A note: I am attending a meeting of the American Astronomical Society in Seattle. I will blog as much as I can from this meeting, as there is a LOT of news coming out, as well as lots of fun and wonderful scientific geekiness. This particular blog entry is a bit long as I have to explain some relatively complex things to get to the point. I think most of my reporting will be somewhat less wordy. But no promises! I love this stuff, and I love to talk about it.
Today, astronomers released news about the largest and most detailed survey of the deep Universe ever made. It used telescopes in space and on the ground to make a huge census of matter across the Universe, from local regions out to a distance of about 6 billion light years. It’s called COSMOS, for the Cosmic Evolution Survey, the telescopes involved were Hubble, XMM-Newton, Spitzer, Keck, the Very Large Telescope in Chile, the Very Large (radio telescope) Array in New Mexico, and the Subaru observatory. It involved over 100 scientists from more than a dozen countries.
This survey is incredible: it mapped the location of more than two million galaxies over an area two degrees on a side on the sky– bigger than 16 full Moons. In the end, astronomers made what is essentially a three-dimensional large-scale map of normal matter (the stuff that makes up you, me, doorknobs, snakes, planes, everything we can see and touch).
Here’s a (very) small piece of the survey image from Hubble:
Click on it for a much higher-resolution version. It’s very pretty.
Amazingly, the map of galaxies made is not the most interesting part of this survey. What makes COSMOS unique is that using sophisticated techniques, the astronomers were also able to map out the location of dark matter as well! This is the stuff that makes up the vast majority of matter in the Universe, but which we cannot detect directly. It’s been known to exist for decades — it was first postulated in 1933 — but the evidence has been indirect. Dark matter still has gravity, and so we see it through its effects — galaxies surrounded by dark matter halos rotate differently than they would without them, and dark matter in clusters of galaxies reveals itself through the motion of those cluster members.
But a trick of relativity winds up betraying the presence of dark matter, too. As Einstein postulated, matter bends space, the way a heavy weight in a bed will warp the mattress. Light traveling though empty space will move in a straight line, but if matter is warping space, light will travel along the bent space as well. Imagine light from a distant galaxy is on its way to us. But between this galaxy and us is some large mass, like a clump of dark matter. The light from the galaxy will bend around the matter, and when it gets to us it will be slightly distorted, just as if the light has passed through a lens. This process, in fact, is called gravitational lensing (for more about this, see my writeup about the Bullet Cluster, image #4 in my Top 10 Images of 2006).
So astronomers can map out the location of dark matter by very carefully taking observations of large areas of the sky and painstakingly teasing out the distortions in the shapes of background galaxies. The observations need to be done from space because the background objects are faint, small, and very close together. Space-based telescopes can more easily see fainter objects than ground-based ’scopes, and have better resolution– they can separate closely spaced objects better. That’s why Hubble was used for this survey. In fact, the survey was massive: it took 10% of Hubble’s time over two years. It’s the biggest single project ever done by Hubble.
But Hubble has limitations. To get the dark matter location, the distances to many thousands of galaxies had to be found. This was done from the ground, using the Very Large Telescope and the Subaru Observatory, using a technique called photometric redshift. Basically, the galaxies were observed through many different color filters, and the brightness of a given galaxy in each filter can be used to determine its distance.
Armed with the distortion to the galaxies’ shapes and their distances, astronomers began to map out the location the dark matter.
Let me pause for just a second here– we’ve known about dark matter for a long time, but the problem is, the dang stuff is dark. It’s hard to see. People have been arguing over whether it even exists, yet now, not only do we know it’s there, we know where it is! This is an amazing advance.
There is one very big result you can see just by glancing at the observations:
The left image, in red, shows the location of normal matter on the sky. The right image, in blue, is where the dark matter sits. They match! It’s been theorized for some time that as the Universe cooled after the Big Bang, dark matter formed long filaments many millions of light years across. As that happened, normal matter would be attracted to it gravitationally. Today, the normal matter should trace the location of the dark matter. Now we can see this is true!
But it gets better. Because astronomers were able to see dark and normal matter at very large distances, they were able to track how the stuff changes over time. That’s because the farther away we look, the farther back in time we see — we see an object a million light years away as it was a million years ago. So by looking back far enough, you can actually see how stuff behaved in the distant past, billions of years ago.
And things have changed! Perhaps the most important thing astronomers saw in their data is that dark matter was smoothly distributed at times early in the Universe, and became clumpier as time wore on. They created an image to show this. It’s a 3D map of the dark matter:
You can think of the left hand side of the image being dark matter that is nearby, and the right side being farther away. But remember, distance=time. You can see that dark matter now (on the left) is clumpy, whereas dark matter was smoother a long time ago (on the right). Again, that is just what models predict. Over time, the smooth distribution of the matter in the Universe became lumpy as small ripples in the matter were amplified by gravity. In other words, any place where there was a little more matter had more gravity, and attracted even more matter. This process continued, until after billions of years we got our current Universe: clumpy, lumpy, and full of wonderful galaxies, stars, and planets.
