Cosmic Fuggedaboudit: Dark Matter May Not Exist At All

A once-improbable theory is challenged by a new, even less probable one

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ESA / Hubble / NASA

The dwarf galaxy NGC 5477

When the idea of dark matter first pushed its way into astronomers’ consciousness a few decades ago, the primary reaction was: “Seriously? There’s a mysterious, invisible substance out there, with a mass six or more times greater than that of the visible stars and galaxies, only we have no way of detecting it, but really, it’s there? OK then.” Or something like that, albeit in more formal scientific language.

These days, dark matter is a firmly established principle of cosmology; most of the questions now focus on how the stuff is distributed through the universe, and which of many possible subatomic particles it’s made of.

Most of the questions, but not all. Ever since the early 80’s, a competing theory has been struggling for acceptance. Known as MOND, for Modified Newtonian Dynamics, it posits that dark matter’s main effect — allowing galaxies to spin faster than they should — isn’t caused by extra stuff, but instead by a change in how gravity works under certain conditions.

(MORE: Telescope to Hunt For Missing 96% of the Universe)

That underdog theory has now gotten a boost: using MOND-based models, and assuming no dark matter whatever, astronomers have successfully predicted the orbital speeds of stars in 15 faint dwarf galaxies that hover around the nearby Andromeda spiral galaxy. MOND can already explain galaxies that spin like the Milky Way — not surprisingly, since the theory was invented to do just that. But this is its first test in galaxies that aren’t spinning as a whole, but whose individual stars are instead following their own random orbits. MOND predicted how fast those stars should be moving, and, says Stacy McGaugh of Case Western Reserve University, lead author of a paper on the predictions, “It’s spot-on.”

Whether this will change the minds of mainstream cosmologists about the existence of dark matter is another question entirely. McGaugh himself was completely dismissive about MOND when he first heard about it. “Who wants to waste their time hearing about that crap,” he recalls thinking when MOND’s creator, the Israeli astrophysicist Mordehai Milgrom, showed up to give a presentation many years ago. McGaugh went to listen anyway. His reaction afterward? “This is crazy talk.”

But maybe not. Gravity weakens rapidly the further you move from the attracting body — the Earth say. Milgrom’s idea is that at very low intensity, like out at the edges of galaxies, that weakening should slow. If that were true, the attraction produced by visible matter at those great distances would be greater than current estimates suggest — perhaps enough to allow the edges of galaxies to rotate unexpectedly fast, without the help of any invisible, unknown matter holding them together. The same phenomenon would allow galaxies in clusters to orbit one another other at surprisingly high speed without the distances among them steadily widening.

(MORE: Solved: How Cosmic rays Are Made)

This alone wouldn’t make MOND a competitor to conventional dark-matter theory, which explains those high speeds equally well. But the mainstream theory does have some shortcomings that MOND avoids. Conventional theory predicts, for example, that there should be thousands of small clumps of dark matter floating around in the so-called Local Group of galaxies, and that these clumps should have formed the seeds for thousands of dwarf galaxies. But in fact, the Local Group has only a few dozen dwarfs — at least, that anyone has found so far.

Numbers aside, the theory says that any dwarf galaxies we do see should have dense knots of dark matter at their cores. But as far as anyone can tell by carefully measuring the orbital speeds of individual stars, they don’t. MOND, on the other hand is agnostic on how many dwarf galaxies there should be; it’s fine with just a dozen. It’s also better than conventional dark-matter theory at explaining the mass-to-light relation in so-called low-surface-brightness galaxies, another class of objects that are dim, like dwarfs, but not especially small.

(MORE: Discovered: The Most Adorable Planet Yet)

That’s what eventually won McGaugh over. “I bothered to learn about MOND,” he says. “Many of the more vocal critics choose to remain willfully ignorant.”

But at least one subscriber to the mainstream theory who has taken a serious look at MOND remains unconvinced. “If MOND were purely a theory of modified gravity, that would be one thing,” says Avi Loeb, chair of the astronomy department at Harvard. But even MOND requires some sort of dark matter to explain such crucial phenomena as evolution of structure in the universe — why and how galaxies have been pulled into huge clusters, for example, rather than being smoothly distributed through space. MOND enthusiasts, he says, call on the gravity exerted by giant clouds of neutrinos — a type of fleet, lightweight elementary particle so ethereal that it could zip through a chunk of lead a trillion miles thick without even noticing – to accomplish that feat.

