Showing posts with label science. Show all posts
Showing posts with label science. Show all posts

Tuesday, August 14, 2018

Seeing Earth's Magnetic Fields: Cryptochromes and Blue Light




Birds Can See Earth's Magnetic Fields -- And We Finally Know How That's Possible

By Michelle Starr

The mystery behind how birds navigate might finally be solved: it's not the iron in their beaks providing a magnetic compass, but a newly discovered protein in their eyes that lets them "see" Earth's magnetic fields.

These findings come courtesy of two new papers -- one studying robins, the other zebra finches.

The eye protein is called "Cry4," and it's part of a class of proteins called "cryptochromes" -- photoreceptors sensitive to blue light, found in both plants and animals. These proteins play a role in regulating circadian rhythms.

There's also been evidence in recent years that, in birds, the cryptochromes in their eyes are responsible for their ability to orient themselves by detecting magnetic fields, a sense called "magneto-reception."

We know that birds can only sense magnetic fields if certain wavelengths of light are available -- specifically, studies have shown that avian magneto-reception seems dependent on blue light.

This seems to confirm that the mechanism is a visual one, based in the cryptochromes, which may be able to detect the fields because of "quantum coherence."

To find more clues on these cryptochromes, two teams of biologists set to work. Researchers from Lund University in Sweden studied zebra finches, and researchers from the Carl von Ossietzky University Oldenburg in Germany studied European robins.

The Lund team measured gene expression of three cryptochromes, Cry1, Cry2, and Cry4, in the brains, muscles and eyes of zebra finches. Their hypothesis was that the cryptochromes associated with magnetoreception should maintain constant reception over the circadian day.

They found that, as expected for circadian clock genes, Cry1 and Cry2 fluctuated daily -- but Cry4 expressed at constant levels, making it the most likely candidate for magnetoreception.

This finding was supported by the robin study, which found the same thing.

"We also found that Cry1a, Cry1b, and Cry2 mRNA display robust circadian oscillation patterns, whereas Cry4 shows only a weak circadian oscillation," the researchers wrote.

But they made a couple of other interesting findings, too. The first is that Cry4 is clustered in a region of the retina that receives a lot of light -- which makes sense for light-dependent magnetoreception.

The other is that European robins have increased Cry4 expression during the migratory season, compared to non-migratory chickens.

Both sets of researchers caution that more research is needed before Cry4 can be declared the protein responsible for magnetoreception.

The evidence is strong, but it's not definitive, and both Cry1 and Cry2 have also been implicated in magnetoreception, the former in garden warblers and the latter in fruit flies.

Observing birds with non-functioning Cry4 could help confirm the role it seems to play, while other studies will be needed to figure Cry1's role.

So what does a bird actually see? Well, we can't ever know what the world looks like through another species' eyes, but we can take a very strong guess.

According to researchers at the Theoretical and Computational Biophysics group at the University of Illinois at Urbana-Champaign, whose researcher Klaus Schulten first predicted magnetoreceptive cryptochromes in 1978, they could provide a magnetic field "filter" over the bird's field of view (like in the picture above).

The zebra finch study was published in the "Journal of the Royal Society Interface," and the robin study was published in "Current Biology."

















Wednesday, July 25, 2018

Thomas A. Edison: Poured Concrete House Pioneer

Thomas A. Edison



Thomas A. Edison



Thomas A. Edison



Thomas A. Edison


At 303 North Mountain Avenue in Montclair, New Jersey, there stands a very solid relic to Thomas Edison’s past --  a poured concrete house that was a prototype for what Edison hoped to be the future of urban and suburban development.  

One of only a handful of Edison’s original concrete houses in existence today, 303 North Mountain stands gloriously modern in its concrete design, but is in fact one of Montclair’s antique homes. Thomas Brennan, an actor and director, boasts it as his own and describes it like a piece of art, rather than a structure.



Thomas A. Edison


Speaking of reading the backlog, I’m now reading a compelling bio of Thomas A. Edison, a 2017 Christmas gift.