The COSMOS survey data is incredibly rich, and will be mined for information for years to come. I have only touched on what was learned from it so far, and there is much more scientific knowledge lurking within it. And even now, astronomers are planning even more ambitious surveys of much larger areas of the sky. These surveys will refine the data taken already, and will also start to tackle dark energy, the mysterious force that appears to be accelerating the expansion of the Universe. We know even less about that than we do about dark matter.
As usual, the more we know, the more there is to know. There’s still so much to learn!
January 7th, 2007 at 6:10 pm
Great post, BA! You have the gift of being able to convey complex information and concepts in a way that the layman (such as myself) can understand. You are a true teacher and that’s about the highest compliment I know how to give.
PS; unlike some posters, I also love your more rant oriented posts. It’s all good, and always lots of fun.
January 7th, 2007 at 6:15 pm
Why isn’t it ‘bright yellow with purple spot matter’? That would make life easier!
January 7th, 2007 at 6:16 pm
Oh, and, um… am I right in inferring from the time stamp on your post that you haven’t reset your website to PST from daylight savings? Perhaps a switch to UT is in order?
January 7th, 2007 at 8:48 pm
Mind–and Universe–Expanding Stuff, Phil. Keep it coming!
Tom Epps
USNS Arctic
Persian Gulf
January 7th, 2007 at 9:03 pm
[...] AAS – The Many Ring Circus This is a crazy wonderful place. Over and over, I’ve heard people say this is the super bowl of astronomy. I’m not so sure that is the truth. I feel more like this is the 3 (or 5 or 10) ring circus of astronomy. In every ring there is a new group doing their thing and playing to crowds. I sometimes feel that my attention is getting pulled in every direction as the biggest, the brightest, the shiniest, the newest, all juggle and flip to the music of the stars. This is a place where the big teams present their big results. In fact, the COSMOS team presented dark matter and baryonic matter maps of the large-scale structure of the universe as a function of time. It was a truly tremendous result that Phil Plait wrote an excellent blog entry about at Bad Astronomy. I also caught a short interview with one of the team members, Richard Massey, which I’ll be incorporating into an Astronomy Cast episode in the next week or so. (As new results come out, I’ll be posting about them here.) And everyone is here. This is the place where everyone presents a poster presentation or a 5-minute oral presentation on their latest results (I’ll have my name on two presentations, one on Dorrit Hoffleit, and one on online education). This is a place every student comes to try to schmooze their way into the next stage in their career, whether it be a summer internship, graduate school, or their very first post doc. In fact, this is the place any one in search of a job comes to try and schmooze their way into the next step of their career (including me!). With such a large chunk of the astronomical community in one place, it’s possible to inadvertently run into people whose names usually only exist in things you read. Last night I hung out with Carolyn Collins Peterson, Phil, and other since education folks. Carolyn blogged a bit about it over at the Space Writer Blog. Earlier today I saw Alan Boyle of the Cosmic Log and became a momentary fan chick, thanking him for doing so to promote and help those of us little guys and gals doing independent blogs and podcasts. It seems every time I turn around there is a new neat person to listen too, learn from, and of course foist business cards on to and out of. And there are moments of weirdness. This Conference is at The Washington State Convention and Trade Center, and side by side with our astronomer conference is the The Seattle Wedding Show. This means that at one point a bunch of us were going up the escalator with NASA schwag while a “bunch of bride to beâ€s were coming down the opposite elevator with wedding schwag. It also means that at one point during a press conference on the Andromeda Galaxy’s extended halo, “Here Comes the Bride†could clearly be heard in the background. And sometimes people watching (all bride’s to be aside) is just fun. There are at least 4 people (including me) with unnaturally red hair lurking the conference. And there are the normal freaks and geeks of the community, with their crazy hats, or crazy hair, or just crazy craziness. Anyone who thinks we are a straight-laced community doesn’t know the right people. NASA’s Jeffery Hayes was throwing around the world, occasionally hurling the Earth at unsuspecting souls (he claims Women catch flying terra firma 80% of the time to men’s 20% of the time). People generally flew around grabbing up satellite paper models, posters, the occasional project emblazoned jump drive, and gobs of pens like kids in a candy shop were everything is free. Sure, to look at us, it’s a group of grey haired old men with a few women and flocks of undergraduates mixed in for flavoring, but all the flavoring is really spicy. So it’s a circus, and I am one of the side show freaks, but I’m in good company. Maybe tomorrow I’ll catch a cool release from a data contortionist or have a chance to see the bearded satellite. [...]
