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What If Dark Matter Really Doesn't Exist?
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.'"
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.
If something else is actually causing those effects, the whole theoretical edifice would come crashing down.
As it should.
-Colin
Much like a dog staring at a shiny object, I'm fascinated by this but I don't understand it.
Let me see, changing the process about how galaxy clusters (which are extremely complex phenomena) are LESS disturbing than bringing in multiple forms of unexplanied forms of basic substances and forces into our fundamental model of the universe?
This is the part I do not understand.
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It's a theory. Theories can be wrong.
Jedi don't stand a chance.
HAD
It will be interesting to see how scientists who have staked their entire careers upon the existence of dark matter would react to the discovery that it does not in fact exist. Ideally an invalid theory is dropped, and a new, more "correct" theory is created. However, I have a feeling that a lot of people have invested too much time and effort into dark matter to let it go without some serious evidence.
My patience is infinite, my time is not.
You can't see it, anyway. It's too dark!
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.
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...
Pretty widgets? What pretty widgets?
...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.
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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.
We don't understand something fully? Wow... that's about as brilliant as deciding to cut my sandwich in triangles instead of in squares.
The truth is this. We have such a little understanding of actually governing laws that we can't begin to fathom it. However, that doesn't stop us in progression to learning. Just because this theory might not be right (and probably isn't) doesn't mean we are any less an idiotic species. We've been working on these theories for many millenia. One of them turning out to be wrong won't be a surprise... it's a probability. Without the wrong hypthosesis, we can never stumble onto the correct ones. Its Edison's, "Every time I fail, I know one more way how to NOT build it" idea.
Since we know Dark Suckers aren't useless, dark matter must exist.
Q.E.D.
"What If Dark Matter Really Doesn't Exist?"
Then wait for Star Trek to invent a new theory.
"Derp de derp."
...then 99.9999999% of the world won't notice. But it will be on CNN anyways.
You're right, I wouldn't steal a car. But if it were possible, I sure as hell would download one!
I have read half of this man's short book "a Brief History of Time", and he did not claim, but discussed a theoretical possibility that if this energy pushing the universe outward is moving at a decreasing speed, the trend would eventually reverse and the universe would begin to collapse. As of right now, researchers have determined that the universe is still expanding, if my memory serves me correctly.
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All of this sounds like the core setting of a new Final Fantasy game. I can see it now: the effeminate antagonist finds a way to control this dark matter/energy and threathens to destroy the world, then the spiked-hair, badly dressed hero comes to destroy that antagonist, who happens to be his former friend. Insanity, stupid names and buxon girls ensue.
Wasn't the missing mass accounted for with Dyson spheres?
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.
Table-ized A.I.
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.
"Give orange me give eat orange me eat orange give me eat orange give me you." -Nim Chimpsky
Dark matter had better exist- otherwise, I've wasted a hell of a lot of money on that dark matter damage insurance I bought a couple years back...
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We _ARE_ flying all over the place, so is the sun.. If Dark Energy exists it's probably somewhere in the shredded Enron papers..
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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...
'Sensible' is a curse word.
It's more than that. If Dark Matter doesn't exist, we will be forced to re-examine more than just our current picture of the universe. Galactic Rotation curves, velocity dispersions of galaxy clusters, the flatness of the universe implied by the CMB, type Ia supernovae data, as well as other distance indicators, all imply that the parameter "Omega_mass" (the mass density of the universe divided by the critical density) is about 0.3. If there is no "dark matter", we don't know how to explain this number. Baryons, i.e. stars, planets, gas, etc., make up only an "Omega" of 0.044 +/- 0.009. This constraint is from Big Bang Nucleosynthesis and is very strong. Although there are plenty of open questions about dark matter, it seems to me (just an astrophysics grad student) that there is an overwhelming amount of evidence for not only dark matter, but the model of "cold" dark matter as well. None of the alternatives can explain even half of what Dark Matter can, including modifying gravity. Plus, Dark Matter is consistent with GR, the big bang, and everything else we hold dear about physics and astronomy, whereas other theories don't. Just my two cents... Ethan
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 /.
Dark Matter will be taught to school children as the Aether of 21st century science.
...but theories generally aren't wrong. I think you mean a hypothesis, right ?
There's nothing wrong with a kludge, aesthetics aside. Every evolving line of discovery needs it's necessarily flimsy connectors of reason. It's only when we allow our pride/ignorance/greed etc. to deny that the kludge is just a kludge: this is where mistakes are made, and thus we fail to evolve.
The fact that the universe may not boil down to 3 categories of matter is not earth-shattering. If we discover something to the contrary we must look at it plainly.
