On Nov. 22, 2014 from 5:29 to 6:04 p.m. EST., the moon partially obscured the view of the sun from NASA’s Solar Dynamics Observatory. This phenomenon, which is called a lunar transit, could only be seen from SDO’s point of view.
In 2014, SDO captured four such transits — including its longest ever recorded, which occurred on Jan. 30, and lasted two and a half hours.
SDO imagery during a lunar transit always shows a crisp horizon on the moon — a reflection of the fact that the moon has no atmosphere around it to distort the light from the sun. The horizon is so clear in these images that mountains and valleys in the terrain can be seen.
Could parallel universes exist? If so, what would they look like and how would they form?
Many physicists believe there is a strong connection between the inflationary multiverse and an important feature of string theory.
Although there is not yet evidence favoring the quantum multiverse over several other interpretations of quantum mechanics, it is still consistent with the results of every quantum experiment ever conducted.
“With a body the size of a house, the weight of a herd of elephants, and a weaponized (9-meter, muscled) tail, Dreadnoughtus would have feared nothing,” study co-author Kenneth Lacovara of Drexel University in Philadelphia said of the mighty beast.
“You have this 37-foot-long (11-meter) neck balanced by a 30-foot-long (9-meter) tail in the back. Without moving your legs, you have access to a giant feeding envelope of trees and green ferns. You spend an hour or so clearing out this patch that has had thousands of calories in it, and then you take three steps over to the right and spend the next hour clearing out that patch.”
Summary: The first terrestrial discovery of Ringwoodite confirms the presence of massive amounts of water 400 to 700 kilometers beneath Earth’s surface.
Ringwoodite is a form of the mineral peridot, believed to exist in large quantities under high pressures in the transition zone.
Ringwoodite has been found in meteorites but, until now, no terrestrial sample has ever been unearthed because scientists haven’t been able to conduct fieldwork at extreme depths.
Scientists scanning the deep interior of Earth have found evidence of a vast water reservoir beneath eastern Asia that is at least the volume of the Arctic Ocean.
The discovery marks the first time such a large body of water has found in the planet’s deep mantle. [The World’s Biggest Oceans and Seas]
Water covers 70 percent of Earth’s surface and one of its many functions is to act like a lubricant for the movement of continental plates.
The crust thickness averages about 18 miles (30 kilometers) under the continents, but is only about 3 miles (5 kilometers) under the oceans. It is light and brittle and can break. In fact it’s fractured into more than a dozen major plates and several minor ones. It is where most earthquakes originate.
The Earth’s radius is about 4,000 miles (6,400 kilometers). The main layers of its interior are in descending order: crust, mantle and core.
The mantle is more flexible – it flows instead of fractures. It extends down to about 1,800 miles (2,900 kilometers) below the surface.
The core consists of a solid inner core and a fluid outer core. The fluid contains iron, which, as it moves, generates the Earth’s magnetic field. The crust and upper mantle form the lithosphere, which is broken up into several plates that float on top of the hot molten mantle below.
The “Godzilla of Earths!” is in the foreground. Behind it is the smaller ‘lava world’. Their sun, in the back, appears to have been created only 3 billion years after the Big Bang.
Based on what we know about how solar systems form, researchers thought that a giant rocky planet could not exist. But they just found one that’s 17 times Earth’s mass. They’re calling it the Mega-Earth.
Scientists say the new planet may have “profound implications for the possibility of life” on extra-solar planets, according to a press release from the Harvard-Smithsonian Center for Astrophysics. They announced the finding in a talk at the American Astronomical Society meeting in Boston.
Researchers have always thought Mega-Earths were impossible since any planets that big would attract hydrogen gas, forming a gas planet like Jupiter.
Meet The Mega-Earth
Mega-Earth, also known as Kepler-10c, is 18,000 miles in diameter and 2.3 times as large as Earth. It appears to be as solid as the planet beneath our feet.
Kepler-10c was previously known to astronomers, but they had not yet measured its mass. Due to its size — 2.3 times that of Earth — it was assumed to be a “mini-Neptune,” a planet encased in thick gas. But the new observations have confirmed that it is rocky, not gassy.
It orbits an 11 billion-year-old star named Kepler-10 located 560 light years away from Earth. Its year lasts only 45 days.
Interestingly, this solar system is more than twice as old as our own — it was born less than 3 billion years after the Big Bang.
A Mysterious System
Researchers had previously thought that this kind of planet impossible.
