What’s a safe distance between us and a supernova?

By EarthSky in ASTRONOMY ESSENTIALS | SPACE | May 11, 2018

And how many potentially exploding stars are located within the unsafe distance?

A supernova is a star explosion – destructive on a scale almost beyond human imagining. If our sun exploded as a supernova, the resulting shock wave probably wouldn’t destroy the whole Earth, but the side of Earth facing the sun would boil away. Scientists estimate that the planet as a whole would increase in temperature to roughly 15 times hotter than our normal sun’s surface. What’s more, Earth wouldn’t stay put in orbit. The sudden decrease in the sun’s mass might free the planet to wander off into space. Clearly, the sun’s distance – 8 light-minutes away – isn’t safe. Fortunately, our sun isn’t the sort of star destined to explode as a supernova. But other stars, beyond our solar system, will. What is the closest safe distance? Scientific literature cites 50 to 100 light-years as the closest safe distance between Earth and a supernova.

What would happen if a supernova exploded near Earth? Let’s consider the explosion of a star besides our sun, but still at an unsafe distance. Say, the supernova is 30 light-years away. Dr. Mark Reid, a senior astronomer at the Harvard-Smithsonian Center for Astrophysics, has said:

… were a supernova to go off within about 30 light-years of us, that would lead to major effects on the Earth, possibly mass extinctions. X-rays and more energetic gamma-rays from the supernova could destroy the ozone layer that protects us from solar ultraviolet rays. It also could ionize nitrogen and oxygen in the atmosphere, leading to the formation of large amounts of smog-like nitrous oxide in the atmosphere.

What’s more, if a supernova exploded within 30 light-years, phytoplankton and reef communities would be particularly affected. Such an event would severely deplete the base of the ocean food chain.

Suppose the explosion were slightly more distant. An explosion of a nearby star might leave Earth and its surface and ocean life relatively intact. But any relatively nearby explosion would still shower us with gamma rays and other high-energy radiation. This radiation could cause mutations in earthly life. Also, the radiation from a nearby supernova could change our climate.

No supernova has been known to erupt at this close distance in the known history of humankind. The most recent supernova visible to the eye was Supernova 1987A, in the year 1987. It was approximately 168,000 light-years away.

Before that, the last supernova visible to the eye was was documented by Johannes Kepler in 1604. At about 20,000 light-years, it shone more brightly than any star in the night sky. It was even visible in daylight! But it didn’t cause earthly effects, as far as we know.

How many potential supernovae are located closer to us than 50 to 100 light-years? The answer depends on the kind of supernova.

A Type II supernova is an aging massive star that collapses. There are no stars massive enough to do this located within 50 light-years of Earth.

But there are also Type I supernovae – caused by the collapse of a small faint white dwarf star. These stars are dim and hard to find, so we can’t be sure just how many are around. There are probably a few hundred of these stars within 50 light-years.

The star IK Pegasi B is the nearest known supernova progenitor candidate. It’s part of a binary star system, located about 150 light-years from our sun and solar system.

The main star in the system – IK Pegasi A – is an ordinary main sequence star, not unlike our sun. The potential Type I supernova is the other star – IK Pegasi B – a massive white dwarf that’s extremely small and dense. When the A star begins to evolve into a red giant, it’s expected to grow to a radius where the white dwarf can accrete, or take on, matter from A’s expanded gaseous envelope. When the B star gets massive enough, it might collapse on itself, in the process exploding as a supernova. Read more about the IK Pegasi system from Phil Plait at Bad Astronomy.

What about Betelgeuse? Another star often mentioned in the supernova story is Betelgeuse, one of the brightest stars in our sky, part of the famous constellation Orion. Betelgeuse is a supergiant star. It is intrinsically very brilliant.

Such brilliance comes at a price, however. Betelgeuse is one of the most famous stars in the sky because it’s due to explode someday. Betelgeuse’s enormous energy requires that the fuel be expended quickly (relatively, that is), and in fact Betelgeuse is now near the end of its lifetime. Someday soon (astronomically speaking), it will run out of fuel, collapse under its own weight, and then rebound in a spectacular Type II supernova explosion. When this happens, Betelgeuse will brighten enormously for a few weeks or months, perhaps as bright as the full moon and visible in broad daylight.

When will it happen? Probably not in our lifetimes, but no one really knows. It could be tomorrow or a million years in the future. When it does happen, any beings on Earth will witness a spectacular event in the night sky, but earthly life won’t be harmed. That’s because Betelgeuse is 430 light-years away. Read more about Betelgeuse as a supernova.

How often do supernovae erupt in our galaxy? No one knows. Scientists have speculated that the high-energy radiation from supernovae has already caused mutations in earthly species, maybe even human beings.