This is a nifty format indeed — filled with great graphics — it's somewhere between the classic “young adult” reader’s biography of yore and a graphic novel of today. It’s a whole lot of fun to read. Bonus — it has old comic book pages reproduced and vintage editorial cartoons by R. F. Outcault.

By David J Kenton 

This book is designed to appeal to a wide range of readers who want to learn things about Edison not told in other biographies. Packed with colorful and rare illustrations, “Edison: The Inventor of the Modern World” is visually stunning and the writing is light and easy.

Beginning with his upbringing in Milan, Ohio, and Port Huron, Michigan, the book explores how the insatiable curiosity of "Little Al" made his father wonder if he was a bit dimwitted and led his first teacher to call him "addled." Self-teaching through experiment and reading, young Edison quickly shows his inventiveness and business acumen, leaving his doubters well behind at an early age.

Chapters examine his teen years while the Civil War raged, his early improvements to telegraphs, and his contributions to the art of invention. Edison, now called "Tom," rises to celebrity status with the telephone and telegraph, explores the world in his efforts to build a better light bulb, and fights the intriguing War of the Currents against rivals Westinghouse and Tesla. Along the way he acquires two wives, six children, and friendships with some of the greatest names in business history.

Not slowing down as he aged, Edison becomes a movie mogul, an iron ore magnate, builds houses out of concrete, becomes a botanical rubber expert, writes notes for a science fiction novel, and accomplishes much, much more before passing away in his sleep at the ripe old age of 84.

“Edison: The Inventor of the Modern World” tells the story of a man who has left a legacy that few can hope to equal. He was a great deal more than people know, perhaps in both good and bad ways. All are laid out in easy to read language and with spectacular photos, cartoons, and drawings in a format that blends the best of vivid writing with a graphical novel feel.

I am the author of this book. I hope you enjoy reading it as much as I enjoyed writing it. See also my earlier book, “Tesla: The Wizard of Electricity.”



Thomas A. Edison



Thomas A. Edison



Thomas A. Edison



Thomas A. Edison



Thomas A. Edison










Monday, July 2, 2018

Mid-Century Modern Apollonius Cone Sculpture

Apollonius Cone


Did I really need a Mid-Century Modern wooden Apollonius Cone sculpture? Why, yes -- yes, I did.

The knowledge of conic sections can be traced back to Ancient Greece. Menaechmus is credited with the discovery of conic sections around the years 360-350 B. C. -- it is reported that he used them in his two solutions to the problem of "doubling the cube."

Following the work of Menaechmus, these curves were investigated by Aristaeus and of Euclid. The next major contribution to the growth of conic section theory was made by the great Archimedes. Though he obtained many theorems concerning the conics, it does not appear that he published any work devoted solely to them. 

Apollonius, on the other hand, is known as the "Great Geometer" on the basis of his text "Conic Sections," an eight-book (or in modern terms, chapter) series on the subject. The first four books have come down to us in the original Ancient Greek, but books V-VII are known only from an Arabic translation, while the eighth book has been lost entirely.

In the years following Apollonius the Greek, geometric tradition started to decline, though there were developments in astronomy, trigonometry, and algebra. 

Pappus (who lived about 300 A. D.) furthered the study of conic sections somewhat, in minor ways. After Pappus, however, conic sections were nearly forgotten for 12 centuries. 

It was not until the sixteenth century, in part as a consequence of the invention of printing and the resulting dissemination of Apollonius' work, that any significant progress in the theory or applications of conic sections occurred -- but when it did occur, in the work of Kepler, it was as part of one of the major advances in the history of science.



Apollonius Cone



Apollonius Cone



Apollonius Cone



Apollonius Cone





Tuesday, September 1, 2015

Claude E. Shannon and the Minivac 601

The Minivac 601 was a digital computer trainer designed by Claude Shannon in the early 1960s. It has six relays, six switches, six buttons, twelve indicator lamps, a 3 x 3 matrix plug board and a 16-position rotating input/output device.






