While neutrinos are known to exist, however, it’s not clear they can do what MOND supporters claim. Dark matter, by contrast, explains both cosmic structure and the behavior of individual galaxies in a much simpler way. “With [the extra factor of neutrinos], MOND loses its appeal,” says Loeb, “because it is no longer purely a modified theory of gravity.” For his money, that’s just too speculative.

That doesn’t make MOND crazy, though. As physicist Anthony Aguirre, of the University of California, Santa Cruz, wrote a few years ago, “MOND is out of the mainstream, but it is far from wacky.” That’s more than many astrophysicists would have said for dark matter a generation ago.

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124 comments
st3v3
st3v3

Before the big bang absolute nothing. Everyone imagines space expanding as a perfect closed balloon.  I imagine space expanding imperfectly like a wheel of swiss cheese. The areas they call dark matter are just the holes in the wheel of swiss cheese just areas of absolute nothing. Meaning there is enough mass in the universe because the universe isn't as big as they thought due to the holes of absolute nothing. Also they say they can see the dark matters gravity by the way it effects light. Well if light can only travel through space it would have to go around these holes causing the illusion of gravity. So just as a galaxy isn't a perfect solid ball of matter, having large areas of open space, the universe isn't a perfect ball of space, having large areas of absolute nothing. maybe?

Ugebig
Ugebig

Hi, I am from South Africa and I have a theory about why the universe is expanding and accelerating. I don't really want to blurt it out on this blog, I'd rather publish something so that somebody else doesn't steal my discovery. It is very simple and I am driving my wife mad because she simply can't grasp it. We are so blinded from the trees that we cannot see the forest. I'm not a scholar of quantum physics, nor do I have any qualifications, I am a builder, a jack of all trades and master of one - the one that disproves dark matter. They all dance around and suppose, but the secret sits on the OUTSIDE and knows...
can anybody direct me to a place where I can publish something?


captmurphysealab
captmurphysealab

As a pure novice, I have never liked dark matter. It smacked of being deus ex machina. I think the fact that we don't properly understand gravity is a far more logical and likely case than some mysterious unseen, (but more importantly) unprecedented stuff floating around that happens to solve all of the cosmological problems we have encountered.

RickGillespie
RickGillespie

I have a short paper on ResearchGate.net  that goes over an error in the interpretation of a galactic speed limit of the velocity of the speed of light. (https://www.researchgate.net/publication/236212521_There_is_a_Fundamental_Error_in_Limiting_Travel_to_c) And even though I agree that e=mc2 has been proven, I do not believe "c" should be read as a velocity as opposed to the transformation that is described which is actually an acceleration.  So the real problem is now taking that to the cosmic level of E=Mc2 that implies there was just one transformation of all Energy to Mass at the Big Bang. e=mc2 is a transformation that is going on in both ways all across the universe. Stars are created and black holes are converting mass back to energy.

RoccoJohnson
RoccoJohnson

These things never cease to convince me how closed-minded the scientific community can be. I'm making no statement about a particular position regarding black hole theory or any other cosmological or scientific position, other than to say that far too many of these researchers take their entrenched positions and defend them to the death, without sincere consideration of other ideas. 

Stacy McGaugh's statement “Who wants to waste their time hearing about that crap” is a perfect example of this. When a researcher has built an entire career on one position their objectivity goes out the window, as they now have a vested interest in ensuring they're not wrong. 

Science without honesty has no integrity, and the respected scientific community lowers itself to the level of wacko pseudo science mongers.

tfdrumm
tfdrumm

When there is a massive shortage of something your theory absolutely needs to remain current--and you haven't thought of a theory to replace it, GO DARK!

mariodesouza.ufs
mariodesouza.ufs

Yes, Dark Matter does not exist at all. At the APS April 2013 meeting I'll present the paper: A new model without dark matter for the rotation of spiral galaxies which shows that Dark Matter does not exist in spiral galaxies.

RogerE.Clairborne
RogerE.Clairborne

 If you take the elements of differing solar systems as a whole, or maybe just their outer most polar charged layer, I suspect their net charge of either predominately negative elements or positive elements are opposites and thus lock each solar system in a positive to negative layered alignment; a trailing chain like formation similar to a string of beads being swung from one end in a circle over your head.

Now it has been noticed that sometimes the centers of Galaxies spin faster than the outer bands rotate around them. Yet the outer bands don’t seem to be pulled in and wrap around the hub like a string of beads would under such unsynchronized speeds. There are various energy wave theories proposed but I think the solution to this problem is much simpler and more logical than all that. First visualize the positive to negative chain of solar systems locked together on a single string. Next try to visualize if you will different layers of strings swinging side by side. Finally imagine the positive to negative net charged solar systems being lined up just enough with positive beads swinging next to repelling positive beads on the next string to keep each string and solar system from crashing into each other. If you add the net charges of clusters of these solar system string of beads together, eventually you will get even wider repelling gaps between clusters as the opposing net charges increase with the mass and density between clusters.

akbmuruhan
akbmuruhan

If space can exert gravity,  the gravitational force does not fade farther from celestial objects, because of the presence of space. This goes with what MOND expects.

middleroad
middleroad

i'm an engineer not a scientist and I have never believed in 'dark matter', 'time travel', 'wormholes', 'big bang', 'space/time continum' or any other of these 'theories'. While theories are very important, today's scientists are far too interested in getting their 'theories' published to the world that they perform very poor science, ignore variables and other procedural techniques that years ago would have gotten you tossed out of the scientific community. Its a battle for funding, so if you don't come up with an 'advancement' you get no more money, so by default you need to rig your experiment to 'conclude' something. As for dark matter, we don't even understand why gravity exists so pretending there is a 'magic' matter that exudes this force that we don't even understand is pretty silly. My answer, "we simply don't understand the system nor do we have tools capable of detecting what we need to detect in an accurate manner, so there is obviously something going on with planetary movement we don't understand." not very sexy but it covers the issue. why is it so hard today to admit you don't know?

NathanielGatewood
NathanielGatewood

I'm not a physicist (just an admirer).  But, dark matter has always seemed a little to..convenient for me.  I've never liked the idea.  It doesn't really seem..creative enough of an answer; it seems too simplistic (if that makes sense).  to me, we're thinking too human. "Oh, the mass doesn't add up?  There must be an invisible, undetectable particle that takes up most of our universe."

Like I said, I'm not a physicist.  And I understand.  We tend to always gravitate to the simplistic answer.  Most of the time, that's the correct one.  But what if our understanding of gravity over large distances is flawed?  What if there's a large chunk we're leaving out?

Honestly, I really don't know.  The math adds up for dark matter, so that's what we need to go with.  But, I welcome all theories like MOND (working, theories..not just anything) to throw a monkey wrench in our science.  Sometimes, I think we get a little too comfortable with the status quo; even in science.

ReidBarnes
ReidBarnes

Yet the article says there seem to be problems with this new theory, MOND, also: "But at least one subscriber to the mainstream [dark matter] theory who has taken a serious look at MOND remains unconvinced. 'If MOND were purely a theory of modified gravity, that would be one thing,' says Avi Loeb, chair of the astronomy department at Harvard. But even MOND requires some sort of dark matter to explain such crucial phenomena as evolution of structure in the universe — why and how galaxies have been pulled into huge clusters, for example, rather than being smoothly distributed through space." On the other hand, it escapes me why dark matter proponents would cling to relativistic theories flawed by self-contradicting non-Euclidean geometry. We seem to be ignoring the prospects of plasma models and also the prospects of something called Zero Point Energy, a term actually coined by Einstein. I tend to think Einstein was wrong about space curvature (because of the flawed non-Euclidean geometry) but right about dice.https://www.facebook.com/notes/reid-barnes/not-the-god-particle-the-god-field-if-you-must-call-it-that/519767374742508

stacy.mcgaugh
stacy.mcgaugh

I agree with some of what ialsoagree says, but some of it is wrong.  MOND is not contradicted by many observed facts.  There are indeed claims to this effect, which I have reviewed extensively - most recently in a review invited by the journal Living Reviews in Relativity: http://relativity.livingreviews.org/Articles/lrr-2012-10/fulltext.html.  Very few of these claims hold water, and I am disturbed by how readily some of the more absurd claims are accepted uncritically.  The sociology seems to boil down to: if it supports dark matter, it must be right; if it supports MOND, it must be wrong.

I do not understand why ialsoagree asserts that there would be no cosmic microwave background (CMB) in MOND.  This is not the case.  I correctly predicted the amplitude ratio of the first to second peak in the power spectrum of the CMB using a model motivated by MOND.  Nobody else got that right ahead of time.  The same model fails to get the third peak right (this debate would be over if it had), but by some strange coincidence the first-to-second peak ratio is still measured to be exactly what I predicted ahead of time.

So yes, MOND has a ways to go, but it has already come farther than seems to be appreciated.  ADS: http://adsabs.harvard.edu/abstract_service.html - use it to search the literature.

I do agree that MOND suffers problems in clusters, and have said so many times.  It is not the only piece of evidence.  Some evidence favors LCDM (our current standard cosmological model), some favors MOND.  What conclusion you come to depends on how you weigh the evidence.  See http://astroweb.case.edu/ssm/mond/LCDMmondtesttable.html.  You don't have to agree with my evaluation of the evidence, but I have considered all the things people seem to be fond of asserting automatically exclude MOND.  It just isn't that clear.

LCDM has enormous trouble doing the things MOND does easily.  Where MOND explains galaxy dynamics with a single free parameter per galaxy, the unavoidable conversion from measured starlight to the mass of the stars producing it, LCDM requires a minimum of three parameters.  That doesn't really work, so we invoke "feedback" which brings at least another three free parameters  Even then it still doesn't manage as well as MOND.  I'm sure we can keep adding free parameters until we get it right, but this is a pretty blatant violation of Occam's razor.  If I were to adopt the same attitude as MOND's critics, I would assert that it is impossible for LCDM to do what the data require and therefore it is falsified.  That is no less fair a statement than the legitimate complaints about MOND.  So again, I don't think it is that easy to choose.

And yes, MOND is a scientific theory, in the same sense that Newton's Law of Universal Gravitation is.  MOND is an extension of that theory.  In the modern parlance, it can be derived from a Lagrangian.  What MOND is NOT is an extension of General Relativity.  Reconciling the two is a big challenge for theorists.  So far we haven't been able to reconcile General Relativity with the other fundamental forces in a would-be theory of everything, or even quantize gravity satisfactorily.  So I hesitate to say there can be no surprises in gravitational theory.

Dark Matter is a concept, not a theory.  We can develop specific hypotheses for what the dark matter can be, and construct legitimate theories therefrom.  But "dark matter" by itself could be just about anything, and is not subject to falsification.  Didn't see enough brown dwarfs?  Must be WIMPs.  No WIMPs? OK, Axions then.  If not that, we can always make up something else.

This subject always brings out the big questions.  All we said in the paper (and the press release) was that we applied MOND to the newly discovered dwarfs of Andromeda, and it seems to work.  It didn't have to be so.  We also make some a priori predictions that have yet to be tested, so maybe it will still fail.  It that not interesting?

ialsoagree
ialsoagree

Just to clarify, as some people seem confused.

MOND is not a scientific theory, it is a hypothesis, and a hypothesis that is contradicted by many observed facts (gravitational lensing, general relativity, cosmic microwave background radiation, models for the formation of cosmic bodies).

Dark matter is a scientific theory, and it is not contradicted by any observed phenomenon.

That doesn't gaurantee that dark matter is correct and MOND wrong. But when cosmologists have to use a model for the universe, the only model that makes logical sense to use at this time - and the only model that will lead them to conclusions that are supported by observation - is a model of the universe containing dark matter.

Is MOND worth further exploration? Of course!

But that doesn't mean it's ready to compete with dark matter as a valid explanation - at least not yet.

CloudZ1116
CloudZ1116

So basically what MOND is saying is that the 1/r^2 law for gravity doesn't hold over long distances? Would be very interesting if it were true. There are some guys at the University of Washington who have been looking for deviations from the 1/r^2 relationship with a fine tooth comb, since any variation would have huge implications for string theory. However, they haven't turned up anything... yet.

CharlesBoyer
CharlesBoyer

With both theories, the details (i.e. the math) are what matters, and that is far beyond the scope of a general-science article in mass-media.  It is, however, an interesting discussion about two competing theories, and a good jumping off point for those it interests to do more learning about MOND and the state of the art of dark matter research.  

It is amusing, however, for people who have no idea of how research into physics works to say that it is bunk.  Einstein, for example, was well known for his thought experiments that he used to suss out relativity, and they had nothing to do with direct observation.  From there, he used mathematical modeling and once he had that working to his satisfaction, direct observation to finally prove or disprove what he was working on.  Obviously, it worked as Relativity is a foundational theory yet to be credibly disproven while it has been confirmed many times over.  In terms of cosmological theory such as dark matter or MOND, we are still in the first two stages and eventually there will be confirmation or repudiation by observation...and none of it is bunk.  Science is a means, not an end.


cronenborrough
cronenborrough

I love how science can propose its own idea, and then punch the numbers into a "model", and then its proves thesis.   Where else can that happen?  Gee, I have 3 dollars and I'm going to put it in this hat and pull out eleven...  Clearly there are things that we don't know, and possibly can't  Making up theories about things with no evidence is like writing a novel.  No matter how great our technology we can't know anything without actually touching or measuring it.  Ever stood on the top of the Eiffel Tower?  No?  Then on what basis are you going to describe the view and the smell and the experience of actually being there?  Impossible. 

acwhitney
acwhitney

This seems to be a simpler explanation of many of the phenomena attributing to dark matter.  I find it hard to believe any credible scientist would say a simpler explanation that has been observed in experiment would not be worth more research.  Science makes its biggest leaps when we find out what we know is wrong.  If anything the community would be excited about the possibility of designing new experiments to try and prove/disprove the new theory.

JamesSavik
JamesSavik

I'm not burning the physics book yet.

Common sense tells you that there has to be a whole lot of "dark" matter in the universe. It doesn't have to be exotic. 

It is simply matter that is not blazing away in a star.


JoshEison
JoshEison

This is definitely surprising news. Does that mean that the lack of matter affects gravitational fields? Would that mean the "arms" of galaxies such as spiral and bar galaxies are some kind of indicator of a large scale gravitational field? A "standard" gravitational field on a local level has magnetic field lines that protrude from the source in circular patterns. The arms of galaxies don't appear to have the same patterns. Does this mean the gravitational fields of large mass objects behave differently in vacuums than small gravitational fields do? 

papakojo
papakojo

It seems that anytime a scientific theory is not being accepted by the 'mainstream' , the 'believers' resort to trying to disprove valid scientific theories. All the Newtonian and Relativity math back the existence of dark matter so no need for this sensationalized propaganda 


RickFromTexas
RickFromTexas

I happen to know that they prefer to be called little people galaxies rather than dwarf galaxies.

LelandWilliamsJr.
LelandWilliamsJr.

Keep sending your tax money to the National Science Foundation to keep these Physics PHD's from getting a real job.

DouglasRutledge
DouglasRutledge

What I'd like to know is how MOND fits in with general relativity. Can one take a limiting case of GR and show that MOND falls right out, just like Standard Newtonian gravity?

cpc65
cpc65

Called it. There was no proof that it ever existed and was hypothesized only because astronomers and physicist could not explain certain things about how the universe behaved so they postulated the existence of "dark matter" and "dark energy". Sounds like how the earliest religions got started when early man couldn't explain why the seasons happened, why the tides came and went, or why plants and animals reproduced and grew. So he invented nature spirits, which then evolved over in eons into the "modern" religions we have today. It's all  magic. oOOooOOo!

ialsoagree
ialsoagree

This article misses a very important flaw in MOND:

MOND cannot predict or explain gravitational lensing. The gravitational lensing observed in galaxies completely contradicts MOND.

TeVeS is a modified version of MOND that enables prediction of gravitational lensing while also being able to explain galaxy rotations. But TeVeS has it's own problem, it cannot predict both gravitational lensing AND galaxy rotations at the same time. It needs 2 different values of gravity to do both, which is obviously impossible.

Not to mention, MOND nor TeVeS can explain the CMBR, nor the formation of cosmic bodies.

So, while it's a cute guess, it's still got a long way to go before it's reasonable to start considering it a theory. On the other hand, we can directly observe the effects of things like dark matter (the well known "Bullet Cluster" for example), and dark matter can explain everything we observe while using the current understanding of gravity: CMBR, formation of cosmic bodies, galaxy rotation and the movements of individual stars, gravitational lensing.

It's hard to knock a theory that has both predictive value, explains everything we observe, is consistent with everything we observe, and is the only explanation anyone has come up with that does all of those things.

pbuotte
pbuotte

Much like notions of the divine or supernatural, if dark matter does not exist, why 'will' it into existence by wishful belief?...


zgryphon
zgryphon

"Young man, we are all agreed that your theory is crazy.  What divides us is whether it is crazy enough to have a chance of being correct."

 - Niels Bohr (1885-1962), paraphrased from memory

DeweySayenoff
DeweySayenoff

Much of the animosity among scientists is based on the same thing that powers the animosity that happens between agnostics/atheists and believers: No one likes to admit they may be wrong.  

The difference, of course, is that in science, those with the most compelling, repeatable and verifiable evidence wins - eventually.  There's always resistance in science to upsets in what is commonly perceived to be "the way of things".  That's not because of contradictions in science.  It's because of human nature.  Scientists are, as individuals and groups, only human, after all.  Their motives for maintaining their positions have less to do with grant money than with the notion that they may be studying something that doesn't exist (or exists differently than they had thought).  Very few - especially big name scientists - are willing to concede their misapplication of reason to the available facts.

But despite controversy, in the end, they're also scientists.  This means that eventually, that which is, will be proven to be so.  That which isn't will not be supported by the facts.  And nothing makes a scientist happier than a boatload of facts supporting their assertions.

In the Dark Matter area, as a well informed but not expert individual, I've had no emotional investment in it.  I simply read with interest what has been found, what has been theorized and what has yet to be discovered.  While there are sound scientific theories postulating the existence of dark matter, I've found them a touch more speculative than I'd like.  This "new" theory certainly seems equally viable.  Given the probes that are being readied to search for dark matter, I suspect its existence, or absence, will be confirmed.  But given the inconsistencies in both theories, it makes me wonder, as a relatively impartial observer, whether the seemingly improbable orbital speeds of various galactic objects (based on visible mass) may be governed by a combination of both theories, or from yet other influence either in whole or in part.  After all, we're discovering a ton of new dark objects in our own galaxy in the form of planets around stars.  Conventional wisdom says they don't amount to enough mass to account for the ability of galaxies to hold themselves together as they spin because the overwhelming majority of the mass of a system is in the star itself.

Maybe it isn't.  We have no way to determine that one way or another yet.  The "dark matter" may simply be non-stellar mass or have more mass than previously estimated.  This is merely speculation, of course, and probably wrong, but it highlights the fact that there are still possible explanations for the velocities of galaxies that may have nothing to do with MOND OR dark matter.

The pitfall in science is when interested and invested scientists try to use one, whole, encompassing theory to account for observed data.  Evolution being a prime example.  There are many things that cause evolution to happen.  So I'm inclined to think that despite the consistencies in Newtonian physics on a smaller scale, a much larger scale allows far more latitude for many undiscovered influences to make themselves known.  And the theories discussed - MOND and Dark Matter - may only be two of them.  It's remotely possible that MOND and non-stellar but conventional matter is behind it.  

Thus it would be best if science, and scientists, proceeded with an open mind.  It wouldn't surprise ME if there were many influences.  It shouldn't surprise someone looking for the why's of the universe, either.

dphamil
dphamil

I find Michael Lemonick's article to be balanced, correctly characterizing MOND as a "competing theory struggling for acceptance," "not mainstream," etc. Nevertheless, the fact that MOND can explain galaxy spin rates and now satellite galaxy speeds is surprising. It tells us - at a minimum - that there is something that mainstream cosmologist do not understand about standard dark matter theories. When we do not understand something, the proper scientific response is to look more deeply and, perhaps, in more unlikely places. This is how science advances. The attack by Mr. Siegel on Mr. Lemonick's article and on Dr. McGaugh's research is unfounded.

jschombe
jschombe

MOND makes testable predictions, point, set, match.  All else is opinion and politics.

stacy.mcgaugh
stacy.mcgaugh

Hi Mike.  I warned you that some people reacted emotionally to this subject.  Ethan Siegel is an extreme example of the willful ignorance I was alluding to.  At one point I wrote to him offering to explain how I had come to be skeptical of dark matter after starting as a true believer.  He didn't reply.  When I tried again, I found that he had blocked my email address.  Refusing to listen is an example of willful ignorance.

Ethan asserts that I am not a physical cosmologist.  I wasn't aware that he was the only person designated to bestow that title.  I certainly am an active scientist who works on cosmology, among other topics.  I am a full professor at a research university, achieving this rank first at the University of Maryland before moving to Case Western.  That means, among other accomplishments, that I had to receive glowing letters of recommendation from other scientists, including some very eminent physical cosmologists.

Ethan, on the other hand, is a blogger.  He seems to be fond of overstating his qualifications.  Reading his blog, he seems to have a reasonable understanding of modern cosmology, at the level I would expect of any student who took my graduate course on the subject.  His knowledge of galaxy dynamics, the subject here, does not appear to be at that level.

Check for yourself.  NASA supports the Astrophysical Data System, which allows you to search the scientific literature on this subject: http://adsabs.harvard.edu/abstract_service.html.  If you type my name into the author field and restrict the search to refereed papers, you will see 74 publications.  If you then sort by citations, you will see over 6,000.  That is the record of an active scientist who is well regarded in the field.  If instead you enter "siegel, e." you will see rather less.

I don't claim to know the right answer here.  We have yet to detect dark matter particles in the laboratory, so we can hardly claim to be sure they exist.  MOND, strange as it is, does have some of its predictions come true.  I find both possibilities fascinating.

ralph.dratman
ralph.dratman

If a neutrino "could zip through a chunk of lead a trillion miles thick without even noticing", how is it that we can ever detect even one of them? Neutrino to other neutrino: "That trillion miles of lead we just went through gave me a slight stochastic haircut. Since then I just don't feel 100% myself." Other neutrino: "Feeling like less of yourself? Let me buy you a drink of dark matter. You may feel some slight nausea, but it will bulk you back up."

cyberdactyl
cyberdactyl

So. . . Verner Vinge was right all along in the "Fire Upon the Deep" series?

JonathanMartin
JonathanMartin

One theory explains how the universe formed, but now how it works today, another explains how it works today but not how it formed. A similar problam faces the biological sciences where one set of theories (punctuated equilibrium, self-organising properties of life, panspermia) seem necessary to explain how we got here, but don't fit with what we are observing today. What we now know with reasonable certainty in both fields is that the present is not the key to the past. In both cases, these irreconcilable differences argue strongly in favor of a Creator - who formed things not according to the laws of the present, but according to His supernatural power.

Rotosnitter
Rotosnitter

MOND has no real basis to support it. It is inconsistent with General Relativity and it just assumes a reciprocal vs squared inverse relation to distance. Dark Matter itself is kind of a desperate attempt to explain galactic rotation. It is quite possible we just don't yet have a directly verifiable basis to explain what we see.

ethan.siegel
ethan.siegel

For shame. Mike Lemonick, you have been a mostly great science-and-space writer for a long time, remaining abreast of the curve and generally not falling for specious claims such as McGaugh's contention here that "willful ignorance" and bias is what keeps cosmologists from entertaining MOND as a serious competitor.

It is the entire field of physical cosmology -- developed to high precision over the last 3 decades -- that renders MOND nothing more than a phenomenological curiosity. You would not accept science-by-press-release in climate science, which you now write extensively about at climate central; why would you accept it blindly here without giving an equal voice to the objections of 97% of physical cosmologists? (Which, by the way, McGaugh is not.)

You wouldn't talk to a weather forecaster about their views on clmatology, so why give an entire feature to a galactic dynamics scientist on physical cosmology? Talk to a physical cosmologist instead; this does nothing but grab headlines and undermine the great understanding of physical reality that's developed from the early 1990s to the present. For shame.

dgdoesstuff
dgdoesstuff

:'(

This kind of thing (and others like it) is why I find it hard to study science, even though science is a lot of fun.  The sudden changes don't filter down fast enough for me to catch up, and as soon as I think I understand a theory, it changes and I'm stuck at square one again.