January 7th, 2007 at 11:50 pm
AAS liveblogs…
Rob from Galactic Interactions is here as is Phil from Bad Asronomy I gather Sean and Jennifer are here also, not bumped into any of them. ‘Course my flight was late and I completely missed the opening reception. Phil……
January 8th, 2007 at 6:10 am
Dr. BA, have you Seen this from CNN about the AAS?
Talk about sensationalizing a headline!
Sounds to me like Dr. Schulze-Makuch’s paper at the meeting said something to the effect of “life on Mars may have developed based on Hydrogen Peroxide, and if it did, the Viking Landers wouldn’t have noticed it, and if they happened to scoop some up in their experiments, they would have killed it with the experiments they used.”
Of course, CNN’s headline reads
Did you get to hear the presentation? What’s your take on it?
(Notice I dutifully checked here before posting on it this time!
)
January 8th, 2007 at 6:27 am
Wow, the 3D image really brings it home how the dark matter clumped up over time. That’s a really big advance to actually see where the dark matter is, and how it evolved just as the models predicted.
Very very cool.
January 8th, 2007 at 7:12 am
i didn’t see this coming at all. i was under the impression dark matter was such a distant mystery we’d be decades away from something like this.
January 8th, 2007 at 9:39 am
GREAT Post!!!! As always thanks for sharing your great insight and knowledge!!!
January 8th, 2007 at 9:44 am
[...] You can read a lot more about this at the HubbleSite press release and at Bad Astronomy. I will just include a pretty picture: [...]
January 8th, 2007 at 9:46 am
EGADS, JanieBelle, that is a pretty bad hack by the headline writer. Headline writers suck.
Phil, most of your article is pretty good, but one part confused me.
I don’t understand what this means. I get you’re trying to reference a square 2 degrees on a side, making it have an area greater than 16 full moons, but I don’t get how that fits into the mapping the whole sky.
January 8th, 2007 at 9:59 am
So now all we have to do is figure out what the dark matter characteristics are. I think particle physicists are the next ones up to bat on this subject. Wonder if the big accelerators will provide any insight into these qualities? We’re pretty certain it’s not neutrinos so what the heck IS it?
Ah, the mystery continues,,,maybe the butler did the dirty deed,,,in the pantry,,,
GAry 7
January 8th, 2007 at 10:43 am
I couldn’t agree more with j jonah jansen!
This stuff is why I’m here. I’m reading this during my lunch and the photos coupled with the verbal imagery are breathtaking, literally. The wonder of it all has left me lightheaded.
Keep it up Phil!
January 8th, 2007 at 11:30 am
[...] Fortunately, I don’t have to go into details about the result, as others already have. Phil, Clifford, Rob, and Steinn have all blogged about the finding. Steinn’s post is, admittedly, pretty consise, but he wins points for breaking an even better story — Google is joining the Large Synoptic Survey Telescope consortium! Rob is even live-blogging the entire meeting, which is an heroic undertaking. (Yes, it’s true that he did bump into me up in Seattle, but I’m not there for the meeting! In fact I’m already back in LA. There are reasons to visit Seattle other than the AAS.) [...]
January 8th, 2007 at 12:33 pm
How dense can dark matter get?
Ten to the power of negative fifteen grams per cubic meter is more than enough to have effects on large-scale structures in the universe.
January 8th, 2007 at 12:48 pm
[...] Phil Plait of BadAstronomy has a new very interesting entry: Dark matter and large scale structure. [...]
January 8th, 2007 at 12:53 pm
Makes you wonder if we’ll find anything in the future which doesn’t interact with waves/particles of the electromagnetic spectrum or gravity.
January 8th, 2007 at 12:53 pm
Maybe it is at the other end of the scale , so to speak, but where does it leave ‘Black Holes’? How do they fit into the overall scheme of things?
Just thought I’d ask.
Ivan.
January 8th, 2007 at 1:21 pm
Ok, Dark matter… there’s lots of it… so how much does one Kg of Dm go for, what can we use it for, is it measured in pounds, metres or what. All I ever hear is you brainy guys saying there is a lot of it and you dont know much about it. Is this a goverment coverup ?
January 8th, 2007 at 1:26 pm
I don’t know where I head my head buried for the last few years but I didn’t even ralize the existance of dark matter had been confirmed before BA’s (very cool) top ten photo’s of 2006 post a bit back. And the more that’s posted about it the more mind blowing it gets. Dark matter effects normal matter gravitationally but in no other apparent way? That’s amazing. I wonder if it effects us in other ways we just don’t understand yet. And to the previous poster who wonders what particle physicists will do with it I ask: How the heck do we ever get our (proverbial) hands on any of it? To my knowledge particle accelerators haven’t ever produced anything nearly like this. Or even hints of it. I suppose I’ll keep reading and discover more, as we all do. Great post BA.