The problem with kludges is that it's only a kludge when it's a theory that is revealed to be inherently flawed. Before this realisation, it's just the best theory we have at our disposal. Just because something is revealed to be inelegant doesn't mean it wasn't serviceable, or simply the limit of our reason at the time it was presented.
This wasn't just plain terrible, this was fancy terrible. This was terrible with raisins in it. - Dorothy Parker
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.
This is not a sig.
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.
Actually, most Physicists don't believe in God.
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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.
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If it had been in the New York Times, I'd have bitched about the registration instead. Think of this as a change of pace.
...If we could find a "purer" form of moving energy,..
Oh great, Thanks. Now all I can hear in my head is Spock saying "pure energy" over and over again.
Proverbs 21:19
then whoever said "always bet on black" lost some serious cash
Yeah.. there were invisible dog/bears and aliens with little zap guns and stuff. Had to put a trademark Hoffman Institute smack down on em too.
Stupid Alternity getting cancelled... First Dark Sun, then Dark Matter... screw this, I'm going to go play Cyberball.
So "The Economist" is running an article about how a theoretical framework in Physics may come crashing down?
Can it be that Economic theories have proven so certain and stable over the centuries there just isn't much to write about the possibility of an economic theory being subject to re-thinking?
All sigs should be as funny as possible, but no funnier.
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.
The parent is either the most insightful thing ever posted, or the biggest bunch of doubletalk crap I've ever read.
Would someone please translate this and tell me what the hell is being said?
Overrated / Underrated : Moderation
well, let's see here. 4% of postulated matter in the universe is known to exist. 96% of postulated matter in the universe is NOT known to exist. that's a fine fudge factor to have in a test, and might explain where budget figures come from in the government :-D
:-D
it certainly explains where a lot of my assignments come from at work, lol
if this is supposed to be a new economy, how come they still want my old fashioned money?
At the risk of feeding the trolls...
No, Relativity (neither the Special nor General theory) says that "everything is relative". Special Relativity says that inertial motion is relative in flat spacetime (i.e. in the absence of gravity). This is another way of saying that all inertial coordinate reference frames are equivalent. (Special Relativity says more than that, namely that light propagates at the constant speed 'c' independent of the motion of its source. This is what separates Special Relativity from Galilean Relativity.) General Relativity says that *locally*, accelerated motion is equivalent to inertial motion in a gravitational field. (The "locally" part accounts for the fact that the gravitational field lines are not parallel, but converge on the gravitational source.)
What this boils down to is that circular motion is accelerated motion, not inertial motion, and is not simply relative, and spacetime is not flat surrounding bodies that planets orbit. So no, Relativity does not validate the epicycles theory.
Looks like we're gonna have to stick some moldy olives in a freshly-killed goat and bury it in the sand for 48 weeks. Then we dig it up and soak it in the blood of a 3rd-born virgin girl. If the goat's eyes turn pink, God will give Lyndon Larouche syphilis, if they turn purple, dark matter exists. It's not the cleanest proof, but I say we give it a shot.
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).
I've always wondered how the scientific community would react if someone actually discovered a grand unified theory that works unbelievably well in every concievable respect, but is also unbelievably kludgey?
Basically: what if God had to debug and patch the universe over and over? What if it really, really is a big fat blob of kludgey spaghetti code?
How many scientists would accept that? Considering the value that scientists place on elegance, I don't think many would. In fact, I don't know if I would, myself!
Accountability on the heads of the powerful.
Power in the hands of the accountable.
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?
"Freedom means freedom for everybody" -- Dick Cheney
I would be thrilled to see such a widely accepted theory overturned! It needn't be dark matter, it could be anything. It would be great to witness a moment where pursuit of the best explanation triumphs over all the ego, dogmatism and self-interest rife the academic world. If those who are "wrong" can brush off their dented self-esteem and carry on then it will be a great day.
The crackpots who claim that "the establishment" never listens to new ideas will be left with several fewer legs to stand on.
(Incidentally, I don't blame scientists who have strong feelings in favour of the theories they have developed or are familiar with. It's perfectly natural, and there's not a lot we can do about it other then try to be as grown-up as possible.)
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.
First claim: Analyses of the WMAP data on the cosmic microwave background (CMB) show correlations with galaxy clusters that indicate the official analyses of the data are wrong. I find this highly unlikely. First, the effect of the hot gas in those galaxy clusters on the CMB is well known - it is called the Sunyaev-Zeldovich effect and perturbs the spectrum in a well-known way. Second, the official fits to the WMAP data use a consensus cosmology model with about 12 free parameters to fit a dataset of more than a hundred points... beautifully. Third, the consensus cosmology itself has been built up out of a huge array of other observations (supernova distances; Big Bang nucleosynthesis; the "weighing" of galaxies and galaxy clusters; the age-dating of globular clusters), all of which were pointing to the existence of dark matter (even within our own Galaxy!) long before WMAP was even launched. Fourth, modern theories of particle physics also give us good reason to expect the existence of dark matter particles, independent of any astronomical observations whatsoever. So WMAP has simply been the final nail in the coffin, and anyone who wants to overturn dark matter and dark energy has a great deal of additional work ahead of them.
