Connect with us

Science

Science on the back roads could help us prepare for solar storms (5 images) – TimminsToday

Published

 on


There is science on the back roads and the new Solar Cycle 25 has begun.

The potential upswing in space weather will impact our lives and technology on Earth, as well as astronauts in space and a line of towers near Kapuskasing will play a role in understanding the effects.

The satellite-based economy is here and now, nearly all international banking, internet, television and communications are done by satellite.

Beyond the beauty of the Northern Lights, the space environment is extremely dangerous for the delicate electronic systems on every satellite. Conditions are particularly threatening during “magnetic storms” when astronauts are required to take shelter in the International Space Station and transpolar airline flights are diverted to avoid the dangerous radiation from space. These are storms that originate from the Sun and occur in space near Earth or in the Earth’s atmosphere

With the rising sophistication of our technologies and the number of people that use technology, vulnerability to space weather events has increased dramatically.

This unassuming bank of radar towers, located on Sylvain Road in Kitigan, 10 km east of Kapuskasing, are part of SuperDARN which stands for Super Dual Aurora Radar Network, it is a global program, with 35 radar sites around the globe, managed by sixteen institutes in ten countries. The SuperDARN radar outside provides valuable data over central Canada that promotes understanding of ionosphere processes and phenomena.

Researchers are looking forward to the radar contributing to the upcoming solar maximum during the new solar cycle that just started in early September.

Space Weather

“Extreme solar storms pose a threat to all forms of high-technology,” said Dr. J. Michael Ruohoniemi Associate Professor, Bradley Department of Computer and Electrical Engineering, Virginia Tech (Virginia Polytechnic Institute and State University).

He is the ‘Principle Investigator’ for the Kapusakasing (Kap) radar station as well as Goose Bay, and some others in the U.S.

“They begin with an explosion, a “solar flare”—in the magnetic canopy of a sunspot. X-rays and extreme UV radiation reach Earth at light speed, ionizing the upper layers of our atmosphere; side effects include radio blackouts and GPS navigation errors.”

Minutes to hours later, the energetic particles arrive, moving only slightly slower than light itself. Electrons and protons accelerated by the blast can electrify satellites and damage their electronics.

SuperDARN is a large international collaboration and the operation of the radar in Kapuskasing is funded by the U.S. National Science Foundation (NSF) through an award to Virginia Tech. A large group at the University of Saskatchewan operates five radars including three in the high arctic (‘PolarDARN’).

“Kap was built in 1993 and the site was selected because it has a good geometry with the radar at Saskatoon,” Ruohiniemi. “This means the fields-of-view of the two radars overlap substantially, making it possible to observe the same volume from two directions which is useful if you are trying to measure velocity. We also selected Kap because it is a substantial town with good facilities.”

He also has a personal connection to the town. “My father was born there and I visited my grandparents often as a kid and teenager. When we were looking at potential sites in northern Ontario I thought of the Experimental farm. We wound up going to the other side of town but it was a good start.”

Concern and Awareness

“Definitely the public should know about the potential dangers,” said Ruohoniemi. “The largest source of error on GPS measurements, for example, is space weather in the ionosphere. If GPS is being used to land aircraft this is a serious concern. “

There was a spectacular occurrence in 1859, known as the Carrington event, that interrupted telegraph systems.

“If we had an event of that magnitude again everyone would be aware of the damage to all the electrical systems in use today. The threat is cyclical with the 11-year sunspot cycle with more intense storms happening at the peak and declining phases. There was a near-miss due to a solar superstorm in 2012 – a really big flare went off but just missed Earth. We are in a quiet phase right now. I don’t want to sound alarmist, but yes, we should be paying attention to the danger posed by solar storms.”

The NOAA Space Weather Prediction Center issues a continuous forecast of the weather in Earth’s near-space environment. Solar flares cause impacts that can make the evening news such as the severe geomagnetic storm in 1989; an aurora was seen as far south as Texas and knocked out the Quebec power grid.

“By combining the data from all the radars we get an image of plasma flows in the ionosphere (above 100 km altitude) that looks a lot like a typical weather map with atmospheric winds,” Ruohoniemi said. “The radars, in effect, see something like a radio wave version of the visual aurora and we can use the Doppler shift on the signal coming back to estimate plasma flow velocity.”

