, not prove one.

    That is an empty distinction. The point of science is to gather evidence that bears on the truth or falsity of an important outstanding question, and then sort out the proposed answers (hypotheses) by whether they anticipate the evidence correctly or not. Call it a process of disproof if you want, but proof (in a legal or probabilistic, if not mathematical, sense) is certainly part of the process as most scientists practice it.

    These new hypotheses are currently not as well supported as the dark matter/energy hypothesis, but that doesn't make them a "distraction".

    They may be a distraction to researchers (Fermi: "Not even wrong") if (a) they are internally inconsistent; (b) they are poorly formulated so as to be untestable or unfalsifiable; or (c) they fail to take account of the broad range of our current knowledge of the universe (e.g., General Relativity and its role in cosmology). I'm not saying that any of these are true in this case - just that some theories really are not worth the time it takes to become acquainted with them.

    More importantly, what I was trying to say is that these theories (and the papers that purportedly back them up) are a distraction to the great majority of Slashdot readers, who - as you will gather by reviewing the posts to this story - are still unfamiliar with the basic outlines of our understanding of the universe, which has advanced by leaps and bounds in the last few years. You misinterpreted my closing paean to the consensus cosmology as a call to navel-gazing among the astonomy community, which truly would be silly. We are much better off formulating and testing new hypotheses - and we are! - than sitting on our laurels. Among other arguments, laurel-sitting is a very poor justification for the bright shiny new billion-dollar satellites that we want.


  • by Dr. Zowie (109983) <slashdot@defores[ ]rg ['t.o' in gap]> on Monday February 09, 2004 @07:36PM (#8232103)
    If you convert to (say) Christianity to maximize your "expected return" from life, you're being a hypocrite -- unless you're very different than I am. I don't have a lot of conscious choice about what I believe -- it either happens or not. I do have a conscious choice about how I behave, but to act in contrast to my beliefs is, as they say, to be a hypocrite. No good: hypocrites don't get in to Heaven. In short, for me (and people like me), Pascal's Wager is a canard -- I don't get to choose what I believe, so the dichotomy isn't a real one.

    It seems to me that a central tenet of Christianity is the Good News itself -- that an actual guy actually taught a bunch of people how to be good to each other, and actually came back from the dead. That is (at least in principle) a physical, provable proposition, and finding things like the shroud of Turin is a big part of that. Other religions work the same way -- there're a core set of beliefs that hold in the physical world, and that are thought to be supporting evidence for some metaphysical beliefs.

    It also seems that this thread is pretty far afield from the topic of cosmology. Religion and physical cosmology are somewhat orthogonal.

  • by jafac (1449) on Monday February 09, 2004 @07:44PM (#8232201) Homepage
    That's why it's not enough just to learn Science. Science History lends a crucial perspective on how ideas have evolved over the centuries, and how we've arrived at where we are, and where we may be going tomorrow.
  • by bradbury (33372) <Robert,Bradbury&gmail,com> on Monday February 09, 2004 @08:05PM (#8232402) Homepage
    The whole dark matter/dark energy perspective could be flawed. It depends upon the perspective that the Universe (as viewed) is most probably dead. It does not ask the question of what the Universe would look like if it were alive. But as work by Charles Lineweaver [] (a noted physicist at the Univ. of NSW) and his students have shown that may be a very questionable assumption. Their work suggests *most* of the Earths (60%+) in this Universe should be *much* older than ours.

    So the question must be raised *what* would the Universe look like if /.ers had had a billion or more years to work on it? Yes, I know that many of you will argue that it should not look much different but you have not run the numbers as I have on planetary disassembly [] times. Nor do you understand the limits of nanotechnology to the extent that I do.

    I've tried to explore and address some of these questions in my papers about Matrioshka Brains [] as has Dr. Sandberg in his exploration [] of the various types of Jupiter Brains [].