One estimate suggests there might be one dangerous supernova event in Earth’s vicinity every 15 million years. Another says that, on average, a supernova explosion occurs within 10 parsecs (33 light-years) of the Earth every 240 million years. So you see we really don’t know. But you can contrast those numbers to the few million years humans are thought to have existed on the planet – and four-and-a-half billion years for the age of Earth itself.

And, if you do that, you’ll see that a supernova is certain to occur near Earth – but probably not in the foreseeable future of humanity.

Bottom line: Scientific literature cites 50 to 100 light-years as the closest safe distance between Earth and a supernova.

See also: http://earthsky.org/space/what-will-happen-when-our-sun-dies

Reference: http://earthsky.org/astronomy-essentials/supernove-distance

Fermilab Achieves Milestone Beam Power for Neutrino Experiments

The U.S. Department of Energy’s Fermi National Accelerator Laboratory has achieved a significant milestone for proton beam power. On Jan. 24, the laboratory’s flagship particle accelerator delivered a 700-kilowatt proton beam over one hour at an energy of 120 billion electronvolts.

The Main Injector accelerator provides a massive number of protons to create particles called neutrinos, elusive particles that influence how our universe has evolved. Neutrinos are the second-most abundant matter particles in our universe. Trillions pass through us every second without leaving a trace.

Because they are so abundant, neutrinos can influence all kinds of processes, such as the formation of galaxies or supernovae. Neutrinos might also be the key to uncovering why there is more matter than antimatter in our universe. They might be one of the most valuable players in the history of our universe, but they are hard to capture and this makes them difficult to study.

“We push always for higher and higher beam powers at accelerators, and we are lucky our accelerator colleagues live for a challenge,” said Steve Brice, head of Fermilab’s Neutrino Division. “Every neutrino is an opportunity to study our universe further.”

With more beam power, scientists can provide more neutrinos in a given amount of time. At Fermilab, that means more opportunities to study these subtle particles at the lab’s three major neutrino experiments: MicroBooNE, MINERvA and NOvA.

“Neutrino experiments ask for the world, if they can get it. And they should,” said Dave Capista, accelerator scientist at Fermilab. Even higher beam powers will be needed for the future international Deep Underground Neutrino Experiment, to be hosted by Fermilab. DUNE, along with its supporting Long-Baseline Neutrino Facility, is the largest new project being undertaken in particle physics anywhere in the world since the Large Hadron Collider.

“It’s a negotiation process: What is the highest beam power we can reasonably achieve while keeping the machine stable, and how much would that benefit the neutrino researcher compared to what they had before?” said Fermilab accelerator scientist Mary Convery.

“This step-by-step journey was a technical challenge and also tested our understanding of the physics of high-intensity beams,” said Fermilab Chief Accelerator Officer Sergei Nagaitsev. “But by reaching this ambitious goal, we show how great the team of physicists, engineers, technicians and everyone else involved is.” The 700-kilowatt beam power was the goal declared for 2017 for Fermilab’s accelerator-based experimental program.

Particle accelerators are complex machines with many different parts that change and influence the particle beam constantly. One challenge with high-intensity beams is that they are relatively large and hard to handle. Particles in accelerators travel in groups referred to as bunches.

Roughly one hundred billion protons are in one bunch, and they need their space. The beam pipes – through which particles travel inside the accelerator – need to be big enough for the bunches to fit. Otherwise particles will scrape the inner surface of the pipes and get lost in the equipment.

Such losses, as they’re called, need to be controlled, so while working on creating the conditions to generate a high-power beam, scientists also study where particles get lost and how it happens. They perform a number of engineering feats that allow them to catch the wandering particles before they damage something important in the accelerator tunnel.

To generate high-power beams, the scientists and engineers at Fermilab use two accelerators in parallel. The Main Injector is the driver: It accelerates protons and subsequently smashes them into a target to create neutrinos. Even before the protons enter the Main Injector, they are prepared in the Recycler.

The Fermilab accelerator complex can’t create big bunches from the get-go, so scientists create the big bunches by merging two smaller bunches in the Recycler. A small bunch of protons is sent into the Recycler, where it waits until the next small bunch is sent in to join it. Imagine a small herd of cattle, and then acquiring a new herd of the same size. Rather than caring for them separately, you allow the two herds to join each other on the big meadow to form a big herd. Now you can handle them as one herd instead of two.

In this way Fermilab scientists double the number of particles in one bunch. The big bunches then go into the Main Injector for acceleration. This technique to increase the number of protons in each bunch had been used before in the Main Injector, but now the Recycler has been upgraded to be able to handle the process as well.

