New Observations Agree That the Universe is 13.77 Billion Years old - Universe Today | Canada News Media
Connect with us

Science

New Observations Agree That the Universe is 13.77 Billion Years old – Universe Today

Published

 on


The oldest light in the universe is that of the cosmic microwave background (CMB). This light was formed when the dense matter at the beginning of the universe finally cooled enough to become transparent. It has traveled for billions of years to reach us, stretched from a bright orange glow to cool, invisible microwaves. Naturally, it is an excellent source for understanding the history and expansion of the cosmos.

The CMB is one of the ways we can measure the rate of cosmic expansion. In the early universe, there were small fluctuations of density and temperature within the hot dense sea of the big bang. As the universe expanded, the fluctuations expanded as well. So the scale of fluctuations we see in the cosmic microwave background today tells us how must the universe has grown. On average, the fluctuations are about a billion light-years across, and this gives us a value for the rate (the Hubble parameter) as somewhere between 67.2 and 68.1 km/sec/Mpc.

The Atacama Cosmology Telescope. Credit: Jon Ward

Of course, the CMB isn’t the only way you can measure the Hubble parameter. In an earlier post, I talked about how you can use variable stars and distant supernovae to create a cosmic distance ladder that tells you the rate of expansion. The problem is, this alternative method gives a larger value for the Hubble parameter. If the supernova method is right, then the universe is younger and has expanded more quickly than the CMB scale seems to support. For a while, the hope has been that new observations and new methods of measuring cosmic expansion would solve this problem, but a new study dashes those hopes. This study looked at the cosmic microwave background using the Atacama Cosmology Telescope (ACT) in Northern Chile.

How the CMB arises from last scattering. Credit: Yacine Ali-Haïmoud

Most detailed observations of the CMB are made with satellites such as the Planck satellite. Being in space gives you a clear view of the cosmic remnant heat, letting you measure temperature fluctuations. The Atacama Cosmology Telescope is land-based, but it’s high in the Andes, where the air is very thin and dry, so it gets a reasonably good view of the CMB. But it is also specially designed to look at the polarization of the cosmic light.

The early universe was filled with light, but because it was so hot and ionized, photons couldn’t travel far before scattering off a proton or electron. But around 380,000 years after the big bang, matter in the early universe cooled enough to become neutral hydrogen and helium, which is largely transparent to light. The CMB light we see made one last scattering before things cleared enough for it to reach us. When light scatters off something, it is oriented, or polarized, relative to that scatter. Thus all the CMB light is polarized, and its orientation tells us about the early universe.

The team used this polarization to determine the age and expansion rate of the cosmos. Just as the size of uniform temperature regions in the CMB tells us the rate of cosmic expansion, so does the size of uniform polarization regions. The team measured the polarization scale more precisely than ever before and determined the Hubble parameter is between 66.4 and 69.4 km/sec/Mpc. This gives the age of the universe as 13.77 billion years, which is consistent with Planck’s measurements of the CMB.

So now we have two independent precision measures of cosmic expansion from the CMB, and they agree. But other measurements using supernovae disagree, so there’s clearly something we don’t understand here. At this point what is clear is that some aspect of our cosmological model needs to be revised.

Reference: Choi, Steve K., et al. “The Atacama Cosmology Telescope: a measurement of the cosmic microwave background power spectra at 98 and 150 GHz.” Journal of Cosmology and Astroparticle Physics 2020.12 (2020): 045.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

Published

 on

 

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.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

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.

The Canadian Press. All rights reserved.

Source link

Continue Reading

News

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

Published

 on

 

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.

Source link

Continue Reading

News

B.C. sets up a panel on bear deaths, will review conservation officer training

Published

 on

 

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.

The Canadian Press. All rights reserved.

Source link

Continue Reading

Trending

Exit mobile version