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Accretion Of A Giant Planet Onto A White Dwarf Star

The Neptune-sized planet, which orbits an Earth-sized star, is being slowly evaporated by the white dwarf, causing the planet to lose some 260 million tons of material every day.

For the first time, astronomers have discovered evidence for a giant planet orbiting a tiny, dead white dwarf star. And, surprisingly, the Neptune-sized planet is more than four times the diameter of the Earth-sized star it orbits.

"This star has a planet that we can't see directly. But because the star is so hot, it is evaporating the planet, and we detect the atmosphere it is losing. In fact, the searing star is sending a stream of vaporized material away from the planet at a rate of some 260 million tons per day." Boris Gänsicke from the University of Warwick said in a press release.

The new discovery serves as the first evidence of a gargantuan planet surviving a star's transition to a white dwarf. It suggests that evaporating planets around dead stars may be somewhat common throughout the universe. And because our Sun, like most stars, will also eventually evolve into a white dwarf, the finding could even shed light on the fate of our solar system.

The white dwarf in question, dubbed WDJ0914+1914, sits about 1,500 light-years away in the constellation Cancer. Although the white dwarf is no longer undergoing nuclear fusion like a normal star, its lingering heat means it's still a blistering 49,500 degrees Fahrenheit (25,000 Celsius). That’s some five times hotter than the Sun.

Researchers initially flagged the smouldering stellar core for follow-up after sifting through about 7,000 white dwarfs identified by the Sloan Digital Sky Survey. When the team analyzed the unique spectra of WDJ0914+1914, they detected the chemical fingerprints of hydrogen, which is somewhat unusual. But they also picked out signs of oxygen and sulfur — elements they had never seen in a white dwarf before.

In order to get a better grasp of what was happening in the strange system, the team of researchers used the X-shooter instrument on the ESO's Very Large Telescope in Chile to carry out follow-up observations. Based on the more detailed look, the researchers learned that the unusual elements they thought were embedded in the white dwarf were actually coming from a disk of gas churning around the dead star.

"At first, we thought that this was a binary star with an accretion disk formed from mass flowing between the two stars. However, our observations show that it is a single white dwarf with a disk around it roughly 10 times the size of our Sun, made solely of hydrogen, oxygen and sulfur. Such a system has never been seen before, and it was immediately clear to me that this was a unique star." said Gänsicke.

After realizing just how unusual the white dwarf really was, the team shifted their focus to figuring out what the heck could create such a system.

"It took a few weeks of very hard thinking to figure out that the only way to make such a disk is the evaporation of a giant planet," said Matthias Schreiber, an astronomer at the University of Valparaiso in Chile, who was vital to determining the past and future evolution of the bizarre system. Their detailed analysis of the disk's composition matched what astronomers would expect if the guts of an ice giant like Uranus and Neptune were vaporized into space.

Based on Schreiber's calculations, the white dwarf's extreme temperature means it's bombarding the nearby giant planet — which is located 0.07 astronomical unit (AU) from the star, where 1 AU is the Earth-Sun distance — with high-energy photons. This is causing the planet to lose its mass at a rate of more than 3,000 tons per second.

But according to the paper, published Wednesday in Nature, "As the white dwarf continues to cool, the mass-loss rate will gradually decrease, and become undetectable in about 350 million years. And by then, the paper adds, the giant planet only will have lost "an insignificant fraction of its total mass," or about 0.04 Neptune masses.

Because the giant planet is located so close to the white dwarf, the researchers say it should have been destroyed during the stars' red giant phase. That is unless it migrated inward after the star transitioned to a white dwarf. 

"This discovery is major progress because over the past two decades we had growing evidence that planetary systems survive into the white dwarf stage," said Gänsicke. "We've seen a lot of asteroids, comets, and other small planetary objects hitting white dwarfs, and explaining these events requires larger, planet-mass bodies farther out. Having evidence for an actual planet that itself was scattered in is an important step."

The ultimate fate of our solar system. In 5 billion years, when the Sun burns through the last of the hydrogen in its core, it will move on to fusing concentric shells of hydrogen around its now-inert core. This unstable process will cause the Sun to balloon into a red giant, meaning it will swallow Mercury, Venus, and likely Earth.

But as the Sun expands, its gravitational grasp on its outer envelope of material gets more and more tenuous. Eventually, it will shed its outer layers into space. And once it does that, an alien astronomer would see a beautiful planetary nebula surrounding the Sun's burnt-out, incredibly hot core — known as a white dwarf.

In a companion paper also published Wednesday in Astrophysical Journal Letters, Schreiber and Gänsicke explore this scenario, detailing how the future white-dwarf Sun should, like WDJ0914+1914, evaporate our solar system's giant planets.

What If We had Two Suns in The Solar System?

For a long time, this was a purely theoretical question. Over the past decade or so, however, astronomers have found more than a dozen confirmed instances of “circumbinary planets”—that is, planets that orbit around a close double star.

A particularly interesting case is the planet Kepler-1647b, which circles two roughly sunlike stars. This planet also resides in the “habitable zone,” the region around the two stars where the planet could have the right temperature for liquid water.