“The real bonus is having two machines doing the job,” said Ioanis Kourbanis, who led the upgrade effort. “Before we had the Recycler merging the bunches, the Main Injector handled the merging process, and this was time consuming. Now, we can accelerate the already merged bunches in the Main Injector and meanwhile prepare the next group in the Recycler. This is the key to higher beam powers and more neutrinos.”

Fermilab scientists and engineers were able to marry two advantages of the proton acceleration technique to generate the desired truckloads of neutrinos: increase the numbers of protons in each bunch and decrease the delivery time of those proton to create neutrinos.

“Attaining this promised power is an achievement of the whole laboratory,” Nagaitsev said. “It is shared with all who have supported this journey.”

The new heights will open many doors for the experiments, but no one will rest long on their laurels. The journey for high beam power continues, and new plans for even more beam power are already under way.

Reference: http://military-technologies.net/2017/01/26/fermilab-achieves-milestone-beam-power-for-neutrino-experiments/

Diamonds are Forever

Published on Nov 28, 2016

New technology has been developed that uses nuclear waste to generate electricity in a nuclear-powered battery. A team of physicists and chemists from the University of Bristol have grown a man-made diamond that, when placed in a radioactive field, is able to generate a small electrical current. The development could solve some of the problems of nuclear waste, clean electricity generation and battery life.

Press release: http://www.bristol.ac.uk/news/2016/november/diamond-power.html

See also: http://bigthink.com/philip-perry/scientists-turn-nuclear-waste-in-diamond-batteries-thatll-last-for-thousands-of-years

Asteroid, discovered yesterday, swept past

By Gianluca Masi in SPACE | November 2, 2016

Astronomers discovered asteroid 2016 VA on November 1, 2016, just hours before it passed within 0.2 times the moon’s distance of Earth.

The near-Earth asteroid 2016 VA was discovered by the Mt. Lemmon Sky Survey in Arizona (USA) on 1 Nov. 2016 and announced later the same day by the Minor Planet Center. The object was going to have a very close encounter with the Earth, at 0.2 times the moon’s distance – about 75,000 km [46,000 miles]. At Virtual Telescope Project we grabbed extremely spectacular images and a unique video showing the asteroid eclipsed by the Earth.

The image above is a 60-seconds exposure, remotely taken with “Elena” (PlaneWave 17?+Paramount ME+SBIG STL-6303E robotic unit) available at Virtual Telescope. The robotic mount tracked the extremely fast (570″/minute) apparent motion of the asteroid, so stars are trailing. The asteroid is perfectly tracked: it is the sharp dot in the center, marked with two white segments. At the imaging time, asteroid 2016 VA was at about 200,000 km [124,000 miles] from us and approaching. Its diameter should be around 12 meters or so.

During its fly-by, asteroid 2016 VA was also eclipsed by the Earth’s shadow. We covered the spectacular event, clearly capturing also the penumbra effects.

The movie below is an amazing document showing the eclipse. Each frame comes from a 5-seconds integration.

Asteroid 2016 VA eclipsed by Earth’s shadow. Image via Virtual Telescope Project.

The eclipse started around 23:23:56 UT and ended about at 23:34:46. To our knowledge, this is the first video ever of a complete eclipse of an asteroid. Some hot pixels are visible on the image. At the eclipse time, the asteroid was moving with an apparent motion of 1500″/minutes and it was at about 120,000 km [75,000 miles] from the Earth, on its approaching route. You can see here a simulation of the eclipse as if you were on the asteroid.

Click here to see this article at the Virtual Telescope Project

Help support The Virtual Telescope Project!

Bottom line: An asteroid called 2016 VA was discovered on November 1, 2016 and passed closest to Earth – within 0.2 times the moon’s distance – a few hours later. Gianluca Masi of the Virtual Telescope Project caught images of the asteroid as it swept by.

References:
http://earthsky.org/space/near-earth-asteroid-2016-va-november-1-2016
http://www.virtualtelescope.eu/the-planevawe-17″-f6-8-4322939-mm-corrected-dall-kirkham-astrograph-paramount-me-stl-6303e/

A Manhattan Exhibit With Antiquity on the Clock

In a Roman mosaic from antiquity, a man on a street studies the sundial atop a tall column. The sun alerts him to hurry if he does not want to be late for a dinner invitation.

Sundials were ubiquitous in Mediterranean cultures more than 2,000 years ago. They were the clocks of their day, early tools essential to reckoning the passage of time and its relationship to the larger universe.

The mosaic image is an arresting way station in a new exhibition, ”Time and the Cosmos in Greco-Roman Antiquity,” that opened last week in Manhattan at the Institute for the Study of the Ancient World, an affiliate of New York University. It will continue until April.

The image’s message, the curator Alexander Jones explains in the exhibition catalog, is clearly delivered in a Greek inscription, which reads, “The ninth hour has caught up.” Or further translated by him into roughly modern terms, “It’s 3 p.m. already.” That was the regular dinnertime in those days.