January 8th, 2007 at 1:45 pm
Ivan, as I understand it the current (largely experimentally verified) model of baryogenesis in the universe puts a limit on the maximum amount of normal matter (protons, electrons, neutrons, etc.), and this amount is less than all the matter in the universe. Since black holes are almost certainly formed by ordinary matter, they cannot account for the missing (non-luminous) matter.
January 8th, 2007 at 1:49 pm
I beg to differ with you Flak. The existence of Dark Matter has NOT been confirmed! Only the existence of unexplained gravitational fluctuations has been confirmed. I have yet to see anyone create, generate, capture or otherwise prove it’s existence.
The word ‘Virus’ was coined long ago to explain diseases for which there was no bacteriological explanation. Few believed in the existence of viruses UNTIL SOMEONE WAS ABLE TO POINT AT ONE! Dark Matter, Dark Energy and the recently “discovered” Dark Force are all the Viruses of Physics.
All I want to know is will one of them allow me to exceed the speed of light? If not, they are useless……lol.
January 8th, 2007 at 2:24 pm
I have a question about the analysis that might sound a bit weird, but it’s been puzzling me. How do they set a ‘zero’ to the distortions? I mean, they can find out \delta \rho, but how do they set \rho = 0? Do they just define the minimum of \rho to be zero? I’ll give you an analogy: take a plane slice of glass. It doesn’t cause any lensing, but the density isn’t zero. How do they get rid of this normalization? Also, a void in a non-zero density ( negative \delta rho) acts as a diffraction lens, no? Do you know if anything like this is observed? Best,
B.
January 8th, 2007 at 3:12 pm
Trying to understand dark matter:
It is said to have gravitational “mass” because that’s how it acts, but we don’t know its “composition,” i.e., whether there are elements or particles that we commonly talk about. And that’s why it’s dark, right? So we have an invisible gravity generator.
But does it have inertial mass? Are there frequencies of em radiation that it absorbs? Does it have collisions with normal matter?
These may be elementary questions that have been answered, but I didn’t want to assume that. All that I’ve heard is that “dark matter exists.” That’s not a very satisfying statement without a definition of dark matter in terms of how it’s different from regular matter (if it is).
The technology and science to produce that “map” sound wonderful!
January 8th, 2007 at 3:30 pm
Hey Phil – there’s a video on Youtube now showing the images from the Skepdude calendar. I just wanted to say – your picture? Made of 100% pure awesome.
Hope you’re having fun!
January 8th, 2007 at 3:56 pm
If dark matter exists, and that existence can be shown as this research seems to indicate, then I would think the next step would be to try and gather/make some, yes?
January 8th, 2007 at 4:53 pm
Hi Bill,
But does it have inertial mass
one of the best dark matter candidates are WIMP’s – weakly interacting MASSIVE particles…
Hi Squid,
then I would think the next step would be to try and gather/make some,
indeed, depending on what dark matter is, it might show up at the LHC, or alternatively there are experiments under consideration which would be able to detect dark matter directly even though it’s only extremely weakly interacting.
For more infor see also my post Dark Matter and references therein (don’t miss the comments).
Best,
B.
January 8th, 2007 at 5:51 pm
Does this mean that there are sub-atomic dark quarks?
January 9th, 2007 at 2:20 am
Oldfart Says: …The existence of Dark Matter has NOT been confirmed! Only the existence of unexplained gravitational fluctuations has been confirmed. I have yet to see anyone create, generate, capture or otherwise prove it’s existence.
The word ‘Virus’ was coined long ago to explain diseases for which there was no bacteriological explanation. Few believed in the existence of viruses UNTIL SOMEONE WAS ABLE TO POINT AT ONE! Dark Matter, Dark Energy and the recently “discovered†Dark Force are all the Viruses of Physics.
Before viruses were visualized with the electron microscope we could ‘prove’ the existence of an infectious agent which was not visible with the optic limits of the time. We did this by showing the unseen ‘thing’ caused infection. It could be recovered and passed on again and again with each subsequent exposed organism becoming infected. Immunity could also be confirmed.
We have confirmed the existence of matter in space by its emissions of electromagnetic radiation along the entire spectrum. How do you know a gamma ray burst represents something occurring with normal matter? Maybe the bursts come from something which if observed after the burst, was no longer visible with any detection device?
So with that, here are 2 comments about your comments.
We accept as proof many kinds of evidence besides touching and seeing.
And, something exists we have evidence of but don’t know much about the nature of it. We have labeled it dark matter. Who cares if when we do discover the nature of it it turns out to be even odder than first thought? Maybe we will re-name it dark ether instead of dark matter. But the gravitational anomaly as you correctly call it is still evidence something we have labeled dark matter is in that spot.
It’s there, it exists. Prior to using gravitational lensing, the existence of dark matter was only theoretical based on the physics calculations which said there was not enough visible matter in the Universe for the calculations to be correct. Rather than an anomaly, it was still possible the math was wrong and gravity was the thing which was not as believed.