Not only did they think something that big would be a gas giant, but they didn’t even think the elements that make up a rocky planet existed in our universe when this solar system was born: The early universe had only the lighter elements of hydrogen and helium.
Heavier elements were forged from these lighter ones in stars over billions of years.
Because of this, many scientists hadn’t been looking for rocky planets in these very old solar systems.
The mega-Earth isn’t the only weird planet in its solar system. There’s also a ‘lava-world’ 1.5 times Earth’s size whose year lasts only 20 hours.
Explanation: Recorded on April 15th, this total lunar eclipse sequence looks south down icy Waterton Lake from the Waterton Lakes National Park in Alberta, Canada, planet Earth. The most distant horizon includes peaks in Glacier National Park, USA. An exposure every 10 minutes captured the Moon’s position and eclipse phase, as it arced, left to right, above the rugged skyline and Waterton town lights. In fact, the sequence effectively measures the roughly 80 minute duration of the total phase of the eclipse. Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses – though probably without the benefit of digital clocks and cameras. Still, using geometry, he devised a simple and impressively accurate way to calculate the Moon’s distance, in terms of the radius of planet Earth, from the eclipse duration. This modern eclipse sequence also tracks the successive positions of Mars, above and right of the Moon, bright star Spica next to the reddened lunar disk, and Saturn to the left and below.
Image Credit & Copyright: Yuichi Takasaka
Abū ʿAbdallāh Muḥammad ibn Mūsā al-Khwārizmī (Arabic: عَبْدَالله مُحَمَّد بِن مُوسَى اَلْخْوَارِزْمِي), earlier transliterated as Algoritmi or Algaurizin, (c. 780, Khwārizm – c. 850) was a Persian mathematician, astronomer and geographer during the Abbasid Empire, a scholar in theHouse of Wisdom in Baghdad.
In the twelfth century, Latin translations of his work on the Indian numerals introduced the decimal positional number system to the Western world. His Compendious Book on Calculation by Completion and Balancing presented the first systematic solution of linear and quadratic equations in Arabic. In Renaissance Europe, he was considered the original inventor of algebra, although it is now known that his work is based on older Indian or Greek sources. He revised Ptolemy’s Geography and wrote on astronomy and astrology.
Some words reflect the importance of al-Khwarizmi’s contributions to mathematics. “Algebra” is derived from al-jabr, one of the two operations he used to solve quadratic equations. Algorism and algorithm stem from Algoritmi, the Latin form of his name. His name is also the origin of (Spanish) guarismo and of (Portuguese) algarismo, both meaning digit.
Al-Khwārizmī’s contributions to mathematics, geography, astronomy, and cartography established the basis for innovation in algebra and trigonometry. His systematic approach to solving linear and quadratic equations led to algebra, a word derived from the title of his 830 book on the subject, “The Compendious Book on Calculation by Completion and Balancing” (al-Kitab al-mukhtasar fi hisab al-jabr wa’l-muqabalaالكتاب المختصر في حساب الجبر والمقابلة).
On the Calculation with Hindu Numerals written about 825, was principally responsible for spreading the Indian system of numeration throughout the Middle East and Europe. It was translated into Latin as Algoritmi de numero Indorum. Al-Khwārizmī, rendered as (Latin) Algoritmi, led to the term “algorithm”.
Some of his work was based on Persian and Babylonian astronomy, Indian numbers, and Greek mathematics.
Al-Khwārizmī systematized and corrected Ptolemy’s data for Africa and the Middle East. Another major book was Kitab surat al-ard (“The Image of the Earth”; translated as Geography), presenting the coordinates of places based on those in the Geography of Ptolemy but with improved values for theMediterranean Sea, Asia, and Africa.
He also wrote on mechanical devices like the astrolabe and sundial.
He assisted a project to determine the circumference of the Earth and in making a world map for al-Ma’mun, the caliph, overseeing 70 geographers.
When, in the 12th century, his works spread to Europe through Latin translations, it had a profound impact on the advance of mathematics in Europe. He introduced Arabic numerals into the Latin West, based on a place-value decimal system developed from Indian sources.
Main article: The Compendious Book on Calculation by Completion and Balancing
Further information: Latin translations of the 12th century and Islamic science
Al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa-l-muqābala (Arabic: الكتاب المختصر في حساب الجبر والمقابلة, ‘The Compendious Book on Calculation by Completion and Balancing’) is a mathematical book written approximately 830 CE. The book was written with the encouragement of the Caliph al-Ma’mun as a popular work on calculation and is replete with examples and applications to a wide range of problems in trade, surveying and legal inheritance. The term algebra is derived from the name of one of the basic operations with equations (al-jabr, meaning completion, or, subtracting a number from both sides of the equation) described in this book. The book was translated in Latin as Liber algebrae et almucabalaby Robert of Chester (Segovia, 1145) hence “algebra”, and also by Gerard of Cremona. A unique Arabic copy is kept at Oxford and was translated in 1831 by F. Rosen. A Latin translation is kept in Cambridge.
It provided an exhaustive account of solving polynomial equations up to the second degree, and discussed the fundamental methods of “reduction” and “balancing”, referring to the transposition of subtracted terms to the other side of an equation, that is, the cancellation of like terms on opposite sides of the equation.
Al-Khwārizmī’s method of solving linear and quadratic equations worked by first reducing the equation to one of six standard forms (where b and care positive integers)
squares equal roots (ax2 = bx)
squares equal number (ax2 = c) roots equal number (bx = c) squares and roots equal number (ax2 + bx = c) squares and number equal roots (ax2 + c = bx) roots and number equal squares (bx + c = ax2)
by dividing out the coefficient of the square and using the two operations al-jabr (Arabic: الجبر “restoring” or “completion”) and al-muqābala (“balancing”). Al-jabr is the process of removing negative units, roots and squares from the equation by adding the same quantity to each side. For example, x2 = 40x − 4×2 is reduced to 5×2 = 40x. Al-muqābala is the process of bringing quantities of the same type to the same side of the equation. For example, x2 + 14 = x + 5 is reduced to x2 + 9 = x.
The above discussion uses modern mathematical notation for the types of problems which the book discusses. However, in al-Khwārizmī’s day, most of this notation had not yet been invented, so he had to use ordinary text to present problems and their solutions. For example, for one problem he writes, (from an 1831 translation)
“If some one say: “You divide ten into two parts: multiply the one by itself; it will be equal to the other taken eighty-one times.” Computation: You say, ten less thing, multiplied by itself, is a hundred plus a square less twenty things, and this is equal to eighty-one things. Separate the twenty things from a hundred and a square, and add them to eighty-one. It will then be a hundred plus a square, which is equal to a hundred and one roots. Halve the roots; the moiety is fifty and a half. Multiply this by itself, it is two thousand five hundred and fifty and a quarter. Subtract from this one hundred; the remainder is two thousand four hundred and fifty and a quarter. Extract the root from this; it is forty-nine and a half. Subtract this from the moiety of the roots, which is fifty and a half. There remains one, and this is one of the two parts.”
Several authors have also published texts under the name of Kitāb al-jabr wa-l-muqābala, including |Abū Ḥanīfa al-Dīnawarī, Abū Kāmil Shujā ibn Aslam, Abū Muḥammad al-ʿAdlī, Abū Yūsuf al-Miṣṣīṣī, ‘Abd al-Hamīd ibn Turk, Sind ibn ʿAlī, Sahl ibn Bišr, and Šarafaddīn al-Ṭūsī.
J. J. O’Conner and E. F. Robertson wrote in the MacTutor History of Mathematics archive:
“Perhaps one of the most significant advances made by Arabic mathematics began at this time with the work of al-Khwarizmi, namely the beginnings of algebra. It is important to understand just how significant this new idea was. It was a revolutionary move away from the Greek concept of mathematics which was essentially geometry. Algebra was a unifying theory which allowed rational numbers, irrational numbers, geometrical magnitudes, etc., to all be treated as “algebraic objects”. It gave mathematics a whole new development path so much broader in concept to that which had existed before, and provided a vehicle for future development of the subject. Another important aspect of the introduction of algebraic ideas was that it allowed mathematics to be applied to itself in a way which had not happened before.”
R. Rashed and Angela Armstrong write:
“Al-Khwarizmi’s text can be seen to be distinct not only from the Babylonian tablets, but also from Diophantus’ Arithmetica. It no longer concerns a series of problems to be resolved, but an exposition which starts with primitive terms in which the combinations must give all possible prototypes for equations, which henceforward explicitly constitute the true object of study. On the other hand, the idea of an equation for its own sake appears from the beginning and, one could say, in a generic manner, insofar as it does not simply emerge in the course of solving a problem, but is specifically called on to define an infinite class of problems.”
Al-Khwārizmī’s second major work was on the subject of arithmetic, which survived in a Latin translation but was lost in the original Arabic. The translation was most likely done in the twelfth century by Adelard of Bath, who had also translated the astronomical tables in 1126.
The Latin manuscripts are untitled, but are commonly referred to by the first two words with which they start: Dixit algorizmi (“So said al-Khwārizmī”), orAlgoritmi de numero Indorum (“al-Khwārizmī on the Hindu Art of Reckoning”), a name given to the work by Baldassarre
Boncompagni in 1857. The original Arabic title was possibly Kitāb al-Jamʿ wa-l-tafrīq bi-ḥisāb al-Hind (“The Book of Addition and Subtraction According to the Hindu Calculation”).
Al-Khwarizmi’s work on arithmetic was responsible for introducing the Arabic numerals, based on the Hindu-Arabic numeral system developed in Indian mathematics, to the Western world. The term “algorithm” is derived from the algorism, the technique of performing arithmetic with Hindu-Arabic numerals developed by al-Khwarizmi. Both “algorithm” and “algorism” are derived from the Latinized forms of al-Khwarizmi’s name, Algoritmi andAlgorismi, respectively.
Al-Khwārizmī’s Zīj al-Sindhind (Arabic: زيج “astronomical tables of Sind and Hind”) is a work consisting of approximately 37 chapters on calendrical and astronomical calculations and 116 tables with calendrical, astronomical and astrological data, as well as a table of sine values. This is the first of many Arabic Zijes based on the Indian astronomical methods known as the sindhind. The work contains tables for the movements of the sun, themoon and the five planets known at the time. This work marked the turning point in Islamic astronomy. Hitherto, Muslim astronomers had adopted a primarily research approach to the field, translating works of others and learning already discovered knowledge.
The original Arabic version (written c. 820) is lost, but a version by the Spanish astronomer Maslamah Ibn Ahmad al-Majriti (c. 1000) has survived in a Latin translation, presumably by Adelard of Bath (January 26, 1126). The four surviving manuscripts of the Latin translation are kept at the Bibliothèque publique (Chartres), the Bibliothèque Mazarine (Paris), the Biblioteca Nacional (Madrid) and the Bodleian Library (Oxford).
Al-Khwārizmī’s Zīj al-Sindhind also contained tables for the trigonometric functions of sines and cosine. A related treatise on spherical trigonometryis also attributed to him.
Hubert Daunicht’s reconstruction of al-Khwārizmī’s planisphere.
Al-Khwārizmī’s third major work is his Kitāb ṣūrat al-Arḍ (Arabic: كتاب صورة الأرض “Book on the appearance of the Earth” or “The image of the Earth” translated as Geography), which was finished in 833. It is a revised and completed version of Ptolemy’s Geography, consisting of a list of 2402 coordinates of cities and other geographical features following a general introduction.
There is only one surviving copy of Kitāb ṣūrat al-Arḍ, which is kept at the Strasbourg University Library. A Latin translation is kept at the Biblioteca Nacional de España in Madrid. The complete title translates as Book of the appearance of the Earth, with its cities, mountains, seas, all the islands and rivers, written by Abu Ja’far Muhammad ibn Musa al-Khwārizmī, according to the geographical treatise written by Ptolemy the Claudian.
The book opens with the list of latitudes and longitudes, in order of “weather zones”, that is to say in blocks of latitudes and, in each weather zone, by order of longitude. As Paul Gallez[dubious – discuss] points out, this excellent system allows the deduction of many latitudes and longitudes where the only extant document is in such a bad condition as to make it practically illegible.
Neither the Arabic copy nor the Latin translation include the map of the world itself; however, Hubert Daunicht was able to reconstruct the missing map from the list of coordinates. Daunicht read the latitudes and longitudes of the coastal points in the manuscript, or deduces them from the context where they were not legible. He transferred the points onto graph paper and connected them with straight lines, obtaining an approximation of the coastline as it was on the original map. He then does the same for the rivers and towns.
Al-Khwārizmī corrected Ptolemy’s gross overestimate for the length of the Mediterranean Sea from the Canary Islands to the eastern shores of the Mediterranean; Ptolemy overestimated it at 63 degrees of longitude, while al-Khwarizmi almost correctly estimated it at nearly 50 degrees of longitude. He “also depicted the Atlantic and Indian Oceans as open bodies of water, not land-locked seas as Ptolemy had done.” Al-Khwarizmi thus set the Prime Meridian of the Old World at the eastern shore of the Mediterranean, 10–13 degrees to the east of Alexandria (the prime meridian previously set by Ptolemy) and 70 degrees to the west of Baghdad. Most medieval Muslim geographers continued to use al-Khwarizmi’s prime meridian.
Al-Khwārizmī wrote several other works including a treatise on the Hebrew calendar (Risāla fi istikhrāj taʾrīkh al-yahūd ”Extraction of the Jewish Era”). It describes the 19-year intercalation cycle, the rules for determining on what day of the week the first day of the month Tishrī shall fall; calculates the interval between the Jewish era (creation of Adam) and the Seleucid era; and gives rules for determining the mean longitude of the sun and the moon using the Jewish calendar. Similar material is found in the works of al-Bīrūnī and Maimonides.
Ibn al-Nadim in his Kitab al-Fihrist (an index of Arabic books) mentions al-Khwārizmī’s Kitab al-Tarikh, a book of annals. No direct manuscript survives; however, a copy had reached Nisibis by the 1000s, where its metropolitan, Elias bar Shinaya, found it. Elias’s chronicle quotes it from “the death of the Prophet” through to 169 AH, at which point Elias’s text itself hits a lacuna.
Several Arabic manuscripts in Berlin, Istanbul, Tashkent, Cairo and Paris contain further material that surely or with some probability comes from al-Khwārizmī. The Istanbul manuscript contains a paper on sundials; the Fihrist credits al-Khwārizmī with Kitāb ar-Rukhāma(t). Other papers, such as one on the determination of the direction of Mecca, are on the spherical astronomy.
Two texts deserve special interest on the morning width (Maʿrifat saʿat al-mashriq fī kull balad) and the determination of the azimuth from a height (Maʿrifat al-samt min qibal al-irtifāʿ).
He also wrote two books on using and constructing astrolabes.
Aminatta Forna tells the story of legendary Timbuktu and its long hidden legacy of hundreds of thousands of ancient manuscripts. With its university founded around the same time as Oxford.
Timbuktu is proof that the reading and writing of books have long been as important to Africans as to Europeans.
From the highest volcano to the deepest canyon, from impact craters to ancient river beds and lava flows, this showcase of images from ESA’s Mars Express takes you on an unforgettable journey across the Red Planet.
Mars Express was launched on 2 June 2003 and arrived at Mars six-and-a-half months later. It has since orbited the planet nearly 12 500 times, providing scientists with unprecedented images and data collected by its suite of scientific instruments.
The data have been used to create an almost global digital topographic model of the surface, providing a unique visualisation and enabling researchers to acquire new and surprising information about the evolution of the Red Planet.
The images in this movie were taken by the High Resolution Stereo Camera and the video was released by the DLR German Aerospace Center as part of the ten years of Mars Express celebrations in June 2013. The music has been created by Stephan Elgner of DLR’s Mars Express planetary cartography team. DLR developed and is operating the stereo camera.
Babies only hours old are able to differentiate between sounds from their native language and a foreign language, scientists have discovered. The study indicates that babies begin absorbing language while still in the womb, earlier than previously thought.
Sensory and brain mechanisms for hearing are developed at 30 weeks of gestational age, and the new study shows that unborn babies are listening to their mothers talk during the last 10 weeks of pregnancy and at birth can demonstrate what they’ve heard.
“The mother has first dibs on influencing the child’s brain,” said Patricia Kuhl, co-author and co-director of the Institute for Learning & Brain Sciences at the University of Washington. “The vowel sounds in her speech are the loudest units and the fetus locks onto them.”
Previously, researchers had shown that newborns are born ready to learn and begin to discriminate between language sounds within the first months of life, but there was no evidence that language learning had occurred in utero.
“This is the first study that shows fetuses learn prenatally about the particular speech sounds of a mother’s language,” said Christine Moon, lead author and a professor of psychology at Pacific Lutheran University in Tacoma, Wash. “This study moves the measurable result of experience with speech sounds from six months of age to before birth.”
The results will be published in an upcoming issue of the Journal Acta Paediatrica.
Forty infants, about 30 hours old and an even mix of girls and boys, were studied in Tacoma and Stockholm, Sweden. While still in the nursery, the babies listened to vowel sounds in their native tongue and in foreign languages.
Their interest in the sounds was captured by how long they sucked on a pacifier that was wired into a computer measuring the babies’ reaction to the sounds. Longer or shorter sucking for unfamiliar or familiar sounds is evidence for learning, because it indicates that infants can differentiate between the sounds heard in utero.
In both countries, the babies at birth sucked longer for the foreign language than they did for their native tongue.
The researchers say that infants are the best learners, and discovering how they soak up information could give insights on lifelong learning. “We want to know what magic they put to work in early childhood that adults cannot,” Kuhl said. “We can’t waste that early curiosity.