Dr. Jones, the institute’s interim director, is a scholar of the history of exact science in antiquity. He further imagined how some foot-dragging skeptics then probably lamented so many sundials everywhere and the loss of simpler ways, when “days were divided just into morning and afternoon and one guessed how much daylight remained by the length of one’s own shadow without giving much thought to punctuality.”

An even more up-to-date version of the scene, he suggested, would show a man or a woman staring at a wristwatch or, even better, a smartphone, while complaining that our culture “has allowed technology and science to impose a rigid framework of time on our lives.”

Jennifer Y. Chi, the institute’s exhibition director, said: “The recurring sight of people checking the time on their cellphones or responding to a beep alerting them to an upcoming event are only a few modern-day reminders of time’s sway over public and private life. Yet while rapidly changing technology gives timekeeping a contemporary cast, its role in organizing our lives owes a great deal to the ancient Greeks and Romans.”

The exhibition features more than 100 objects on loan from international collections, including a dozen or so sundials. One is a rare Greek specimen from the early 3rd century B.C. The large stone instruments typically belonged to public institutions or wealthy landowners.

A few centuries later, portable sundials were introduced. Think of pocket watches coming in as movable timekeepers in place of the grandfather clock in the hall or on the mantel. They were first mentioned in ancient literature as the pendant for traveling. The earliest surviving one is from the first century A.D.

Six of these small sundials are displayed in the exhibition. These were owned and used mostly as prestige objects by those at the upper echelons of society and by the few people who traveled to faraway latitudes.

A bronze sundial in the center of one gallery is marked for use in 30 localities at latitudes ranging from Egypt to Britain. Few people in antiquity were ever likely to travel that widely.

A small sundial found in the tomb of a Roman physician suggested that it was more than a prestige object. The doctor happened to be accompanied with his medical instruments and pills for eye ailment, as seen in a display. Presumably he needed a timekeeper in dispensing doses. He may have also practiced some ancient medical theories in which astrology prescribed certain hours as good or bad for administering meals and medicine.

Apparent time cycles fascinated people at this time. One means of keeping track of these cycles was the parapegma, a stone slab provided with holes to represent the days along with inscriptions or images to interpret them. Each day, a peg was moved from one hole to the next. The appearances and disappearances of constellations in the night sky yielded patterns that served as signs of predictable weather changes in the solar year of 365 or 366 days. Not to mention when conditions are favorable for planting and reaping. Not to mention good or bad luck would follow.

For many people, astrology was probably the most popular outgrowth of advances in ancient timekeeping. Astrology — not to be confused with modern astronomy — emerged out of elements from Babylonian, Egyptian and Greek science and philosophy in the last two centuries B.C. Because the heavens and the earth were thought to be connected in so many ways, the destinies of nations as well as individuals presumably could be read by someone with expertise in the arrangements of the sun, the moon, the known planets and constellations in the zodiac.

Wealthy people often had their complete horoscopes in writing and zodiacal signs portrayed in ornamental gems, especially if they deemed the cosmic configuration at their conception or birth to be auspicious.

It is said that the young Octavian, the later emperor Augustus, visited an astrologer to have his fortune told. He hesitated at first to disclose the time and date of his birth, lest the prediction turn out to be inauspicious. He finally relented.

Universe steps on the gas

09/01/16 By Shannon Hall
A puzzling mismatch is forcing astronomers to re-think how well they understand the expansion of the universe.


Astronomers think the universe might be expanding faster than expected.

If true, it could reveal an extra wrinkle in our understanding of the universe, says Nobel Laureate Adam Riess of the Space Telescope Science Institute and Johns Hopkins University. That wrinkle might point toward new particles or suggest that the strength of dark energy, the mysterious force accelerating the expansion of the universe, actually changes over time.

The result appears in a study published in The Astrophysical Journal this July, in which Riess’s team measured the current expansion rate of the universe, also known as the Hubble constant, better than ever before.

In theory, determining this expansion is relatively simple, as long as you know the distance to a galaxy and the rate at which it is moving away from us. But distance measurements are tricky in practice and require using objects of known brightness, so-called standard candles, to gauge their distances.

The use of Type Ia supernovae—exploding stars that shine with the same intrinsic luminosity—as standard candles led to the discovery that the universe was accelerating in the first place and earned Riess, as well as Saul Perlmutter and Brian Schmidt, a Nobel Prize in 2011.

The latest measurement builds on that work and indicates that the universe is expanding by 73.2 kilometers per second per megaparsec (a unit that equals 3.3 million light-years). Think about dividing the universe into grids that are each a megaparsec long. Every time you reach a new grid, the universe is expanding 73.2 kilometers per second faster than the grid before.