    These are not new concepts -- they have been discussed on the Extropians list [] for perhaps a decade. There are a few good astronmers and astrophysicists who discuss these ideas but to a large extent mainstream science seems stuck in the paradigm that the universe simply must be dead.

    Until we deal with whether or not that is a fundamental misconception we may be plagued by concepts like Dark Matter and Dark Energy that could be resting on very questionable evidence.


  • by jensend (71114) on Monday February 09, 2004 @08:26PM (#8232624)
    Other people have explained what the errors are in saying a Ptolmaic system or Brahe's system is "mathematically equivalent." I'll just add a few things- first, the real breakthrough in celestial mechanics was not the idea of Copernicus that planets revolve around the sun- some people had thought that for a long time- but rather Kepler's theory that the planetary orbits are ellipses. Nobody had taken heliocentrists seriously before Kepler, since a heliocentric model with circular planetary orbits actually conflicted with observation to a much greater extent than did the Ptolemaic system.

    In general, the background of the scientific revolution from Copernicus to Newton was the opposite of what it is often taken to be- a revival of observation and experimentation. The Scholastic system, being based on Aristotelianism, put plenty of emphasis on observation. One of the major catalysts for this scientific revolution was rather the appearance of translations of Plato and a subsequent move to attempt to rise above the particulars of the world to the Forms. I think it was Galileo who wrote to one of his associates that he admired and labored to emulate the resolution of men like Copernicus who could, ignoring the input of their senses, contradict these senses in describing how things OUGHT to behave according to ideal laws.

    One thing about the trouble astronomers had with the Catholic Church which is often ignored is that it was a real surprise. For almost a millenium before the Counter-Reformation, the Church was, on the whole, the greatest advocate of learning the world has ever known, though this advocacy had perhaps been on the decline for some time. The picture of a pre-Reformation Church working constantly to supress knowledge and free thought comes from the same sources of misinforming tradition which bring you the 2nd-grade Columbus Day elementary school assembly skits where a kid playing Columbus explains to his astounded peers that he thinks the world is round. (Very few people had believed the world was flat for quite some time, and the reason Columbus ventured west when nobody else would was because his calculations of the circumference of the world were way off; the Greeks had been very nearly right, and nobody had thought to try sailing west because crossing an ocean the width of the Atlantic, Pacific, and North America combined, without any places to stop, would have been far too risky to attempt at least until the advent of steam power.)
  • by fuctape (618618) on Monday February 09, 2004 @09:31PM (#8233135)
    Questioning universal gravitation strikes a chord with me -- after all, if QED (quantum electrodynamics) governs the universe at the smallest scales, why not some other modification of gravity for the larger scales?
  • by jabberjaw (683624) on Monday February 09, 2004 @09:49PM (#8233283)
    Rather competent means just that. I was merely illustrating that one does not have to wait until they are a college senior/junior to grasp the material. A great majority of the general public believes that this material is simply beyond their grasp, which is a shame. One can be introducted to the basic concepts of SR with some knowledge of calculus. As for a true understanding of the material, you are correct, I do not have it. Yet I do have a basic grasp of it which IMHO will serve to enhance my further studies.
    As for Canada, that is great. Unfourtunatly, high school education in America is abysmal. Some have no physics what so ever in high school, others have non-calculus based physics. Thus, they often believe that a basic understanding of these concepts is best left to individuals in ivory towers, which is again a shame.
  • by Epistax (544591) <epistax&gmail,com> on Monday February 09, 2004 @09:50PM (#8233290) Journal
    -Devil's advocate- Could it be that dark matter doesn't exist in any form, but we have some incorrect presumptions?
    For instance we believe that gravity is a distortion of space and is thusly incompatible (except via string theory) with our other friendly forces. Has there been much effort to characterize this distortion with actual numbers? I wouldn't be to surprised if gravity could be represented by our other forces through a distorted space.

