They’re Sure It Exists, But Scientists Still Unable to Detect Dark Matter

Posted July 23rd, 2016 at 12:55 am (UTC-4)
2 comments

Artist impression of the Milky Way. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter. (ESO/L. Calçada)

Artist impression of the Milky Way. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter. (ESO/L. Calçada)

Back in 1933, Caltech astronomer and astrophysicist Fritz Zwicky was observing the Coma cluster, a large group of galaxies located some 321 million light years away in the Coma Berenices constellation.

He noticed the speed of the galaxies rotating within the cluster was much faster than the quantity of its mass he had calculated.

According to Isaac Newton’s theory of gravity, Zwicky thought this difference should have caused the galaxies to spin-off from the cluster.

So, he then figured that for all his observational information to add up with Newton’s theory, along with matter that could be seen, the cluster also had to contain a good amount of some kind of material that couldn’t be seen.

He called this invisible substance “dark matter.”

This false-color mosaic of the central region of the Coma cluster combines infrared and visible-light images to reveal thousands of faint objects - green (NASA / JPL-Caltech / L. Jenkins (GSFC))

A false-color mosaic of the central region of the Coma cluster. (NASA / JPL-Caltech / L. Jenkins (GSFC))

In the years since Fritz Zwicky’s finding, researchers have been trying feverishly to make an actual detection of dark matter.

Most are quite sure of its existence because of the gravitation influence it has on various cosmic objects, such as what Zwicky found with the Coma cluster in 1933.

The way light bends as it makes it way through space is another clue scientists say also points to dark matter.

NASA says this mystery material makes up roughly 27 percent of the known or observable universeDark energy, the force said to be responsible for the expansion of the universe, is thought to make up nearly 68 percent while normal matter, the things we can see and touch, makes up the remaining 5 percent.

Now, some 83 years after Zwicky’s discovery, a group of scientists say that despite searching for twenty months, with what is said to be the world’s most sensitive dark matter detector, they still have not been able to directly detect even a trace of the mysterious stuff .

Scientists with the Large Underground Xenon (LUX) dark matter experiment, presented findings of their experiment’s final run at the Identification of Dark Matter 2016 conference (IDM 2016), held this past week in Sheffield, England.

The dark matter experiment was conducted at the Sanford Underground Research Facility, located  beneath a little more than 1.6 km of earth and rock in the Black Hills of South Dakota.

The scientific consortium found that the sensitivity of their detector, a 370 kg liquid xenon time-projection chamber, was four times greater than they expected. They contend that if any dark matter particles had actually interacted with their device – it would have pointed them out.

To search for dark matter the scientists say their experiment was set-up to look for WIMPS, otherwise known as Weakly Interacting Massive Particles, which is where they think they’ll be able to find dark matter.

Inside the water tank of the LUX detector: The vessel at the center is filled with liquid xenon, which is sensitive to hypothetical dark matter particles called WIMPs. (C. H. Faham/LUX Collaboration)

Inside the water tank of the LUX detector: The vessel at the center is filled with liquid xenon, which is sensitive to hypothetical dark matter particles called WIMPs. (C. H. Faham/LUX Collaboration)

They theorize every second, billions of these WIMP particles are actually passing through our bodies, everything that surrounds us and through the Earth itself.

According to the scientists, we don’t notice this continual bombardment because the interaction of these WIMP particles with ordinary matter is quite weak.

Over its last 20 month run – October 2014 through May 2016 – the researchers say their experiment gathered and then analyzed nearly 500 terabytes or 500,000 gigabytes worth of data.

While they were unable to actually detect any dark matter, the LUX scientists say their experiment did eliminate a good number of possible models where the WIMP particles might be found.

The LUX team says their research and findings will also help future investigators in their hunt for dark matter.

The LUX-ZEPLIN (LZ) experiment, which is set to replace LUX at the Sanford Underground Research Facility will continue the search some time in 2020.

Rick Pantaleo
Rick Pantaleo maintains the Science World blog and writes stories for VOA’s web and radio on a variety of science, technology and health topics. He also occasionally appears on various VOA programs to talk about the latest scientific news. Rick joined VOA in 1992 after a 20 year career in commercial broadcasting.

2 responses to “They’re Sure It Exists, But Scientists Still Unable to Detect Dark Matter”

  1. Judas Asparagus says:

    Scientists aren’t sure, and there are two camps of thought, neither of which can claim to be more successful than the other. The majority camp believes that dark matter is some form of actual matter, while the minority believes new equations are in order.

    A majority opinion is still just that–an opinion.

  2. Mark Donner says:

    Let’s see if I got this straight.. according to the infinitely wise Earth human ape “astronomers” the Giant Bunny Rabbit of Nothingness (GBRN) stomped on a “singulairity” which exploded a universe around 14 billion years ago in a “Big Bada Boom Bang” display, so the universe can’t be older than that can it? And the universe is exploding from some point that Earth apes can’t locate (but they know this since they can build primitive brute force rockets that take eight long months just to reach Mars). And everyhing is expanding and being held together by magic dark matter dust which can’t be measured (but the apes KNOW it exists don’t they so of course it must) Maybe if they build a giant cosmic sewing machine to repair their space/time “fabric” quilt , the magic dust won’t keep falling out through the holes and then they can see it (using their specially designed magic dark matter glasses) Of course they’ll never be able to figure this out because the speed of light is a “constant” and when you get close to that constant all your time is depleted and it goes to zero and you would just freeze up or something.