Although the analysis pegs the Hubble constant to within experimental errors of just 2.4 percent, the latest result doesn’t match the expansion rate predicted from the universe’s trajectory. Here, astronomers measure the expansion rate from the radiation released 380,000 years after the Big Bang and then run that expansion forward in order to calculate what today’s expansion rate should be.

It’s similar to throwing a ball in the air, Riess says. If you understand the state of the ball (how fast it’s traveling and where it is) and the physics (gravity and drag), then you should be able to precisely predict how fast that ball is traveling later on.

“So in this case, instead of a ball, it’s the whole universe, and we think we should be able to predict how fast it’s expanding today,” Riess says. “But the caveat, I would say, is that most of the universe is in a dark form that we don’t understand.”

The rates predicted from measurements made on the early universe with the Planck satellite are 9 percent smaller than the rates measured by Riess’ team—a puzzling mismatch that suggests the universe could be expanding faster than physicists think it should.

David Kaplan, a theorist at Johns Hopkins University who was not involved with the study, is intrigued by the discrepancy because it could be easily explained with the addition of a new theory, or even a slight tweak to a current theory.

“Sometimes there’s a weird discrepancy or signal and you think ‘holy cow, how am I ever going to explain that?’” Kaplan says. “You try to come up with some cockamamie theory. This, on the other hand, is something that lives in a regime where it’s really easy to explain it with new degrees of freedom.”

Kaplan’s favorite explanation is that there’s an undiscovered particle, which would affect the expansion rate in the early universe. “If there are super light particles that haven’t been taken into account yet and they make up some smallish fraction of the universe, it seems that can explain the discrepancy relatively comfortably,” he says.

But others disagree. “We understand so little about dark energy that it’s tempting to point to something there,” says David Spergel, an astronomer from Princeton University who was also not involved in the study. One explanation is that dark energy, the cause of the universe’s accelerating expansion, is growing stronger with time.

“The idea is that if dark energy is constant, clusters of galaxies are moving apart from each other but the clusters of galaxies themselves will remain forever bound,” says Alex Filippenko, an astronomer at the University of California, Berkeley and a co-author on Riess’ paper. But if dark energy is growing in strength over time, then one day—far in the future—even clusters of galaxies will get ripped apart. And the trend doesn’t stop there, he says. Galaxies, clusters of stars, stars, planetary systems, planets, and then even atoms will be torn to shreds one by one.

The implications could—literally—be Earth-shattering. But it’s also possible that one of the two measurements is wrong, so both teams are currently working toward even more precise measurements. The latest discrepancy is also relatively minor compared to past disagreements.

“I’m old enough to remember when I was first a student and went to conferences and people argued over whether the Hubble constant was 50 or 100,” says Spergel. “We’re now in a situation where the low camp is arguing for 67 and the high camp is arguing for 73. So we’ve made progress! And that’s not to belittle this discrepancy. I think it’s really interesting. It could be the signature of new physics.”

Reference: http://www.symmetrymagazine.org/article/universe-steps-on-the-gas

Funneling fundamental particles

Neutrinos are tricky. Although trillions of these harmless, neutral particles pass through us every second, they interact so rarely with matter that, to study them, scientists send a beam of neutrinos to giant detectors. And to be sure they have enough of them, scientists have to start with a very concentrated beam of neutrinos.

To concentrate the beam, an experiment needs a special device called a neutrino horn.

An experiment’s neutrino beam is born from a shower of short-lived particles, created when protons traveling close to the speed of light slam into a target. But that shower doesn’t form a tidy beam itself: That’s where the neutrino horn comes in.

Once the accelerated protons smash into the target to create pions and kaons — the short-lived charged particles that decay into neutrinos — the horn has to catch and focus them by using a magnetic field. The pions and kaons have to be focused immediately, before they decay into neutrinos: Unlike the pions and kaons, neutrinos don’t interact with magnetic fields, which means we can’t focus them directly.

Without the horn, an experiment would lose 95 percent of the neutrinos in its beam. Scientists need to maximize the number of neutrinos in the beam because neutrinos interact so rarely with matter. The more you have, the more opportunities you have to study them.

“You have to have tremendous numbers of neutrinos,” said Jim Hylen, a beam physicist at Fermilab. “You’re always fighting for more and more.”

Also known as magnetic horns, neutrino horns were invented at CERN by the Nobel Prize-winning physicist Simon van der Meer in 1961. A few different labs used neutrino horns over the following years, and Fermilab and J-PARC in Japan are the only major laboratories now hosting experiments with neutrino horns. Fermilab is one of the few places in the world that makes neutrino horns.

“Of the major labs, we currently have the most expertise in horn construction here at Fermilab,” Hylen said.

