The Making of Planet Earth – National Geographic Full Documentary

Published on Jun 19, 2013 ❶ HD Documentary Channel: For all your Space, Universe, Science and Technology documentaries! Published on Oct 4, 2013 This edition of COSMIC JOURNEYS explores the still unfolding story of Earth’s past and the light it sheds on the science of climate change today. While that story can tell us about […]

Published on Jun 19, 2013

? HD Documentary Channel: For all your Space, Universe, Science and Technology documentaries!

Published on Oct 4, 2013
This edition of COSMIC JOURNEYS explores the still unfolding story of Earth’s past and the light it sheds on the science of climate change today. While that story can tell us about the mechanisms that can shape our climate. it’s still the unique conditions of our time that will determine sea levels, ice coverage, and temperatures.

Ice, in its varied forms, covers as much as 16% of Earth’s surface, including 33% of land areas at the height of the northern winter. Glaciers, sea ice, permafrost, ice sheets and snow play an important role in Earth’s climate. They reflect energy back to space, shape ocean currents, and spawn weather patterns.

But there are signs that Earth’s great stores of ice are beginning to melt. To find out where Earth might be headed, scientists are drilling down into the ice, and scouring ancient sea beds, for evidence of past climate change. What are they learning about the fate of our planet… a thousand years into the future and even beyond?

30,000 years ago, Earth began a relentless descent into winter. Glaciers pushed into what were temperate zones. Ice spread beyond polar seas. New layers of ice accumulated on the vast frozen plateau of Greenland. At three kilometers thick, Greenland’s ice sheet is a monumental formation built over successive ice ages and millions of years. It’s so heavy that it has pushed much of the island down below sea level. And yet, today, scientists have begun to wonder how resilient this ice sheet really is.

Average global temperatures have risen about one degree Celsius since the industrial revolution. They could go up another degree by the end of this century. If Greenland’s ice sheet were to melt, sea levels would rise by over seven meters. That would destroy or threaten the homes and livelihoods of up to a quarter of the world’s population.

With so much at stake, scientists are monitoring Earth’s frozen zones… with satellites, radar flights, and expeditions to drill deep into ice sheets. And they are reconstructing past climates, looking for clues to where Earth might now be headed… not just centuries, but thousands of years in the future.

Periods of melting and freezing, it turns out, are central events in our planet’s history.
That’s been born out by evidence ranging from geological traces of past sea levels… the distribution of fossils… chemical traces that correspond to ocean temperatures, and more.

Going back over two billion years, earth has experienced five major glacial or ice ages. The first, called the Huronian, has been linked to the rise of photosynthesis in primitive organisms. They began to take in carbon dioxide, an important greenhouse gas. That decreased the amount of solar energy trapped by the atmosphere, sending Earth into a deep freeze.

The second major ice age began 580 million years ago. It was so severe, it’s often referred to as “snowball earth.” The Andean-Saharan and the Karoo ice ages began 460 and 360 million years ago. Finally, there’s the Quaternary… from 2.6 million years ago to the present. Periods of cooling and warming have been spurred by a range of interlocking factors: the movement of continents, patterns of ocean circulation, volcanic events, the evolution of plants and animals.

The world as we know it was beginning to take shape in the period from 90 to 50 million years ago. The continents were moving toward their present positions. The Americas separated from Europe and Africa. India headed toward a merger with Asia. The world was getting warmer. Temperatures spiked roughly 55 million years ago, going up about 5 degrees Celsius in just a few thousand years. CO2 levels rose to about 1000 parts per million compared to 280 in pre-industrial times, and 390 today.

But the stage was set for a major cool down. The configuration of landmasses had cut the Arctic off from the wider oceans. That allowed a layer of fresh water to settle over it, and a sea plant called Azolla to spread widely. In a year, it can soak up as much as 6 tons of CO2 per acre. Plowing into Asia, the Indian subcontinent caused the mighty Himalayan Mountains to rise up. In a process called weathering, rainfall interacting with exposed rock began to draw more CO2 from the atmosphere… washing it into the sea. Temperatures steadily dropped.

By around 33 million years ago, South America had separated from Antarctica. Currents swirling around the continent isolated it from warm waters to the north. An ice sheet formed. In time, with temperatures and CO2 levels continuing to fall, the door was open for a more subtle climate driver. It was first described by the 19th century Serbian scientist, Milutin Milankovic.

He saw that periodic variations in Earth’s rotational motion altered the amount of solar radiation striking the poles. In combination, every 100,000 years or so, these variations have sent earth into a period of cool temperatures and spreading ice.


