On Wednesday, public alarm broke out due to the news that Earth’s magnetic poles could be about to flip.

Interest in the planet’s magnetic poles has suddenly risen following reports of an impending geomagnetic reversal. Experts said that many times over the past 20 million years, our planet’s poles have reversed. This means that every now and then, the north and south magnetic poles swap places.

According to Daniel Baker, director of the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder, the planet’s weakening magnetic field could be a sign that the poles may soon flip. Evidence indicates that the Earth’s magnetic field has weakened by 15% in the last 200 years.

This is alarming news. The magnetic field is one of the only things protecting us from solar winds and other extraterrestrial threats. However, some experts say it’s not that big of a deal.

In a book written by Alana Mitchell, the author quoted Baker’s comments, writing:

“The dangers: devastating streams of particles from the sun, galactic cosmic rays, and enhanced ultraviolet B rays from a radiation-damaged ozone layer, to name just a few of the invisible forces that could harm or kill living creatures.”

While Baker believes that a geomagnetic reversal would render many parts of our planet uninhabitable, NASA believes otherwise. In an article published by the U.S. space agency in 2011 titled “2012: Magnetic Pole Reversal Happens All The (Geologic) Time,” NASA explained that there has been no real indication that Earth’s magnetic field has disappeared completely in the past or has been the source of such catastrophe.

“A weaker field would certainly lead to a small increase in solar radiation on Earth – as well as a beautiful display of aurora at lower latitudes – but nothing deadly. Moreover, even with a weakened magnetic field, Earth’s thick atmosphere also offers protection against the sun’s incoming particles,” NASA said.

Earth’s magnetic poles are at the north and south end of a powerful magnetic field. This protective barrier surrounds our planet. Interestingly, the field is powered by the gradual cooling of our planet’s liquid, iron-rich core.

According to researchers, 99 percent of the magnetic field remains within the planet’s core. However, one percent of it manages to escape into space and acts as another barrier that protects us from dangerous solar winds and radiation.

To date, geophysicists still don’t have any concrete explanation about why geomagnetic reversal or the flipping of magnetic poles happen. However, many of them agree that it has something to do with the planet’s metallic outer core.

The last complete reversal happened over 700,000 years ago. The event is called the Brunhes-Matuyama reversal after its discoverers, Bernard Brunhes and Motonori Matuyama. In the last 20 million years, it’s estimated that our planet’s magnetic field has flipped once every 200,000 to 300,000 thousand years. If that’s the case, we’re more than 20,000 years or so overdue for even a geomagnetic change.

While the Earth’s magnetic field tends to weaken by around 5% per decade, it doesn’t necessarily mean that a reversal will happen anytime soon. There’s no reason for panic as reversals don’t happen in a blink of an eye or overnight. According to the University of Leeds professor Phil Livermore, it takes about one thousand to five thousand years for a reversal to be completed.

Even if the magnetic field weakens, Livermore emphasized that the risks are low. Based on fossil record from the Brunhes-Matuyama reversal period, both animals and plants were fine. However, should solar weather bring highly energetic particles into our atmosphere, it could affect electrical infrastructures and power grids. This could potentially cause major blackouts in the surface of our planet. However, although it could significantly damage our global infrastructure, it will have no significant direct impact on the health of humans, plants and other living organisms.

Scientists measure the magnetic field of the black hole binary V404 Cygni, revealing a significantly weaker magnetic field than previously thought. Black holes are famous for their muscle: an intense gravitational pull known to gobble up entire stars and launch streams of matter into space at almost the speed of light.

Image on the top: An illustration of a black hole. Credit: Michael McAleer, University of Florida

It turns out the reality may not live up to the hype.

In a paper published today in the journal Science, University of Florida scientists have discovered these tears in the fabric of the universe have significantly weaker magnetic fields than previously thought.

A 40-mile-wide black hole 8,000 light years from Earth named V404 Cygni yielded the first precise measurements of the magnetic field that surrounds the deepest wells of gravity in the universe. Study authors found the magnetic energy around the black hole is about 400 times lower than previous crude estimates.

The measurements bring scientists closer to understanding how black holes’ magnetism works, deepening our knowledge of how matter behaves under the most extreme conditions — knowledge that could broaden the limits of nuclear fusion power and GPS systems.

The measurements also will help scientists solve the half-century-old mystery of how “jets” of particles traveling at nearly the speed of light shoot out of black holes’ magnetic fields, while everything else is sucked into their abysses, said study co-author Stephen Eikenberry, a professor of astronomy in UF’s College of Liberal Arts and Sciences.

“The question is, how do you do that?” Eikenberry said. “Our surprisingly low measurements will force new constraints on theoretical models that previously focused on strong magnetic fields accelerating and directing the jet flows. We weren’t expecting this, so it changes much of what we thought we knew.”

Study authors developed the measurements from data collected in 2015 during a black hole’s rare outburst of jets. The event was observed through the lens mirror of the 34-foot Gran Telescopio Canarias, the world’s largest telescope, co-owned by UF and located in Spain’s Canary Islands, with the help of its UF-built infrared camera named CIRCE (Canarias InfraRed Camera Experiment).

Smaller jet-producing black holes, like the one observed for the study, are the rock stars of galaxies. Their outbursts occur suddenly and are short-lived, said study lead author Yigit Dalilar and co-author Alan Garner, doctoral students in UF’s astronomy department. The 2015 outbursts of V404 Cygni lasted only a couple of weeks. The previous time the same black hole had a similar episode was in 1989.

“To observe it was something that happens once or twice in one’s career,” Dalilar said. “This discovery puts us one step closer to understanding how the universe works.”

Publication: Yigit Dallilar, et al., “A precise measurement of the magnetic field in the corona of the black hole binary V404 Cygni,” Science 08 Dec 2017: Vol. 358, Issue 6368, pp. 1299-1302; DOI: 10.1126/science.aan0249

Source: University of Florida

For the first time, scientists have studied the magnetic field of a black hole inside the Milky Way in multiple wavelengths - and found that it doesn't conform to what we previously thought.

According to researchers at the University of Florida and the University of Texas at San Antonio, the black hole called V404 Cygni's magnetic field is much weaker than expected - a discovery that means we may have to rework our current models for black hole jets.

V404 Cygni, located around 7,800 light-years away in the constellation of Cygnus, is a binary microquasar system consisting of a black hole about 9 times the mass of the Sun, and its companion star, an early red giant slightly smaller than the Sun.

In 2015, the system flared into life, and, over the course of about a week, periodically flashed with activity as the black hole devoured material from its companion star.

At times, it was the brightest X-ray object in the sky; but it also showed, according to NASA-Goddard's Eleonora Troja, "exceptional variation at all wavelengths" - offering a rare opportunity to study both V404 Cygni and black hole feeding activity.

It was this period that the team, led by Yigit Dallilar at the University of Florida, studied.

When black holes are active, they become surrounded by a brightly glowing accretion disc, lit by the gravitational and frictional forces that heat the material as it swirls towards the black hole.

As they consume matter, black holes expel powerful jets of plasma at near light-speed from the coronae - regions of hot, swirling gas above and below the accretion disc.

Previous research has shown that these coronae and the jets are controlled by powerful magnetic fields - and the stronger the magnetic fields close to the black hole's event horizon, the brighter its jets.

This is because the magnetic fields are thought to act like a synchrotron, accelerating the particles that travel through it.

Dallilar's team studied V404 Cygni's 2015 feeding event across optical, infrared, X-ray and radio wavelengths, and found rapid synchrotron cooling events that allowed them to obtain a precise measurement of the magnetic field.

Their data revealed a much weaker magnetic field than predicted by current models.

"These models typically talk about much larger magnetic fields at the base of the jet, which many assume to be equivalent to the corona," Dallilar told Newsweek.

"Our results indicate that these models might be oversimplified. Specifically, there may not be a single magnetic field value for each black hole."

Black holes themselves don't have magnetic poles, and therefore don't generate magnetic fields. This means that the accretion disc corona magnetic fields are somehow generated by the space around a black hole - a process that is not well understood at this point.

This result doesn't mean that previous findings showing strong magnetic fields are incorrect, but it does suggest that the dynamics may be a little more complicated than previously thought.

The team's research did find that synchrotron processes dominated the cooling events, but could not provide data on what caused the particles to accelerate in the first place. It is, as one has come to expect from black holes, a finding that answers one question and turns up a lot more in need of further research.

"We need to understand black holes in general," said researcher Chris Packhamof the University of Texas at San Antonio.

"If we go back to the very earliest point in our universe, just after the big bang, there seems to have always been a strong correlation between black holes and galaxies. It seems that the birth and evolution of black holes and galaxies, our cosmic island, are intimately linked.

The research has been published in the journal Science.

Article was originally published on ScienceAlert. Read the Original article here.