How they work

The proton beam first strikes the target that sits inside or just upstream of the horn. The powerful proton beam would punch through the aluminum horn if it hit it, but the target, which is made of graphite or beryllium segments, is built to withstand the beam’s full power. When the target is struck by the beam, its temperature jumps by more than 700 degrees Fahrenheit, making the process of keeping the target-horn system cool a challenge involving a water-cooling system and a wind stream.

Once the beam hits the target, the neutrino horn directs resulting particles that come out at wide angles back toward the detector. To do this, it uses magnetic fields, which are created by pulsing a powerful electrical current — about 200,000 amps — along the horn’s surfaces.

“It’s essentially a big magnet that acts as a lens for the particles,” said physicist Bob Zwaska.

The horns come in slightly different shapes, but they generally look on the outside like a metal cylinder sprouting a complicated network of pipes and other supporting equipment. On the inside, an inner conductor leaves a hollow tunnel for the beam to travel through.

Because the current flows in one direction on the inner conductor and the opposite direction on the outer conductor, a magnetic field forms between them. A particle traveling along the center of the beamline will zip through that tunnel, escaping the magnetic field between the conductors and staying true to its course. Any errant particles that angle off into the field between the conductors are kicked back in toward the center.

The horn’s current flows in a way that funnels positively charged particles that decay into neutrinos toward the beam and deflects negatively charged particles that decay into antineutrinos outward. Reversing the current can swap the selection, creating an antimatter beam. Experiments can run either beam and compare the data from the two runs. By studying neutrinos and antineutrinos, scientists try to determine whether neutrinos are responsible for the matter-antimatter asymmetry in the universe. Similarly, experiments can control what range of neutrino energies they target most by tuning the strength of the field or the shape or location of the horn.

Making and running a neutrino horn can be tricky. A horn has to be engineered carefully to keep the current flowing evenly. And the inner conductor has to be as slim as possible to avoid blocking particles. But despite its delicacy, a horn has to handle extreme heat and pressure from the current that threaten to tear it apart.

“It’s like hitting it with a hammer 10 million times a year,” Hylen said.

Because of the various pressures acting on the horn, its design requires extreme attention to detail, down to the specific shape of the washers used. And as Fermilab is entering a precision era of neutrino experiments running at higher beam powers, the need for the horn engineering to be exact has only grown.

“They are structural and electrical at the same time,” Zwaska said. “We go through a huge amount of effort to ensure they are made extremely precisely.”

Reference: http://news.fnal.gov/2016/08/funneling-fundamental-particles/

Scientists Devise New Way to Find an Elusive Element: Helium

By HENRY FOUNTAIN JUNE 28, 2016

You may not know much about helium, except that it fills birthday balloons and blimps and can make even the most stentorian voice sound a bit like Donald Duck.

But helium is an important gas for science and medicine. Among other things, in liquid form (a few degrees above absolute zero) it is used to keep superconducting electromagnets cold in equipment like M.R.I. machines and the Large Hadron Collider at CERN, the European Organization for Nuclear Research, which uses 265,000 pounds of it to help keep particles in line as they zip around.

Helium’s role in superconductivity and other applications has grown so much that there have been occasional shortages. The gas forms in nature through radioactive decay of uranium and thorium, but exceedingly slowly; in practical terms, all the helium we will ever have already exists. And because it does not react with anything and is light, it can easily escape to the atmosphere.

Until now, it has been discovered only as a byproduct of oil and gas exploration, as the natural gas in some reservoirs contains a small but commercially valuable proportion of helium. (The first detection of helium in a gas field occurred in the early 1900s when scientists analyzed natural gas from a well in Dexter, Kan., that had a peculiar property: It would not burn.)

But now scientists have figured out a way to explore specifically for helium. Using their techniques, they say, they have found a significant reserve of the gas in Tanzania that could help ease concerns about supplies.

“We’re essentially replicating the strategy for exploring for oil and gas for helium,” said Jonathan Gluyas, a professor of geoenergy at the Durham University in England. One of his graduate students, Diveena Danabalan, presented research on the subject on Tuesday in Yokohama, Japan, at the Goldschmidt Conference, a gathering of geochemists.

One key to developing the technique, Dr. Gluyas said, is understanding how helium is released from the rock in which it forms. Ordinarily, a helium atom stays within the rock’s crystal lattice. “You need a heating event to kick it out,” he said. Volcanoes or other regions of magma in the earth can be enough to release the gas, he said.

Once released, the helium has to be trapped by underground formations — generally the same kind of formations that can trap natural gas, and that can be found using the same kind of seismic studies that are undertaken for oil and gas exploration. The helium, which is mixed with other gases, can be recovered the same way natural gas is: by drilling a well.