Second claim: Measurements of the masses (actually, the luminosities and temperatures) of high-redshift galaxy clusters indicate a high fraction of baryonic mass, removing one of the justifications for positing dark matter. This finding is even more fishy-sounding. To understand this, realize that the group in question has deliberately chosen the most-distant and therefore hardest-to-study clusters to study, and adopted temperature-mass relationships that are calibrated in the local universe (and may not apply at these great distances) in order to find that their sample differs from the standard model predictions. Without even bothering to list all the ways in which they might be wrong, let me simply state that even if they are right there is a lot of independent support for the dark matter + dark energy picture that neither of these groups is addressing.
Rather than distract yourself by trying to figure out why the carefully constructed consensus cosmology might be wrong, then, I think it is more useful to examine the remarkable ways in which it has been proven right in the last few years. Altogether it is truly a wonder of the modern world - even if it may at some point be shown inadequate to the universe we live in.
-renard
Same idea here. Kepler's laws reduced a nightmarish tangle of mathematics to a three line "program", if you will. Out current model of how various things in our universe interact requires a degree in cosmology to fully grasp, and a PhD to do any meaningful work in. Imagine reducing that to one chapter of a freshman-level physics or astronomy course.
Einstein's Special and General Relativity, Maxwell's Equations, and Schrodinger's Equation are all expressed in a few lines of equations. But you need extensive math and physics training to relate them to the familiar world around us. Simple doesn't mean easy. Theoretical physicists are already busily looking for theoretical formulations in which dark matter and dark energy arise naturally, rather than as a kluge. Of course, if the original observations turn out to have been misinterpreted, they may be wasting their time.
Relativity holds between non-accelerating frames of reference. In such frames, one can not perform a local experiment to determine one's velocity absolute velocity. One can only define a reference frame and perform an experiment to determine one's velocity relative to that frame. Hence, the concept is called relativity.
Orbital motion results from acceleration caused by gravity. One can measure acceleration locally at any point within the influence of the gravitational field. Thus, symmetry between difference frames of reference are broken, and a natural "center" is defined as one of the points where one experiences no acceleration. In reality, you never have a true "center" in a multibodied system such as our solar system. However, the Sun is so massive that we can say, to reasonable accuracy, that the center of our solar system is approximately at the position of the sun.
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.
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.
Only a "scientist" who believes that a random sample omitting him must be biased against a god in which he believes would believe in such a god.
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As the parent points out, not everything with regard to position and motion is described by Einstein's Special Theory of Relativity. Only constant non-accelerated motion. A frame of reference which obeys this constraint is termed an "Inertial Reference Frame."
A common misconception, with an easy to learn answer.
This answer can then be applied to say that Einstein does not support Ptolemy, as Ptolemy's theory describes motion that does change. In rotating even at a constant rate around a fixed point, the orthogonal ("at right angles") components of the motion (e.g. East-West versus North-South) each oscillate between maximum and minimum values. That's the acceleration. The total magnitude of this acceleration may be constant, but its direction isn't. The reason for it in the case of the planets wasn't even apparent in Kepler's time. It took Newton to find laws which approximately described this effect (his laws of motion and of universal gravitation) and this model was further refined by Einstein with General Relativity published the year after the Special Theory.
The fact is that Kepler had no more sophisticated ideas of the mechanism underlying orbital motion than did Ptolemy. Kepler is better than Ptolemy on the grounds of superficial description of the motion alone.
This is far from an indictment of Kepler, but speaks rather to Kepler's imagination, trust to observation (notably from the perspective of history, Tycho Brahe's data), and willingness to challenge the accepted theory, which authority at the time was backed up by armies and courts of Inquisition.
The late Richard P. Feynman's little treatise "The Character of Physical Law" (MIT Press) is the best introduction to this history, and features Feynman's extrodinarily hilarious expository style, as well as his legendary insistance on accuracy with regard to interpretations of both the various physical theories, and their canonical histories.
I wish to God that Feynman were still with us. Goodbye, Dick, we hardly knew you.
... but I play one on TV.
So:
"If dark matter doesn't exist, there will be a lot of erasers sold to the astrophysics department of your friendly neighbourhood university"
DG
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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.
This line no sig
Preprint archives to the rescue: Problems with the Current Cosmological Paradigm, a talk recently given by Tom Shanks. Maybe a real cosmologist can tell us how much authority Tom Shanks has in the international community, and whether his view is taken seriously or that it is sceptically set aside as yet another attempt to kick the establishment.