In other words, we can see something, we have labeled it dark matter, it isn’t Newton who was wrong. We have established dark matter exists, whether it turns out to be matter or an anomaly as you label it.
Feel free to correct my understanding of things here. I am not a physicist.
January 9th, 2007 at 2:25 am
And I would add, gravitational lensing does indeed ’see’ things otherwise invisible. It would be like back-lighting an object and revealing its outline. If you accept infrared detection devices ’see’ things, why be so reluctant to accept gravitational detection is evidence as well?
January 9th, 2007 at 4:22 am
Pah. Dark matter is just bent space. Leave enough ordinary mass in one place long enough and space/time can be permanently warped. A black hole can actually put a kink in it. There’s a certain amount of hysteresis.
Space is clumpy because it’s dented.
January 9th, 2007 at 4:49 am
That’s pretty slick… but… why does the term “phlogiston” come to mind every time I hear about dark matter?
January 9th, 2007 at 5:00 am
It’s also interesting that the physicists aren’t falling over themselves in a rush to tell us what dark matter is. [There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy]
Higgs bosons may prove snooty, less elusive than reclusive, preferring the exclusive company of their own kind and disdaining interactions with lesser particles. Might there even be elder, heavier, haughtier such?
January 9th, 2007 at 6:30 am
“Pah. Dark matter is just bent space. Leave enough ordinary mass in one place long enough and space/time can be permanently warped. A black hole can actually put a kink in it. There’s a certain amount of hysteresis.
Space is clumpy because it’s dented. ”
Could you elaborate on these statements? How does the space get permanently warped and how do you prove such an assumption?
“Let me pause for just a second here– we’ve known about dark matter for a long time, but the problem is, the dang stuff is dark.”
Dark matter is not dark, Phil, it’s transparent. Despite that, it was a great read, thank you a lot!
January 9th, 2007 at 1:36 pm
Until recently the best alternative to “dark matter” has been something called “modified Newtonian gravity”. The basic idea behind it is that on very large distance scales the inverse square law that describes the gravitational force (both in Newton’s and Einstein’s gravity models) changes slightly. The last I head about it this modified gravity law worked pretty well in a classical situation but had not been made consistant with relativity.
However, with this level of detailed mapping of dark matter locations, I wonder if modified gravity laws would still be consistant with the observations, or can we give up on that one completely now? Anybody up on the latest literature on this?
January 9th, 2007 at 2:56 pm
Balstrome Says: “Ok, Dark matter… there’s lots of it… so how much does one Kg of Dm go for, what can we use it for, is it measured in pounds, metres or what. All I ever hear is you brainy guys saying there is a lot of it and you dont know much about it. Is this a goverment coverup ?”
Obviously the fault of the Bush administration…
January 9th, 2007 at 3:01 pm
Flak Says: “Dark matter effects normal matter gravitationally but in no other apparent way? I wonder if it effects us in other ways we just don’t understand yet.”
Yes, it surrounds you with “cosmic energy” and affects your very personality. Soon people will be able to predict the events in your life by deterimining the position of the dark matter in the sky. They’ll have daily predictions for you every day on the comics page.
- Jack
January 9th, 2007 at 3:03 pm
Carnifex Says: “‘Leave enough ordinary mass in one place long enough and space/time can be permanently warped. A black hole can actually put a kink in it. Space is clumpy because it’s dented.’
Could you elaborate on these statements? How does the space get permanently warped and how do you prove such an assumption?”
I believe it was a joke, just like my last post.
- Jack
January 9th, 2007 at 3:03 pm
Good one Phil! I linked to your explanation from my blog; ya done good!
January 9th, 2007 at 5:46 pm
I think Carnifex had a reasonable statement that there was room for doubt about dark invisible matter being proved. I think with all the additional data and the gravitational lensing, I’m going to go with the evidence it is there and does exist. But the dented space hypothesis is a reminder there may be other explanations not yet thought of.
Invisible matter isn’t correct either. Unless you take the literal definition cannot be actually seen. If we make a false color image of the gravitational evidence we can see the dark matter just as we can see a false color image of incoming electromagnetic data outside the visible range.
January 9th, 2007 at 5:47 pm
It’s dark because it doesn’t interact with light.
January 9th, 2007 at 11:22 pm
Dave – the recent TeVeS theory extends MOND to be relativistic, and I’d think (although it’s not my field) that the DM tracing the light would make explaining it with MOND-type theories easier. Far harder is where the mass and the light don’t go together (see past BA blogs for the example, whose name escapes me) – but the MOND proponents claim that this can be explained with neutrinos (an ‘allowed’ DM in that theory) rather than needing CDM, so the alternatives to DM are still alive.
Talking of alternative theories, has anyone in Seattle talked to the guy with the ‘alternative theory vs Big Bang’ stand? in the middle of the main hall?