What if Earth had two suns instead of one? Let’s consider a simple scenario. Suppose we replaced the sun with two closely matched stars, each half as bright as the Sun. In that case, the amount of energy reaching the Earth would still be the same, and life would still be possible here. Such equal-mass binaries are not uncommon, so this scenario seems perfectly plausible.

The mass of each of our new suns would be about 85% of the mass of our current sun. That may seem surprising, but the luminosity of a star is extremely sensitive to mass. Roughly speaking, luminosity goes as the 4th power of mass, so doubling the mass of a star increases its brightness by a factor of 16. A 15% mass reduction is enough to cut a star’s brightness in half.

The combined mass of Sun 1 and Sun 2 would be 1.7 times the mass of our current sun. Since their total gravity would be stronger, the length of a year would be a bit less: about 280 days instead of 365 days. Not that radical of a change, really.

So far so good. But would the Earth be stable in its new configuration, orbiting around two stars instead of one? The case of Kepler-1647b and other circumbinary stars gives a strong YES answer here. As long as the distance to the planet is at least about 4 times as great as the separation between the two stars, the planet just happily orbits around the stars’ centre of mass. If Sun 1 and Sun 2 are less than 15 million kilometres apart, then all of the planets in the solar system (even Mercury) could potentially be stable.

Just to be safe, let’s put the stars closer together, about 5 million kilometres apart. That’s not so different than the two stars of Kepler-1647, which are about 7 million miles apart. Our Sun 1 and Sun 2 would orbit each other once every 10 days or so. They would also each rotate with a 10-day period, which would make them a little more active than our current sun, but not outrageously so. The Kepler-1647 stars are reasonably peaceful.

The two suns would probably appear to orbit each other roughly edge-on as seen from Earth, which would lead to a strange new phenomenon: an eclipse of the sun by another sun! Because of the 10-day orbit, Sun 1 and Sun 2 would pass in front of each other every 5 days. The eclipses would last about 6 hours, and at peak would reduce the amount of energy reaching the Earth by about 30%–40%, depending on the exact geometry.

Eclipse days would be chilly, but the periods of reduced sunshine would be brief enough to average out smoothly into Earth’s overall climate. The double suns wouldn’t even look all that strange in the sky. At maximum separation, Sun 1 and Sun 2 would be only 2 degrees apart in the sky, just enough to give shadows a double edge. For about a half-day on either side of an eclipse, they'd seem to merge, though if they slipped behind a cloud you'd see an odd, oval shape from the overlapping disks. Sunsets would be pretty, a little different each night.

All the evidence so far, then, is that a planet like Tatooine in Star Wars really could exist, and Earth would do just fine if it were orbiting a double star instead of our one lonely sun. There’s really just one huge unsettled question: Could such a planet form in the first place?

Kepler-1647b is a giant gas planet, nearly twice the mass of Jupiter. Even the smallest known circumbinary planet, called Kepler-453b, is a heavyweight, bigger than Neptune.

It may be that the environment around a double star is too chaotic to create small, rocky planets like Earth. Then again, it’s also possible that other Earths with two suns are common, and our telescopes simply are not sensitive enough to find them. At least, not yet.

Fortunately, better instruments are coming soon. In the coming decade, the PLATO space telescope and huge new ground-based observatories like the Giant Magellan Telescope and the Extremely Large Telescope will tell us a lot more about all kinds of planets around other stars—including possible Earthlike planets with double suns lighting up their skies.

Black Holes Are Strange Sure But White Holes Are Mind-Blowing

White holes are black ones in reverse, spewing out matter– and they could give us our first glimpse of the quantum source of space-time.

In the textbooks, Gravitation and Cosmology, Nobel prizewinning physicist Steven Weinberg wrote that the existence of black holes “very hypothetical”, there is no [black hole] in the gravitational field of any known object of the universe”. He was dead wrong. Radio astronomers had already been detecting signals from matter falling into black holes for decades without realising. Today we have lots of evidence that the sky is teeming with them.

The story may now be repeating itself with white holes, which are essentially black holes in reverse. In another renowned textbook, the world-leading relativity theorist Bob Wald wrote that “there is no reason to believe that any region of the universe corresponds to” a white hole – and this is still the dominant opinion today. But several research groups around the world have recently begun to investigate the possibility that quantum mechanics could open a channel for these white holes to form. The sky might be teeming with white holes, too.

The reason to suspect white holes exist is that they could solve an open mystery: what goes on at the centre of a black hole. We see great amounts of matter spiralling around black holes and then falling in. All this falling matter crosses the surface of the hole, the “horizon” or point of no return, plummets towards the centre, and then? Nobody knows.

White holes are completely theoretical mathematical concepts. In fact, if you do black hole mathematics for a living, I'm told, ignoring the mass of the singularity makes your life so much easier.

They are not things that actually proven to exist. It's not like astronomers detected an unusual outburst of radiation and then developed hypothetical white hole models to explain them.

if white holes did exist, they would behave like reverse black holes – just like the math predicts. Instead of pulling material inward, a white hole would blast material out into space like some kind of white chocolate fountain.

White Holes only theoretically exist as long as there isn't a single speck of matter within the event horizon. As soon as a single atom of hydrogen drifted into the region, the whole thing would collapse. Even if white holes were created back at the beginning of the universe, they would have collapsed long ago, since our universe is already filled with stray matter.

