The remote galaxies hail from a time when the 13.7-billion-year-old cosmos was less than 5 billion years old. Yet measurements reveal that the bodies are just as massive as galaxies like the modern-day Milky Way, which took at least 10 billions years to mature.
The findings appear to call into question the leading theory of galaxy formation, known as the dark matter model
http://www.sciencenews.org/view/generic/id..._young_universe
Quatermass
So??? It's not like those theories are written in stone. Problems with theories often lead to better answers.
Grumpy
QUOTE
The findings appear to call into question the leading theory of galaxy formation, known as the dark matter model
So??? It's not like those theories are written in stone. Problems with theories often lead to better answers.
Grumpy
And the Dark Matter model of galaxy formation is not the sole evidence for Dark Matter or even the best evidence for Dark Matter.
QUOTE (rpenner+Apr 7 2009, 06:55 AM)
And the Dark Matter model of galaxy formation is not the sole evidence for Dark Matter or even the best evidence for Dark Matter.
What is the best evidence for Dark Matter?
What is the best evidence for Dark Matter?
People measure the rotation of galaxies with observations, not only of light, but with the radio waves of invisible clouds of gas which surround galaxies. What was discovered, that instead of orbital linear velocity falling off rapidly like Kepler or Newton would suggest for a limited central mass, the velocity of clouds in a spiral galaxy often stay nearly constant out 5-6 times the radius of the star-filled disk. This suggests, to a 1/r^2 theorist, that galaxies are both more massive than just their stars and gas clouds suggest and this mass is spread out in a halo which is not so disk-shaped. This is the best evidence that dark matter is ubiquitous.
The gravitational lensing of the Bullet cluster is a strong suggestion that dark matter is real in a particle sense and not just some weird gravity effect that the 1/r^2 theorists haven't noticed before.
The gravitational lensing of the Bullet cluster is a strong suggestion that dark matter is real in a particle sense and not just some weird gravity effect that the 1/r^2 theorists haven't noticed before.
Thanks for the answer. I did ask because I already (sorta) knew the answer. So here's another question that I already know the answer to ...
To confirm the existence of theorized Dark Matter won't we have to be looking at Quanta instead of the "physics of the large"? Of course, the answer is that particle physicists have been and continue to do exactly so.
So ... While observational evidence from cosmology/astronomy might point to Dark Matter's existence couldn't same those observations also confirm predictions from other theories. I don't know if WSM or EU or any other cosmology predicts such galactic velocities but it wouldn't surprise me if such observations matched their predictions as well.
And just for sake of truth in advertising, I don't buy that redshift is an indication of an expanding universe. So until the Quantum guys come out and tell me they've got a cup-fulla-DM, you can call me very skeptical.
To confirm the existence of theorized Dark Matter won't we have to be looking at Quanta instead of the "physics of the large"? Of course, the answer is that particle physicists have been and continue to do exactly so.
So ... While observational evidence from cosmology/astronomy might point to Dark Matter's existence couldn't same those observations also confirm predictions from other theories. I don't know if WSM or EU or any other cosmology predicts such galactic velocities but it wouldn't surprise me if such observations matched their predictions as well.
And just for sake of truth in advertising, I don't buy that redshift is an indication of an expanding universe. So until the Quantum guys come out and tell me they've got a cup-fulla-DM, you can call me very skeptical.
An expanding universe is entirely consistent with General Relativity. What, pray tell, is your preferred explanation for the red-shifting of distant galaxies which goes hand-in-hand with time dilation of supernova light curves?
I find the WSM explanation interesting. It proposes an effect due to what it calls a "Hubble Sphere" (essentially the observable universe versus the eternal universe) whereby the redshift is an effect of overlapping spheres. But I'm not fully versed there ...
I also find noncosmological redshift a viable explanation ... (so did Hubble)
In both cases more observation is necessary ... so if people like Geoffrey Burbridge can actually get some telescope time then perhaps that can be all be fleshed out.
Intuitively (for whatever my intuition is worth); I suppose I'm predisposed to believe that the universe is dramatically older than BBT says.
I also find noncosmological redshift a viable explanation ... (so did Hubble)
In both cases more observation is necessary ... so if people like Geoffrey Burbridge can actually get some telescope time then perhaps that can be all be fleshed out.
Intuitively (for whatever my intuition is worth); I suppose I'm predisposed to believe that the universe is dramatically older than BBT says.
QUOTE (Cusa+Apr 15 2009, 09:09 PM)
We haven't been here long enough but I believe we will see galactic expansion. This is true if there are no prefered scale. This implies that galaxies evolve in a sense as the universe expands. If the galaxies expand with the universe then the Milky Way will to. But it will not change its orginal shape even if it has become bigger.