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.
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At least they have observations. And astronomers in general are a genial bunch. Anyone who finds (and this is the most likely case) that there is dark matter, but not nearly enough of it, is assured of nothing more that a few years of ostracism before enough new scientists come into the field who don't have the same emotional investment in dark matter theories.
Compare that to the potential fate of the poor wretch who disproves the Riemann Hypothesis, and undoes almost all progress in pure mathematics since the beginning of the 20th century. I know for a fact that there is a basement in Cambridge where this person will live out their days being forced to review unsolicited "proofs" of duplicating the cube, trisecting the angle, and squaring the circle.
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E_NOSIG
Dark matter was postulated because galaxies spin at the wrong rate for the amount of observable matter they contain. That's not some obscure thing having to do with background radiation or age of the universe, it's a pretty concrete problem that can't be easily be explained away by reinterpreting measurements.
The existence of dark matter has also been inferred from other observations (see above link), but even if that observation doesn't hold up, the odd behavior of galaxies still remains.
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.
Don't blame me, I voted for Durga.
The author of the article seems to be an idiot. People who study dark matter and (especially) dark energy do this because they think that our theories are not sufficient to explain what is observed. They are trying to gather enough clues to prove that current theories are wrong and to learn how things actually work.
I don't think this is a very fair comparison to make. Ptolemy's theories were a kludge. They were accepted as fact by many people, accepted by the church as the "official" version of how God had designed all things, and anyone who contradicted it would be risking execution and ridecule.
Even Galileo, who'd agreed quite strongly with the sun-centered Copernicus theories, had to promote it as merely a method to more effectively predict where planets would be rather than an explanation of how things actually worked.
Of course you could apply Copernican theories and they'd explain where planets moved quite well, but everyone already "knew" that the real system that God had made was of transparent spheres with more spheres attached and glowing lights spinning around on them. Trying to prove or demonstrate anything otherwise was ludicrous, and trying to prove that it was correct was even sillier because it was plainly obvious that "this was how God had created the world".
Modern theories of dark matter aren't nearly the same -- everyone knows that it only takes one contradiction to be found, and a theory will die. (in terms of scientific acceptance, at least). Although dark matter is a theory that's widely accepted as being likely, it's not yet accepted as fact and anyone who does fully accept it as such wouldn't go down well amongst others. This is why, right now, there are people out there that are trying to think of ways to prove that dark matter does exist, designing experiments and observations, and carrying them out.
The fact that millions of dollars get allocated to experiments like this, just to try and prove a theory that's already thought to be likely, should demonstrate how important it's considered to prove theories correct before relying on them too seriously. It should also demonstrate why it's a different environment to that which was dictated, defined and ruled over by the church. Even the thought of such actions would have been silly in during the time that the church so heavily dictated people's beliefs.
Dark matter is simply a theory. If Newtonian mechanics is correct (we don't even need to worry about relativistic corrections here), and the laws of physics are the same everywhere (a fundamental principle of science), then there is a lot more matter than we can see (i.e., that is glowing). We can tell this by looking at the rotation curves of galaxies, and even the behavior of clusters of galaxies. There must be a lot of matter there that we can't see, if Newtonian mechanics is a reasonable approximation. It's called dark matter.
Dark matter in and of itself is really not a revolutionary concept. In most wavelengths of light, for instance, you qualify as dark matter (you emit no visible light, although you do emit infrared radiation, so you're not completely dark matter). Look around your room or office. How many things emit electromagnetic radiation. Your computer and your monitor, sure. Your light fixtures and other electronic equipment either emit light or heat. But most of the stuff around you emits internal radiation. A pen is dark matter. A cup of dark matter (once its reached thermal equilibrium, of course). That book is dark matter. The concept of dark matter is not only not revolutionary and mind-blowing, it's downright mundane. Given the survey of stuff in your office/room, is it any surprise that most of the junk in the Universe doesn't emit radiation on its own?
When we start getting into the weird realms of dark matter is when we start applying the Standard Model and find out that it doesn't seem like all that dark matter can be explained by baryonic matter (basically, protons and neutrons -- what we would normally consider matter). That's where things start getting sketchy and speculative, although we have some theories about what might be responsible. But dark matter in and of itself is simply a consequence of the mediocrity principle (that is, the laws of physics operate elsewhere just the same as they do here) and Newtonian gravitation.
All the popular media's fascination with dark matter is only so much hoopla.
Let me clarify what I mean by that. As I see it, one of the main goals of science is satisfying our curiousity. The mission of science (or one of the missions to be precise) is to learn about nature so that everyone who is eager to know why things are the way they are can learn and understand.