In theory, a black hole singularity would compress down until the smallest possible size predicted by physics. Then it would rebound as a white hole. But because of the severe time dilation effect around a black hole, this event would take billions of years for even the lowest mass ones to finally get around to popping.

If there were microscopic black holes created after the Big Bang, they might get around to decaying and exploding as white holes any day now. Except, according to Stephen Hawking, they would have already evaporated.

Another interesting idea put forth by physicists is that a white hole might explain the Big Bang since this is another situation where a tremendous amount of matter and energy spontaneously appeared.

White Hole exists or not is still a mystery but it's a very fascinating topic. The more we study and understand our universe, the more our brain gets blown away.

This Star Just Won't Stop Exploding!

This star has been going nova every year, for millions of years. A nova star is like a vampire that siphons gas from its binary partner. As it does so, the gas is compressed and heated, and eventually, it explodes. The remnant gas shell from that explosion expands outward and is lit up by the stars at the centre of it all. Most of these novae explode about once every 10 years.

But now astrophysicists have discovered one remnant so large that the star that created it must have been erupting yearly for millions of years. The team of astrophysicist published their findings in a letter in the journal Nature.

The star in question is in the Andromeda galaxy, and it’s called M31N 2008-12a. When it erupts as a nova, it brightens by a million times and the ejected material travels outward at thousands of miles per second. The team behind the study thinks that M32N 2008-12a goes nova every year, and the result is what they’re calling a “super remnant” that measures almost 400 light-years across.

The team of astrophysicists, which includes members from San Diego State University and from the Liverpool John Moores University in England, used observations from the Hubble Space Telescope and ground-based telescopes. They studied the chemical composition of the expanding remnant to confirm its association with the star at the centre, M31N 2008-12a.

The interesting thing about this distant nova is its possible connection to something larger in the Universe, something that astronomers inherently rely on to understand the Universe: Type 1a Supernovae.

Most people are familiar with supernovae overall. A star several times more massive than our Sun eventually burns enough of the hydrogen in its core that the outward pressure from its own fusion can’t sustain itself against the inward force of its own gravity. The whole star collapses in on itself and then explodes outward in one of nature’s most powerful and most luminous phenomenon.

But that’s just one type of supernova. There are other types, including the Type 1a. A type 1a supernovae start with two normal stars in a binary pair. As the pair ages together, one-star inevitably becomes more massive than the other. The large one will start to siphon off-gas from the other, expanding and engulfing the smaller star in its envelope.

Eventually, the two stars spiral together in their common envelope of gas, and as time goes on, the common envelope of gas is ejected away from the binary pair. Then things get interesting again.

The core of the larger star collapses and becomes a white dwarf. The other star is ageing, too, and eventually, it can’t hold onto its outer layers of gas. The white dwarf begins to siphon off the gas, and once it gains enough mass, it breaches what’s known as its Chandrasekhar limit, which is the maximum mass limit for a white dwarf star.

Once that limit is breached, a couple different things can happen. A bunch of the white dwarf’s mass can undergo rapid nuclear fusion, brightness increases to about 5 billion times that of our Sun, and an expanding shock wave is ejected at several thousand km per second, leaving behind only a pretty-much dead zombie star.

It can go another way, too. The explosion can completely destroy the star, leaving behind only the expanding shell. Those are pretty rare events, and the last one of those in our galaxy was in the 1600s.

Or, we get a nova. In a nova, the white dwarf erupts every so often, shedding any mass in excess of its Chandrasekhar limit. This is what appears to be the case with M31N 2008-12a, but what’s unusual is that it’s happening every year, instead of every 10 years or so. So what’s that all about?

The exact nature of these events is not understood. We have theories that explain them, but we don’t know all the detail. Our current theory says that as these novae flare up frequently, creating a massive remnant like this one, they harbour a white dwarf that is getting closer and closer to its Chandrasekhar limit, and will eventually exceed it. The astronomers think that M31N 2008-12a is on its way to becoming a supernova.

The reason all of this matters is that these type 1a supernovae have another name in astronomy: standard candles. Standard candles are very useful objects. They give off a predictable, uniform light. Astronomers measure the light from standard candles in distant galaxies to find out how far away those galaxies are, and to measure the rate of expansion of the Universe.

This study has isolated one such standard candle, in effect before it becomes one. Observing it might help us understand where these standard candles come from, how they form, and how plentiful they might be.

The team is hoping to find more of these massive remnants, to see if they can find more white dwarfs undergoing repeated eruptions like this one, and to confirm that they lead to standard-candle supernovae. They want to know if this one is a rarity, or if there is an unseen population of stars like M31N 2008-12a.

As the authors say in their study, “The discovery of additional super-remnants around other accreting white dwarfs will point to systems undergoing regular eruptions over long periods of time.” How long of a period of time? According to the authors, the white dwarf in this binary system will exceed its Chandrasekhar limit in about 40,000 years. At that time, any astronomers still alive will be able to watch what happens. 

They will either witness the destruction of the star in a massive explosion, or a core-collapse to a neutron star. Either way, the chemical composition of the underlying white dwarf will finally be revealed, and we’ll learn something about recurring novae and standard candles.

Cryonics | Can We Cheat Death?