Science has to wait to "test" my hypothesis to watch galaxies grow.
Mitch Raemsch
Tosh, tosh, and thrice tosh, you stunningly pathetic idiots, idiots, imbecilic idiots idiot ...... future galactic size and shape will largely depend on collisions/mergers with other galaxies.
Science has to wait to "test" my hypothesis to watch galaxies grow.
Mitch Raemsch
Tosh, tosh, and thrice tosh, you stunningly pathetic idiots, idiots, imbecilic idiots idiot ...... future galactic size and shape will largely depend on collisions/mergers with other galaxies.
QUOTE (Geoff Mollusc+Apr 16 2009, 01:04 AM)
Tosh, tosh, and thrice tosh, you stunningly pathetic idiots, idiots, imbecilic idiots idiot ...... future galactic size and shape will largely depend on collisions/mergers with other galaxies.
What I think Cusa means (from past posts) is that he believes the material in a galaxy is insufficient to keep it forever in that shape and that all galaxies started more compact than we see them today and are "opening up" over time, so expanding with their current material.
What I think Cusa means (from past posts) is that he believes the material in a galaxy is insufficient to keep it forever in that shape and that all galaxies started more compact than we see them today and are "opening up" over time, so expanding with their current material.
QUOTE (uaafanblog+Apr 15 2009, 01:14 PM)
What is the best evidence for Dark Matter?
Look at Andromeda or any other detailed image of a galaxy. It's Laid out as though it were made from light matter only. This is despite there supposedly being maybe six times as much DM as LM. There are no abberations in shape due to unseen gravitation pulls. If DM were in the halo of the galaxy as some claim, we would have ring doughnut shaped galaxies.
There is no idea what DM is supposed to be. Some have said it's light as an electron and others fifty times as heavy as a proton (90,000 times difference). It has been said to be at several thousand centigrade but does not lose heat. It always moves at about 9,000 mph. It cannot form small structures but only large structures, which is strange to say the least. Despite only working gravitationally, it never got caught up in the building of moons, planets, stars, etc because it only works gravitationally as DM believers want it to.
The best evidence for DM is a belief that gravity works the same on all scales and is fully understood. Also computer models where you get out what you put in and little white blobs in huge photos, with these blobs representing whole galaxies.
Look at Andromeda or any other detailed image of a galaxy. It's Laid out as though it were made from light matter only. This is despite there supposedly being maybe six times as much DM as LM. There are no abberations in shape due to unseen gravitation pulls. If DM were in the halo of the galaxy as some claim, we would have ring doughnut shaped galaxies.
There is no idea what DM is supposed to be. Some have said it's light as an electron and others fifty times as heavy as a proton (90,000 times difference). It has been said to be at several thousand centigrade but does not lose heat. It always moves at about 9,000 mph. It cannot form small structures but only large structures, which is strange to say the least. Despite only working gravitationally, it never got caught up in the building of moons, planets, stars, etc because it only works gravitationally as DM believers want it to.
The best evidence for DM is a belief that gravity works the same on all scales and is fully understood. Also computer models where you get out what you put in and little white blobs in huge photos, with these blobs representing whole galaxies.
QUOTE (uaafanblog+Apr 15 2009, 05:16 PM)
I also find noncosmological redshift a viable explanation ... (so did Hubble)
Yeah there are a number of problems with it. Hundreds of redshifts that are conveniently forgotten as they don't work as they should. There are a number of sites with further information. Ultimate proof of an expanding universe could only be gained with a time scale where we can actually see that galaxies have moved further away from us, so not possible.
My own explanation of the redshift is that it is due to a sea of gravity caused by a universe full of gravitational sources. It makes more sense than the nonsensical big bang idea.
Yeah there are a number of problems with it. Hundreds of redshifts that are conveniently forgotten as they don't work as they should. There are a number of sites with further information. Ultimate proof of an expanding universe could only be gained with a time scale where we can actually see that galaxies have moved further away from us, so not possible.
My own explanation of the redshift is that it is due to a sea of gravity caused by a universe full of gravitational sources. It makes more sense than the nonsensical big bang idea.
QUOTE (Quatermass+Apr 16 2009, 05:58 PM)
Look at Andromeda or any other detailed image of a galaxy. It's Laid out as though it were made from light matter only.
This is simple lying.
Andromeda (M31) was an early source of evidence of dark matter outside our own galaxy, such as the departure of it's rotation curve from the predictions of gravity based just on the stars. But it wasn't until the 1970s when people got fired up about the idea.
