Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2008 May 21

A Dangerous Sunrise on Gliese 876d
Illustration Credit & Copyright: Inga Nielsen (Hamburg Obs., Gate to Nowhere)

Explanation: On planet Gliese 876d, sunrises might be dangerous. Although nobody really knows what conditions are like on this close-in planet orbiting variable red dwarf star Gliese 876, the above artistic illustration gives one impression. With an orbit well inside Mercury and a mass several times that of Earth, Gliese 876d might rotate so slowly that dramatic differences exist between night and day. Gliese 876d is imagined above showing significant volcanism, possibly caused by gravitational tides flexing and internally heating the planet, and possibly more volatile during the day. The rising red dwarf star shows expected stellar magnetic activity which includes dramatic and violent prominences. In the sky above, a hypothetical moon has its thin atmosphere blown away by the red dwarf's stellar wind. Gliese 876d excites the imagination partly because it is one of the few extrasolar planets known to be close to the habitable zone of its parent star.

Original here

No Doomsday in 2012

If you're new here, you may want to subscribe to my RSS feed. Thanks for visiting!

Apparently, the world is going to end on December 21st, 2012. Yes, you read correctly, in some way, shape or form, the Earth (or at least a large portion of humans on the planet) will cease to exist. Stop planning your careers, don't bother buying a house, and be sure to spend the last years of your life doing something you always wanted to do but never had the time. Now you have the time, four years of time, to enjoy yourselves before… the end.

So what is all this crazy talk? We've all heard these doomsday predictions before, we're still here, and the planet is still here, why is 2012 so important? Well, the Mayan calendar stops at the end of the year 2012, churning up all sorts of religious, scientific, astrological and historic reasons why this calendar foretells the end of life as we know it. The Mayan Prophecy is gaining strength and appears to be worrying people in all areas of society. Forget Nostradamus, forget the Y2K bug, forget the credit crunch, this event is predicted to be huge and many wholeheartedly believe this is going to happen for real.

For all those 2012 Mayan Prophecy believers out there, I have bad news. There is going to be no doomsday event in 2012, and here's why…

The Mayan Calendar
So what is the Mayan Calendar? The calendar was constructed by an advanced civilization called the Mayans around 250-900 AD. Evidence for the Maya empire stretches around most parts of the southern states of Mexico and reaches down to the current geological locations of Guatemala, Belize, El Salvador and some of Honduras. The people living in Mayan society exhibited very advanced written skills and had an amazing ability when constructing cities and urban planning. The Mayans are probably most famous for their pyramids and other intricate and grand buildings. The people of Maya had a huge impact on Central American culture, not just within their civilization, but with other indigenous populations in the region. Significant numbers of Mayans still live today, continuing their age-old traditions.

The Mayans used many different calendars and viewed time as a meshing of spiritual cycles. While the calendars had practical uses, such as social, agricultural, commercial and administrative tasks, there was a very heavy religious element. Each day had a patron spirit, signifying that each day had specific use. This contrasts greatly with our modern Gregorian calendar which primarily sets the administrative, social and economic dates.

Most of the Mayan calendars were short. The Tzolk'in calendar lasted for 260 days and the Haab' approximated the solar year of 365 days. The Mayans then combined both the Tzolk'in and the Haab' to form the "Calendar Round", a cycle lasting 52 Haab's (around 52 years, or the approximate length of a generation). Within the Calendar Round were the trecena (13 day cycle) and the veintena (20 day cycle). Obviously, this system would only be of use when considering the 18,980 unique days over the course of 52 years. In addition to these systems, the Mayans also had the "Venus Cycle". Being keen and highly accurate astronomers they formed a calendar based on the location of Venus in the night sky. It's also possible they did the same with the other planets in the Solar System.

Using the Calendar Round is great if you simply wanted to remember the date of your birthday or significant religious periods, but what about recording history? There was no way to record a date older than 52 years.

The end of the Long Count = the end of the Earth?
The Mayans had a solution. Using an innovative method, they were able to expand on the 52 year Calendar Round. Up to this point, the Mayan Calendar may have sounded a little archaic - after all, it was possibly based on religious belief, the menstrual cycle, mathematical calculations using the numbers 13 and 20 as the base units and a heavy mix of astrological myth. The only principal correlation with the modern calendar is the Haab' that recognised there were 365 days in one solar year (it's not clear whether the Mayans accounted for leap years). The answer to a longer calendar could be found in the "Long Count", a calendar lasting 5126 years.

I'm personally very impressed with this dating system. For starters, it is numerically predictable and it can accurately pinpoint historical dates. However, it depends on a base unit of 20 (where modern calendars use a base unit of 10). So how does this work?

The base year for the Mayan Long Count starts at "0.0.0.0.0". Each zero goes from 0-19 and each represent a tally of Mayan days. So, for example, the first day in the Long Count is denoted as 0.0.0.0.1. On the 19th day we'll have 0.0.0.0.19, on the 20th day it goes up one level and we'll have 0.0.0.1.0. This count continues until 0.0.1.0.0 (about one year), 0.1.0.0.0 (about 20 years) and 1.0.0.0.0 (about 400 years). Therefore, if I pick an arbitrary date of 2.10.12.7.1, this represents the Mayan date of approximately 1012 years, 7 months and 1 day.