    As a specific question, have we shown gravity to exist to the amount we expect the nanoscopic scale, such as two single protons, or two single neutrons? Again it wouldn't be surprising if gravity came from proton/neutron interaction, and the masses we determined for both actually don't make sense on the single boson level.

    I don't mean to be any sort of a science troll, I just haven't heard of this kind of thing being addressed.
  • I have to disagree (Score:3, Interesting)

    by cagle_.25 (715952) on Monday February 09, 2004 @09:57PM (#8233337) Journal
    I have trouble with your post. Not an "I'm offended" kind of trouble, but an "I really disagree" kind of trouble. Here it is:

    I think AC, your post comes from one who does not get it, and by rushing to the defense of religion where no assault is being perpetrated, you miss the mark completely.

    Well, it turns out that parent was responding to this:

    Excellent response. It's too bad religion isn't as honest in their theories.

    which is certainly an attack -- it's a charge of dishonesty. Mild by /. standards, but also typical fare for this site. So, yes, there was an attack.

    It is human nature to "know" how or why things are the way they are. You choose your explanation to be God. It is a nice and easy way to go about life, believing that everything has a purpose, but you do not need know what that is because you have God. Scientists, on the other hand, have a driving desire to learn. This has nothing to do with "anti-religion" or a desire to prove there is no God. In fact, you may find that quite a few scientists do believe in God or a "creator" or what have you. They just don't try to use this "God" concept to explain away the unexplainable.

    I think this severely misunderstands the state of Christian thought. If you look at the work of, for example, J.P. Moreland [] or Alvin Plantinga [], you will see that they do not appeal to God as an explanation for the inexplicable. Instead, they believe in God because they believe that the evidence points firmly in that direction.

    I teach science: H.S. Chem and Physics. I have a driving desire to learn, and I try to spark in my students a driving desire to learn and to analyze carefully, critically, and honestly. I also am an evangelical Christian (to use a loaded, ill-defined term) with an (additional) academic background in theology. I guess I would fit your description of the scientist who does believe in a God. So I have no problem with your suggestion that science and Scripture might converge on "God" as the "final answer to the Theory of Everything", and I heartily endorse your suggestion that science can give us a greater understanding of God. Indeed, I teach my students to think that way.
    The problem I have is that you portray scientists as neutral pursuers and purveyers of knowledge. They aren't. It turns out (speaking philosophically here) that everyone has a prior notion of the answer to the "does God exist?" question. This is why the question has been and continues to be unresolved philosophically. Our prior judgment on that question entirely colors our judgment as to what "counts" as proof of God's existence. It's a vicious circle, and philosophers have been unable to untangle it.

    Scientists are no exception to the rule, and it comes out in all sorts of ways. For instance, take Richard Dawkins [], chair of the "Public Understanding of Science" at Oxford. He has written extensively promoting evolutionary thought. So far, a seemingly neutral scientific question, right? But his books contain not only an scientific defense of evolution, but also several defamatory comments about Christianity. It turns out that he integrates his scientific worldview with his atheistic worldview, and uses his position to promote [] both simultaneously. And so it goes in the world at large. No man is a neutral player on the "God question"; no evidence is ever evaluated without a priori judgments as to how much proof is enough proof. That is where "faith" comes in. For careful thinkers, Faith is not a substitute for evidence. Instead, it is a willingness to evaluate a certain amount of evidence in favor of God's existence, over agains

  • by Barlo_Mung_42 (411228) on Monday February 09, 2004 @10:24PM (#8233500) Homepage
    I always like this question and I think Descartes' answer is a cop out.
    In truth I can't. He said "I think therefore I am" but when you read his whole argument you see that it goes in a circle.
    The best I can do is say that it doesn't matter. I do think. The fact that I think may not mean that I exist (it could be your caffeine addled mind thinking I'm thinking). But it doesn't matter from my perspective. My only option is to go about my life assuming that I exist until I'm proven wrong. What is the alternative?