How it Works

“Village Media readers may be familiar with Ham radio, people who have a tall antenna by their house and a little room crammed with equipment to send and receive High Frequency (HF) radio signal. Because this signal bounces off the ionosphere at heights of 100-300 km, it can be received by other Hams a great distance away. The ionosphere is highly variable because of solar storms and sometimes the Hams can make amazing connections with people on the other side of the world but can’t connect to each other a few hundred kilometres apart. Our radar works basically like a Ham radio except that we have many antennas (16) and we are interested in how the signal bounces off the ionosphere and what that tells us about the space environment, not in communicating with other people (although we could). Not very much power is required and the radars operate continuously under computer control with connections to research labs in Canada, the U.S., and other countries.”

SuperDARN has shown how the circulation of plasma in the ionosphere (‘plasma winds’) at high latitudes is tightly controlled by the solar wind. The plasma consists of ions and electrons and can move at speeds greater than 1 km per second, so these winds are incredibly fast compared to the wind that blows in the atmosphere at ground level. “When viewed from well above the North Pole, you can see the winds forming giant cells of circulation similar to atmospheric winds. When the solar wind changes, especially when its magnetic field reverses direction, the pattern of circulation can flip in a matter of minutes. By combining data from multiple SuperDARN radars we are able to image these changes as they happen and to study the physics of the sun-earth connection, which is the basis for space weather.”

The back roads hold a lot of oddities.

This bank of radar towers doesn’t appear to be anything special but when the physics behind this space weather interaction is understood it can be seen in a different light. Scientists working on predictive models will one-day forecast space weather much like meteorologists forecast weather on Earth.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

How to literally drive the coronavirus away – Deccan Herald

Published

 on


Over the past year, as health authorities have tried to curb the Covid-19 pandemic, researchers have trained their scientific attention on a variety of potentially risky environments: places where large groups of people gather and the novel coronavirus has ample opportunity to spread. They have swabbed surfaces on cruise ships, tracked case numbers in gyms, sampled ventilation units in hospitals, mapped seating arrangements in restaurants and modeled boarding procedures in airplanes.

They have paid less attention to another everyday environment: the car. A typical car, of course, does not carry nearly enough people to host a traditional superspreader event. But cars come with risks of their own; they are small, tightly sealed spaces that make social distancing impossible and trap the tiny, airborne particles, or aerosols, that can transmit the coronavirus.

“Even if you’re wearing a face covering, you still get tiny aerosols that are released every time you breathe,” said Varghese Mathai, a physicist at the University of Massachusetts, Amherst. “And if it’s a confined cabin, then you keep releasing these tiny particles, and they naturally would build up over time.”

Read: Decoding how airflow inside car may affect Covid-19 transmission risk

In a new study, Mathai and three colleagues at Brown University — Asimanshu Das, Jeffrey Bailey and Kenneth Breuer — used computer simulations to map how virus-laden airborne particles might flow through the inside of a car. Their results, published in early January in Science Advances, suggest that opening certain windows can create air currents that could help keep both riders and drivers safe from infectious diseases like Covid-19.

To conduct the study, the research team employed what are known as computational fluid dynamic simulations. Engineers commonly use these kinds of computer simulations, which model how gases or liquids move, to create race cars with lower drag, for instance, or airplanes with better lift.

The team simulated a car loosely based on a Toyota Prius driving at 50 mph with two occupants: a driver in the front left seat and a single passenger in the back right,  a seating arrangement that is common in taxis and ride shares and that maximizes social distancing. In their initial analysis, the researchers found that the way the air flows around the outside of the moving car creates a pressure gradient inside the car, with the air pressure in the front slightly lower than the air pressure in the back. As a result, air circulating inside the cabin tends to flow from the back of the car to the front.

Next, they modeled the interior air flow — and the movement of simulated aerosols — when different combinations of windows were open or closed. (The air conditioning was on in all scenarios.) Unsurprisingly, they found that the ventilation rate was lowest when all four windows were closed. In this scenario, roughly 8% to 10% of aerosols exhaled by one of the car’s occupants could reach the other person, the simulation suggested. When all the windows were completely open, on the other hand, ventilation rates soared, and the influx of fresh air flushed many of the airborne particles out of the car; just 0.2% to 2% of the simulated aerosols traveled between driver and passenger.

The results jibe with public health guidelines that recommend opening windows to reduce the spread of the novel coronavirus in enclosed spaces. “It’s essentially bringing the outdoors inside, and we know that the risk outdoors is very low,” said Joseph Allen, a ventilation expert at the Harvard T.H. Chan School of Public Health. In an op-ed last year, he highlighted the danger that cars could pose for coronavirus transmission, and the potential benefits of opening the windows. “When you have that much turnover of air, the residence time, or how much time the aerosols stay inside the cabin, is very short,” Allen said

Because it is not always practical to have all the windows wide open, especially in the depths of winter, Mathai and his colleagues also modeled several other options. They found that while the most intuitive-seeming solution — having the driver and the passenger each roll down their own windows — was better than keeping all the windows closed, an even better strategy was to open the windows that are opposite each occupant. That configuration allows fresh air to flow in through the back left window and out through the front right window and helps create a barrier between the driver and the passenger.

“It’s like an air curtain,” Mathai said. “It flushes out all the air that’s released by the passenger, and it also creates a strong wind region in between the driver and the passenger.”

Richard Corsi, an air quality expert at Portland State University, praised the new study. “It’s pretty sophisticated, what they did,” he said, although he cautioned that changing the number of passengers in the car or the driving speed could affect the results.

Read | Consumers prioritising car ownership post-coronavirus lockdown, 74% want own vehicle: Survey

Corsi, a co-author of the op-ed with Allen last year, has since developed his own model of the inhalation of coronavirus aerosols in various situations. His results, which have not yet been published, suggest that a 20-minute car ride with someone who is emitting infectious coronavirus particles can be much riskier than sharing a classroom or a restaurant with that person for more than an hour.

“The focus has been on superspreader events” because they involve a lot of people, he said. “But I think what sometimes people miss is that superspreader events are started by somebody who’s infected who comes to that event, and we don’t speak often enough about where that person got infected.”

In a follow-up study, which has not yet been published, Mathai found that opening the windows halfway seemed to provide about the same benefit as opening them fully, while cracking them just one-quarter of the way open was less effective.

Mathai said that the general findings would most likely hold for many four-door, five-seat cars, not just the Prius. “For minivans and pickups, I would still say that opening all windows or opening at least two windows can be beneficial,” he said. “Beyond that, I would be extrapolating too much.”

Ride-sharing companies should be encouraging this research, Mathai said. He sent a copy of his study to Uber and Lyft, he said, but has not received a response.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

The Olduvai Gorge gives up two-million-year-old secrets – Varsity

Published

 on


Few archaeological sites can claim to be famous, but the Olduvai Gorge in northern Tanzania is chief among them. With the word ‘olduvai’ coming from a misspelling of the Maasai word, ‘oldupai,’ a name for a plant that grows in the area, the fossil-rich region is famous for offering up some of the first evidence of fossil remains and stone tools used by early hominins, ancestors of today’s humans.

In the 1930s, Louis and Mary Leakey were working in Olduvai when they uncovered stone tools from early humans. Since then, it has become a popular archaeological site. The gorge lent an even older name — the Oldoway Gorge — to the paleolithic culture discovered there before the Abbevillian culture and, subsequently, their tools. Oldowan tools are often either large hammering stones or smaller, sharper flake stones used for cutting. They were used by precursors to modern Homo sapiens, such as Homo habilis.

Now, an international research team comprised of scientists from around the world, including from U of T, have conducted a thorough search of the Olduvai Gorge and concluded that hominins were living and building tools in the site as early as two million years ago. Moreover, their continual occupation of the gorge, extending over a 235,000-year period, shows how early hominins could adapt to changing environments — a skill that might have aided in their expansion out of Eastern Africa.

A wide source of information

The researchers combed through a wide array of sources to reach their findings. They took samples from previously excavated fossils and tools and compared them against samples of pollen, plants, and charcoal from wildfires, which were all deposited into the soil millions of years ago. The result was a pattern of human activity in the same place across time.

The prehistoric Olduvai landscape contained a variety of environments, such as streams, floodplains, woody forest, dry steppe, and even patches of land covered by ash from volcanic activity. Early hominins were able to exploit all of these environments, partly by bringing materials they needed for tools with them. Some of the rocks used to make tools originated 12 kilometres from where they were found. Others were made using what was at hand.

However, it is not clear which hominin species made these tools, largely because no new fossils were found. One possible candidate is Homo habilis because their fossils have been excavated nearby.

Rethinking the past

Oldowan tools have been excavated in nearby Ethiopia dating back to 2.6 million years ago, so this study does not represent the earliest discovery of stone tools. But it does extend the timeline of the Olduvai Gorge specifically. Previously, the oldest use of tools in the region was dated to 1.85 million years ago, so these findings push that start point by about 150,000 years. 

Moreover, these new findings demonstrate that early hominins had a robust ability to adapt to new environments. Julio Mercader Florin, lead author and professor at the University of Calgary, wrote in The Conversation that “This is a clear sign that 2 million years ago humans were not constrained technologically and already had the capacity to expand geographic range.”