However, the way the physical science has been progressing lately, the more we "learn" about the universe, the farther we are from our goal. Before 20th century, the scientific knowledge could be explained to anyone, you didn't need any complex formulas, almost any law of physics could be explained in simple terms. People indeed could learn and understand.
Now look at what science has become. In order to understand field theory, or cosmology, students study for 10 years in school, then 4 years in college, then several more years in grad. school and only then they start getting a grasp at what this whole thing is, and start to understand how it all works.
It is practically impossible now for anyone except a very small group of very specialized people to understand the recent theories in physics. We seem to discover new things every day but noone understands them except a few chosen.
I remember that Einstein used to say in the beginning of the 20th century that in the 21st century special relativity will seem just as obvious and normal to every kid as steam engine was to kids back then. Yet today, I am a graduate student in physics, and I cannot claim to really understand special relativity, I only understand how to use the formulas to predict how things behave.
I think the way things stand now, science is failing one of its most important missions. We no longer understand our universe. All we do is learn how to predict the behaivor of things with greater and greater precision, which is very useful and all, but we are getting further and further from _understanding_ the universe which really is the inpiration of science.
Human history becomes more and more a race between education and catastrophe.
H.G. Wells, "The Outline of History"
Dark Energy on the other hand is the equivalent of Einstein's Universal Constant. For some unknown reason, the universe is accelerating in its expansion (counteracting the gravity that SHOULD be causing it to slow down), instead of slowing down (and eventually ending in a Big Crunch) as we previously had thought.
Just FYI.I know I'll get some flame mail for this idea, but I think God is humanity's longest living kludge out there. 95% of all people accept God to be true, but have we found out either way? No. We can only believe and hope it's true.
There is no decent explaination... emergent intelligence...
it may explain why things can be completely random at a quantum mechanical level, but balance out in larger systems...
It's called the Central Limit Theorem and Superposition. You've got billions of identical particles (low variance), and a huge sample size at macroscopic scales, thus your mean (likelyhood of "expected" things, the precision, and thus "intelligence" in systems) will be pointy as a pin.
I am 100% dead serious.
Perhaps maybe your REAL question is "why are quarks so damned sticky, protons so stable, and h_bar conveniently small?" because that encapsulates the huge gap between the quantum world and the stable world we live in.
THIS THING CAN TURN ON A DIME, MACROSSZERO STYLE ALSO FUCK BETA, ~NYORON
The Economist is one of the most respected news magazines in the world. It's merely not well known in the United States. They focus on economics-related news, but all of their coverage, including policitcs and science, is superb.
I second the comment from "pclminion"; the parent comment should not have been modded "insightful". All it demonstrates is ignorance of what it's talking about.
"Dark Matter" and "Dark Energy" are convenient labels to talk about unexpected observations. Either dark matter and dark energy exist or gravity and space-time don't behave the way we think they do.
What's important is that we have a way to talk about unexpected observations. We observe stronger than expected gravity and it makes sense to talk about that in terms of matter which does not otherwise interact. If it were interacting, we'd have seen it. Perhaps it's really matter in an adjacent universe. But that's as unreal and inacessible as dark matter.
Similarly, dark energy is a way to talk about the acceleration of the expansion of the Universe. So far, it's the simplest explanation which explains the current observations. Perhpas the real explanation is that the gravitational constant, G, varies over time. But without a mechanism to understand how and why G changes, it's not a very fruitful path.
Physicists talk about new phenenoma in terms of familiar objects. It allows them to organize the observations and try to fit them into a well understood framework. Eventually, if enough observations are made which can not be fit into the framework, a new framework is necessary.
Science is provisional.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
There is always, and will always be, a difference between the technical understanding of a phenomenon and the folk model understand of same. Unless (and if) we ever achieve planet-wide educational parity that may always be the case.
That said, I think some of the complexity we see in physics and other fields is self-inflicted, by necessity. We theorize on what might be causing certain events. Obviously, since we don't understand everything, fitting particularly ill-understood events into our current perspective can get messy. But that's the best we can do until our understanding has improved. In the meantime, if you want the best explanation available, you need to be on board with the current theories, publications, etc.
All of this doesn't mean science is failing. It just means we have more knowledge now and the bar is higher in terms of establishing a baseline of working knowledge.
Please mod this post only if you think others should/n't read this. I have enough ego^H^H^Hkarma. Thanks!
Evolution is falsifiable. All it takes is a human skeleton in a rock layer more than a few million years old....
Evolution (that organisms change with time as a result of alterations in genotype) is a simple and elegant fact that anyone can observe by picking up rocks and looking at the fossils. Its far stronger as a fact than atomic theory, as no-one really understands quantum mechanics.
Alexander Shulgin's writeup of the "Infinitely Old Universe" idea (in place of the Big Bang) seems more poignant than ever....
Listen to what I say, not what I mean...
> 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?)
Sheesh, evil *and* a jerk. -- Jade
Natural selection is obvious, and, sorry, you're wrong about evolution. Evolution has been demonstrated repeatedly in both the lab and in the field. New species have been created in the lab and observ ed to evolve in the field. What definitin of evolution are you using? It is not necessary to watch the life of a planet from start to finish to demonstrate evolution any more than it is necessary to watch every movie ever made, or even watch one all the way through, to know that movies exist
Some mornings it's hardly worth chewing through the restraints to get out of bed.
You take the facts, come up with a working theory that fits the facts. As more facts come in, you continue to test your theory against the facts. When too many anomolies show up, it's time to come up with a new theory.
And there is nothing wrong with that. Is Newtonian physics worthless just because it couldn't explain everything? No, but we had to be willing to look for new answers when we began to see evidence that the old answers didn't work for everything we observe. It's called a paradigm shift.
Check out Thomas Kuhn's Structure of Scientific Revolutions
** The opinions expressed here are my own, and do not reflect those of my employers - past, present, or future**
Correct me if I am wrong, but I thought scientists had already created ( in sub-microscopic amounts ) anti-matter in laboratories, and measured it's presence.
Or is this "dark matter" something different than anti-matter?
Someone please explain, the article is high on fluff but low on details.
I'm reading the presentation at the moment, but my math's a bit rusty (20 years rusty, if truth be told), so I can't comment on it.
oh brave new world, that has such people in it!
Hello readers from the future!
You are probably reading these comments trying to get a feel for all of the silly things we believed in way back here in the 2000's and boy you've hit a gold mine with this "web site" (pardon the archaic terminology, and for the record a "gold mine" was a place where people dug Gold out of the ground. Gold was worth a lot because it was a rare metal that couldn't be created artificially very economically).
I just wanted to point out that these views certainly aren't representative of the educated among us, so please don't think we're all stuck on magical explanations for things that seem pretty obvious.
Anyways, hope you're all doing well.
However in this case your comment is only slightly wrong and therefore I have some hope that my reply might be a useful contribution.
You are correct that mathematical proofs are based on axioms. However there is still a crucial difference between a mathematical proof and a scientific theory. A mathematical proof is an absolute certainty. Note that I am not claiming that the underlying axioms are certain. I am only claiming that the proof itself is certain.
To put it another way, mathematicians are never certain about their underlying axioms but they are absolutely certain that if those axioms hold then the result stated in the proof also holds. It's kind of like a building with indestructible walls but no foundation.
Scientific theory is a whole different kettle of fish. You cannot prove a scientific theory with absolute certainty. In fact it is not even clear to me how one can define certainty within the framework of the scientific method. You never have any guarantee in science that future observations will be consistent with past observations.
In science you can prove a theory in the sense of preponderance of the evidence. You can even sometimes prove a theory beyond all reasonable doubt. But there is no way to eliminate the unreasonable doubts. Any endeavour based on empirical observation suffers from the fundamental limitation that you can never be sure of the next observation.
Finally, regarding 1+1=2, the foundational proof of this fact using the standard propositional axioms of mathematics really does require 362 pages. You can see the 362nd page on the bottom half of this Russell's paradox site.
Or had he just invented the Fourier series a millenium and a half too soon? More seriously, I would be interested to know if the theory of epicycles was computationally useful - did it allow the ancients to predict planetary positions for considerable periods in advance. Did they do this? If so, the theory can hardly be said to be "wrong" anymore than Newtons Laws of Motion can be said to be wrong.
Squirrel!
Not laughable, and still usefull, even if it is 'wrong.' It is still 'right' in most circumstances, and we know what those circumstances are. We know when to use it as a good enough approximation, and when we need to use more accurate theories.
Theories can never be proved. We will never fully understand the universe. We may develop theories that accurately predict every phenomenon, then the next day, something new could come along and show us we were wrong.
What is important is for scientists to fully understand that theories are always merely theories, not facts.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
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.
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.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
"Sure, one can argue that if two theories are functionally equivalent, there's no downside to taking the simpler one. But has anyone demontrated this logically or mathematically?"
It's really a postulate, an unprovable given. If the 2 theories are really functionally equivalent you must accept the simpler. The more complex one only wins if it can explain behaviour that the simple one can't. Then they aren't really equivalent, are they?
Assume for the moment that Einstein's physics and Newton's physics are functionally equivalent. Einstein's is more complex. If both came out in Newton's time, Einstein's would have to be rejected. Einstein's explains many things that Newton's doesn't - but back then they didn't realize that those things needed explaining. The only thing that could be pointed to then that Newton's didn't capture is slight misprediction of the orbit of Mercury. I'm not sure they could even measure it's orbit accurately enough to detect the misprediction back then. Not really good enough for Einstein to be percieved as more than a crank.
As time goes on more and more evidence accumulates that Einstein can explain and Newton can't. They become less and less equivalent.
-- your Web browser is Ronald Reagan
Let's say our limited perspective from our solar system were somehow enhanced by a telescope/sensor at a neighboring solar system. Wouldn't this give us a much more accurate map of the universe than our current narrow view? For all we know most of the matter might not be visible because something is standing between us and it. The very fabric of space gets distorted by the weak gravitational field of our small star and each and every bit of matter floating around out there and we believe that larger gravitational forces exist, like black holes. If we can't even completely understand how and why our star warps the fabric of space how can we expect to KNOW the universe and all the matter contained within it?
We don't understand the laws of this universe. We've barely been able to explain it with simple mathematics. The universe, for all we know, might require higher mathematics than the human brain can easily comprehend. And what if there are other universes? But what do I know, I'm just one small voice in this titanic harmony-challenged choir. I'm sure one day someone with a lot of money will figure it out and tell all of us about it in an infomercial late at night on TV.
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.
Robert
They are all made-up, most likely by someone with Schizotypal syndrome.
Help fight continental drift.
1) Pascal's wager doesn't work - lots of religions make countervailing or contrary claims to being correct. The question that most people have to decide is not whether to have faith in anything or not, but whether to believe in Christanity or Hinduism or Judaism or Islam or... Many of these choices are exclusive or contradictory, so believing in something won't necessarily save you - only believing in the right thing will. In addition, believing in something excludes options from the here and now - if you hold a religious belief, you must act consistently with it, excluding some possible actions that might benefit you. Pascal's Wager is not cost-free, and since its benefits are unclear (if all beliefs lead to the same place, Pascal's wager holds; if some beliefs lead to Hell (or some other bad place) then the value of choice may be much smaller and on the order or the cost of choosing and the opportunity costs of actions you cannot do), it isn't really a very good argument for religious belief.
2) Science and religion are not exclusive unless one forces them to be. Science takes a pragmatic view of the world - what effects we can observe or measure are those of consequence to science. The immeasureable is not science's purview. Religious beliefs ask different, perhaps broader questions: What are we doing here? What do we do with our lives? How does everything work? Science can be considered a subset of this. Multiple religious beliefs may be consistent with a physical phenomenon - the things that distinguish them exist in a place science can't get to and thus has no legitimate say in. The problems occur when religious and scientific claims occupy the same ground and are contrary. In this case, science usually wins because it can be tested, whereas religion depends upon claims that cannot be tested (but which can only be trusted).
In my opinion, it is not the "anti-religionists" who have betrayed us, but a subset of religionists. Religion and science have existed side by side for some time and were not considered inconsistent. In the last few hundred years, some religious folk have tried to "prove" their beliefs by misusing logic and science to their ends (creationism/intelligent design/creation science, for example). Trying to prove the unprovable only further hardens the demands of people for proof before they will believe, undercutting the faith; after all, if the people who claim to most strongly believe something require proof to believe in it, how much faith can they really have? There is also the bonus of trying to force people to have a faith whose value derives from chosen belief (thus destroying the object of belief for others). In addition, the likely purpose of the logical legerdemain (to compel others to behave as one would like) only serves to alienate those who would otherwise be quietly accepting of the faith of others. Vehement (and sometimes illogical) people who don't believe in religion probably come at least in part from this.
But since we showed up after the heavy lifting got done, what we're stuck with is building the simplest explanation that looks like it'll work trying it out for a while, and finding out that, no, it doesn't do the job either, and adding more complexity or precision to one of the edges of the model, or developing new tools that help with problems we didn't know how to solve earlier. The Greeks were starting pretty much from scratch, building ugly kluges like Epicycles to account for the times their simple theories failed. Kepler and Copernicus eventually straightened that stuff out to the point that Newton could start over with gravity and Newtonian physics, which gave you some simple ways to solve the problems for medium-sized objects. That turned out not to do a good enough job for bigger objects (like stars' gravity bending light) or really small objects (anything where quantum effects matter), but it was enough of a start for people like Einstein and all the 20th century cosmologists to kick out from.
The Universe still seems to be a really messy complicated place, full of division by zero (black holes), round-off errors (much of quantum effects), and more parts missing than the socks that vanished in the dryer. If you want to see farther than your companions, you're going to either have to find some giants' shoulders to stand on, or go sneak around under the feet of dwarves and steal a glance at the real plans.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
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.)
For that matter, what about the so-called alleged putative "Big Bang," huh? Doesn't "the beginning of Time" make your skin crawl? Keep tripping the Rift, phlogiston buffs!
``Tension, apprehension & dissension have begun!'' - Duffy Wyg&, in Alfred Bester's _The Demolished Man_
-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.
Well, it turns out that parent was responding to this:
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.
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
Human being (n.): A genetically human, genetically distinct, functioning organism.
74% .... The dark side of the force is always more seductive and apparently stronger ....
Well, if Dark Mmmmatter doesn't exist, we'll have to rethink gravity, won't we?
:-)
IMO (very humble indeed) the Dark Matter theory looks more like a shortcut, a quick patch than a solid sound theory. Yes, it fits the observed facts, but probably just because from how little we know right now, we can safely fill in the huge blanks with the right numbers. Those blanks are easy to be filled because they're totally unobservable.
I read something very interesting on gravity in deep space. A scientist who revised the rules of gravity so that the model worked without all this invisible stuff around. The amazing thing is that while this guy does exactly the same as dark matter believers - filling in blank spots until the model fits reality - he's not taken seriously at all.
While I as a non-scientist will just have to wait and see until someone explains it weally well in small words, I am betting 10 to 1 on a revision of the general theory of gravity.
Who's in?
I think, therefore I am...I think.
This thread misses an important point. Even though Ptolemy's theory was wrong, it was a lot closer to the truth than previous ideas like "the lights in the sky are gods with flashlights." The point is that even theories that are wrong add to our knowledge by providing a starting place for deeper inquiries.
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
I should know better than to argue evolution on Slashdot, but what the hey, I'll bite.
First, my field is MIS. Yes, I've read the posts about worthless MIS profs, and I'm probably one of them. You can reference my many GNU apps I've contributed to OSS. I've contributed patches to several OSS projects, most recently Spyce. I know assembly, C, C++, currently teach Java, python, and a few others. Yes, I've programmed several genetic algorithms for use in real situations. However, I was trained in the scientific method just like other scientists. Most PhDs are very much the same as far as science goes. But no, I'm not a specialist in evolution or biology. I should have been more clear.
I won't nitpick your post. Let me just talk about the mathematics of evolution. I may believe in God, but I am not against evolution. God and evolution are not mutually exclusive, and evolution may just be right. My post said that from a scientific perspective, evolution doesn't seem to hold weight with me.
The human body is a base-4 computer (A,G,C,T). Take one side of DNA, and you essentially have computer code. The human genome project suggests we have about 30,000 genes. While genes is not the same as bits (it's a collection of base-4 "bits", I'll use them for the mathematics.
To get to where we are now, we'd need at least 30,000 mutations (actually quite a bit more) that were useful enough to select over other mutations. If we assume an x percent successful mutation (quite liberal) rate, we'd need x^30,000 mutations.
The universe is believed to be about 13 billion years old. Thats 297648000 billion seconds, or y^17. How many mutations would be required per second to get to x^30,000? Statistically, I just don't see it.
Again, I'm not against evolution from a "God" perspective. I'm against it from a mathematics perspective. Just like any theory, it's useful because it allows us to model the world and understand at some level. I think evolution will be a great step to a more correct theory at some point.
I just get very bothered that people (even some scientists) think evolution is "truth", when science never proclaims to find truth. It's a *theory*.
Newton, Einstein, and others were all shown to be wrong in time, even though their theories were elegant and helped us do wonderful things (like go to the moon, fly, etc.). String theory right now is quite interesting, but it's probably not the final theory either.
(Let us know if someone needs to explain it to you.)
Sheesh, evil *and* a jerk. -- Jade
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.
I couldn't tell if you were experimenting with poor-man's cryogenics or looking for the orange sherbet.
Ok, so let's assume that there is only
The formula you're really looking for is 30,000/x.
Now, with the correct equation, even if we assume there is only
Please go back and revise your math. And try another approach, this one simply doesn't work.
You're a scientist. I'm 17.
That's so incredibly wrong, I don't even know where to begin. Fourier sequences are about transformation into the frequency domain. Epicycles are about imaginary circles.
This should be modded "funny"
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.
If we were ants living on a Rubik's cube, differential geometry would be a little more confusing.
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.
Hugh Ross is an "Old-Earth" Christian who argues that the universe itself gives evidence for design.
Michael Behe is the point-man for the Irreducible Complexity argument.
Alvin Plantinga (link found in first post) rejuventates a much older line of thought called the "Transcendence Argument".
Those will get you started; some other time, if you are interested, I can give you links and bibliography for the philosophical side of things. Gotta go teach!
Regards,
Jeff Cagle
Human being (n.): A genetically human, genetically distinct, functioning organism.