  • To develop on this a little, what if our current laws of nature are not fundamental but merely a phase? They could change in the future based on some larger circumstance outside our present sphere of perception. The fact that from our point of view the universe looks as if it is and has been behaving under a set of coherant rules may be merely a coincidence. All our so-called natural laws could simply go away, leaving formless, meaningless chaos. But this is a theme fairly commonly explored in science fiction.

    Fortunately, in my humble opinion, the formless, meaningless chaos must be truly infinite, and so 'contain' an infinite number of sets of coherent systems. Any of these systems including ours will be finite [] by definition.
  • by JumperCable (673155) on Tuesday February 10, 2004 @12:11AM (#8234194)
    Again there have been attempts to prove the existance of these particles, mainly involving mine shafts and a lot of water, and again there have been no conclusive results.

    This sounded too interesting to not look up:
    Mine Shafts and a lot of water []
    Organization running experiment []
  • Re:Theory. (Score:3, Interesting)

    by cybermace5 (446439) <> on Tuesday February 10, 2004 @12:29AM (#8234280) Homepage Journal
    Ah, so first you make a couple of claims that are based only on conjecture, one of which actually works against your claim; then you realize they are not convincing enough, so you close the argument by saying "And if you don't agree with this, you are ignorant?" Silly you, don't you realize the sun revolves around the earth? It's scientific fact. And the smallest possible particles are protons, neutrons, and electrons, all of which are indivisible? This gets back to the post that started this thread; you must not cling too tightly to what are thought as scientifically proven facts. If you do, soon you lose track of why you think a certain thing, and only focus on the fact that you do believe it.

    There's a little concept I came up with, called "The Theory of Evolution of The Theory of Evolution." It is possible to take the identical principles that evolutionists claim shaped living species, and apply them to the development of the theory itself. You take a stress; in this case, perhaps a desire to prove the concept of creation wrong, for whatever reasons. So you float a few arguments, look for examples that support your point. Some of these arguments and examples will be thrown out, or disproved, so you move to arguments that require more and more effort to throw out and disprove. Over many years, and across many researchers and scholars, a gradual building of knowledge is gathered. Bones are assembled, animals are conjectured from these bones, dating methods developed. And all the while, the theory itself is evolving: a certain nook in a fossil looks slightly different if the viewer assumes evolution is taking place. The more firmly set that theory becomes, the bolder the scientist can become in making assertions that are based on assumed evolutionary principles. Eventually, the theory itself is no longer subject to questioning. The words "probably" and "might have" become read as "definitely" and "did." Theories that were easy to disprove fell away, and the ones that survive are based on thousands of observations, each successively building upon the next with the assumption of evolution coloring how the results are perceived, and those results applied to future observations. At the end, you have evolved an entire system that is based on a single belief, but that belief has influenced so many successive observations that everything is taken as an item of proof. Unfortunately, you are no longer left with a simple way to prove the theory; all that is left is blind faith and name-calling, as you have shown here.
  • by Mt._Honkey (514673) on Tuesday February 10, 2004 @01:05AM (#8234524)
    Note: I am a physics undergrad with some galactic dynamics / astronomy / cosmology education.

    What if this is only a *very* good approximation for all normal purposes, and even for things as large as the solar system (in the same way that Newtonian mechanics is good enough for all earthly based stuff).

    What if gravity doesn't quite work this way at galactic scales?
    This is a possibility that is NOT being ignored by the astrophysics community. There have been several attempts (presumably like the one you reference, though I haven't checked it out) to modify gravity theories much like you say. Up close they predict the orbits of planets and such very well, but over longer distances they change the behavior of gravity as to match some of the observations. The problem with them thus far is that they fail to explain every observed system, such as galaxy interactions and clustering. They can only get some parts to work, not all. This doesn't imply, however, that there is no such theory, it is entierly possible that we haven't thought of it yet.

