adplus-dvertising
Connect with us

Science

Brock expert explains math and science behind rarity of total solar eclipse – PelhamToday.ca

Published

 on


NEWS RELEASE
BROCK UNIVERSITY
*********************
The rarity of a total solar eclipse, set to take place over Niagara and select areas across North America April 8, can be better understood by breaking down the math and science involved, says a Brock University expert. 

The celestial phenomenon, in which the moon completely blocks the sun and turns the daytime sky dark enough to see stars for several minutes, will be a once-in-a-lifetime experience for many.

Jan Vrbik, a Professor of Mathematics who studies the movement of the sun, planets and moons, says there are four factors that make witnessing a total solar eclipse quite rare.

The distances of the sun and moon from the Earth

“Even though the sun is 400 times larger than the moon, when we look at them in the sky, they appear to be practically the same size,” says Vrbik. “This is because their distances from Earth are roughly in the same 400 to one ratio.”

It’s why the moon can obscure the sun, either partially or fully, to create a solar eclipse.  

The tilt of the moon’s orbit

The moon’s orbit around the Earth is not a perfect circle — it’s an ellipse — so the distance of the moon from Earth fluctuates depending on where it is along its orbit. 

“It varies by 11 per cent each month, which implies that the moon’s disk also fluctuates in size compared to the sun,” says Vrbik. 

About 35 per cent of the time, the moon’s disk is bigger than the sun’s disk, and the other 65 per cent of the time, it’s the reverse, he says.

The intersection of the sun and moon’s orbits 

The Earth orbits the sun once a year, while the moon circles the Earth once a month. If the sun and moon’s orbits were on the same plane, an eclipse would happen every month, but the moon’s orbit is tilted by about five degrees from the sun’s orbit. 

“This means that at most new moons, the moon is either visibly higher or lower in the sky than the sun,” says Vrbik. “Nevertheless, the moon needs to cross the plane of the sun’s orbit twice during its monthly cycle, at an intersection called a ‘node.’ Eclipses happen only when, during a new moon, the sun’s direction is closely aligned with one of these nodes, which happens regularly twice a year.”

He says 23 per cent of solar eclipses are ‘total,’ when the moon fully covers the sun, and 42 per cent are ‘annular,’ when the moon’s disk is smaller than the sun’s disk and a ‘ring of fire’ is seen. 

“Thirty-five per cent of solar eclipses run so much off the Earth’s centre that only a partial eclipse is observed on one side of the globe — with the actual path of totality missing the Earth entirely,” he says.

The moon’s shadow along the path of totality

For both an annular and total solar eclipse, the moon’s shadow needs to cross the Earth’s surface.

The size of the moon’s shadow varies depending on how close in time the event is to when the moon is at its closest to Earth. Typically, the shadow is 150 kilometres (km) in a circular area. A much larger part of the Earth’s surface, about 7,000 kms across, will at the same time experience a partial eclipse, in which only a part of the sun’s disk is covered by the moon. 

Vrbik says the shadow’s path across the globe is a combination of the moon’s straight-line motion of about one km per second and the Earth’s rotation of close to 0.5 km per second, complicated more by the fact that the Earth’s axis is tilted. 

If people are in the right place at the right time, they can witness a total solar eclipse for three to four minutes. 

Adding it all up

“When one considers the movement of the sun, the Earth and the moon, as well as their orbits, speed, distance and alignment from each other, it is easier to understand why a total solar eclipse is so rare,” says Vrbik.

While a total solar eclipse occurs on Earth every 18 months, it usually occurs over water. The last time a total solar eclipse occurred over Ontario was in 1979. The next one won’t happen again over the province until 2099.

“If you know the length of each celestial body’s cycle, you can easily predict when an eclipse will happen again,” he says. “Experiencing a total solar eclipse from a specific location is a rare privilege, typically separated from the next such occurrence by several centuries.”

Vrbik will be among a group of Brock experts leading discussions and educational exhibits around the solar eclipse during ‘Eclipse on the Escarpment,’ a free community event being held on Brock’s main campus Monday, April 8. 

*********************

Adblock test (Why?)

728x90x4

Source link

Continue Reading

News

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

Published

 on

 

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. ”

___

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

___

Follow Seth Borenstein on Twitter at @borenbears

___

Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

Source link

Continue Reading

Science

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

Published

 on

 

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.

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

Trending