The Drake Equation

The Flake Equation ESTIMATING THE NUMBER OF PEOPLE WHO HAVE EXPERIENCED THE PARANORMAL OR SUPERNATURAL Michael Shermer The Drake Equation is the famous formula developed by the astronomer Frank Drake for estimating the number of extraterrestrial civilizations: N = R … Continue reading

The Flake Equation

ESTIMATING THE NUMBER OF PEOPLE WHO HAVE
EXPERIENCED THE PARANORMAL OR SUPERNATURAL

Michael Shermer


The Drake Equation is the famous formula developed by the astronomer Frank Drake for estimating the number of extraterrestrial civilizations:

N = R × fp × ne × fl × fi × fc × L where…

  • N = the number of communicative civilizations,
  • R = the rate of formation of suitable stars,
  • fp = the fraction of those stars with planets,
  • ne = the number of earth-like planets per solar system,
  • fl = the fraction of planets with life,
  • fi = the fraction of planets with intelligent life,
  • fc = the fraction of planets with communicating technology, and
  • L = the lifetime of communicating civilizations.

The equation is so ubiquitous that it has even been employed in the popular television series The Big Bang Theory for computing the number of available sex partners within a 40-mile radius of Los Angeles (5,812). My favorite parody of it is by the cartoonist Randall Munroe as one in a series of his clever science send-ups, entitled “The Flake Equation” (on xkcd.com) for calculating the number of people who will mistakenly think they had an ET encounter.

Such multiplicative equations for calculating the product of an increasingly restrictive series of fractional values are effective tools for making back-of-the-envelope calculations to solve problems for which we do not have precise data. To that end I thought it a useful addition to the Skeptic toolbox to create a Flake Equation for all paranormal and supernatural experiences (and in the Flake Equation I’m interested not in beliefs but in actual experiences that people report and that we hear about, because this becomes the foundation of paranormal and supernatural beliefs):

N = Pw × fp × fm × ft × nt × no × fm where…

  • N = Number of people we hear about who report having experienced a paranormal or supernatural phenomena,
  • Pw = Population of the United States (January 1, 2012: 312,938,813),
  • fp = Fraction of people who report having had an anomalous psychological experience or witnessed an unusual physical phenomena (1/5),
  • fm = Fraction of people who interpret such experiences and phenomena as paranormal or supernatural (1/5),
  • ft = Fraction of people who tell someone about their experience (1/10),
  • nt = Number of people they tell (15),
  • no = Number of other people told the story by original hearers (15), and
  • fm = Fraction of such stories reported in the media or on Internet blogs, tweets, and forums (1/10).

N = 28,164,493, or about 9 percent of the U.S. population.

To compute this figure I used the 2005/2007 Baylor Religion Survey, which reports that

  • 23.2% say that they have “witnessed a miraculous, physical healing,”
  • 16.3% “received a miraculous, physical healing,”
  • 27.5% “witnessed people speaking in tongues at a place of worship,”
  • 7.7% “spoke or prayed in tongues,”
  • 54.5% experienced being “protected from harm by a guardian angel,”
  • 5.9% “personally had a vision of a religious figure while awake,”
  • 19.1% “heard the voice of God speaking to me,”
  • 26.1% “had a dream of religious significance,”
  • 52% “had an experience where you felt that you were filled with the spirit,”
  • 22.1% “felt at one with the universe,”
  • 25.7% “had a religious conversion experience,”
  • 13.8% “had an experience where you felt that you were in a state of religious ecstasy,”
  • 14.2% “had an experience where you felt that you left your body for a period of time,”
  • 40.4% “had a dream that later came true,” and
  • 16.7% “witnessed an object in the sky that you could not identify (UFO).”

This works out to an average of 24.4 percent, thereby justifying my conservative 20 percent figure for fp and fm. The other numbers I gleaned from research on gossip and social networks, conservatively estimating that 10 percent of people will tell someone about their unusual experience, and that within their average social network of 150 people they will tell at least 10 percent of them (15) who in turn will pass on the story to 10 percent of their social network of 150 (15). Finally, I estimate that 10 percent of such stories will be reported in the media or recounted in blogs, tweets, forums, and the like.