In pursuit of life everlasting, some turn to God. Others turn to science. Medicine is aimed at improving and extending healthy lives but it can't stop the ultimate frontier DEATH. But with evolving technology, we might have a way around it in future. Until then what to do? Here comes in rescue Cryonics.

Cryonics is the practice of preserving human bodies in extremely cold temperatures with the hope of reviving them sometime in the future. The idea is that, if some­one has "died" from a disease that is incurable today, he or she can be "frozen" and then revived in the future when a cure has been discovered. A person preserved this way is said to be in cryonic suspension.

To understand the technology behind cryonics, think about the news stories you've heard of people who have fallen into an icy lake and have been submerged for up to an hour in the frigid water before being rescued. The ones who survived did so because the icy water put their body into a sort of suspended animation, slowing down their metabolism and brain function to the point where they needed almost no oxygen.

If you've ever hoped to be cryogenically frozen, you might come across a legal hurdle: while human cryonics is legal in several countries, you have to be dead before going into the cryonics tank. Otherwise, freezing someone alive is tantamount to killing. People who undergo this procedure must first be pronounced legally dead -- that is, their heart must have stopped beating.

But if they're dead, how can they ever be revived? According to scientists who perform cryonics, "legally dead" is not the same as "totally dead." Total death, they say, is the point at which all brain function ceases. Legal death occurs when the heart has stopped beating, but some cellular brain function remains. Cryonics preserves the little cell function that remains so that, theoretically, the person can be resuscitated in the future.

Until the day comes that humanity masters the art of resurrection, so scientists can reanimate them and cure their ailments or upload their consciousness into the cloud, whichever comes first. Who simply hope to be cryopreserved go throw cryonic suspension process after pronounced legally dead. 

The first body to be frozen with the hope of future revival was James Bedford's, a few hours after his cancer-caused death in 1967. His body was frozen by Robert Nelson, a former TV repairman with no scientific background before the body was turned over to Bedford's relatives. Bedford's corpse is the only one frozen before 1974 still preserved today. In 1976, Ettinger founded the Cryonics Institute; his corpse was cryopreserved in 2011. Nelson was sued in 1981 for allowing nine bodies to thaw and decompose in the 1970s; in his defence, he claimed that the Cryonics Society of California had run out of money.

As of now, four facilities exist in the world to retain cryopreserved bodies: three in the U.S. and one in Russia.

Russian cryonics company KrioRus plans to buy a bunker in Switzerland and convert it to a cryopreservation lab. People with one foot in the grave could fly in from around the world and be placed in a cryopreservation tank.

KrioRus is the first Eurasian company to preserve people and pets, hosting 50 human bodies or heads and 20 animals in tanks in Moscow and St. Petersburg. They have so far only worked with people who have been declared legally dead. Freezing your body is $36,000 and ahead will set you back $12,000.

There's no guarantee that the pursuit of pre-mortem freezing will go anywhere, let alone conquer mortality. Perhaps the field of cryonics is just trading one eternal, icy embrace for another.

What Happens To Our Brain As We Get Older?

Brain ageing is inevitable to some extent, but not uniform; it affects everyone, or every brain, differently. Slowing down brain ageing or stopping it altogether would be the ultimate elixir to achieve eternal youth. Are there steps, we can take to reduce the rate of decline?

At around 3 Kg in weight, the human brain is a staggering feat of engineering with around 100 billion neurons interconnected via trillions of synapses. Throughout our lifetime our brain changes more than any other part of our body. From the moment the brain begins to develop in the third week of gestation to old age, its complex structures and functions are changing, networks and pathways connecting and severing.

During the first few years of life, a child's brain forms more than 1 million new neural connections every second. The size of the brain increases fourfold in the preschool period and by age 6 reaches around 90% of adult volume.

The frontal lobes - the area of the brain responsible for executive functions, such as planning, working memory and impulse control - are among the last areas of the brain to mature, and they may not be fully developed until 35 years of age.

As we age, all our body systems gradually decline - including the brain. "Slips of the mind" are associated with getting older. People often experienced those same slight memory lapses in their 20s and yet did not give it a second thought.

Older individuals often become anxious about memory slips due to the link between impaired memory and Alzheimer's disease. However, Alzheimer's and other dementias are not a part of the normal ageing process.

Common memory changes that are associated with normal ageing include 1. Difficulty learning something new: Committing new information to memory can take longer. 2. Multitasking: Slowed processing can make processing and planning parallel tasks more difficult. 3. Recalling names and numbers: Strategic memory that helps the memory of names and numbers begins to decline at age 20. 4.  Remembering appointments: Without cues to recall the information, appointments can be put safely in storage and then not accessed unless the memory is jogged.

While some studies show that one-third of older people struggle with declarative memory (memories of facts or events that have been stored and can be retrieved), other studies indicate that one-fifth of 70-year-olds perform cognitive tests just as well as their 20-year-old counterparts.

Scientists are currently piecing together sections of the giant puzzle of brain research to determine how the brain subtly alters over time to cause these changes. General changes that are thought to occur during brain ageing include: 

1. Brain mass: Shrinkage in the frontal lobe and hippocampus - areas involved in higher cognitive function and encoding new memories - starting around the age of 60 or 70 years.

2.Cortical density: Thinning of the outer-ridged surface of the brain due to declining synaptic connections. Fewer connections may contribute to slower cognitive processing.

3.White matter: White matter consists of myelinated nerve fibres that are bundled into tracts and carry nerve signals between brains cells. Myelin is thought to shrink with age, and as a result, slow processing and reduce cognitive function.

4.Neurotransmitter systems: Researchers suggest that the brain generates less chemical messengers with ageing, and it is this decrease in dopamine, acetylcholine, serotonin, and norepinephrine activity that may play a role in declining cognition and memory and increased depression.

Several brain studies are ongoing to solve the brain-ageing conundrum, and discoveries are being frequently made. Recently, researchers from Albert Einstein College of Medicine in New York revealed in a mouse study that stem cells in the brain's hypothalamus likely control how fast ageing occurs in the body.

"Our research shows that the number of hypothalamic neural stem cells naturally declines over the life of the animal, and this decline accelerates ageing," says Dr. Dongsheng Cai, Ph.D., professor of molecular pharmacology at Einstein. "But we also found that the effects of this loss are not irreversible. By replenishing these stem cells or the molecules they produce, it's possible to slow and even reverse various aspects of ageing throughout the body."

Injecting hypothalamic stem cells into the brains of normal old mice and middle-aged mice, whose stem cells had been destroyed, slowed or reversed measures of ageing. The researchers say this is a first step toward slowing the ageing process and potentially treat age-related diseases.

While many questions remain regarding the ageing brain, research is making progress in illuminating what happens to our cognitive functions and memory throughout our lifetime, and it is emphasizing ways we can preserve our mental abilities to improve our quality of life as we advance into older adulthood.

Insulin Should Be Cheap. Here’s Why It's Not

When inventor Frederick Banting discovered insulin in 1923, he refused to put his name on the patent. He felt it was unethical for a doctor to profit from a discovery that would save lives. Banting’s co-inventors, James Collip and Charles Best, sold the insulin patent to the University of Toronto for a mere $1. They wanted everyone who needed their medication to be able to afford it.

Today, Banting and his colleagues would be spinning in their graves: Their drug, which many people with diabetes rely on, has become the poster child for pharmaceutical price gouging.

The cost of the four most popular types of insulin has tripled over the past decade, and the out-of-pocket prescription costs patients now face have doubled. By 2016, the average price per month rose to $450 — and costs continue to rise, so much so that as many as one in four people with diabetes are now skimping on or skipping lifesaving doses.

The ‘big three’ insulin producers – Eli Lilly, Novo Nordisk and Sanofi – dominate more than 90% of the world insulin market by value. Often only one of these companies supplies insulin in a country, which means they more or less hold a monopoly there and can set prices as they wish. In some countries like  India and China, there are domestic insulin companies that help drive down the price. 

When it comes to the question of generic insulin, we are faced with another complicated issue. Insulin is a therapeutic biological product (or 'biologic'), rather than a chemically synthesized molecule. This means it cannot be made as generic in the same way as other drugs. Creating what is called a biosimilar is a lot more complicated and expensive than just duplicating a chemical molecule.

There is a little market incentive to produce biosimilars because it costs nearly as much as making a new drug and companies must go through all the approval stages and trials that a new drug is required to go through. Not to mention, current biosimilar insulins on the market – primarily produced by the ‘big three’ – have only reduced the price by about 10-15%.

A ‘Pay for delay’ agreement is a patent dispute settlement in which a generic (in the case of insulin, a biosimilar) manufacturer acknowledges the original patent of a pharmaceutical company and agrees to refrain from marketing its product for a specific period of time. In return, the company receives a payment from the patent-holder. This means it is actually legal for one insulin producer to pay another one not to enter the market.

A few years ago the company Merck announced plans to sell a biosimilar version of Sanofi’s Lantus. Sanofi sued, and eventually, Merck announced that it was no longer pursuing its biosimilar, presumably due to payments from Sanofi to stay away. If Pay for delay schemes don’t work, the ‘big three’ can still sue other players, prolonging processes and pushing players out of the market because of legal fees and time-wasting. All of these are win-wins for companies and lose-lose for patients.

Physicians in many countries are allowed to collect fees from pharmaceutical companies for talks, advice and more. Supposedly, these are to compensate physicians for their expertise and time. However, they can create loyalty to a company and may influence prescribing habits – a belief shared by some pharmaceutical salespeople. In countries like India, physicians are allowed to sell and profit off insulin directly through patients, or through pharmacies they themselves own, cutting out middlemen and the retail pharmacies. Thus, they lose the incentive to find the lowest price insulin for their patients. Insulin companies also focus on ‘insulin-starts’, or the insulin the physician diagnosing patients begins with. As patients are reluctant to change, a number of marketing and financial incentives are employed to influence this decision.

Patients are speaking out about these issues all around the world. In the USA where prices have skyrocketed especially, T1International Chapters are being formed where patient advocates are educating and pushing for policy change.

An Afterglow Of GRB That Featured The Highest Energy Photons

Gamma-ray bursts (GRBs) are the most powerful explosions in the cosmos. These explosive events last a fraction of a second to several minutes and emit the same amount of gamma rays as all the stars in the universe combined. Such extreme amounts of energy can only be released during catastrophic events like the death of a very massive star or the merging of two compact stars, and are accompanied by an afterglow of light over a broad range of energies that fades with time.

It has been decades since the discovery of the first gamma-ray burst, yet some of their fundamental traits remain unclear. An international team of researchers, including two astrophysicists from the George Washington University, Chryssa Kouveliotou and Alexander van der Horst, now has taken the next step in understanding the physical processes at work during these events with a recent discovery published today in the journal Nature.

The researchers observed a gamma-ray burst with an afterglow that featured the highest energy photons -- a trillion times more energetic than visible light -- ever detected in a burst.

"This very high energy emission had been previously predicted in theoretical studies but never before directly observed," Dr. van der Horst, an assistant professor of physics at GW, said.

"After over 45 years of observing GRBs, we just confirmed the existence of yet another unknown component in their afterglows, which increases the gamma-ray burst overall energy budget dramatically," Dr. Kouveliotou, a professor of physics at GW, added.

On Jan. 14, 2019, researchers detected a burst labelled GRB 190114C. The discovery triggered an extensive campaign of observations across the electromagnetic spectrum using more than 20 observatories and instruments around the world. This collaborative effort allowed an international team to gather an unprecedented level of information about GRB 190114C, capturing the evolution of the gamma-ray burst afterglow emission across 17 orders of magnitude in energy.

As part of the joint efforts, Dr. van der Horst and Dr. Kouveliotou were part of a subteam responsible for tracking the emission of radio waves in the afterglow of GRB 190114C. The team used the new MeerKAT radio telescope in South Africa to record the emission, which is at the opposite end of the spectrum compared to very high energy gamma rays.

"MeerKAT is a new radio observatory with very good sensitivity," Dr. van der Horst said. "It is a great facility to observe this kind of event. Our team is carrying out a multi-year program to observe many more gamma-ray bursts and other cosmic explosions in the coming years."

GRB 190114C is unique in that researchers were able to observe photons with teraelectronvolt (TeV) energies for the first time in its afterglow emission. Using the MAGIC Collaboration telescopes in La Palma, Spain, researchers noticed this emission of TeV photons was 100 times more intense than the brightest known steady source at TeV energies, the Crab Nebula. As expected though, this very high energy emission quickly faded in about half an hour after the event onset, while the afterglow emission in other parts of the spectrum persisted for much longer.

The researchers noted that the shape of the observed spectrum of afterglow light was indicative of an emission process called inverse Compton emission. This event supports the possibility that inverse Compton emission is commonly produced in gamma-ray bursts.

"MAGIC, the TeV photon detector in La Palma, Spain, opened up a new window for research on gamma-ray bursts," Dr. Kouveliotou said. "We are looking forward to understanding their physics and true energy release in gamma-ray bursts with more detections in the future."

What Would Happen If A Gamma Ray Bursts Hit The Earth?

From the big freeze to the big crunch, planet x to strangelets converting all normal matter into strange matter. The likelihood of any of those events happening are very small. Nevertheless — that does not mean the Earth is not in danger of some cataclysmic event taking place before the sun swells into a red-giant, overtaking the orbits of the innermost planets in our solar system. 

Now, I thought it was only fitting to discuss the possibility of a gamma-ray burst bathing our planet in deadly cosmic rays or gamma radiation…especially since most of the other scenarios are not nearly as horrifying as being baked alive, leaving the rest of the planet to die a slow, painful, suffocating death!

Gamma-ray bursts are a special flavour of a supernova. As the core of a massive stars collapses to form a black hole or a neutron star/pulsar, the outer layers explode outwards, producing two high-powered beams of gamma radiation. These gamma-ray bursts are capable of producing more raw energy than our sun will produce in its entire lifespan, all in a few quick moments. 

While the beams are extremely energetic and damaging to anything that lies in their path, they are also very narrow. The beams would have to be aimed straight toward an object before striking it. Of course, there would be no warning, since the particles travel at nearly the speed of light. Thus, the particles would reach us at almost the same time as the light from the supernova.

Assuming the beam of harmful rays did hit Earth, it would be capable of doing irreparable damage to Earth’s atmosphere — maybe even causing a mass extinction event that eradicates humankind entirely. Even a short burst that lasts 10 seconds could deplete over 25% of our ozone later, sending a barrage of ultraviolet rays to the surface of the planet. Even the damage our species has done to the ozone layer over thousands of years would be nothing in comparison to those numbers. The best estimate scientists have given thus far puts the depletion of the ozone layer between 3% to 4% to date.

A nearby gamma-ray burst could also trigger smog formation that’s capable of blocking out a percentage of our sunlight, potentially cooling the planet down exponentially. In this scenario, gamma rays would break apart nitrogen molecules in our air and transform them into nitrogen dioxide, which has a reddish-brown hue. 

Since nitrogen dioxide is water-soluble, it would precipitate acid rain on our planet like the Earth’s evil twin, Venus. The side of our planet that was bathed in the radiation would be far more damaged than the side that was facing away at the time when it arrived.

It would be the equivalent of that entire portion of the planet being blasted with a nuclear explosion. In fact, evidence has been uncovered that suggests such a beam of radiation might have hit Earth back in the 8th century

let's not panic! There are many uncertainties about these gamma-ray bursts that are not well understood. First, we aren’t sure when a nearby star will go supernova. It could happen any time in the next hundred or thousand years. Nor are we even sure if stars like WR 104 are capable of producing certain gamma-ray bursts in the first place. More gamma-ray bursts must be observed before the evidence is conclusive!

A Nearby Gamma Ray Burst Might Have Caused The Ordovician Extinction

Despite the obvious doom and gloom associated with mass extinctions, they have a tendency to capture our imagination. After all, the sudden demise of the dinosaurs, presumably due to an asteroid strike, is quite an enthralling story.

But not all mass extinctions are quite as dramatic and not all have an easily identified culprit. The Ordovician extinction (one of the “big five” in Earth’s history) occurred around 450 million years ago when the population of marine species plummeted. Evidence suggests that this occurred during an ice age and a Gamma-Ray burst is one of several possible mechanisms that may have triggered this extinction event.

Gamma-Ray Bursts (GRBs) are the brightest electromagnetic blasts known to occur in the Universe and can originate from the collapse of the most massive types of stars or from the collision of two neutron stars. Supernovae are stellar explosions that also can send harmful radiation hurtling towards Earth. Both GRBs and supernovae are usually observed in distant galaxies but can pose a threat if they occur closer to home, where they can strip the Earth’s upper atmosphere of its protective ozone layer leaving life exposed to harmful ultraviolet radiation from the Sun.

Normally, the ozone layer in the upper atmosphere shields the Earth’s surface from harmful ultraviolet light. But a GRB or supernova would quickly eviscerate that layer. As the UV rays penetrate the planet’s surface they would break apart oxygen molecules and ground-level ozone would form, according to Washburn University astrophysicist Brian Thomas.

We see this kind of ozone on hot, polluted days when smog alerts warn us to stay indoors for health reasons. But would the ground-level ozone created after a GRB pose a longterm biological threat? Thomas and his colleague Byron Goracke investigated the severity of this ground-level ozone and its potential effects on life using an atmospheric model to simulate a particular case of a GRB occurring over the South Pole.

“A GRB could happen over any latitude or time but we chose the South Pole mainly to look at a very high depletion case,” explains Thomas. “When the radiation enters the atmosphere over a pole, the depletion is concentrated there instead of spread around the globe.”

This is because the radiation produces chemical changes in the middle atmosphere and atmospheric transport from this region is mainly towards the pole making the effect of the GRB most extreme in this location. A burst at the South Pole fits in with theories of the Ordovician extinction because the measured extinction rates match the models that predict latitude-dependent biological damage.

Thomas and his team of researchers used computer models to determine that the amount of ozone present in the lower atmosphere following a GRB concentrated on the South Pole is around 10 parts per billion (ppb) and this amount varies with the seasons.

However, it takes at least 30 ppb of ozone to increase the risk of death due to respiratory failure in humans. Ground-level ozone can also damage plants by reducing chlorophyll production or killing the cells outright, but once again there needs to be at least 30 ppb in the atmosphere before ozone becomes a risk to vegetation.

Ozone is also water-soluble, which is particularly relevant to the Ordovician mass extinction as most life at the time was marine life. If all of the 10 ppb of ozone generated by a GRB became dissolved in the oceans, it would still only have a very minor impact, if any, on some bacteria and fish larvae, and wouldn’t have played a part in the Ordovician mass extinction. It’s quite clear, therefore, that a GRB event alone does not cause the kind of elevated ground-level ozone that’s deadly to life.

However, this negative result is still vital to understanding what would or wouldn’t happen to the Earth’s atmosphere and its inhabitants following the energy from a GRB or supernova reaching our planet. A GRB would deplete the ozone layer in the upper atmosphere, allowing harmful UV radiation to reach the ground and thus have dire consequences for life. However, the ground-level ozone caused by the GRB would not be an additional hazard for life.

Understanding what causes mass extinctions is also important for the search for life in the Universe. Discovering a planet that ticks all the boxes for habitability may sound promising, but perhaps less so if a GRB or supernova recently occurred nearby. In the hunt for the life we also need to consider the possibility that any life that might have existed on a distant planet could already be extinct.

What If The Earth Had Two Moons?

The idea of an Earth with two moons has been a science fiction staple for decades. The properties of the Moon’s far side has many scientists thinking that another moon used to orbit the Earth before smashing into the Moon and becoming part of its mass. But what if the Earth actually had a second permanent moon today? How different would life be?

Our Earth-Moon system is unique in the solar system. The Moon is 1/81 the mass of Earth while most moons are only about 3/10,000 the mass of their planet. The size of the Moon is a major contributing factor to complex life on Earth. It is responsible for the high tides that stirred up the primordial soup of the early Earth. It’s the reason our day is 24 hours long. It gives light for the variety of life forms that live and hunt during the night and it keeps our planet’s axis tilted at the same angle to give us a constant cycle of seasons.

A second moon would change that. And it wouldn't be pretty. Imagine the Moon's identical twin comes hurtling by and is trapped by Earth's gravity. As it settles into orbit, halfway between Earth and our original moon, it yanks violently at the oceans. In the real world, this is how our original Moon helps generate tides.