January 10th, 2007 at 2:03 am
The jape about bent space was mine. It’s really not that much different than saying there’s a bunch of unobservable massive stuff out there, since (at least in the traditional theory) gravity is equivalent to the warping of space.
To attribute memory or hysteresis to space itself would, I suspect, also impute mass, thus begging the question. It’s really an ether hypothesis, where the ether is something like taffy.
In contrast, dark energy (to my limited understanding) could be just a coefficient in the gravity equation, Einstein’s cosmological constant.
January 10th, 2007 at 2:15 am
There’s also the issue of where all the antimatter went. According to scripture, matter and antimatter should initially have been created in equal proportion, yet in the observable universe antimatter is essentially absent. Perhaps, rather than being immediately eliminated moments after the creation of the universe, the antimatter collapsed into innumerable small black holes. (This, though it might explain the abundance of dark matter, wouldn’t explain its shyness.)
How do we really know that the next galaxy over isn’t antimatter, though?
January 10th, 2007 at 7:57 am
How do we really know that the next galaxy over isn’t antimatter, though?
I guess we’d see annihilation effects around it. Even the space between galaxies isn’t empty.
January 17th, 2007 at 4:45 pm
[...] For more information on this survey, visit the COSMOS home page, the Hubble press release page, and the Bad Astronomy site which has details on the results. [...]
February 2nd, 2007 at 12:37 am
The MOND theory was developed so that it would conform to the Tully Fisher law which says that the total luminosity of a galaxy is proportional to its highest orbital velocity.
We cannot believe that the Tully Fisher law “says what it says it means”. We have to believe that mass has some inherent yet-to-be described property that transmits itself through a vacuum and attracts neighboring mass or warps space.
The light pressure studies tell us that light is repulsive not attractive as implied by the Tully Fisher law. Guess what I have performed numerous experiments that indicate that the “radial spreading of infrared luminosity” is attractive. I can get as much as 10% increase in weight with a hot plate heating element attached to a convex-up colander.
Furthermore, my luminosity-based gravity theory provides a “close to experience” explanation for the higher-than-expected rotation curves of galaxies which make the dark matter “superfluous” (in the immortal single word of Einstein who came up with a theory that did away with the “luminiferous ether” by making the results of the speed of light studies mean what they said they meant).
February 2nd, 2007 at 10:53 am
[...] Carnivals like this one seem to be gaining popularity, a welcome thing because they offer pointers to sites I hadn’t known about, and the topics are always interesting. Good coverage of the American Astronomical Society meeting shows up here, along with work on dark matter, the Antikythera Mechanism, and a wonderful explanation of light cones and Einsteinian relativity. I’m pleased that Philosophia Naturalis includes two recent posts on the James Webb Space Telescope from these pages. [...]
February 3rd, 2007 at 7:37 pm
“Balstrome Says: “Ok, Dark matter… there’s lots of it… so how much does one Kg of Dm go for, what can we use it for, is it measured in pounds, metres or what. All I ever hear is you brainy guys saying there is a lot of it and you dont know much about it. Is this a goverment coverup ?â€
Jack Hagerty says..”Obviously the fault of the Bush administration.”
Give these posters time, they’ll figure out a convoluted way and use mental gymnastics to assign blame to Bush. Seemingly everything that is wrong with the world is Bush’s fault, dontcha know!
Meanwhile, over a thousand surveys went out and only 10% came back with stated acknowledged pressure from Bush’s administration officials. You would think that if the pressure was so pervasive, there would be a response rate of a lot more than 17%! But, alas, only 60% of the lowly 17% responders said that there was.
This is all that it took for the BA minions to pounce on Bush. They came to this conclusion with a total lack of due diligence because it must be evaluated on a relative basis, not an absolute one. How does this 10% compare to prior administrations? There is seemingly no data on that, so one can not make a reasonable conclusion. But, never fear, illogical Bush bashers are here and damn anything relative.
February 12th, 2007 at 10:08 am
Just curious. Have you ever heard any good arguments why dark matter cannot be plain old cold plasma, gas, dust, etc. that has not managed to condense into self gravitating accumulations?
April 6th, 2007 at 7:53 pm
Being only a layman with an interest in the subject, I’m not even sure how to present an idea on dark matter that I’ve had for a very long time. But in a nutshell:
Dark matter is merely anti-matter. As anti-matter, it creates anti-gravity and other forms of anti-energy. It seems that an anti-matter universe exists in a commingled way with our material universe. There are anti-stars, anti-planets, anti-galaxies, even anti-light. The reason we cannot see the ‘dark matter’ is because gravity and anti-gravity will ‘push’ against each other as opposed to ‘pull’. Even anti-light approaching earth would be pushed away by the gravity of our galaxy, sun, earth and even individual atoms. Even if some form of anti-radiation were to reach our region of matter and actually come into full contact, it would be annihilated. The meeting of matter/energy and anti-matter/anti-energy would simply cancel each out of existence. This is largely avoided due to the repulsion of the two opposing forms of matter.