Of course the final figure for N will vary considerably depending on what numbers are plugged into the equation, but the result will almost always be a number in the tens of millions, which goes a long way toward explaining why belief in the paranormal and supernatural is so ubiquitous. Experiencing is believing!


end of the world

Eschatology i/ˌɛskəˈtɒlədʒi/ (from the Greek ἔσχατος/ἐσχάτη/ἔσχατον, eschatos/eschatē/eschaton meaning “last” and -logy meaning “the study of”, first used in English around 1550)[1] is a part of theology, physics, philosophy, and futurology concerned with what are believed to be the final events of history, theultimate destiny of humanity — commonly referred to as the “end of the … Continue reading

Eschatology Listeni/??sk??t?l?d?i/ (from the Greek ???????/??????/???????, eschatos/eschat?/eschaton meaning “last” and -logy meaning “the study of”, first used in English around 1550)[1] is a part of theologyphysicsphilosophy, and futurology concerned with what are believed to be the final events of history, theultimate destiny of humanity — commonly referred to as the “end of the world” or “end time“.[2]

The Oxford English Dictionary defines eschatology as “The department of theological science concerned with ‘the four last things: deathjudgementheaven and hell’.”[3]

In the context of mysticism, the phrase refers metaphorically to the end of ordinary reality and reunion with the Divine. In many religions it is taught as an existing future event prophesied in sacred texts or folklore. More broadly, eschatology may encompass related concepts such as the Messiah or Messianic Age, the end time, and the end of days.

History is often divided into “ages” (Gk. aeons), an age being a period when certain realities are present. One age comes to an end and a new age, where different realities are present, begins. When such transitions from one age to another are the subject of eschatological discussion, the phrase, “end of the world”, is replaced by “end of the age”, “end of an era”, or “end of life as we know it”. Much apocalyptic fiction does not deal with the “end of time” but rather with the end of a certain period of time, the end of life as it is now, and the beginning of a new period of time. It is usually a crisis that brings an end to current reality and ushers in a new way of living / thinking / being. This crisis may take the form of the intervention of a deity in history, a war, a change in the environment or the reaching of a new level of consciousness.

Most modern eschatology and apocalypticism, both religious and secular, involves the violent disruption or destruction of the world, whereas Christian and Jewish eschatologies view the end times as the consummation or perfection of God’s creation of the world. For example, according to ancient Hebrew belief, life takes a linear (and not cyclical) path; the world began with God and is constantly headed toward God’s final goal for creation.

Eschatologies vary as to their degree of optimism or pessimism about the future (and in some eschatologies, conditions are better for some and worse for others, e.g. “heaven and hell”).

Researchers in futures studies and transhumanism are investigating how the accelerating rate of scientific progress may lead to a technological singularity in the 21st century that would profoundly and unpredictably change the course of human history, and result in Homo sapiens no longer being the dominant life form on Earth.

The Sun at the center of the Solar System will turn into a red giant in about 5 billion years. As a red giant, the Sun will have a maximum radius beyond the Earth’s current orbit. The Sun’s expansion will not lead to the end of the Universe — its effects will be limited to the Solar System. Life on Earth will become impossible due to a rise in temperature long before the planet is actually swallowed up by the Sun.

Some forms of Buddhism hold a belief in cycles in which the life span of human beings changes according to human nature. In the Cakkavati sutta, the Buddha explained the relationship between life span of human beings and their behaviour. According to this sutta, unwise behavior was unknown among the human race in the past. As a result, people lived for an immensely long time — 80,000 years — endowed with great beauty, wealth, pleasure, and strength. Over the course of time, though, they began behaving in various unwise ways. This caused the human life span gradually to shorten, to the point where it now stands at 100 years, with human beauty, wealth, pleasure, and strength decreasing proportionately.[citation needed]

Ultimately, conditions will deteriorate to the point of a “sword-interval,” in which swords appear in the hands of all human beings, and they hunt one another like game. A few people, however, will take shelter in the wilderness to escape the carnage, and when the slaughter is over, they will come out of hiding and resolve to take up a life of wise and virtuous action again. With the recovery of virtue, the human life span will gradually increase again until it reaches 80,000 years, with people attaining sexual maturity at 500.

According to Tibetan Buddhist literature, the age of the first Buddha was 1,000,000 years and his height was 100 cubits while the 28th Buddha, Siddhartha Gautama (563BC–483BC) lived 80 years, and his height was 20 cubits.

In other traditions, such as Zen, a somewhat utilitarian view is taken. The notion often exists that within each moment in time, both birth and death are manifest. As the individual “dies” from moment to moment, they are equally “reborn” in each successive moment, in what one perceives as an ongoing cycle. Thus the practitioner’s focus is shifted from considerations regarding an imagined future endpoint, to mindfulness in the present moment. In this case, the worldview is taken as a functional tool for awakening the practitioner to reality as it exists, right now.


Written in your genes—and atoms

A review of Neil Shubin’s «The Universe Within,» a book that points to all the interconnectedness of nature, and how events in the geologic past have determined who we are and what kind of world we live in.

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A review of The Universe Within: Discovering the Common History of Rocks, Planets, and People, by Neil Shubin (Pantheon, New York, 2013).

Popularizing science, and writing science trade books for general audiences, is a challenging business. As an author of trade science books myself, I know how hard it is to write a book that sells well. Many of my fellow scientist-writers complain that the trade science book market is vanishing as fewer and fewer people read much any  more, and those who do read a lot don’t read non-fiction/science. Only a handful of scientists (Carl Sagan, Isaac Asimov, Stephen Jay Gould, Richard Dawkins, and just a few others) have managed to do it well for a long time. They are among the few that have reached the best-seller lists and achieved celebrity status so they are recognizable names and faces (and some have even appeared on The Simpsons, the ultimate arbiter of pop-culture status). Some of these people (especially Sagan) were attacked and scorned by their scientific peers for being “too popular” and no longer serious about their science, even though studies have shown that Sagan and Gould and the others were just as productive in their peer-reviewed science even as they reached superstar status. On the other hand, many people have cried out for the scientific community to provide us with more Sagans and Goulds who can make science interesting and comprehensible to a public that is becoming increasingly ignorant of science, or sucked into pseudoscience of UFOs and Bigfoot, or the junk science of creationists, anti-vaxxers, and climate change deniers.

Into this pantheon of scientific luminaries has stepped Neil Shubin, author of the previous mega-best seller,  Your Inner Fish, which explored the evidence of evolution as shown by our anatomy, and described in parallel the story of his field research that led to the discovery of the “fishibian” Tiktaalik. I’ve known Neil since he was a eager young Columbia undergrad, taking classes with me at the American Museum of Natural History when I was a graduate student there. Together, we worked on a revision of the Oligocene horses Mesohippus and Miohippus, which was one of Neil’s first scientific papers and finally published in 1989. After graduating from Columbia, Neil got his doctorate at Harvard working on the evo-devo of tetrapod limbs. Then he spent many years at Penn where he focused on finding more fossils showing the transition from fish to amphibian, and finally was lured to University of Chicago, where he has risen through the ranks to become Associate Dean of Biological Sciences.

His newest book, The Universe Within: Discovering the Common History of Rocks, Planets, and People, has made a big splash in the media, and garnered Neil his second appearance on the Colbert Report (the first was associated with Your Inner Fish). In many ways, it follows the successful elements of his previous books: interwoven with tales of his own research and the hardships of his field expeditions in the Arctic are vivid anecdotes and examples from the structure of nature that reinforce the point that evolution is apparent all around us, at every level from ecosystems to atoms. In this book, however, he weaves a thread of stories about famous people and events in the history of science that lead to a particular discovery about our world. For example, his account of Big Bang cosmology is leavened with the story of the “Harvard Computers.” This was not an early computer in the modern sense, but a group of women hired to do tedious mathematical calculations for Harvard astronomer Edward Charles Pickering. Some of them went on to their own discoveries, such as the method of determining an object’s distance by its brightness. Shubin then completes the tale by talking about Hubble and Mt. Wilson and the expanding universe, and then the accidental discovery of the cosmic background radiation by Bell Lab engineers Penzias and Wilson, who were just looking to get the noise and static out of their new microwave receiver. This leads to the point that we are all made of “stardust”, elements born during the first milliseconds of the Big Bang, and that those elements have been recycled through the universe many times. Shubin discusses the fact that we are the only planet that ended up with liquid water. He describes how the gravitational pull of Jupiter affects certain key processes on earth, and even the shape and distribution of the rest of the mass in the solar system. Shubin describes the events that led to the formation of the moon, which were not understood until the Apollo astronauts brought back moon rocks. He talks about the discovery of our internal biological clocks, and how we are slaves of circadian rhythms that operate even on the cellular level, so that our attempts to adjust to “jet lag” or travel multiple time zones are not just annoying, but unhealthy.

Shubin’s remaining chapters discuss the people and events that led to the discovery of plate tectonics; the issues about the origin of life, and the evolution of multicellularity and an oxygenated atmosphere;  the early discovery of mass extinction in the fossil record, leading to the battles over the possibility of periodic extinctions (and the interesting stories of the major players in each of these developments); and the events that led to the end of the greenhouse world of the dinosaurs and the modern icehouse world. Here, he follows the Raymo and Ruddiman idea that increased Himalayan uplift and weathering was the carbon sink that got rid of the Mesozoic greenhouse gases. Unfortunately, more recent research (discussed in my book Greenhouse of the Dinosaurs) points to other causes. (Besides, the Raymo-Ruddiman model cannot get around the evidence that the Himalayas rose in the Miocene, but the cooling began in the middle Eocene, at least 30 million years earlier). His chapter on the Ice Ages recounts the amazing stories of Louis Agassiz, the discovery of the orbital variation cycles by Croll and Milankovitch, and the accidental discovery of the importance of Greenland ice cores as a side effect of the now-abandoned Camp Century military effort. His final chapter recounts many of the unlikely coincidences and factors (from the drying of the African savannah to the effects of rapid climate change) that may have led to the success of one bipedal primate in Africa that became us.

In short, Shubin’s book is a primer on some basic science concepts from astronomy and cosmology to earth chemistry and paleoclimatic history, to basic evolution and biology and a bit of anthropology, all surrounded by colorful and sometimes amazing anecdotes about the people who made these discoveries. It is intended as easy reading for a lay audience, so experienced scientists will find parts of it within their own fields too elementary, but there’s something in it for everyone. Over and over again, Shubin emphasizes how much of this science was found by accident by people looking for something else (e.g., the Penzias-Wilson discovery of the microwave background radiation), or as a side effect of a much bigger effort (such as Camp Century, a military failure but a scientific success). Like his mentor, Stephen Jay Gould, he also reminds us of the elements of chance and contingency in nature, so that if any part of the experiment were run differently (e.g., no Jupiter to dominate the solar system), we would not be here to discuss it. In many ways, the book reminds me of the late 1970s BBC series “Connections” with James Burke, which explored how events of the past are interconnected, and determine what kind of world we have today. All of the universe, and all of life, is interconnected at many different levels, and this is a lesson we in the sciences should not forget.

pohualli

The tonalpohualli, a Nahuatl word meaning “count of days”, is a 260-day sacred period (often termed a “year”) in use in pre-Columbian Mesoamerica, especially among the Aztecs. This calendrical period is neither solar nor lunar, but rather consists of 20 … Continue reading

The tonalpohualli, a Nahuatl word meaning “count of days”, is a 260-day sacred period (often termed a “year”) in use in pre-Columbian Mesoamerica, especially among the Aztecs. This calendrical period is neither solar nor lunar, but rather consists of 20 trecena, or 13-day periods. Each trecena is dedicated to and under the auspices of a different deity.

In part due to the sheer antiquity of the tonalpohualli, its origin is unknown. Several theories have been advanced for this unique calendrical period: that it represents a Venusian cycle, that it represents the human gestation period, or that it represents the number of days when the sun is not overhead between August 12 and April 30 in the tropical lowlands. On the other hand, some scholars including J. E. S. Thompson suggest that the tonalpohualli was not based on natural phenomenon at all, but rather on the integers 13 and 20, both considered important numbers in Mesoamerica.

The other major Aztec calendar, the xiuhpohualli, is a solar calendar, based on 18 months of 20 days. A xiuhpohualli was designated by the name of its first tonalpohualli day. For example, Hernan Cortes met Moctezuma II on the day 8 Wind in the year 1 Reed (or November 8, 1519 in the Julian calendar).

The xiuhpohualli and the tonalpohualli would coincide every 52 years. The “year” 1 Reed was the 1st in that 52 year cycle.

It is extremely unlikely that the 260-day cycle could have been based upon any natural
phenomenon that was not continuously repetitive and that was not observable in the
greater part of the area in which the sacred almanac was in use.

The nature of the 260-day cycle does not force the conclusion that it was based
upon a natural phenomenon. It could simply have resulted from the permutation of its
subcycles (13 and 20, both important numbers in Mesoamerican thought), in the same
way that the 52-year cycle resulted from the permutation of the 260-day cycle against the
solar year (4). Thus, any argument for a correspondence with some natural phenomenon
must be not merely plausible but compelling.

The earliest presently known Mesoamerican calendar system — probably (but not
unequivocally) involving a typical 260-day cycle — is that of Monte Albán I and II of
highland Oaxaca.

tonalpohualli (“count of the days”) refers to the 260-day cycle, and tonalámatl (“book of the days”) refers to the books in which it was depicted; xiuhmolpilli (“binding of the years”) was the Náhuatl word for the 52-year cycle (8). The term used by the Maya for the 260-day cycle is unknown; tzolkin, which would mean “count of the days” in Yucatec Maya, is a creation of modern Mayanists.

In the Aztec calendar, there are twenty day signs.

Nahuatl Translation
Cipactli Caiman or aquatic monster
Ehecatl Wind
Calli House
Cuetzpalin Lizard
Coatl Snake
Miquiztli Death
Mazatl Deer
Tochtli Rabbit
Atl Water
Itzcuintli Dog
Ozomahtli Monkey
Malinalli Grass
Acatl Reed
Ocelotl Ocelot or Jaguar
Cuauhtli Eagle
Cozcacuauhtli Vulture
Ollin Movement or Earthquake
Tecpatl Flint or Knife
Quiahuitl Rain
Xochitl Flower

The Xiuhpohualli (literally, year/xiuhitl-count/pohualli) was a 365-day calendar used by the Aztecs and other pre-Columbian Nahua peoples in central Mexico. It was composed of eighteen 20-day “months,” called veintenas or metztli (the contemporary Nahuatl word for month) with a separate 5 day period at the end of the year called the nemontemi. Whatever name that was used for these periods in pre-Columbian times is unknown. Through Spanish usage, the 20 day period of the Aztec calendar has become commonly known as a veintena. The Aztec word for moon is metztli, and this word is today to describe these 20-day periods, although as the sixteenth-century missionary and early ethnographer, Diego Durán explained:

In ancient times the year was composed of eighteen months, and thus it was observed by these Indian people. Since their months were made of no more than twenty days, these were all the days contained in a month, because they were not guided by the moon but by the days; therefore, the year had eighteen months. The days of the year were counted twenty by twenty.

The xiuhpohualli calendar, also known as the “vague year,”[citation needed] had its antecedents in form and function in earlier Mesoamerican calendars, and the 365-day count has a long history of use throughout the region. The Maya civilization version of the xiuhpohualli is known as the haab’, and 20-days period was the uinal. The Maya equivalent of nemontemi is Wayeb’. In common with other Mesoamerican cultures the Aztecs also used a separate 260-day calendar (in Nahuatl: ‘tonalpohualli). The Maya equivalent of the tonalpohualli is the tzolk’in. Together, these calendars would coincide once every 52 years, the so-called “calendar round,” which was initiated by a New Fire ceremony.

Aztec years were named for the last day of the 18th month according to the 260-day calendar the tonalpohualli. The first year of the Aztec calendar round was called 2 Acatl and the last 1 Tochtli. The solar calendar was connected to agricultural practices and held an important place in Aztec religion, with each month being associated with its own particular religious and agricultural festivals.

Each 20-day period started on a Cipactli (Crocodile) day of the tonalpohualli for which a festival was held. The eighteen veintena are listed below. The dates in the chart are from the early eye-witnesses, Diego Durán and Bernardino de Sahagún. Each wrote what they learned from Nahua informants. Sahagún’s date precedes the Durán’s observations by several decades and is believed to be more recent to the Aztec surrender to the Spanish. Both are shown to emphasize the fact that the beginning of the Native new year became non-uniform as a result of an absence of the unifying force of Tenochtitlan after the Mexica defeat.

The 20-day months (veintenas) of the Aztec solar calendar were called (in two sequences):

  1. Izcalli
  2. Atlcahualo or Xilomanaliztli
  3. Tlacaxipehualiztli
  4. Tozoztontli
  5. Hueytozoztli
  6. Toxcatl or Tepopochtli
  7. Etzalcualiztli
  8. Tecuilhuitontli
  9. Hueytecuilhuitl
  10. Tlaxochimaco or Miccailhuitontli
  11. Xocotlhuetzi or Hueymiccailhuitl
  12. Ochpaniztli
  13. Teotleco or Pachtontli
  14. Tepeilhiuitl or Hueypachtli
  15. Quecholli
  16. Panquetzaliztli
  17. Atemoztli
  18. Tititl

The five days inserted at the end of a year and which were considered unlucky:

  • Nemontemi
Duran Time Sahagun Time Fiesta Names Symbol English Translation
1. MAR 01 – MAR 20 1. FEB 02 – FEB 21 Atlcahualo, Cuauhitlehua MetzliAtlca.jpg Ceasing of Water, Rising Trees
2. MAR 21 – APR 09 2. FEB 22 – MAR 13 Tlacaxipehualiztli MetzliTlaca.jpg Rites of Fertility; Xipe-Totec
3. APR 10 – APR 29 3. MAR 14 – APR 02 Tozoztonli ..MetzliToz.jpg Small Perforation
4. APR 30 – MAY 19 4. APR 03 – APR 22 Huey Tozotli .MetzliToz2.jpg Great Perforation
5. MAY 20 – JUN 08 5. APR 23 – MAY 12 Toxcatl ..MeztliToxcatl.jpg Dryness
6. JUN 09 – JUN 28 6. MAY 13 – JUN 01 Etzalcualiztli. MeztliEtzal.jpg Eating Maize and Beans
7. JUN 29 – JULY 18 7. JUN 02 – JUN 21 Tecuilhuitontli MeztliTecu.jpg Feast for the Revered Ones
8. JULY 19 – AUG 07 8. JUN 22 – JUL 11 Huey Tecuilhuitl MeztliHTecu.jpg Feast for the Greatly Revered Ones
9. AUG 08 – AUG 27 9. JUL 12 – JUL 31 Miccailhuitontli MeztliMicc.jpg Feast to the Revered Deceased
10. AUG 28 – SEP 16 10. AUG01 – AUG 20 Huey Miccailhuitontli MeztliMiccH.jpg Feast to the Greatly Revered Deceased
11. SEPT 17 – OCT 06 11. AUG 21 – SEPT 09 Ochpaniztli MeztliOch.jpg Sweeping and Cleaning
12. OCT 07 – OCT 26 12. SEPT10 – SEPT 29 Teotleco MeztliTeo.jpg Return of the Gods
13. OCT 27 – NOV 15 13. SEPT 30 – OCT 19 Tepeilhuitl MeztliTep.jpg Feast for the Mountains
14. NOV 16 – DEC 05 14. OCT 20 – NOV 8 Quecholli MeztliQue.jpg Precious Feather
15. DEC 06 – DEC 25 15. NOV 09 – NOV 28 Panquetzaliztli MeztliPanq.jpg Raising the Banners
16. DEC 26 – JAN 14 16. NOV 29 – DEC 18 Atemoztli MetzliAtem.jpg Descent of the Water
17. JAN 15 – FEB 03 17. DEC 19 – JAN 07 Tititl MeztliTitl.jpg Stretching for Growth
18. FEB 04 – FEB 23 18. JAN 08 – JAN 27 Izcalli MeztliIzcalli.jpg Encouragement for the Land & People
18u. FEB 24 – FEB 28 18u.JAN 28 – FEB 01 nemontemi (5 day period) MeztliNem.jpg Empty-days (nameless, undefined)

Note: Aztec years were named for the first day of the first month according to the 260-day calendar the tonalpohualli.


voyage across the cosmos

National Geographic presents the first accurate non-stop voyage from Earth to the edge of the Universe using a single, unbroken shot through the use of spectacular CGI (Computer-Generated Imagery) technology. Building on images taken from the Hubble telescope, Journey to … Continue reading

National Geographic presents the first accurate non-stop voyage from Earth to the edge of the Universe using a single, unbroken shot through the use of spectacular CGI (Computer-Generated Imagery) technology.
Building on images taken from the Hubble telescope, Journey to the Edge of the Universe explores the science and history behind the distant celestial bodies in the solar system.

This spectacular, epic voyage across the cosmos, takes us from the Earth, past the Moon and our neighboring planets, out of our Solar System, to the nearest stars, nebulae and galaxies and beyond — right to the edge of the Universe itself.

When you finish this video, you will walk away from it with an awareness that you never had before, of the unseen astronomically massive universe that we float around on like a spec of dust in the ocean.
This video takes you on a journey through the universe as if you are watching a Sci Fi adventure. Yet you constantly have to remind yourself that what you’re seeing is really out there.


The Gregorian calendar

The Gregorian calendar, also called the Western calendar and the Christian calendar, is internationally the most widely accepted civil calendar.[1][2][3] It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582; the decree, apapal bull, is known by its opening words, Inter gravissimas.[4] The Gregorian calendar was adopted initially by the Catholic countries of Europe, […]

The Gregorian calendar, also called the Western calendar and the Christian calendar, is internationally the most widely accepted civil calendar.[1][2][3] It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582; the decree, apapal bull, is known by its opening wordsInter gravissimas.[4] The Gregorian calendar was adopted initially by the Catholic countries of Europe, with other countries adopting it over the following centuries.

The motivation for the Gregorian reform was that the Julian calendar assumes that the time between vernal equinoxes is 365.25 days, when in fact it is presently almost 11 minutes shorter. The discrepancy results in a drift of about three days every 400 years. At the time of Gregory’s reform there had already been a drift of 10 days since Roman times, resulting in the spring equinox falling on 11 March instead of the ecclesiastically fixed date of 21 March, and moving steadily earlier in the Julian calendar. Because the spring equinox was tied to the celebration of Easter, the Roman Catholic Church considered this steady movement in the date of the equinox undesirable.

The Gregorian reform contained two parts: a reform of the Julian calendar as used prior to Pope Gregory’s time and a reform of the lunar cycle used by the Church, with the Julian calendar, to calculate the date of Easter. The reform was a modification of a proposal made by the Calabrian doctorAloysius Lilius (or Lilio).[5] Lilius’s proposal included reducing the number of leap years in four centuries from 100 to 97, by making 3 out of 4 centurial years common instead of leap years: this part of the proposal had been suggested before by, among others, Pietro Pitati. Lilio also produced an original and practical scheme for adjusting the epacts of the moon when calculating the annual date of Easter, solving a long-standing obstacle to calendar reform.

The Gregorian calendar thus modified the Julian calendar’s regular cycle of leap years as follows:

Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100; the centurial years that are exactly divisible by 400 are still leap years. For example, the year 1900 is not a leap year; the year 2000 is a leap year.[6]

In addition to the change in the mean length of the calendar year from 365.25 days (365 days 6 hours) to 365.2425 days (365 days 5 hours 49 minutes 12 seconds), a reduction of 10 minutes 48 seconds per year, the Gregorian calendar reform also dealt with the accumulated difference between these lengths. Between AD 325 (when the First Council of Nicaea was held, and the vernal equinox occurred approximately 21 March), and the time of Pope Gregory’s bull in 1582, the vernal equinox had moved backward in the calendar, until it was occurring on about 11 March, 10 days earlier. The Gregorian calendar therefore began by skipping 10 calendar days, to restore March 21 as the date of the vernal equinox.

Because Protestants and Eastern Orthodox Christians did not recognize the authority of the Pope, many European countries did not initially follow the Gregorian reform, and maintained their old-style systems. Eventually other countries followed the reform for the sake of consistency, but by the time the last adherents of the Julian calendar in Eastern Europe (Russia and Greece) changed to the Gregorian system in the 20th century, they had to drop 13 days from their calendars, due to the additional difference between the two calendars accumulated after 1582.

The Gregorian calendar continued the previous year-numbering system (Anno Domini), which counts years from the traditional date of the nativity, originally calculated in the 6th century and in use in much of Europe by the High Middle Ages. This year-numbering system, now also called Common Era, is the predominant international standard today


NASA | Computer Model Shows a Disk Galaxy’s Life History

Published on Oct 19, 2012 This cosmological simulation follows the development of a single disk galaxy over about 13.5 billion years, from shortly after the Big Bang to the present time. Colors indicate old stars (red), young stars (white and bright blue) and the distribution of gas density (pale blue); the view is 300,000 light-years […]

Published on Oct 19, 2012
This cosmological simulation follows the development of a single disk galaxy over about 13.5 billion years, from shortly after the Big Bang to the present time. Colors indicate old stars (red), young stars (white and bright blue) and the distribution of gas density (pale blue); the view is 300,000 light-years across. The simulation ran on the Pleiades supercomputer at NASA’s Ames Research Center in Moffett Field, Calif., and required about 1 million CPU hours. It assumes a universe dominated by dark energy and dark matter. Credit: F. Governato and T. Quinn (Univ. of Washington), A. Brooks (Univ. of Wisconsin, Madison), and J. Wadsley (McMaster Univ.).

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http://svs.gsfc.nasa.gov/vis/a010000/a011000/a011087/

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green bean galaxy

Astronomers have spilled the beans on a new galaxy and it’s turned out to be green. The multi-national Gemini Observatory has discovered rare galaxies with a weak black hole at the centre which they call ‘green bean’ because of the color. ­Most galaxies have a black hole which sucks in matter at their core. These […]

Astronomers have spilled the beans on a new galaxy and it’s turned out to be green. The multi-national Gemini Observatory has discovered rare galaxies with a weak black hole at the centre which they call ‘green bean’ because of the color.

­Most galaxies have a black hole which sucks in matter at their core. These newly discovered ‘green bean’ galaxies have less active black holes which give off ionized gas which gives them a green hue.

The astronomers think the color could signal star formation. Mischa Schirmer at the Gemini Observatory was the first to notice an unusual green spot while looking for galaxy clusters using their telescopes in Chile and Hawaii. With the help of European scientists the researchers began scanning the stars looking for similar galaxies. Out of the hundreds of billions of galaxies in the Universe the scientists have only found 16 of the ‘green bean’ variety.

They are one of the rarest objects in the universe, and it’s estimated there will be on in a cube of space with a side measuring 1.3 billion light years.

Schirmer says discovering a new galaxy class is a very inspiring “once-in-a-lifetime event,” he believes it’s an “astronomer’s dream come true”.