Monday, August 31, 2015

From the Brainpickings Newsletter: Oliver Sacks

Oliver Sacks on Storytelling, the Curious Psychology of Writing, and What His Friendship with the Poet Thom Gunn Taught Him About Creativity and Originality

by 
“The act of writing is an integral part of my mental life; ideas emerge, are shaped, in the act of writing… a special, indispensable form of talking to myself.”
Who we are and who we become is in large part the combinatorial product of the people and ideas we surround ourselves with — what William Gibson so memorably termed our“personal micro-culture” and Brian Eno called“scenius.” The more different those people are from us, the more they expand the echo chamber of our own mind, the more layered and beautiful the symphony of the spirit becomes. Nowhere is this self-expansion via relationship more evident than in the friendships between great artists and great scientists, one of the most heartening examples of which is the friendship between legendary neurologist Oliver Sacks and the poet Thom Gunn.
In On the Move: A Life (public library) — the immeasurable and incompressible rewards of which I have previously extolled at great length and with great love— Dr. Sacks, a Thoreau of the mind, recounts how his relationship with Gunn shaped his own evolution as a writer. In fact, his very autobiography is titled after Gunn’s poem “On the Move” from his 1959 collection Sense of Movement.
Thom Gunn in the early 1960s, around the time Dr. Sacks met him (Courtesy of Oliver Sacks)
To be sure, Sacks’s love affair with writing predates his meeting Gunn and even his foray into science. Nicknamed Inky as a boy for his voracious appetite for pen and paper, which covered everything in ink, he began journaling at an early age — a formative practice of learning to think on paper and converse with himself. Joining the extensive roster of celebrated writers who championed the creative benefits of keeping a diary and speaking to the potency of journaling as an antidote to Tom Waits’s complaint about the inopportune timing of the muse, Sacks writes:
I started keeping journals when I was fourteen and at last count had nearly a thousand. They come in all shapes and sizes, from little pocket ones which I carry around with me to enormous tomes. I always keep a notebook by my bedside, for dreams as well as nighttime thoughts, and I try to have one by the swimming pool or the lakeside or the seashore; swimming too is very productive of thoughts which I must write, especially if they present themselves, as they sometimes do, in the form of whole sentences or paragraphs…
But for the most part, I rarely look at the journals I have kept for the greater part of a lifetime. The act of writing is itself enough; it serves to clarify my thoughts and feelings. The act of writing is an integral part of my mental life; ideas emerge, are shaped, in the act of writing.
My journals are not written for others, nor do I usually look at them myself, but they are a special, indispensable form of talking to myself.
Dr. Sacks captures a thought in his journal at Amsterdam's busy train station (Photograph: Lowell Handler)
He adds:
The need to think on paper is not confined to notebooks. It spreads onto the backs of envelopes, menus, whatever scraps of paper are at hand. And I often transcribe quotations I like, writing or typing them on pieces of brightly colored paper and pinning them to a bulletin board.
What Sacks is describing is akin to a commonplace book — that Medieval Tumblr in which thinkers recorded quotations and ideas from whatever they were reading, assembling a personal archive of the ideas that shaped their own minds. (Brain Pickings is essentially one giant commonplace book, and this very piece a sort of bulletin board pinned to which is my discourse with Sacks’s extraordinary text.)
Another thought recorded atop a car roof on the side of the road (Courtesy of Oliver Sacks)
By the time he was in graduate school, Sacks began externalizing these inner conversations, doing for others what he had been doing for himself on the pages of his journals — clarifying the complexities of mental life at the intersection of science and storytelling, honing the singular gift for which he is so beloved today.
He was so electrified by working with patients at a migraine clinic in the mid-1960s that he felt compelled to transmute these insights into a book. But when he finally finished the manuscript and showed it to his boss at the clinic — a prominent but petty and egomaniacal neurologist by the name of Arnold P. Friedman — he was curtly told that the manuscript was garbage, that he had to destroy it, and that he dare not think about turning it into a book ever again; or else, Friedman threatened, Sacks would be promptly fired and barred from getting another job anywhere in America. Friedman confiscated the manuscript and locked it away.
Still, Sacks trusted that he had written something substantive and important — something that might forever change our understanding of how the mind works. He suppressed his feelings for months but, finally, the resentment exploded into action: One night, with the help of the clinic’s janitor, he sneaked in and, between midnight and 3 A.M., arduously copied his own notes by hand. The next day, he told Friedman he was taking a long leave to London and when his boss demanded a reason, Sacks responded that he had no choice but to write the forbidden book.
He was fired via telegram a week later. And yet a strange sense of liberation set in, which he poured into the writing.
