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Fresh Twist to Debate Over Universe’s Age From New View of the Oldest Light in the Universe – SciTechDaily

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Atacama Cosmology Telescope

The Atacama Cosmology Telescope measures the oldest light in the universe, known as the cosmic microwave background. Using those measurements, scientists can calculate the universe’s age. Credit: Image courtesy of Debra Kellner

Atacama Cosmology Telescope findings suggest the universe is 13.8 billion years old.

From a mountain high in Chile’s Atacama Desert, astronomers with the National Science Foundation’s Atacama Cosmology Telescope have taken a fresh look at the oldest light in the universe. Their new observations, plus a bit of cosmic geometry, suggest that the universe is 13.77 billion years old, give or take 40 million years.

The new estimate matches the one provided by the standard model of the universe and measurements of the same light made by the Planck satellite, a space-based observatory that ran from 2009-2013.

This adds a fresh twist to an ongoing debate in the astrophysics community, said Simone Aiola, first author of one of two new papers on the findings posted July 15 to arXiv.org. The trouble is that research teams measuring the movements of galaxies have calculated that the universe is hundreds of millions of years younger than the Planck team predicted. That discrepancy suggested that a new model for the universe might be needed, and sparked concerns that one of the sets of measurements might be incorrect.

“Now we’ve come up with an answer where Planck and the Atacama Cosmology Telescope agree,” said Aiola, a researcher at the Flatiron Institute’s Center for Computational Astrophysics in New York City. “It speaks to the fact that these difficult measurements are reliable.”

A portion of a new picture of the oldest light in the universe taken by the Atacama Cosmology Telescope. This part covers a section of the sky 50 times the moon’s width, representing a region of space 20 billion light-years across. The light, emitted just 380,000 years after the Big Bang, varies in polarization (represented here by redder or bluer colors). Astrophysicists used the spacing between these variations to calculate a new estimate for the universe’s age. Credit: Image courtesy of ACT Collaboration

The age of the universe also reveals how fast the cosmos is expanding, a number called the Hubble constant. The Atacama measurements suggest a Hubble constant of 67.6 kilometers per second per megaparsec. This result agrees almost exactly with the previous estimate of 67.4 by the Planck satellite team, but it’s slower than the 74 inferred from the measurements of galaxies.

“Making this independent measurement is really exciting because there’s a mystery in the field, and this helps us sharpen our understanding of that mystery,” said Jeff McMahon, an associate professor of astronomy and astrophysics at the University of Chicago who led the design of the detectors and other new technologies used to make this measurement. “This confirms the ongoing discrepancy. And we still have much more data to analyze, so this is just the beginning.”

Assoc. Prof. Jeff McMahon

The close agreement between the Atacama Cosmology Telescope and Planck results and the standard cosmological model is bittersweet, Aiola said: “It’s good to know that our model right now is robust, but it would have been nice to see a hint of something new.” Still, the disagreement with the 2019 study of the motions of galaxies maintains the possibility that unknown physics may be at play, he said.

Like the Planck satellite and its earthbound cousin the South Pole Telescope, the Atacama Telescope peers at the afterglow of the Big Bang. This light, known as the cosmic microwave background, or CMB, marks a time 380,000 years after the universe’s birth, when protons and electrons joined to form the first atoms. Before that time, the cosmos was opaque to light.

If scientists can estimate how far light from the CMB traveled to reach Earth, they can calculate the universe’s age. That’s easier said than done, though. Judging cosmic distances from Earth is hard. So instead, scientists measure the angle in the sky between two distant objects, with Earth and the two objects forming a cosmic triangle. If scientists also know the physical separation between those objects, they can use high school geometry to estimate the distance of the objects from Earth.

Subtle variations in the CMB’s glow offer anchor points to form the other two vertices of the triangle. Those variations in temperature and polarization resulted from quantum fluctuations in the early universe that got amplified by the expanding universe into regions of varying density. (The denser patches would go on to form galaxy clusters.) Scientists have a strong enough understanding of the universe’s early years to know that these variations in the CMB should typically be spaced out every billion light-years for temperature and half that for polarization. (For scale, our Milky Way galaxy is about 200,000 light-years in diameter.)

The Atacama Cosmology Telescope measured the CMB fluctuations with unprecedented resolution and sky coverage, taking a closer look at the polarization of the light. “The Planck satellite measured the same light, but by measuring its polarization in higher fidelity, the new picture from Atacama reveals more of the oldest patterns we’ve ever seen,” said Suzanne Staggs, the telescope’s principal investigator and the Henry deWolf Smyth Professor of Physics at Princeton University.

This measurement was possible thanks to new technology designed and built by McMahon’s team. “Basically, we figured out how to make the detectors measure two colors and to pack as many into each camera as possible,” McMahon said. “Then we developed new lenses out of metamaterials.” (Metamaterials are a type of material that’s engineered to produce properties that don’t exist naturally.)

From conception to deployment at the telescope to analysis, the process has spanned nearly 10 years, McMahon said. “Working with this amazing team to develop this project all the way from concept sketches to producing results at the forefront of cosmology, has been absolutely fantastic.”

[embedded content]
Prof. Wendy Freedman explains a new method for measuring the expansion of the universe.

Sara Simon, now at Fermi National Accelerator Laboratory, made significant contributions to detector design; UChicago graduate student Joey Golec developed methods to fabricate the metamaterial optics; and UChicago graduate student Maya Mallaby-Kay is now working to make the datasets public.

As the Atacama Cosmology Telescope continues making observations, astronomers will have an even clearer picture of the CMB and a more exact idea of how long ago the cosmos began. The team will also scour those observations for signs of physics that doesn’t fit the standard cosmological model. Such strange physics could resolve the disagreement between the predictions of the age and expansion rate of the universe arising from the measurements of the CMB and the motions of galaxies.

“We’re continuing to observe half the sky from Chile with our telescope,” said Mark Devlin, the telescope’s deputy director and the Reese W. Flower Professor of Astronomy and Astrophysics at the University of Pennsylvania. “As the precision of both techniques increases, the pressure to resolve the conflict will only grow.”

“I didn’t have a particular preference for any specific value — it was going to be interesting one way or another,” said Cornell University’s Steve Choi, first author of the other paper posted to arXiv.org. “We find an expansion rate that is right on the estimate by the Planck satellite team. This gives us more confidence in measurements of the universe’s oldest light.”

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References:

“The Atacama Cosmology Telescope: DR4 Maps and Cosmological Parameters” by Simone Aiola, et al., 14 July 2020, Astrophysics > Cosmology and Nongalactic Astrophysics.
arXiv: 2007.07288

“The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectra at 98 and 150 GHz” by Steve K. Choi, et al., 14 July 2020, Astrophysics > Cosmology and Nongalactic Astrophysics.
arXiv: 2007.07289

The ACT team is an international collaboration, with scientists from 41 institutions in seven countries. The telescope is supported by the National Science Foundation and contributions from member institutions.

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Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

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More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

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Follow AP’s climate coverage at https://apnews.com/hub/climate

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Follow Seth Borenstein on Twitter at @borenbears

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‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

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It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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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.”

The Canadian Press. All rights reserved.

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