The idea of anti-matter and, therefore, anti-gravity, may be a possible explanation for the continued expansion of the universe.
Any comments on this line of thinking would be greatly appreciated.
Lance Knoechel
lknoechel@cinci.rr.com
August 6th, 2007 at 7:14 pm
well but milk woudnt stay forever in the fridge that is acording to the cosmlagistic theory
October 7th, 2007 at 6:27 pm
“Dark Matter”! Good description if you have no idea what it is. Or, if it exists. Does anybody have any postulations as to the composition of “Dark Matter”. Is sort of like a cross between Jello and window putty? What would it taste like? Was it created from the “BIG BANG” and then went on to coalesce into stuff that we can see? Why isn’t there any dark matter close to the earth? Why would it only exist a real long ways away? Maybe if we stopped concentrating on such huge distances, we might discover some close by. Why not have a good look around in New York City? They’ve got everything else there. And on this expansion of the universe thing. Just what in hell is the universe expanding into if that is not in itself, The Universe? How do we know it is expanding at all. Maybe it is contracting from another direction. That’s the problem with scientists. They have allowed ethnocentricity (does anybody know how to spell that) to color their thinking. Where is the center of the universe? Maybe we are the ones who are way the hell out toward the edge. Edge! Now that gets me going. Does this mean that the celestial objects that are caught up in the accelerating expansion are going to eventually bounce of a cosmic wall? If the universe started with a big bang, where did the stuff to go “Bang” come from and how is it that there was a “SPACE” in which the “Big Bang” could take place.
Some of you may have guessed by now that I do not know squat about astroni
my. Actually, I wouldn’t even be bothering with this were it not for the fact I’m trying to avoid kitchen chores by pretending to be working.
Have a happy
October 29th, 2007 at 10:37 pm
Dark matter, as described in current physics, consists of particles that don’t interact with matter and light as we know it, or does so very weakly, with the exception of gravitation. The concept of dark matter was originally introduced to explain why galaxies rotate as fast as they do without all the matter flying off. There either was a flaw in Newton’s law of gravity or there was matter that couldn’t be seen. MOND, which stands for MOdified Newtonian Dynamics, was the competing theory to dark matter, and it required that gravitational effects drop off in quanta at extreme distances that allowed for a greater apparent effect. The math was quirky and no one seemed comfortable with it. Anyway, dark matter as a blanket term can also refer to cold normal matter like brown dwarves. The entire reason for dark matter is explain where the “rest” of the matter in the universe resides.
January 10th, 2008 at 11:54 am
[...] amazing aspects of looking into deep, deep space is that the path there is tortured and twisted. Space itself can be distorted by mass; it gets bent, like a road curves as it goes around a hill. And like a truck that must follow that [...]
February 21st, 2008 at 7:13 pm
LoL I love Astronomy the colors are so lovely that if you over lay them you would get a good 3D image with the right glasses. lol As to the research ranting or not it is still very interesting. ^_^
April 21st, 2008 at 11:15 am
[...] Team of researchers in Italy claims to have directly detected dark matter Short background: we know dark matter exists. We also know it must be made up of particles that are very difficult to detect (or else we’d [...]
January 14th, 2009 at 2:02 pm
I have a theory of what (some) of the Dark Matter, and Dark Energy is. I believe it is matter traveling too fast to be folded into space-time. Matter traveling at just less then the speed of light squared.
During the big bang, all possible speeds were achieved. Soon after the big bang space-time / the sub light speed universe was created.
For matter/energy to have an existence in our universe, it does not have to be folded into space-time. Matter energy must interact with space-time prior to the end of the universe. It must be converted to energy at just above the speed of light. Most of this matter will only interact with space-time at the end of our universe when all matter in the known universe is accelerated back to the speed of light. For some of the dark matter the entire span of existence of our universe would be very short let us say 1 second. However, that time or fraction of that would be enough for this matter to be created, exist, and be converted to energy that interacts with space-time prior to the end of the universe allowing such matter to exist.
I believe the speed of light restricts matter transfer in either direction. Know matter can not travel faster then the speed of light, and matter that is traveling at speeds multiple times the speed of light can not slow down to enter into our space time. It is the slowing of dark matter and it is burning up at the speed of light barrier that creates some of the dark energy.
I have no little explanation why Dark Matter does not crash into matter in our space-time other than it cannot and still have an existence shortly after time space was formed.
Dark matter is a cold thin matter that passes thru protons / neutrons without interaction, or I would like to think it is a chameleon and not have a specific nature, when it hits a lead molecule its lead, when it hits zinc its zinc. Dark Matter does not have a specific nature, as we know it.
I think Dark Matter does interact with electrons.
Of course, for dark matter, electrons would be standing still, and they would be flying past. In large voids between galaxies, the lack of electrons to interact with would cause a slowing of this matter, and its destruction/conversion to energy as it neared the speed of light.