But if this wasn’t courageous enough an act, he soon performed what is perhaps the greatest act of creative courage — the same one John Steinbeck had performed three decades earlier in destroying a manuscript he didn’t feel was good enough and rewriting it from scratch into what would become his Pulitzer-winning novel The Grapes of Wrath, the cornerstone of his Nobel Prize. Sacks recounts:
I was dissatisfied with my 1967 manuscript and decided to rewrite the book. It was the first of September, and I said to myself, “If I do not have the finished manuscript in Faber’s hands by September 10, I shall have to kill myself.” And under this threat, I started writing. Within a day or so, the feeling of threat had disappeared, and the joy of writing took over. I was no longer using drugs, but it was a time of extraordinary elation and energy. It seemed to me almost as though the book were being dictated, everything organizing itself swiftly and automatically. I would sleep for just a couple of hours a night. And a day ahead of schedule, on September 9, I took the book to Faber & Faber. Their offices were in Great Russell Street, near the British Museum, and after dropping off the manuscript, I walked over to the museum. Looking at artifacts there — pottery, sculptures, tools, and especially books and manuscripts, which had long outlived their creators — I had the feeling that I, too, had produced something. Something modest, perhaps, but with a reality and existence of its own, something that might live on after I was gone.
I have never had such a strong feeling, a feeling of having made something real and of some value, as I did with that first book, which was written in the face of such threats from Friedman and, for that matter, from myself. Returning to New York, I felt a sense of joyousness and almost blessedness. I wanted to shout, “Hallelujah!” but I was too shy. Instead, I went to concerts every night — Mozart operas and Fischer-Dieskau singing Schubert — feeling exuberant and alive.
Sacks’s jubilant intuition wasn’t misplaced — that manuscript became his 1970 debut Migraine, which was welcomed with wholehearted critical acclaim and catapulted him into the status of masterful science storyteller. When the book came out, he found out that Friedman had adapted the original manuscript and attempted to publish it under his own name — a tragicomic testament to the fact that it is Sacks’s singular gift as a writer and storyteller, not his scientific genius alone, that make him the cultural icon he is today.
Dr. Sacks recovering in the hospital with nothing but a typewriter by his side. He had broken his leg in Norway, falling down a slippery canyon while being chased by a bull. (Courtesy of Oliver Sacks)
Sacks had befriended Thom Gunn in the early 1960s, but it wasn’t until after the publication of Migraine that he was able to engage with the poet in conversations about writing more confidently — a confidence further nurtured by Gunn’s encouraging feedback which, alongside the staunch support of Sacks’s beloved aunt Lennie, was instrumental in emboldening the budding writer to embark upon this far from easy path.
He talked with Gunn about “the process of writing, the rushes and stoppages, the illuminations and darknesses, which seemed to be part and parcel of the creative process.” Long before cognitive scientists came to study the psychology of writing, Gunn captured the mysterious psychological messiness of the process in one of his letters to Sacks:
I am a bit slothful at the moment. My pattern seems to be: a long cessation of any coherent writing after I have completed a MS, then a tentative start followed by, during the next few years, various separate bursts of activity, ending with a sense of the new book as a whole, in which I make discoveries about my subject(s) that I have never anticipated. It’s strange, the psychology of being a writer. But I suppose it’s better not to be merely facile — the blocks, the feelings of paralysis, the time when language itself seems dead, these all help me in the end, I think, because when the “quickenings” do come they are all the more energetic by contrast.
Sacks reflects on the sincerity of his friend’s values:
It was crucial for Thom that his time be his own; his poetry could not be hurried but had to emerge in its own way… “My income,” [he] wrote, “averages about half that of a local bus-driver or street sweeper, but it is of my own choosing, since I prefer leisure to working at a full-time job.” But I do not think Thom felt too constrained by his slender means; he had no extravagances (though he was generous with others) and seemed naturally frugal. (Things eased up in 1992, when he received a MacArthur Award, and after this he was able to travel more and enjoy some financial ease, to indulge himself a bit.)
I was particularly taken, and felt a deep kinship, with Sacks’s parenthetical note about Gunn’s ethos regarding writing about the writing of others:
Thom rarely reviewed what he did not like, and in general his reviews were written in the mode of appreciation.
Despite knowing his friend’s disposition toward criticism, Sacks recounts:
I sometimes felt terrified of his directness — terrified, in particular, that he would find my writings, such as they were, muzzy, dishonest, talentless, or worse.
But their relationship lived up to Emerson’s assertion that “a friend is a person with whom [one] may be sincere” — Gunn’s feedback, always in the spirit ofSamuel Beckett’s masterwork of constructive criticism, was monumentally beneficial to Sacks’s development as a writer, who was “eager for [Gunn’s] reactions, depended on them, and gave them more weight than those of anyone else.”