    Several decades ago, the Big Bang theory wasn't universaly accepted by the cosmology community. Another thoery, the Steady State Theory had about as big of a following. Over time though, holes and failed predictions started showing up, and they kept mounting and mounting, while the Big Bang theory kept matching new observational discoveries. It has been modified now and then (like by adding inflation), but the basic concept is still the same, and now it is thought to be true (or at least the general idea) by the vast majority of cosmologists. The mountain of observational evidence is impossible to ignore. The weaker theory has been weeded out, and the consistent one has thrived.

    Maybe a new theory of gravity or some other theory will come forth that explains the same thing that Dark Matter does, and maybe it will have correct predictions where dark matter fails. If that is the case then Dark Matter will be all but cast aside. It seems extremely unlikely though, since several entierly different sources have had the same predictions for dark matter / dark energy breakdowns. Observations of type Ia supernovae in distant galaxies gave the first major hints that the universe expansion is accelerating. It gave values for the relative amounts of dark matter and dark energy. A totaly unrelated observation (WMAP []) of something with no relationship to type Ia supernovae gave effectivly the same results. Big Bang Nucleosynthesis theory starts with very few premises and derives a the same ratios of various mass particles that WMAP and other more conventional observations show. It would take something truly extrodanry to overthrow this theory.

    But who knows? It can still happen. The community really is open to it, if a good theory comes forth, though they have gotten comfortable where they are.
  • One Word: (Score:4, Interesting)

    by Betelgeuse (35904) on Tuesday February 10, 2004 @01:05AM (#8234530) Homepage
    Or, an acronym, actually.

    MOND [] = Modified Newtonian Dynamics

    It's one of those theories that sounds totally crackpot when you first hear it (and, admittedly, has some problems), but many would argue that it's no weirder than a bunch of dark stuff that we know nothing about. The destain with which astronomers and physicists view MOND is quite surprising, since they are asking us to be believe that (something like) 95% of the matter in the universe is composed of some sort of weird, non-Baryonic particle (most people favor WIMPs over MaCHOs now-a-days).

    Anyway, just food for thought.
  • by Red Pointy Tail (127601) on Tuesday February 10, 2004 @01:32AM (#8234666)

    IMHO, the only way the idea of God can stand up to any rational scrutiny is to have it pared down to first principles, like a prime-mover of God or a necessary being, that is basically unprovable. Even science relies on the basis of first principles that we take for granted but are not provable (like induction, verifiability, falsifiability...). Consider Dawkins argument on why science is not a religion [] and you see him lapsing rather unscientifically on his conviction and intuition. The existence of God rests on a similar insight, something you either accept or you don't, based on your intuition. It is not that philosophers have not untangled it. It is fundamentally untangleable.

    I am an atheist, but that does not mean I would not be able to appreciate the position of other point of views. So why don't I accept science, but not religion? My reason is simply Occam's razor: do not make unnecessary assumptions. Given all these transcendental insights, I must draw the line on what I will believe (induction) and what I will not believe (unicorns, God). Induction and science further my knowledge of the world and is required for the world to function. As for God, to quote Laplace, 'I have no need for that assumption'. The world can get by merrily without assuming Him or Her. But not gravity. And as for the retort that God created gravity, I've no need for that assumption either. :)

    [ To cover bases: argument that God is the simplest assumption you can make about the world, is a misunderstanding of Occam's razor - which does not argue on simplicity, but on neccesity. Positing a God will still require the laws of gravity to be laid out. Is God a necessary being? The jury is out there! ]
  • by Dread_ed (260158) on Tuesday February 10, 2004 @02:39AM (#8234969) Homepage
    "My guess is because there is precious little left to explain, as most of our daily life has been easily described by science."

    I don't like to post in this kind of language but: WHAT THE FUCK WERE YOU THINKING WHEN YOU POSTED THIS?!?!?!?

    All of our scientific explanations are just a glossy finish over a gaping chasm of ignorance.