To me (a construction worker), this explanation resolves several questions I have about Physic’s.
1.) If the speed of light squared, is an achievable space for matter, and the majority of possible speeds from zero to the speed of light squared being well above the speed of light why is not most of the matter in the universe traveling faster than light speed.
2.) If a person falling in a Black hole is stretched out like a noodle as they speed up, how could matter possibly slow down to enter space-time. Matter would be landing in multiple places at once, the effect would be like a meteor entering the atmosphere.
3.) Why do galaxies speed up the further they travel from each other?
4.) Why an electron can be seen as a wave or a particle, because it interacting with a material that is faster than light, that travels on the surface of space-time.
5.) I do not have the ability to give you a diagram, so if you could imagine the effect over the span of the universe existence, like cannon ball trajectories landing on the surface of space-time, I believe it would explain why the effect would increase over time.
For my theory to be possible, all dark matter would have to be converted to dark energy prior to the end of the universe.
The total amount of dark matter if converted to energy would be equal to the energy required to accelerate all matter in the known universe to the speed of light.
I am not sure if dark energy and matter are converted back and forth repeatedly over the history of the universe, but I would suspect that the further you look back in time, you would see more Dark Matter and less Dark Energy.
Thank you for taking the time to read my thoughts on the subject, I would be glad to hear some of the expanations of why my ideas are in error.
Gary Knoeppel
January 16th, 2009 at 7:55 am
It appears no one read my last comments so please forgive my further rambling.
I believe Dark matter was created in the big bang, and was locked out of space time as matter slowed down, and space-time was created. I think interaction with matter in space-time was a prohibited action for materials attempting to exist, the interaction would distroy space-time. So the matter/energy that is nearly locked out of space time would take infenantly complex routes thru space time in order to exist, this is material that had it’s entire existance thru time planned when it became part of our universe.
image a board full of nails, and this matter as a magentic string drawn to the board, and repeled by the nails. The string will fall to the board, in the simplest configuration, but it fall to the board.
Therefore, when space-time was formed, this matter/energy followed infinitely complex routes thru space-time that did not allow interaction with material in the sub-light universe. The key to this is Time-Space had already been mostly formed, and entire existence / route this material takes thru the span space time existence was determined as it was folded into existence, no matter how complex that route would have to be.
I believe it is part of all matter, and the lack of sub-light matter to interact with causes it to slow, and be destroyed as it attempts to enter space-time. I believe this is matter that is there, but since it is skipping over the surface of space-time, it cannot interact with us. It does not interact the gas cloud, the Sun that is created, or carbon molecule on the planet that follows it is part of or comes in contact with, because to that molecule it is all three at once. This matter would only have an existence as we understand it when it is destroyed attempting to sub-light universe.
January 16th, 2009 at 12:22 pm
My final summary of what Dark Matter and Dark Energy are for this blog.
Matter / energy from the big bang that was not incorporated into fabric of space-time at the beginning of the universe due to its speed.
Once the fabric of space-time was created, no matter was able to enter. I would like to call this the speed of light barrier.
Dark matter can only “exist” as an energy release interaction as this matter is pulled into the fabric of space-time and destroyed.
If matter or energy currently occupies the location where Dark Matter is attempting to enter the fabric space-time, it is prohibited from entry/existence.
Due to the speed of time difference, the fusion release of energy would occur over long periods, and would appear as a very weak energy release.
When the universe reached a larger size, it allowed more Fast/Dark matter to be destroyed as it joined into space-time. The effect kept the universe from collapsing in on its self due to the pull of gravity.
I suspect the effect would look like this.
If you were looking at two galaxies on the same path traveling away from us, it would appear Dark Energy was on our side of the nearer galaxy, and Dark Matter was intermingled with the galaxy, and also on the far edge of the nearer galaxy. A large amount of Dark Energy should be behind the further galaxy; with the amount of energy dropping off quickly at a point were you near the far side of the closer galaxy.
February 22nd, 2010 at 12:01 pm
Cosmology seems to be dominated by mathematicians with very vivid imaginations. I would be embarrassed if I introduced a theory that relied on 70% (let alone 95%) speculation about a unkwown and unseen material or force. I for one do not subscribe to the theory of “dark matter” or “dark energy” because they were invented to fill holes in the existing mainstream theory. In my mind, “gravitational lensing” is more likely a manifestation of electromagnetic phenomenon or some other yet to be discovered effect. To my very simple mind, talking to so-called experts on cosmology today is like trying to get a straight answer from a political hack. You only get the party line. I know it is hard to make an honest living as a cosmologist, and hence, the more proposterous the theory the more books you can sell. I don’t believe in time travel, wormholes, parallel universes, astral projection, or any of the other ridiculous, ludicrous, proposterous, and outlandish ideas I am seeing out there.