Shades Of Life

Shades Of Life

Adele A. Wilby London Guardian

by Adele A Wilby

Many decades ago, I packed my bags and left the shores of Australia and headed to the United Kingdom (UK). My secondary years of education had taught me to believe that my journey to the UK would amount to a ‘return’ to the ‘motherland’. A ‘return to the motherland’? Really? That says more about the education system I was exposed to, than just how naïve I was. However, having learned after my arrival that the UK was not, in fact, my ‘motherland’, I did discern that it had more to offer in terms of being ‘in’ the world than the distant shores of Australia, and I decided to stay. Thus, after many years resident in the UK, I considered myself as someone familiar with the country, until, that is, a change in my life circumstances provided me the opportunity to know the UK, or more specifically, England, in a totally different way.

Acting on the advice of a friend concerned with what he considered to be my solitary life following the death of my husband, I joined the Ramblers’ Association in the UK. Involvement with activities of the Ramblers didn’t last too long; group walking was not my thing. I did learn however, that walking was something I relished; it literally, put a spring in my step. The more regularly I walked the more the country opened up to me, an England loaded with complexity, diversity, mystery, and an alluring, limitless beauty: the English countryside.

In many ways, the countryside is how England can be: cold and aloof, requiring time to get to know; a place where one can feel a sojourner in its midst; a place where its nuances and secrets take time to understand. But it is too a place that tolerates your presence, and, as long as you remain respectful, it will allow you to saunter and relish the attributes that it has to offer, undisturbed and secure. That, to me, is fair enough; I don’t ask for more. I have no wish to disturb its existence, or indeed, undermine any aspect of its life.

The UK is exceptional for its network of public footways and bridleways; walking routes where ramblers are permitted to cross farmers’ property, to pass through private driveways and gardens and around farm buildings, if that is where the public right of way takes its direction.

From amongst the countless number of walking routes throughout the UK, I have spent most of my walking time in South England, which includes the Surrey Hills. It is not without reason that the Surrey Hills, with such places such as Box Hill, Leith Hill, Tilford, the Fensham Ponds, and St Martha’s Church has been designated as an Area of Outstanding Natural Beauty: it offers an endless array of stunning portraits of the countryside.

Of these portraits, small hamlets on the edge of a woodland or fringing a remote country road constitute the quintessential image of the English countryside. From the roofs of the cottages neatly thatched by the skilled hands of a trade from a different era, to slate roofs dipping under the weight of age, and the bricked walls bending with the ravages of time, we can assess to which period of history these hamlets and their structures belong; they are original England.

These family cottages are frequently surrounded by a galaxy of coloured flowers and fragrances compelling a halt in my footsteps, and drawing me to the borders of an English country garden. Who can help but wonder at the yellow hues, and the pouting trumpets and petals that the different varieties of daffodils bring forth. If I am very lucky, I might spot a jonquil tucked away somewhere in the garden, and then I linger a little longer, my nose buried in its petalled face, inhaling, for as long as is socially permissible, the depth of its beguiling perfume. A heavy, sweet scent in my nostrils often directs me to the clusters of tiny pink flowers on a daphne shrub. The English rose, that symbol of English history, is a common sight, roses of all colours, flourishing within the confines of the gardens. Sadly, the existence of the perfumed rose seems to be on the wane, and I frequently have to be content with admiring the fullness of blooms before I continue on my way along the public right of way.

As I ramble along the designated paths, I often find myself having to hurdle stiles and stepping into fields where I am surrounded by the ripening cobs of shoulder high maize crops, or knee high amongst wheat ears and the beards of oats, or the ankle high crops of vegetables waiting to be picked and packed. The paths thread the way through crops, on into pastureland where herds of cattle stroll leisurely, grazing on the succulence of the grass, fattening themselves oblivious to their fate that lies ahead. Cows sidle up to me, their long black eyelashes blinking coquettishly from the other side of the fence as their large, dark, glassy eyes look down their noses into my face, sizing me up to determine whether I am friendly or not. So too, do I enjoy catching the gaze of a sheep not quite sure if it should get up and run away, or if it should continue with its lazing amongst its brethren under the leaden clouds of the English sky. Horses too are the favourites of many who live in the English countryside. I have to be content with the odd occasion when a horse’s curiosity gets the better of it, and it will momentarily abandon its grazing and stroll over to me as I walk, and allow me to sneak a gentle pat of its nose. Such moments remind me of just how glad I am to be a vegetarian.