Working with scientists from the University of Oxford and a small Norwegian start-up company called Helium One, the researchers prospected in a part of Tanzania where studies from the 1960s suggested helium might be seeping from the ground. The area is within the East African Rift, a region where one of Earth’s tectonic plates is splitting. The rifting has created many volcanoes.

Dr. Gluyas said the gas discovered in Tanzania may be as much as 10 percent helium, a huge proportion compared with most other sources. The researchers say the reservoir might contain as much as 54 billion cubic feet of the gas, or more than twice the amount currently in the Federal Helium Reserve, near Amarillo, Tex., which supplies about 40 percent of the helium used in the United States and is being drawn down.

The next step would be for Helium One or one of the major helium suppliers around the world to exploit the find. But for Dr. Gluyas, the research opens up the possibility of finding the gas in new places.

“We’re in the position where we could map the whole world and say these are the sorts of areas where you’d find high helium,” he said.

Reference: http://www.nytimes.com/2016/06/29/science/helium-superconductivity-tanzania.html

You might also enjoy: http://www.wired.com/2016/06/dire-helium-shortage-vastly-inflated/

The Best Teacher I Never Had

Thirty years ago I went on vacation and fell for Richard Feynman.

A friend and I were planning a trip together and wanted to mix a little learning in with our relaxation. We looked at a local university’s film collection, saw that they had one of his lectures on physics, and checked it out. We loved it so much that we ended up watching it twice. Feynman had this amazing knack for making physics clear and fun at the same time. I immediately went looking for more of his talks, and I’ve been a big fan ever since. Years later I bought the rights to those lectures and worked with Microsoft to get them posted online for free.

In 1965, Feynman shared a Nobel Prize for work on particle physics. To celebrate the 50th anniversary of that honor, the California Institute of Technology—where he taught for many years before his death in 1988—asked for some thoughts about what made him so special. Here’s the video I sent:

In that video, I especially love the way Feynman explains how fire works. He takes such obvious delight in knowledge—you can see his face light up. And he makes it so clear that anyone can understand it.

In that sense, Feynman has a lot in common with all the amazing teachers I’ve met in schools across the country. You walk into their classroom and immediately feel the energy—the way they engage their students—and their passion for whatever subject they’re teaching. These teachers aren’t famous, but they deserve just as much respect and admiration as someone like Feynman. If there were a Nobel for making high school algebra exciting and fun, I know a few teachers I would nominate.

Incidentally, Feynman wasn’t famous just for being a great teacher and a world-class scientist; he was also quite a character. He translated Mayan hieroglyphics. He loved to play the bongos. While helping develop the atomic bomb at Los Alamos, he entertained himself by figuring out how to break into the safes that contained top-secret research. (Feynman cultivated this image as a colorful guy. His colleague Murray Gell-Mann, a Nobel Prize–winner in his own right, once remarked, “Feynman was a great scientist, but he spent a great deal of his effort generating anecdotes about himself.”)

Here are some suggestions if you’d like to know more about Feynman or his work:

  • The Messenger Lectures on Physics. These are the talks that first captivated me back in the 1980s and that you see briefly in the video above. The site is a few years old, but you can watch for free along with some helpful commentary.
  • Six Easy Pieces: Essentials of Physics Explained by Its Most Brilliant Teacher is a collection of the most accessible parts of Feynman’s famous Caltech lectures on physics.
  • He recounted his adventures in two very good books, Surely You’re Joking, Mr. Feynman! and What Do You Care What Other People Think? You won’t learn a lot about physics, but you’ll have a great time hearing his stories.

Reference: https://www.gatesnotes.com/Education/The-Best-Teacher-I-Never-Had

The Advanced Nuclear Industry

By Samuel Brinton  Published June 15, 2015

Introduction

The American energy sector has experienced enormous technological innovation over the past decade in everything from renewables (solar and wind power), to extraction (hydraulic fracturing), to storage (advanced batteries), to consumer efficiency (advanced thermostats).

What has gone largely unnoticed is that nuclear power is poised to join the innovation list.

A new generation of engineers, entrepreneurs and investors are working to commercialize innovative and advanced nuclear reactors.

This is being driven by a sobering reality—the need to add enough electricity to get power to the 1.3 billion people around the world who don’t have it while making deep cuts in carbon emissions to effectively combat climate change.

Third Way has found that there are nearly 50 companies, backed by more than $1.3 billion in private capital, developing plans for new nuclear plants in the U.S. and Canada. The mix includes startups and big-name investors like Bill Gates, all placing bets on a nuclear comeback, hoping to get the technology in position to win in an increasingly carbon-constrained world.

This report introduces you to the advanced nuclear industry in North America. It includes the most comprehensive set of details about who’s working on these reactor designs and where. We describe the money and momentum building behind advanced nuclear, and how the technology has evolved since the Golden Age of Nuclear.

To be clear, this is not your grandfather’s nuclear technology. While developers in some cases are working off of technology designs conceived in our national laboratories during the 1950s and 1960s, the advanced reactor technologies being developed are safer, more efficient and need a fraction of the footprint compared to the nearly 100 light water reactors (LWRs) that provide almost 20% of the U.S.’s electricity today (and 65% of its carbon-free power). New plants could be powered entirely with spent nuclear fuel sitting at plant sites across the country, built at a lower cost than LWRs and shut down more easily in an emergency.

The need for nuclear power has never been clearer. To stem climate change, the world needs 40% of electricity to come from zero-emissions sources, according to the International Energy Agency (IEA). While we can and must grow renewable energy generation, it alone will leave us far short of meeting that demand, the U.N. Intergovernmental Panel on Climate Change (IPCC) and the U.S. Environmental Protection Agency (EPA) have said. This is why the IPCC in November issued an urgent call for more non-emitting power, including the construction of more than 400 nuclear plants in the next 20 years. That would represent a near doubling of the 435 plants operating globally today.

Nuclear power is on the cusp of a comeback. The technology may be the best opportunity we have to address climate change and meet the world’s growing energy needs.

Introducing the Advanced Nuclear Industry

The energy sector has experienced enormous technological innovation over the past decade in everything from renewables (solar power), to extraction (hydraulic fracturing), to storage (advanced batteries), to consumer efficiency (advanced thermostats). What has gone less noticed is that nuclear power is poised to join the innovation list. Third Way original research has identified a new generation of engineers, entrepreneurs, and investors, along with several established nuclear companies, who are working to commercialize innovative and advanced nuclear reactors in North America. In total, we have found nearly 50 projects in companies and organizations working on small modular reactors based on the current light water reactor technology of today’s reactors, advanced reactors using innovative fuels and alternative coolants like molten salt, high temperature gas, or liquid metal instead of high-pressure water, and even fusion reactors, to generate electricity.

These companies are being built and funded because the innovators and investors see profit in creating an answer to the global energy paradox – there are 1.3 billion people in the world without access to reliable electricity; they will get that electricity, and advanced nuclear can provide it to them while cutting global carbon emissions. Our table and map of the advanced nuclear industry in North America is the most comprehensive listing to date of who is working on these reactor designs. In compiling this list, four important trends became clear:

  1. Coast to Coast: Research is not isolated to one state or even one coast. The companies and organizations leading the design revolution reach up and down both the East and West coasts of the United States and into Canada. In all, twenty different states host entities researching advanced nuclear energy.
  2. One Size Doesn’t Fit All: In interviews Third Way conducted with many of the companies on this list, we found real diversity in size and structure, ranging from lone entrepreneurs, to venture capital supported university spin-offs, to large international corporations. Each is making strides and bringing a unique perspective to the industry.
  3. A Compendium of Coolants: While water does a great job of cooling and moderating the atomic fissions of nuclear reactors, the next generation of nuclear reactors is looking to broaden our options. These include liquid metal, high temperature gases, and molten salt. Nuclear reactors using these coolants can be even safer than most light water reactors. The higher operating temperatures of coolants like helium, liquid metals, and molten salts more readily lend themselves to industrial applications requiring high temperature process heat.1
  4. Not Just Fission Anymore: Along with the evolution from large light water reactors to small modular light water reactors and beyond, Third Way has found major investment and interest in nuclear fusion from both small and large companies. Though this technology has much left to refine before commercialization, the growth has been staggering.

When thinking of the emerging advanced nuclear industry, it is important to understand how it compares to other sectors with a number of potentially new entrants. Let’s take the Internet. On the surface, there are similarities. As with the Internet today, the advanced nuclear space includes startups led by recent Ph.D. graduates, established Fortune 500 multinationals, and everything in between. And just like Internet companies, financing includes seed capital provided by angel investors, investments by established venture capital firms, and companies spending their own capital on significant R&D budgets.

The differences between the advanced nuclear companies and the companies spurring the latest Internet revolution are just as important. While the latest software or hardware improvement can take significant funding and research, the dollars and time required are a relative pittance in comparison to the funding necessary and regulation that must be navigated to design and build a new nuclear reactor. But despite these obstacles, nearly 50 companies and organizations are moving ahead, and a decade from now we may be seeing a brand new reactor revolutionizing the energy industry.

See the balance of this article, relevant data, an interesting infographic alongside references at:
http://thirdway.org/report/the-advanced-nuclear-industry

See also:
Op-Ed Nuclear power must be a part of greener future

Reference: Advanced Nuclear Summit & Showcase