Indeed, the beautiful spiral structure of M31 is stable against the formation of bars only if there is a light disk embedded in a massive halo.
H.C. van de Hulst, E. Raimond, H. van Woerden Bull. Astron. Inst. Neth. 14, 1. (1957).
Chapter 20 of G. Bertin Dynamics of Galaxies (2000)
This is simple lying.
Andromeda (M31) was an early source of evidence of dark matter outside our own galaxy, such as the departure of it's rotation curve from the predictions of gravity based just on the stars. But it wasn't until the 1970s when people got fired up about the idea.
Indeed, the beautiful spiral structure of M31 is stable against the formation of bars only if there is a light disk embedded in a massive halo.
H.C. van de Hulst, E. Raimond, H. van Woerden Bull. Astron. Inst. Neth. 14, 1. (1957).
Chapter 20 of G. Bertin Dynamics of Galaxies (2000)
If 1/4M doesn't see something with his own eyes, then it can't exist. And if he does see it, he doesn't understand it.
QUOTE (Quatermass+Apr 16 2009, 06:07 PM)
Yeah there are a number of problems with it. Hundreds of redshifts that are conveniently forgotten as they don't work as they should. There are a number of sites with further information. Ultimate proof of an expanding universe could only be gained with a time scale where we can actually see that galaxies have moved further away from us, so not possible.
My own explanation of the redshift is that it is due to a sea of gravity caused by a universe full of gravitational sources. It makes more sense than the nonsensical big bang idea.
I tend not to think so. Gravity bends space and light bends along with it but light is not slowed by Gravity.
I think we don't fully understand the mechanisms of Intertia. I believe it has a relationship with Gravity and could be another factor contributing to the velocity "anomoly" (sorry .. best word I could come up with) that rpenner described above. I've got NOTHING really to back that up but it seems to me that Mach was onto something that he didn't even realize himself. Einstein saw it and it inspired him but I think he missed something too.
My own explanation of the redshift is that it is due to a sea of gravity caused by a universe full of gravitational sources. It makes more sense than the nonsensical big bang idea.
I tend not to think so. Gravity bends space and light bends along with it but light is not slowed by Gravity.
I think we don't fully understand the mechanisms of Intertia. I believe it has a relationship with Gravity and could be another factor contributing to the velocity "anomoly" (sorry .. best word I could come up with) that rpenner described above. I've got NOTHING really to back that up but it seems to me that Mach was onto something that he didn't even realize himself. Einstein saw it and it inspired him but I think he missed something too.
It's difficult to argue with invincible ignorance.
And they don't come any more ignorant than 1/4M.
And they don't come any more ignorant than 1/4M.
QUOTE (rpenner+Apr 16 2009, 08:02 PM)
This is simple lying.
Andromeda (M31) was an early source of evidence of dark matter outside our own galaxy, such as the departure of it's rotation curve from the predictions of gravity based just on the stars. But it wasn't until the 1970s when people got fired up about the idea.
Indeed, the beautiful spiral structure of M31 is stable against the formation of bars only if there is a light disk embedded in a massive halo.
H.C. van de Hulst, E. Raimond, H. van Woerden Bull. Astron. Inst. Neth. 14, 1. (1957).
Chapter 20 of G. Bertin Dynamics of Galaxies (2000)
OK, I'll explain the obvious.
DM only exists if gravitation is exactly the same on all scales, whether Earth-Moon or a whole spiral galaxy. Also if an interpretation of the redshift is correct, that it works solely by speed of recession, and that the largely discredited big bang idea is right.
I was not referring to rotation speed but merely structure, so no need to start chucking insults about as usual and accusing me of lying.
DM outweighs LM by a factor of SIX TIMES! Where are the anomalies where DM has changed the shape of a galaxy like M31? There are none. Structurally, it looks like LM only, as I pointed out.
DM aka fairy dust since no one has any evidence of what it might be so it may be fairy dust, only does what is needed of it. By some magic it cannot form small structures but only large structures. Heard of black holes? They are not a respecter of DM's structures. They just suck the lot up as they travel around the galaxy as many have done upto maybe 40 times since their birth. They would over time literally sweep the galaxy clean of DM structures. As they sucked in DM, more DM would fall into it's place, filling the empty area, and in turn be sucked in by a black hole. It would be like walking through a smoky football stadium with hoovers. Eventually that stadium would be smoke free. I cannot see why ordinary stars would not suck up DM too.
Take our solar system right out to the Oort cloud. We are supposed to believe that there is six times as much unseen material around us that in no way diminishes light, in no way affects the gravitational pull of any of the bodies of the solar system, even the comets. Crazy! Then again, our gravitational measurements of the solar system do not allow for DM so if it exists outside, our gravitational extrapolations are messed up.
Some say DM is in the halo around a galaxy. When I see a ring doughnut galaxy, I'll believe that trash.
As to spiral arms, they have been shown to rotate at a slower pace further out, so that structure of fairy dust, sorry DM, does not work to well since where there is less LM material, they move slower. Why should there be so much movement inside galaxies if everything is held in place by DM, where we can see stars which are known to move above and below the plane of the galaxy?
Back in the 1970's people were talking about a coming Ice Age and saying we would run out of meat by the year 2000.
Andromeda (M31) was an early source of evidence of dark matter outside our own galaxy, such as the departure of it's rotation curve from the predictions of gravity based just on the stars. But it wasn't until the 1970s when people got fired up about the idea.
Indeed, the beautiful spiral structure of M31 is stable against the formation of bars only if there is a light disk embedded in a massive halo.
H.C. van de Hulst, E. Raimond, H. van Woerden Bull. Astron. Inst. Neth. 14, 1. (1957).
Chapter 20 of G. Bertin Dynamics of Galaxies (2000)
OK, I'll explain the obvious.
DM only exists if gravitation is exactly the same on all scales, whether Earth-Moon or a whole spiral galaxy. Also if an interpretation of the redshift is correct, that it works solely by speed of recession, and that the largely discredited big bang idea is right.
I was not referring to rotation speed but merely structure, so no need to start chucking insults about as usual and accusing me of lying.
DM outweighs LM by a factor of SIX TIMES! Where are the anomalies where DM has changed the shape of a galaxy like M31? There are none. Structurally, it looks like LM only, as I pointed out.
DM aka fairy dust since no one has any evidence of what it might be so it may be fairy dust, only does what is needed of it. By some magic it cannot form small structures but only large structures. Heard of black holes? They are not a respecter of DM's structures. They just suck the lot up as they travel around the galaxy as many have done upto maybe 40 times since their birth. They would over time literally sweep the galaxy clean of DM structures. As they sucked in DM, more DM would fall into it's place, filling the empty area, and in turn be sucked in by a black hole. It would be like walking through a smoky football stadium with hoovers. Eventually that stadium would be smoke free. I cannot see why ordinary stars would not suck up DM too.
Take our solar system right out to the Oort cloud. We are supposed to believe that there is six times as much unseen material around us that in no way diminishes light, in no way affects the gravitational pull of any of the bodies of the solar system, even the comets. Crazy! Then again, our gravitational measurements of the solar system do not allow for DM so if it exists outside, our gravitational extrapolations are messed up.
Some say DM is in the halo around a galaxy. When I see a ring doughnut galaxy, I'll believe that trash.
As to spiral arms, they have been shown to rotate at a slower pace further out, so that structure of fairy dust, sorry DM, does not work to well since where there is less LM material, they move slower. Why should there be so much movement inside galaxies if everything is held in place by DM, where we can see stars which are known to move above and below the plane of the galaxy?
Back in the 1970's people were talking about a coming Ice Age and saying we would run out of meat by the year 2000.
QUOTE (AlexG+Apr 18 2009, 08:24 PM)
And they don't come any more ignorant than 1/4M.
I tend to agree.
How smart is a foolish person using a search engine? Smarter than an idiot who relies on his/her own foolish misconceptions *shakes head*
I tend to agree.
How smart is a foolish person using a search engine? Smarter than an idiot who relies on his/her own foolish misconceptions *shakes head*
QUOTE (Quatermass+Apr 23 2009, 11:37 AM)
bm1957's idea of science.
1/4M's idea of an answer.
He's using it for all replies.
1/4M's idea of an answer.
He's using it for all replies.
QUOTE (Cusa+Apr 17 2009, 03:26 AM)
I can't see how dark matter and light matter could end up in different places of galactic structure if they both orginated together at the Big Bang. All I see is an equal mix throughout.
Mitch Raemsch
#
God has to be a real fool to think
that the >99% Hidden Universe
has no control of his <1% Visible Universe. And if he
knew this then he would not be a god but a physicist.
And if he was a smart physicist he would be laughing
at just how much less than 1% a universe really needs
to appear really real.
/ O'no. /
===============
Mitch Raemsch
#
God has to be a real fool to think
that the >99% Hidden Universe
has no control of his <1% Visible Universe. And if he
knew this then he would not be a god but a physicist.
And if he was a smart physicist he would be laughing
at just how much less than 1% a universe really needs
to appear really real.
/ O'no. /
===============
QUOTE (Quatermass+Apr 16 2009, 07:07 PM)
There are no abberations in shape due to unseen gravitation pulls. If DM were in the halo of the galaxy as some claim, we would have ring doughnut shaped galaxies.
Not true. If its in a spherical halo then by such things as Newton's Shell Theorem is would not alter the distribution of other matter but would allow it to spin faster due to more mass in the galaxy.
Not true. If its in a spherical halo then by such things as Newton's Shell Theorem is would not alter the distribution of other matter but would allow it to spin faster due to more mass in the galaxy.
QUOTE (Quatermass+Apr 16 2009, 07:07 PM)
There is no idea what DM is supposed to be. Some have said it's light as an electron and others fifty times as heavy as a proton (90,000 times difference).
So the fact physicists say "We're not sure, we need to do more experiments" is a bad thing!? There's plenty of suggestions for what it might be, from neutrinos to supersymmetric particles. Some things have seen been ruled out, like neutrinos, but there are candidates.
QUOTE (Quatermass+Apr 16 2009, 07:07 PM)
It has been said to be at several thousand centigrade but does not lose heat.
How does an object lose heat? Radiation? Well dark matter doesn't emit light so it can't cool down by emitting photons, like the Sun or a bulb does. Conduction? Well it's not a cohesive blob, so that's out. Convection, knocking into things. Dark matter at best interacts via gravity and the weak force, just like neutrinos and look how good they are at knocking into things! So its very hard for them to give heat to each other and other things.
QUOTE (Quatermass+Apr 16 2009, 07:07 PM)
It always moves at about 9,000 mph.
I'm not sure about that figure, got a source?
QUOTE (Quatermass+Apr 16 2009, 07:07 PM)
. It cannot form small structures but only large structures, which is strange to say the least.
No, it isn't. Consider an ice cube. If you heat it up it melts. If you heat it up some more it becomes steam. Not that steam is a thing in and of itself but it's got no small scale structure, its not able to clump due to its energy. If you let it cool it'll form small scale structures, ie water droplets and then ice. A huge heated cloud of gas only forms 'small' structures like planets and stars when it shrinks and cools. To do that it must radiate energy. Dark matter has trouble doing this. They are unable to slow down in enough quantity to make small things.
QUOTE (Quatermass+Apr 16 2009, 07:07 PM)
espite only working gravitationally, it never got caught up in the building of moons, planets, stars, etc because it only works gravitationally as DM believers want it to.
This smacks of Kaneda's typical "I don't understand it, I don't like it so I won't try to understand it" attitude. Firstly, I've already commented that dark matter can also interact via the weak force, but it's no help really. Secondly, how could dark matter be built into moons and planets, it can't form chemical bonds with things, it can only be gravitationally captured.
Suppose I have a blob of normal matter and I throw it at the Sun. The blob slams into the Sun, interacts with it via electromagnetism and is absorbed. If I throw a blob of dark matter at the Sun it'll pass right through it. Sure, its path will be gravitationally deflected, akin to a comet, but unlike a comet it doesn't get slowed by the physical bulk of the Sun. Thus normal matter doesn't really 'gather up' dark matter, only sort of push it around by gravity.
But rather than you take the time to find out what physicists actually say about dark matter its much easier for you to just lie and make things up, isn't it Kaneda?
Suppose I have a blob of normal matter and I throw it at the Sun. The blob slams into the Sun, interacts with it via electromagnetism and is absorbed. If I throw a blob of dark matter at the Sun it'll pass right through it. Sure, its path will be gravitationally deflected, akin to a comet, but unlike a comet it doesn't get slowed by the physical bulk of the Sun. Thus normal matter doesn't really 'gather up' dark matter, only sort of push it around by gravity.
But rather than you take the time to find out what physicists actually say about dark matter its much easier for you to just lie and make things up, isn't it Kaneda?
G'day from the land of ozzzzzz
Hello Alphanumeric
Please define dark matter and dark energy as you apply them.
Hello Alphanumeric
Please define dark matter and dark energy as you apply them.
PhysOrg scientific forums are totally dedicated to science, physics, and technology. Besides topical forums such as nanotechnology, quantum physics, silicon and III-V technology, applied physics, materials, space and others, you can also join our news and publications discussions. We also provide an off-topic forum category. If you need specific help on a scientific problem or have a question related to physics or technology, visit the PhysOrg Forums. Here you’ll find experts from various fields online every day.
To quit out of "lo-fi" mode and return to the regular forums, please click here.