But South England is not all flatland walking routes, or meandering paths over the soft curves of the hills in these areas. Inclines are frequent, and steep, but the view that fans out in front of my eyes from the peak of these hills is sufficient reward for the expenditure of energy required to get me to the top in the first place. From these scenic locations swathes of seasonal colour spread out before me like a patchwork quilt draped haphazardly over an unmade bed, with clumps of trees intervening as if the quilt were full of holes. But as the old cliché goes, ‘what goes up, must come down’, and so after coming to terms with the bewildering beauty of the view, and ready to move on, the moment comes to descend to ground level once more.

A walk up or down one of the many hills in the area frequently involves traversing a woodland. Entering the domain of trees, bushes and all the other resident creatures in the woodland can be akin to entering a monastery of monks committed to a vow of silence, so still and calm it is, the difference being that while the world of the monk is constituted of monotonous routine, deprivations, and limited social contacts, the woodlands are thriving metropolises of harmony and mystery in a wonderland of interconnected life forms. From the heights of trees and beyond the vision of the eye, the melody of birds singing to each other adds to the ambiance of calm in the woods. The sweet fragrance of wild honeysuckle wafting from somewhere amongst the scrubby hedges excites the nostrils, while the smell of pine provides a freshness, and the odour of mould from the damp carpets of leafy undergrowth remind us of nature recycling at work. Nettles behave naughtily, ever willing to cause irritating itchiness to the body should a negligent rambler ignore their presence, and dare to brush against them while winding through the paths of undergrowth. At times too, I have had to remind myself that I am walking in a woodland and not in a kitchen, such is the smell of wild garlic that occupies ground floor space of some wooded areas. But for many ramblers, it is the blue bells that are the star of the show in late spring. The blue of the small bell shaped flowers carpeting the woodland floor, and pitted against the greens and browns of the forest is a spectacle not to be missed should the opportunity avail itself to see them.

Despite the considerable competition from so many contestants in the popularity contest for most favourite life forms in the English woodlands and countryside, the jewels in the crown, so to speak, are, for me, the trees: silver birches, willows, ashes, scots pines, pines, horse chestnuts and sweet chestnut trees, maples, cherry, and so many more. Who doesn’t love trees? and we each have our favourites, if that is at all possible, and those for me are the beech and the oak trees.

Little is popularly known about the ‘life’ of trees. Are they social creatures interacting with each other? Do the various types of trees live harmoniously with each other in the woodland? Are they competitive with one another? Do they send out warnings to neighbouring trees in times of danger? Do they support one another during times of stress?

I frequently find myself thinking about the possibility that trees might actually give each other a helping hand in times of difficulty. That this might be so occurs to me when walking paths sunken into the ground by centuries of rain water washing down through them, and the heavy load of human footprints. Huge, old beech trees often border these paths, and the interlacing of their exposed roots suggest a support mechanism for each other given the precariousness to their existence that the heavily eroded banks of the paths pose to them.

Such stretches of beech trees also make the routes a haven of shade, or dark and dingy, even eerie, depending on the season one traverses the paths. But most of all, I never cease to wonder at what I am witnessing as I make my way along these paths. Networks of roots with shaded greens of moss crawling over them create beautiful and original sculptures beyond even the artistic scope of the human hand. I regret the passing of these galleries of natural sculptures as I come to the end of those stretches of paths and I have to leave them behind as I continue on my journey through the English countryside.

Beech trees have established their identity throughout the countryside, but so too have those trees so frequently identified with the English landscape: the oak trees.

Many varieties of oak trees exist in the UK, but I am more familiar with the English oak, the Sessile Oak and the Turkey Oak. Should anybody wonder why the English oaks hold a special place in my sentiments, do take a stroll across an open field and confront a single oak in the distance; be prepared for its beauty to take your breath away, and to stand and gaze at the life form ahead of you. ‘Regal’ perhaps best sums up the tree. Alone in the field, it stands tall, its branches extended, like a colossus supporting its perfectly shaped luxurious crown of green foliage and the myriad forms of life that have made it their home.

But not all English oaks are so perfectly shaped, particularly the old ones, the hundreds of years old English oak trees. Very old English oaks are not unlike us in the ageing process. The accumulated years have seen them shrink, and it is sometimes difficult to imagine they might have towered over the woodlands at the height of forty metres. Their girths are substantially thickened, so thick indeed that it might take two, or even three people, holding hands to circle them. Varieties of growths reminiscent of warts, or evidence of disease on their bodies deprive their bark of its youthful regularity. Their branches are thick, but the knots and bends in the them look less like the strength of their younger days, and more like ageing limbs experiencing difficulty in supporting the weight of their adornments. Their crowns too, are thinning of the lush growth of their heyday. Still, like us subjected to the force of age, they clothe themselves with the best they have at hand, and, in doing so, they retain their dignity.

Standing at the foot of an old English oak and looking up through its branches, I cannot but escape a sense that the old tree might bend over, and with its thick and twisted arms scoop me up like a cuddly grandparent, and reassure me all will be well. I wish, in such moments, the old oak tree could speak and share with me the events of history that it would have witnessed over the centuries, and dispense the wisdom accumulated from such longevity.

For many of these old English oak trees, living is more behind them than ahead. Still, there is much life in them yet, and I am certain many more ramblers will stand at the foot of their trunks and gaze up at them in awe the way I do, knowing that they will still be there, old, and regal, long after my days of experiencing the joy of walking the English countryside have come to an end.

Water on Europa

How Do You Find an Alien Ocean? Margaret Kivelson Figured It Out

For forty years, the physicist at U.C.L.A. has been uncovering the outer solar system’s secrets. Few scientists know more about the mysteries of Jupiter and its icy moons.

Profiles in Science

Margaret Kivelson in her office at the University of California, Los Angeles.Jenna Schoenefeld for The New York Times

LOS ANGELES — The data was like nothing Margaret Kivelson and her team of physicists ever expected.

It was December 1996, and the spacecraft Galileo had just flown by Europa, an icy moon of Jupiter. The readings beamed back to Earth suggested a magnetic field emanating from the moon. Europa should not have had a magnetic field, yet there it was — and not even pointed in the right direction.

“This is unexpected,” she recalled saying as the weird data rolled in. “And that’s wonderful.”

It would be the most significant of a series of surprises from the Jovian moons. For Dr. Kivelson’s team, the mission should not have been this exciting. 

She and her colleagues had devised the magnetometer returning the anomalous data. The instrument’s job was to measure Jupiter’s massive magnetic field and any variations caused by its moons. Those findings were likely to interest space physicists, but few others. Dr. Kivelson’s instrument was never supposed to change the course of space exploration.

And then it did. Dr. Kivelson and her team would soon prove that they had discovered the first subsurface, saltwater ocean on an alien world.

An image captured by the Voyager spacecraft in 1979 shows Jupiter and two of its moons: Io, left, and Europa.NASA/JPL

Dr. Kivelson, who will turn 90 this month, is professor emerita of space physics at the University of California, Los Angeles. For forty years she has been an active part of almost every major NASA voyage beyond the asteroid belt. She has a wry sense of humor, and her modesty belies the magnitude of her scientific achievements. 

Her team transformed the way magnetometers are used on space missions, making them an essential tool of discovery. Having established, essentially, the art of ocean detection, the outer solar system is now a hot zone in the search for habitability.

Most recently, Dr. Kivelson is a co-investigator working on the plasma instrument for the Europa Clipper, NASA’s next great voyage to the outer solar system. Scheduled to launch as early as 2022, the spacecraft will study the habitability of Jupiter’s ocean moon. Her work will help answer whether life could be there by determining the ocean’s depth and salinity, and the thickness of the ice shell above it.

But the story started with Galileo’s unusual encounters with Jupiter’s moons. Inscrutable Europa, it turned out, had its own way of doing things. 

“We came up with a lot of wrong ideas,” said Dr. Kivelson. Years after the first flyby, however, they found their answer.Harvard and hydrogen

Dr. Kivelson in the mid-1960s. “Physicists had saved the world with the atom bomb and radar," she said. "And suddenly people noticed that physics was not only a wonderfully fundamental discipline, but that it was also useful.”via Dr. Margaret Kivelson

Dr. Kivelson was born in New York City. Her father was a physician. Her mother was a schoolteacher. Margy, as her friends call her, excelled in mathematics at an early age. 

“I liked it,” she said. “I thought it was one of the easier subjects, and I knew that opinion was not common.”

She graduated and was accepted to Harvard, which formally excluded women, consigning them officially to Radcliffe College — a separate school without a faculty. Harvard professors would walk across the commons to repeat their lectures to women. “Women were not invited into the Harvard classrooms,” she said.

It was there that she found physics, which allowed her to use math in such a way that answers had to make physical sense.

“I had the good fortune of starting my studies at a time when physics was regarded as the most exciting field. This was right after World War II,” she said. “Physicists had saved the world with the atom bomb and radar. And suddenly people noticed that physics was not only a wonderfully fundamental discipline, but that it was also useful.”

By her sophomore year, there were no separate classes. In the wonderland of the atomic age, physics professors no longer had time to repeat their lectures. “It was ridiculous to lecture to 10 women for one hour and then to 400 men the next,” she said. 

Not that the situation suddenly improved for Harvard women. When she entered the physics graduate program, she was often the only woman in her classes.

In 1955, she joined the RAND Corporation, a firm founded to provide research to the Defense Department, including nuclear weapons research. She was assigned to work on an equation describing the state of hydrogen at a pressure equivalent to one million Earth atmospheres.

“There are two places where you run into that kind of pressure in hydrogen,” she said. “One of them is in a hydrogen bomb, and the other is at the center of Jupiter.”

Her background in theoretical physics and eventual expertise in celestial science brought her to U.C.L.A. in 1967. Her RAND research made her the local expert on Jupiter, and she soon became well known in space physics for her theoretical work on some of the most fundamental ideas in the field.Dr. Kivelson at a Department of Defense science seminar in 1964.via Dr. Margaret Kivelson

Fieldwork

Following the Voyager spacecraft’s encounter with Jupiter in 1979, scientists at the American Geophysical Union conference in San Francisco debated how the moon Io could drive a mysterious million-amp current between itself and Jupiter. 

Dr. Fran Bagenal, professor emerita of planetary science at the University of Colorado, recalled Dr. Kivelson’s contributions to that debate.

“This small, diminutive woman — who was not officially on the Voyager team, but writing papers and thinking about the problem — walks into the room, walks to the podium, pulls down the microphone so she could be heard and speaks her case, and shatters everyone’s ideas in the room,” Dr. Bagenal said of the scene at the conference.

“She ended up being correct in the end,” Dr. Bagenal added. “She was not to be argued with. She knew her stuff.”

When NASA announced what would become the Galileo mission to Jupiter, Dr. Kivelson was well positioned to propose a magnetometer.

“I was very immersed in the science that was already available related to Jupiter’s magnetic field and particle environment,” she said.

As the proposal deadline neared, she spent weeks working each day until midnight. When her instrument was chosen, “the champagne came out,” she said. “Everybody was really thrilled.”From left: the assembly of the Galileo spacecraft; the space shuttle Atlantis launching from Cape Canaveral, with Galileo as its payload; and Galileo just after separating from Atlantis, six hours after launch.JSC/NASAAn image of Jupiter taken by the Juno spacecraft, which reached the planet's orbit in 2016.NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstäd/Seán Doran

Galileo entered orbit around Jupiter in 1995. The first major discovery by Dr. Kivelson and her team was an internal magnetic field on Ganymede, Jupiter’s largest moon. 

Dr. Carol Paty, an associate professor of earth sciences at the University of Oregon, said nobody really expected an object so small and cold to have the chemistry, thermodynamics and interior structure necessary to create its own magnetic field. 

“Its discovery reshaped the scientific understanding of the inner workings of planetary bodies,” she said.

Then came the series of encounters between Europa and Galileo.

Geologists had suspected that the icy moon once had a subsurface ocean, but could not say whether it still existed or had frozen solid long ago. That would still be a mystery were it not for the anomalous data received by the Galileo magnetometer. 

Something strange was happening, and Dr. Kivelson and her vexed team worked out several ways of explaining it. That’s when they came on the idea that Europa’s magnetic field was being induced by Jupiter.

“It is the same principle governing the metal detector at an airport,” said Dr. Krishan Khurana, a geophysicist at U.C.L.A. who was part of the ocean’s discovery.

When you walk through the gate, a metal detector produces a high-frequency magnetic wave. If there is a key in your pocket, the wave causes a current to flow through the key, which in turn generates a little magnetic field of its own. This induced magnetic field is what triggers the metal detector.

How it might work on a Jovian scale: As Europa moves through Jupiter’s magnetic field, a current courses through a subsurface conductor of some sort on the moon, creating a miniature magnetic field flipped to oppose the field of Jupiter. This, in effect, set off the Galileo metal detector. 

The hypothesis was not conclusive, however. It was possible that Europa had its own odd, intrinsic magnetic field, which only happened to be oriented opposite to Jupiter’s.A color-enhanced view of Europa's icy, fractured surface taken by Galileo in 1998. NASA/JPL-Caltech/SETI Institute

Because Jupiter’s magnetic equator (as opposed to its geographic equator) is tilted by 10 degrees, sometimes Europa is above it, and sometimes below it. What the magnetometer team needed were measurements when Europa was on the other side of the tilt. 

If the moon’s magnetic field changed directions, that would mean the field was induced by Jupiter — and therefore possessed an internal conductor. The only thing that would fit the bill would be a subsurface, saltwater ocean.

Dr. Kivelson made the case to the Galileo project for a flyby of Europa at a specific orientation — no small request given a spacecraft with limited resources flying on borrowed time. She prevailed, and the flyby in January 2000 found precisely what models made by her team had predicted: definitive evidence of a global ocean.

“It’s one of the most fundamental discoveries ever in planetary science,” said Dr. Louise Prockter, the director of the Lunar and Planetary Institute in Houston. “It spawned a revolution, really.”

Dr. Robert Pappalardo, the project scientist of NASA’s pending Europa Clipper mission said the discovery had ramifications not only for Europa but for the entire solar system.

“It really swung the pendulum toward the plausibility of oceans in icy worlds,” he said. “We went pretty quickly from ‘maybe’ to ‘almost certainly’ to ‘where else?’ That was a pretty quick transition, considering the term ‘ocean world’ didn’t even exist back then. Now it’s a class of objects, thanks to Margy’s fundamental work.”

Ready for the next set of problemsDr. Kivelson with other U.C.L.A. faculty and students head to dinner on a recent Wednesday. Her gatherings are a decades-long tradition.Jenna Schoenefeld for The New York Times

Dr. Kivelson is not finished unlocking the secrets of Jupiter.

In addition to her work on the upcoming Europa Clipper, she is contributing to the European Space Agency’s Jupiter Icy Moons Explorer mission, expected to launch in 2022. And her own research focuses on a longstanding puzzle in the gas giant’s magnetosphere related to the mysterious heating of plasma as it diffuses outward from Io.

She still works in her office each day and hosts a weekly dinner and meeting on Wednesday nights at U.C.L.A. for graduate students and faculty, a tradition she started 33 years ago.

Attendees share their current research and discuss the latest advances in space physics. The reviews of one another’s work can be rollicking — sharp and animated, but not heated or antagonistic. Participants spend hours critiquing equations and models projected onto a white screen. When challenged, they take to a blackboard, leaving behind a chalky mélange of exponents, cosines and the Greek alphabet.

When laptops lining the table fail them, the scientists dash to their offices to pull out fifty-year-old textbooks to win one point or another. Humor punctuates disagreements, and attendees pass chocolate around the table as they work.

At a recent session, Steve Tomlinson, a graduate student, faced constant questioning from nine physicists as he presented research on structures in the sun’s coronal mass ejections.

Dr. Kivelson was in the thick of it, probing for answers and deeper reflection, her questions leading Mr. Tomlinson to better explain his work.

“It looks as if you have a very nice set of problems here,” said Dr. Kivelson, content with what she had seen after an hour of inquiry and ready for the next presentation.

Jenna Schoenefeld for The New York Times