Dr. Sacks on the set of the cinematic adaptation of his book Awakenings, with Robin Williams, 1989 (Courtesy of Oliver Sacks)
But the feedback that most touched him was about his 1973 book Awakenings — a cultural classic that was eventually made into a film starring Robin Williams as Sacks. Gunn wrote:
Awakenings is, anyway, extraordinary. I remember when, some time in the late Sixties, you described the kind of book you wanted to write, simultaneously a good scientific book and worth reading as a well-written book, and you have certainly done it here… I have also been thinking of the Great Diary you used to show me. I found you so talented, but so deficient in one quality — just the most important quality — call it humanity, or sympathy, or something like that. And, frankly, I despaired of your ever becoming a good writer, because I didn’t see how one could be taught such a quality… Your deficiency of sympathy made for a limitation of your observation… What I didn’t know was that the growth of sympathies is something frequently delayed till one’s thirties. What was deficient in these writings is now the supreme organizer of Awakenings, and wonderfully so. It is literally the organizer of your style, too, and is what enables it to be so inclusive, so receptive, and so varied… I wonder if you know what happened. Simply working with the patients over so long, or the opening-up helped by acid, or really falling in love with someone (as opposed to being infatuated). Or all three…
Sacks adds:
I was thrilled by this letter, a bit obsessed, too. I did not know how to answer Thom’s question. I had fallen in love — and out of love — and, in a sense, was in love with my patients (the sort of love, or sympathy, which makes one clear-eyed).
But it was in Gunn’s poetry that Sacks found something else — something tremendously important to our understanding of how creativity works and the constant, necessary dialogue between influence and so-called originalitymediated by our imperfect memory, of which Sacks has written beautifully. Reflecting on Gunn’s intricate tapestry of influences — his creative lineage of what Margaret Mead termed our “spiritual and mental ancestors” — Sacks writes:
I loved the sense of history, of predecessors, in many of Thom’s poems. Sometimes this was explicit, as in his “Poem After Chaucer” (which he sent me as a New Year’s card in 1971); more often it was implicit. It made me feel at times that Thom was a Chaucer, a Donne, a Lord Herbert, who now found himself in the America, the San Francisco, of the late twentieth century. This sense of ancestors, of predecessors, was an essential part of his work, and he often alluded to, or borrowed from, other poets and other sources. There was no tiresome insistence on “originality,” and yet, of course, everything he used was transmuted in the process.
Gunn himself, echoing Montaigne’s sentiments about originality, addressed this in an autobiographical essay:
I must count my writing as an essential part of the way in which I deal with life. I am however a rather derivative poet. I learn what I can from whom I can. I borrow heavily from my reading, because I take my reading seriously. It is part of my total experience and I base most of my poetry on my experience. I do not apologize for being derivative… It has not been of primary interest to develop a unique poetic personality, and I rejoice in Eliot’s lovely remark that art is the escape from personality.
Dr. Sacks at home on City Island, the Bronx (Courtesy of Oliver Sacks)
And yet art requires undisturbed personal space for the “quickenings” of the creative process to unfold slowly — something Sacks protected with great discipline as he blossomed into a prolific writer himself. In his house on City Island, he tacked a sign to the wall above his desk that simply read “NO!” — “reminding myself to say no to invitations so I could preserve writing time,” he explains. It is no accident that Sacks dedicates the final sentences in his autobiography to this great love of writing and, in a sentiment that calls to mindthe psychology of flow, fuses it with his great gift for science:
I am a storyteller, for better and for worse.
I suspect that a feeling for stories, for narrative, is a universal human disposition, going with our powers of language, consciousness of self, and autobiographical memory.
The act of writing, when it goes well, gives me a pleasure, a joy, unlike any other. It takes me to another place — irrespective of my subject — where I am totally absorbed and oblivious to distracting thoughts, worries, preoccupations, or indeed the passage of time. In those rare, heavenly states of mind, I may write nonstop until I can no longer see the paper. Only then do I realize that evening has come and that I have been writing all day.
Over a lifetime, I have written millions of words, but the act of writing seems as fresh, and as much fun, as when I started it nearly seventy years ago.
Oliver Sacks writing in his seventies (Photograph: Bill Hayes)
Every page of the altogether magnificent On the Move emanates this contagious delight in writing and furnishes an equivalent delight in reading — a sense of being invited, in the most generous way possible, into a lifetime of Sacks’s conversations with his own luminous, incessantly quickening mind. Take another step inside.
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Friday, September 19, 2014