So, the second moon would amplify the effect. Causing peak tides that would be 6 times higher, eroding shorelines and flooding many of our world's greatest cities including New York, Singapore, London, Mumbai - gone.

But not all destruction would happen on Earth. The combined pull of the planet and the original moon would also yank on the second moon. The second moon would be caught in a tug of war between Earth and the original moon. The gravitational pull back and forth from both ends would warp the second moon's surface triggering tremendous volcanic activity. Flooding the second moon's surface with red-hot rivers of lava. Just like hundreds of the volcanoes you see today on Jupiter's hellish moon, Io.

But even that's not the end of the spectacle. Right now, our current moon is spiralling away from Earth at 3.8 cm a year. That's about how fast your fingernails grow. At the same time, it pulls on the Earth slowing down the planet's rotation. Which is actually lengthening our days by around 1 second every 40,000 years. It may not sound like much, but with two moons in place, it would accelerate this process even more.

Millions of years from now, the day will have grown by 16%! Lasting longer than 28 hours! Now, a little extra time in the day may sound pretty nice, but here's the problem: the extra moon would drift towards the current Moon. And that's where the real danger comes in.

After millions of years, the two moons would collide! The impact would be so massive it would rip the very core of the moons apart. Lava would erupt from their centre - like a runny egg in space. Casting a vivid red light in the sky on Earth. Meanwhile, debris would go hurtling in all directions, where some of it would inevitably strike Earth, forming massive craters miles wide.

It would be an apocalypse for all life on Earth. And what didn't hit the planet would instead be trapped by Earth's gravity. Forming a ring of debris around the equator. Similar to the rings around Saturn - but not for long. Within just a few years, those chunks would clump together, forming one large, single body. 

Perhaps any life that survived will call it the Moon or maybe something even better. Anyhow, There would be many other indirect and far-reaching effects on Earth due to the presence of two moons. So as it turns out, it’s good that we have only one moon and it’s even better that it’s going to stay that way in the near future.

Limitless Fusion Power Using Plasma Guns!!!

Generating endless energy with zero emissions by just slamming hydrogen atoms together has been somewhat of a pipe dream for decades. Building a fusion reactor isn't that hard, all things considered. But building a useful one is a different matter. Now, scientists may be getting a tiny step closer to feasible fusion power, thanks to a futuristic experiment and dozens of plasma guns. 

Eighteen of 36 plasma guns are in place on the machine that could make fusion power a reality. Those guns are the key components of Los Alamos National Laboratory's Plasma Liner Experiment (PLX), which uses a new approach to the problem. PLX, if it works, will combine two existing methods of slamming single-proton hydrogen atoms together to form two-proton helium atoms. That process generates enormous amounts of energy per speck of fuel, much more than splitting heavy atoms (fission) does. The hope is that the method pioneered in PLX will teach scientists how to create that energy efficiently enough to be worthwhile for real-world use.
The promise of fusion is that it produces tons of energy. Every time two hydrogen atoms merge into helium, a small portion of their matter converts into a whole lot of energy. The problem of fusion is that no one's figured out how to generate that energy in a useful way.

The principles are simple enough, but the execution is the challenge. Right now, there are plenty of hydrogen-fusion bombs in the world that can release all their energy in a flash and destroy themselves (and everything else around for miles). The occasional kid even manages to build a tiny, inefficient fusion reactor in their playroom. But existing fusion reactors suck up more energy than they create. No one's yet managed to create a controlled, sustained fusion reaction that spits out more energy than gets consumed by the machine creating and containing the reaction.

The first of the two methods PLX combines is called magnetic confinement. This is what's used in fusion reactors called tokamaks, which use powerful magnets to suspend the superheated, ultradense plasma of fusing atoms inside the machine so it keeps fusing and doesn't escape. The biggest of these is ITER, a 25,000-ton (23,000 metric tons) machine in France. But that project has faced delays and cost overruns, and even optimistic projections suggest it won't be complete until the 2050s.

The second approach is called inertial confinement. Lawrence Livermore National Laboratory, another Department of Energy facility, has a machine called the National Ignition Facility (NIF) that is taking this route to fusion. The NIF is basically a very big system for firing super-powerful lasers at tiny fuel cells containing hydrogen. When the lasers hit the fuel, the hydrogen heats up and trapped within the fuel cell fuses. The NIF is operational, but it doesn't generate more energy than it uses.

PLX, according to a statement from the American Physical Society (APS), is a little different than either of those two. It uses magnets to contain its hydrogen, like a tokamak. But that hydrogen is brought to fusion temperatures and pressures by hot jets of plasma shooting out of the guns arrayed around the device's spherical chamber, employing the guns instead of lasers like those used at NIF.

The physicists leading the PLX project have done some early experiments using the 18 guns already installed, according to APS. Those experiments have offered researchers early data on how the plasma jets behave when they collide inside the machine and researchers presented that data on Oct. 21 at the Annual Meeting of the APS Division of Plasma Physics in Fort Lauderdale, Florida. That data is important, the researchers said, because there are contradictory theoretical models of exactly how plasma behaves when it collides in these sorts of collisions.

Los Alamos said that the team hopes to install the remaining 18 guns in early 2020 and conduct experiments using the full 36-plasma-gun battery by the end of that year.

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