Scientists Say Dark Matter Doesn't Exist

Professur

Well-Known Member
By Ker Than
Staff Writer
posted: 29 October 2007
06:07 am ET

Two Canadian astronomers think there is a good reason dark matter, a mysterious substance thought to make up the bulk of matter in the universe, has never been directly detected: It doesn't exist.

Dark matter was invoked to explain how galaxies stick together. The visible matter alone in galaxies—stars, gas and dust—is nowhere near enough to hold them together, so scientists reasoned there must be something invisible that exerts gravity and is central to all galaxies.

Last August, an astronomer at the University of Arizona at Tucson and his colleagues reported that a collision between two huge clusters of galaxies 3 billion light-years away, known as the Bullet Cluster, had caused clouds of dark matter to separate from normal matter. Many scientists said the observations were proof of dark matter's existence and a serious blow for alternative explanations aiming to do away with dark matter with modified theories of gravity.

Now John Moffat, an astronomer at the University of Waterloo in Canada, and Joel Brownstein, his graduate student, say those announcements were premature.

In a study detailed in the Nov. 21 issue of the Monthly Notices of the Royal Astronomical Society, the pair says their Modified Gravity (MOG) theory can explain the Bullet Cluster observation.

Using images of the Bullet Cluster made by the Hubble, Chandra X-ray and Spitzer space telescopes and the Magellan telescope in Chile, the scientists analyzed the way the cluster's gravity bent light from a background galaxy—an effect known as gravity lensing. The pair concluded that dark matter was not necessary to explain the results.

"Using Modified Gravity theory, the 'normal' matter in the Bullet Cluster is enough to account for the observed gravitational lensing effect," Brownstein said. "Continuing the search for and then analyzing other merging clusters of galaxies will help us decide whether dark matter or MOG theory offers the best explanation for the large scale structure of the universe."

Moffat compares the modern interest with dark matter to the insistence by scientists in the early 20th century on the existence of a "luminiferous ether," a hypothetical substance thought to fill the universe and through which light waves were thought to propagate.

"They saw a glimpse of special relativity, but they weren't willing to give up the ether," Moffat told SPACE.com. "Then Einstein came along and said we don't need the ether. The rest was history."

Douglas Clowe, the lead astronomer of the team that linked the Bullet Cluster observations with dark matter (and now at Ohio University), says he still stands by his original claim.

"As far as we're concerned, [Moffat] hasn't done anything that makes us retract our earlier statement that the Bullet Cluster shows us that we have to have dark matter," Clowe said. "We're still open to modifying gravity to reduce the amount of dark matter, but we're pretty sure that you have to have most of the mass of the universe still in some form of dark matter."


No shit
 

unclehobart

New Member
Any scientist that claims there isn't dark matter obviosuly hasn't been to the bathroom of a hot wings bar ... pee-yew. There's more dark matter in there than you can shake a stick at.
 

2minkey

bootlicker
upon reading the thread title i was certain that some sort of excretory reference would be made.

nice work.
 

Professur

Well-Known Member
New Measurements: The Universe Weighs Less
By Ker Than
Staff Writer
posted: 12 November 2007
06:31 am ET

The universe just got a little bit slimmer.

Revised calculations indicate the universe contains less normal and dark matter than previously thought, resulting in a "weight loss" of 10 to 20 percent.

Dark matter is a mysterious substance that is invisible to current technologies and which scientists think outnumbers normal "baryonic" matter by about 5-to-1.

The new weight estimate, detailed in the Oct. 20 issue of Astrophysical Journal, comes from new observations of the galaxy cluster Abell 3112. In 2002, astronomers announced they had traced X-rays in the cluster to clouds of dust and gas between the galaxies. But new observations by NASA's Chandra X-ray Observatory failed to detect the light signature, or "spectral emission lines," that should be given off by atoms in the clouds.

The team now thinks the X-rays are the result of collisions between lightweight electrons and photons in space. This changes the mass estimate of the cluster.

"This means the mass of these X-ray emitting clouds is much less than we initially thought it was," said study team member Max Bonamente, an astrophysicist at the University of Alabama in Huntsville.

Dark matter was initially invoked to provide the extra gravity needed to explain how galaxies can spin so fast without breaking apart. If there is less normal matter in Abell 3112, then less dark matter is needed to hold the cluster together, Bonamente said.

If the results also apply to other galaxy clusters, then "the universe as a whole ends up being a little bit lighter," he told SPACE.com.

It's as if billions of lights thought to come from billions of aircraft carriers were found to instead emanate from billions of extremely bright fireflies.

Confirmation of the team's finding will have to await the launch of future space missions, Bonamente said, which can scan the skies for emission lines of normal matter more probingly.

Well, there goes yet another 20% of the fabricated dark universe.

Source
 

SouthernN'Proud

Southern Discomfort
the lab coats said:
Dark matter was invoked to explain...

Translation: We don't know, and there CAN'T be anything to creationism, so here, we made this up so we'd sound smart and be able to keep our grants.

Fucking shamans.
 

Professur

Well-Known Member
Giant black holes just got bigger
By Jonathan Amos
Science reporter, BBC News

Some of the biggest black holes in the nearby Universe may be much larger than previously thought.

A reassessment of the monster hole at the core of the M87 galaxy suggests it could have 6.4 billion times the mass of our own Sun.

This result is two to three times the estimates from earlier studies.

Dr Karl Gebhardt told an American Astronomical Society meeting that his investigations led him to believe many other holes were under-recorded, also.

Most galaxies are thought to contain gargantuan central black holes. Indeed, there is thought to be a very tight correlation between the size of a galaxy and the core which consumes all matter that comes too close to it.

If a hole gets too big, too fast, however, it starts to push back, spewing high-velocity jets of matter out into space.

"There are processes that happen around the black hole that affect how much material you can dump on it," explained Dr Karl Gebhardt from the University of Texas at Austin.

"Eventually, it gets so massive that the jets that are common in these galaxies blow out and they can actually halt the material that falls in."

But if supermassive black holes are actually bigger than previously thought, the assumptions that help describe the relationship to their host galaxies might now have to be re-evaluated, the researcher said.

Big calculations

Astronomers weigh supermassive black holes by studying the size of their host galaxies and, critically, the speed with which stars move around inside those galaxies.

The new study used novel computer modelling techniques to tease apart the relative contributions to the total mass of M87 from its visible stars, its black hole and its "dark halo".
Chandra X-ray Image of M87, Close-Up (Nasa)
A close-up X-ray image of M87 shows a jet of material from the black hole

The dark halo is a spherical region surrounding the galaxy that extends beyond its main visible structure.

It contains "dark matter", an as yet unidentified material that cannot be directly detected by telescopes but which astronomers know is there from its gravitational interaction with everything else that can be seen.

"In order to get the small-scale analysis correct, you have to include what the stars are doing at the outer envelope of the galaxy, ie you have to understand the effect of the dark halo because that is where the dark halo lives - at the edge of the galaxy."

Dr Gebhardt and colleague Dr Jens Thomas, from the Max Planck Institute for Extraterrestrial Physics, are the first group to incorporate the dark halo into the mass calculations and the complexity of their effort required the use of a supercomputer.

"This model took a few days [to run] whereas in the past it would have taken 10 years," Dr Gebhardt said.

Distant puzzle

The results of the research, presented at the 214th meeting of the AAS in Pasadena, California, suggest that all black hole masses for the biggest galaxies may have been underestimated.

Dr Gebhardt told the meeting that this assessment was supported by data coming from the most recent - although not yet published - observations using the world's most sophisticated telescopes.

Realising that nearby supermassive black holes are actually bigger than previously thought also goes some way to solving a paradox concerning the masses of giant black holes in the distant Universe.

The black holes that power quasars - the compact but extremely luminous galaxies seen in early cosmic history - are considerably bigger than anything seen in the local Universe. This has always puzzled astronomers.

"By increasing masses [of local black holes] by two to three, it almost makes that problem go away," Dr Gebhardt said.

"That is, we're beginning to resolve the differences between the masses of the black holes in quasars and the masses of black holes from nearby galaxies. That's quite exciting when things start to come together."

source

Off by 2 to 3 times.
 

Altron

Well-Known Member
yeah, dark matter holds spacetime together, and luminiferous ether allows the propagation of light through a vacuum.

there have been many scientific phenomenon that were mathematically theorized to exist long before they were actually discovered. But, there have been just as many that were theorized and turned out to not exist.

Don't treat dark energy as a proven fact. It's a placeholder, so to speak. We observed something, namely redshift and the acceleration of the expansion of the universe, and fabricated something to explain it. Maybe it's right, and dark matter exists exactly how we theorized. It's happened. The outer planet's orbits were inconsistent with Kepler and Newtonian gravity, and someone predicted that a magical extra planet existed in order to cause this. Lo and behold, once astronomers knew where to look, Neptune was discovered right where it was supposed to be.
But, there's also been situations where a fabricated explaination has been completely false. Scientists didn't know how waves, which typically required a medium to propagate through, were able to travel in space. They invented "luminiferous ether", a magical gas that space is full of, which permits the transmission of light waves. This was false. It wasn't until wave particle duality and the emergence of subatomic particle physics that we were able to fully explain how this could occur with no medium of propagation.
 

MrBishop

Well-Known Member
That's science for you... see a problem, propose a theorem, test it, place it out there for others to verify or discount etc etc... rince, repeat.
 

Professur

Well-Known Member
That's science for you... see a problem, propose a theorem, test it, place it out there for others to verify or discount etc etc... rince, repeat.

Works well, until you start insisting that you're right ... this time.... again.
 

spike

New Member
Sciences gets refined. If nobody ever thought they were right you wouldn't have a computer.
 

Professur

Well-Known Member
They're perfectly allowed to think they're right. It's when they go to the effort of convincing the sheeple they're right beyond question that I have a problem. What they've done is said ... our calculations can't be wrong, so this must exist to prove us right ... instead of saying ... Ok, this doesn't add up .... what's wrong.

Sorry, but when you have to invent 80% of the universe out of whole cloth to make your calculations fit .....
 
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