Natural Beauties: More Fine Minerals































From yee Wiki:

A mineral is a naturally occurring substance that is solid and inorganic representable by a chemical formula, usually abiogenic, and has an ordered atomic structure. It is different from a rock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition. The exact definition of a mineral is under debate, especially with respect to the requirement a valid species be abiogenic, and to a lesser extent with regard to it having an ordered atomic structure. The study of minerals is called mineralogy.

There are over 4,900 known mineral species; over 4,660 of these have been approved by the International Mineralogical Association (IMA). The silicate minerals compose over 90% of the Earth's crust. The diversity and abundance of mineral species is controlled by the Earth's chemistry. Silicon and oxygen constitute approximately 75% of the Earth's crust, which translates directly into the predominance of silicate minerals. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish various species, and these properties in turn are influenced by the mineral's geological environment of formation. Changes in the temperature, pressure, and bulk composition of a rock mass cause changes in its mineralogy; however, a rock can maintain its bulk composition, but as long as temperature and pressure change, its mineralogy can change as well.

Minerals can be described by various physical properties which relate to their chemical structure and composition. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, and specific gravity. More specific tests for minerals include reaction to acid, magnetism, taste or smell, and radioactivity.

Minerals are classified by key chemical constituents; the two dominant systems are the Dana classification and the Strunz classification. The silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a base unit of a [SiO4]4- silica tetrahedra—that is, a silicon cation coordinated by four oxygen anions, which gives the shape of a tetrahedron. These tetrahedra can be polymerized to give the subclasses: orthosilicates (no polymerization, thus single tetrahedra), disilicates (two tetrahedra bonded together), cyclosilicates (rings of tetrahedra), inosilicates (chains of tetrahedra), phyllosilicates (sheets of tetrahedra), and tectosilicates (three-dimensional network of tetrahedra). Other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates.