This undated photo provided by researchers in June 2023 shows the Arecibo Telescope in Puerto Rico. This and several other telescopes around the world were used to observe the slow gravitational waves — faint ripples made by massive black holes — that are constantly stretching and squeezing everything in the universe ever so slightly, described in a report released on Wednesday, June 28, 2023. Credit: NAIC via AP
Scientists have observed for the first time the faint ripples caused by the motion of black holes that are gently stretching and squeezing everything in the universe.
They reported Wednesday that they were able to “hear” what are called low-frequency gravitational waves—changes in the fabric of the universe that are created by huge objects moving around and colliding in space.
“It’s really the first time that we have evidence of just this large-scale motion of everything in the universe,” said Maura McLaughlin, co-director of NANOGrav, the research collaboration that published the results in The Astrophysical Journal Letters.
Einstein predicted that when really heavy objects move through spacetime—the fabric of our universe—they create ripples that spread through that fabric. Scientists sometimes liken these ripples to the background music of the universe.
In 2015, scientists used an experiment called LIGO to detect gravitational waves for the first time and showed Einstein was right. But so far, those methods have only been able to catch waves at high frequencies, explained NANOGrav member Chiara Mingarelli, an astrophysicist at Yale University.
Those quick “chirps” come from specific moments when relatively small black holes and dead stars crash into each other, Mingarelli said.
This illustration provided by researchers in June 2023 depicts gravitational waves stretching and squeezing space-time in the universe. On Wednesday, June 28, 2023, researchers reported signals from what they call low-frequency gravitational waves — changes in the fabric of the universe that are created by huge objects moving around and colliding in space. It took decades of work by scientists across the globe to track down the evidence for these super-slow wobbles. Credit: Aurore Simonnet/NANOGrav Collaboration
In the latest research, scientists were searching for waves at much lower frequencies. These slow ripples can take years or even decades to cycle up and down, and probably come from some of the biggest objects in our universe: supermassive black holes billions of times the mass of our sun.
Galaxies across the universe are constantly colliding and merging together. As this happens, scientists believe the enormous black holes at the centers of these galaxies also come together and get locked into a dance before they finally collapse into each other, explained Szabolcs Marka, an astrophysicist at Columbia University who was not involved with the research.
The black holes send off gravitational waves as they circle around in these pairings, known as binaries.
“Supermassive black hole binaries, slowly and calmly orbiting each other, are the tenors and bass of the cosmic opera,” Marka said.
This photo provided by researchers shows NANOGrav team members meeting at Green Bank Observatory in Green Bank, W. Va., in 2018. On Wednesday, June 28, 2023, researchers reported signals from what they call low-frequency gravitational waves — changes in the fabric of the universe that are created by huge objects moving around and colliding in space. It took decades of work by scientists across the globe to track down the evidence for these super-slow wobbles. Credit: NANOGrav via AP
No instruments on Earth could capture the ripples from these giants. So “we had to build a detector that was roughly the size of the galaxy,” said NANOGrav researcher Michael Lam of the SETI Institute.
The results released this week included 15 years of data from NANOGrav, which has been using telescopes across North America to search for the waves. Other teams of gravitational wave hunters around the world also published studies, including in Europe, India, China and Australia.
The scientists pointed telescopes at dead stars called pulsars, which send out flashes of radio waves as they spin around in space like lighthouses.
These bursts are so regular that scientists know exactly when the radio waves are supposed to arrive on our planet—”like a perfectly regular clock ticking away far out in space,” said NANOGrav member Sarah Vigeland, an astrophysicist at the University of Wisconsin-Milwaukee. But as gravitational waves warp the fabric of spacetime, they actually change the distance between Earth and these pulsars, throwing off that steady beat.
This undated photo provided by researchers in June 2023 shows the Green Bank Observatory in Green Bank, W. Va. This and several other telescopes around the world were used to observe the slow gravitational waves — faint ripples made by massive black holes — that are constantly stretching and squeezing everything in the universe ever so slightly, described in a report released on Wednesday, June 28, 2023. Credit: Jay Young/Green Bank Observatory via AP
By analyzing tiny changes in the ticking rate across different pulsars—with some pulses coming slightly early and others coming late—scientists could tell that gravitational waves were passing through.
The NANOGrav team monitored 68 pulsars across the sky using the Green Bank Telescope in West Virginia, the Arecibo telescope in Puerto Rico and the Very Large Array in New Mexico. Other teams found similar evidence from dozens of other pulsars, monitored with telescopes across the globe.
So far, this method hasn’t been able to trace where exactly these low-frequency waves are coming from, said Marc Kamionkowski, an astrophysicist at Johns Hopkins University who was not involved with the research.
Instead, it’s revealing the constant hum that is all around us—like when you’re standing in the middle of a party, “you’ll hear all of these people talking, but you won’t hear anything in particular,” Kamionkowski said.
This undated photo provided by researchers in June 2023 shows the Very Large Array radio telescope in New Mexico. This and several other telescopes around the world were used to observe the slow gravitational waves — faint ripples made by massive black holes — that are constantly stretching and squeezing everything in the universe ever so slightly, described in a report released on Wednesday, June 28, 2023. Credit: NRAO/AUI/NSF via AP
Journalists and scientists attend a news conference to discuss the contributions of Chinese scientists using the Five-hundred-meter Aperture Spherical Telescope (FAST) in southern China to an international collaboration on gravitational waves at the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) in Beijing, Tuesday, June 27, 2023. On Wednesday, June 28, 2023, researchers reported signals from what they call low-frequency gravitational waves — changes in the fabric of the universe that are created by huge objects moving around and colliding in space. It took decades of work by scientists across the globe to track down the evidence for these super-slow wobbles. Credit: AP Photo/Mark Schiefelbein
The background noise they found is “louder” than some scientists expected, Mingarelli said. This could mean that there are more, or bigger, black hole mergers happening out in space than we thought—or point to other sources of gravitational waves that could challenge our understanding of the universe.
Researchers hope that continuing to study this kind of gravitational waves can help us learn more about the biggest objects in our universe. It could open new doors to “cosmic archaeology” that can track the history of black holes and galaxies merging all around us, Marka said.
“We’re starting to open up this new window on the universe,” Vigeland said.
More information:
Gabriella Agazie et al, The NANOGrav 15 yr Data Set: Evidence for a Gravitational-wave Background, The Astrophysical Journal Letters (2023). DOI: 10.3847/2041-8213/acdac6
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Scientists have finally ‘heard’ the chorus of gravitational waves that ripple through the universe (2023, July 2)
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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