The researchers discovered that the tools used remained the same regardless of what environment they were found in. It might have been human adaptability, then, that enabled our ancestors to thrive in the Olduvai Gorge and beyond.

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Test fire of NASA's SLS moon rocket ends prematurely – CTV News

Published

 on


NASA’s Space Launch System rocket ignited its four main engines Saturday on a test stand in Mississippi, but the engines shut down earlier than the agency planned.

The hot fire test was the last of eight tests that make up what NASA calls a “green run,” a series of ground tests aimed at ensuring the vehicle doesn’t have any major structural or engineering issues before it is put on a launch pad. The rocket is the most powerful launch vehicle the space agency has ever constructed.

The SLS was supposed to light its engines for about eight minutes, the length of time the engines will have to fire to propel the rocket on its orbital missions.

It’s not yet clear why the engines powered down after little more than a minute at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. The test was still useful for gathering data and “teams are assessing the data on early engine shutdown,” the space agency tweeted.

During a Saturday night news conference, John Honeycutt, the SLS program manager, said NASA officials will go over the data gathered in the test to identify the issue.

“What we learned was — is that we didn’t have the pressurization valve modeled appropriately,” Honeycutt said.

Officials had hoped to run the test for at least 250 seconds, he said.

During the hot fire test, engineers “power up all the core stage systems, load more than 700,000 gallons of cryogenic, or supercold, propellant into the tanks and fire all four engines at the same time,” according to NASA.

It is unclear if another test will be needed before the rocket is shipped to Florida, the launch site where the rocket is expected to make its first journey into outer space.

Rick Gilbrech, director of the Stennis Space Center, said his site would need at least four to five days to prepare the fuel for another test if the rocket is ready. He and his team aren’t discouraged by Saturday’s test and are proud of what they’ve accomplished this year, especially during the Covid-19 pandemic, he said.

NASA administrator Jim Bridenstine said the test was “not a failure.”

“This is not a failure. This is a test, and we tested today in a way that is meaningful where we’re going to learn … we’re going to make adjustments, and we’re going to fly to the moon,” he said.

“This was a successful day. We didn’t get everything we wanted and yes we’re going to learn, we’re going to have to make adjustments,” he said. “But again, this is a test. And this is why we test.”

 

Yet another delay

 

SLS has been haunted by critiques of long delays and cost overruns, and with the premature end of the critical hot fire test, its launch may be delayed once again.

“We got lots of data that we’re going to go through and be able to sort through and get to a point where we can make determinations as to whether or not, you know, launching in 2021 is a possibility or not,” Bridenstine said.

The rocket is a key part of NASA’s Artemis lunar exploration program, which aims to send the first woman and next man to the moon by 2024. NASA officials also hope the SLS will be used to reach Mars and other “deep space destinations.”

SLS has been under development for a decade. Under the Obama administration, NASA was already planning to use SLS to take astronauts back to the moon by 2028, and that remained the plan until Vice President Mike Pence directed the space agency to drastically accelerate its timeline in 2019.

Boeing was contracted in 2012 to build SLS’s main components, and the rocket was originally expected to start flying in December 2017. But Boeing has been blasted in several government oversight reports for “poor performance,” costly schedule slips and ballooning expenses. That made SLS a touchy political talking point, and many in the space industry remain suspicious that a 2024 moon landing is possible.

At one point, Bridenstine reportedly considered skipping the green run test to expedite SLS’s development. But more recently he has asserted that the tests are essential to ensuring the rocket is safe enough to carry humans into space and to work out any potential engineering problems before attempting an orbital launching.

Bridenstine is expected to step down when President-elect Joe Biden is inaugurated next week. It’s not clear if NASA will stick with the 2024 timeline under the new administration, though the official Democratic platform calls for “continuity” in NASA’s space programs between presidential administrations.

The SLS rocket stands taller than the Statue of Liberty and has about 15% more thrust at liftoff than the Saturn V rockets that powered the Apollo missions about 50 years ago.

NASA’s Artemis I mission is expected to launch by the end of 2021 with two test flights around the moon without astronauts.

A crewed test mission, Artemis II, is set to launch in 2023 in preparation to have the Artemis III mission return astronauts to the surface of the moon in 2024 for the first time since the 1970s.

Artemis is named after the Greek goddess of the moon and is the twin sister of Apollo, which was name NASA used for the missions and spacecraft that first took Americans to the moon in 1969.

Let’s block ads! (Why?)



Source link

Continue Reading

Trending