    If we truly understood our surrondings the scientific method would be irrelevant. Experiments would be unnecessary, we would know the outcomes before we started. Since we don't understand we fiddle with this and fiddle with that and observe the workings of the mystic algorythm and try to draw conclusions.

    We observe and infer about the very big and the very small and shamefully think ourselves the wiser. How contradictory that we constantly argue about how the world and humanity got here, and we haven't even progressed beyond the abilities of single celled organisms when it comes to organic chemistry. We don't even understand ourselves, physically, "psychologically," or spiritually.

    How is it that even a three year old can quickly surpass the limits of human knowledge with a single sylable mantra of "why?" Sit down with a monomanicaly inquisitive child sometime, and if you can overcome your frustration you will realize that the basis of that feeling is the irony and embarrasment of a child reminding you that your understanding is an illusion.

    In the future, when you start to think that mankind has made some vast and commendable stride in some field just think about a few things. First, think "How much do we truly know about the universe?" Then think, "If we knew everything about the universe, how different would our approach to this current subject be?" Apply this to new knowledge and discoveries, and to old. Meditate on it for awhile and maybe some of the ingrained human arogance will start to fall away.

    Sheesh man, even the article we are posting under is lamenting the uncertainty of our macrocosmic understanding. And people think that the "givens" in our realm of knowledge are any differnt? My bet is that EVERYTHING we think we understand is truly vastly different that we currently believe. Fortunately, time and history are on my side in this. If you look at the past timeline, just about everyone has been wrong so far...this is why the ancient Egyptians didn't have micropocessors. If you project the future timeline I think it will be more of the same.

    I find it sad that we are permeated by the mystery of our universe and yet we constantly seem to find ways to ignore the utter splendor and mystery of all things.

    But hey, who am I, right? Nobody. But, just maybe you can take someone else's word for it...

    The only true wisdom is in knowing you know nothing.

    Have a nice day, and try to remember that we live in an amazing, beautiful, mysterious playground, full of unknowns, unfathomables, and things that man was not meant to know (tm).

    What's the matter officer? I have obeyed all of your silly Earth laws!
  • Re:the economist? (Score:2, Interesting)

    by astroboscope (543876) <> on Tuesday February 10, 2004 @04:41AM (#8235442) Homepage
    The Economist is one of the most respected news magazines in the world. ... all of their coverage, including policitcs and science, is superb.

    I'd hardly call this article superb. By focusing on a problem with clusters and ignoring independent evidence for dark energy from supernovae, problems with MOND, and expectations from particle physics of at least some dark(ish) matter, it seemed to be saying "The very foundations of science are shaking, and you heard it here first!". I'd call that sensationalism. Of course, I'm being sensationalist too and exaggerating a bit.

  • by jandersen (462034) on Tuesday February 10, 2004 @08:18AM (#8236153)
    The purpose of a scientific theory is to give the best - and simplest - explanation that fits the obsevations, within the limits of current knowledge. In this respect Ptolemaios'es theory was good: maths with equations, algebra, differential theory etc didn't exist, only simple geometry. He formulated a theory within this framework that actually fitted fairly well; and as it turned out, the reality wasn't radically different. Planets do (almost) move on cirles, and seen from Earth, they do indeed (almost) move on epicycles.

    As for dark matter - the evidence suggests that something holds the universe together, something we haven't been able to detect so far. Ie. there is some unexplained gravity (~ space-time curvature) in the universe; that gravity is equivalent with mass is a fundamental concept in modern physics. All in all, I'd say that the existence of dark matter is beyond reasonable doubt.

    As for the scientists that have their doubts - that's what a scientist get paid for: having doubts. Apart from that - there are also people with a scientific education, who never the less reject the evolution theory and believe the world was created in 6 times 24 hours. What is good science is not determined by whether there are some sceptics, but whether it stands up to continued scrutiny by large numbers of scientists.

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