This is all very interesting, but what has this got to do with the end of the world? The Mayan Prophecy is wholly based on the assumption that something bad is going to happen when the Mayan Long Count calendar runs out. Experts are divided as to when the Long Count ends, but as the Maya used the numbers of 13 and 20 at the root of their numerical systems, the last day could occur on 13.0.0.0.0. When does this happen? Well, 13.0.0.0.0 represents 5126 years and the Long Count started on 0.0.0.0.0, which corresponds to the modern date of August 11th 3114 BC. Have you seen the problem yet? The Mayan Long Count ends 5126 years later on December 21st, 2012.

Doomsday
When something ends (even something as innocent as an ancient calendar), people seem to think up the most extreme possibilities for the end of civilization as we know it. A brief scan of the internet will pull up the most popular to some very weird ways that we will, with little logical thought, be wiped off the face of the planet. Archaeologists and mythologists on the other hand believe that the Mayans predicted an age of enlightenment when 13.0.0.0.0 comes around; there isn't actually much evidence to suggest doomsday will strike. If anything, the Mayans predict a religious miracle, not anything sinister.

Myths are abound and seem to be fuelling movie storylines. It looks like the new Indiana Jones and the Kingdom of the Crystal Skull is even based around the Mayan myth that 13 crystal skulls can save humanity from certain doom. This myth says that if the 13 ancient skulls are not brought together at the right time, the Earth will be knocked off its axis. This might be a great plotline for blockbuster movies, but it also highlights the hype that can be stirred, lighting up religious, scientific and not-so-scientific ideas that the world is doomed.

Some of the most popular space-based threats to the Earth and mankind focus on meteorite impacts, black holes, Gamma Ray Bursts from nearby galaxies, a rapid ice age and a polar (magnetic) shift. There is so much evidence against these things happening in 2012, it's shocking just how much of a following they have generated. Each of the above "threats" needs their own devoted article as to why there is no hard evidence to support the hype.

But the fact remains, the Mayan Doomsday Prophecy is purely based on a calendar which we believe hasn't been designed to calculate dates beyond 2012. Mayan archaeo-astronomers are even in debate as to whether the Long Count is designed to be reset to 0.0.0.0.0 after 13.0.0.0.0, or whether the calendar simply continues to 20.0.0.0.0 (approximately 8000 AD) and then reset. As Karl Kruszelnicki brilliantly writes:

"…when a calendar comes to the end of a cycle, it just rolls over into the next cycle. In our Western society, every year 31 December is followed, not by the End of the World, but by 1 January. So 13.0.0.0.0 in the Mayan calendar will be followed by 0.0.0.0.1 - or good-ol' 22 December 2012, with only a few shopping days left to Christmas." - Excerpt from Dr Karl's "Great Moments in Science".

Original here

Space Euphoria: Do Our Brains Change When We Travel in Outer Space?

In February, 1971, Apollo 14 astronaut Edgar Mitchell experienced the little understood phenomenon sometimes called the “Overview Effect”. He describes being completely engulfed by a profound sense of universal connectedness. Without warning, he says, a feeing of bliss, timelessness, and connectedness began to overwhelm him. He describes becoming instantly and profoundly aware that each of his constituent atoms were connected to the fragile planet he saw in the window and to every other atom in the Universe. He described experiencing an intense awareness that Earth, with its humans, other animal species, and systems were all one synergistic whole. He says the feeling that rushed over him was a sense of interconnected euphoria. He was not the first—nor the last—to experience this strange “cosmic connection”.

Rusty Schweikart experienced it on March 6th 1969 during a spacewalk outside his Apollo 9 vehicle: “When you go around the Earth in an hour and a half, you begin to recognize that your identity is with that whole thing. That makes a change…it comes through to you so powerfully that you’re the sensing element for Man.” Schweikart, similar to what Mitchell experienced, describes intuitively sensing that everything is profoundly connected.

Their experiences, along with dozens of other similar experiences described by other astronauts, intrigue scientists who study the brain. This “Overview Effect”, or acute awareness of all matter as synergistically connected, sounds somewhat similar to certain religious experiences described by Buddhist monks, for example. Where does it come from and why?

Andy Newberg, a neuroscientist/physician with a background in space medicine, is learning how to identify the markers of someone who has had the experience. “You can often tell when you’re with someone who has flown in space,” he says, “It’s palpable.” Andy scans brains for a living: praying nuns, transcendental mediators, and others in the act of focused states.

Newberg can pinpoint regions in subjects’ gray matter that correlate to these circumstances. Newberg is seriously looking at how to fly equipment that could study—in action—the brain functions of space travelers. If this Overview Effect is a real, physiological phenomenon—he wants to watch it happen.

Newberg’s first test subject will not be a paid astronaut, but rather a paying space tourist: Reda Andersen slated to fly with Rocketplane Kistler says, “It would be criminal NOT to study the first of us (space adventure travelers).”

After decades of study and contemplation about his experience, Ed Mitchell believes that the feeling of “oneness” with the Universe that he and others have experienced is a consequence of little understood quantum physics.

In a recent interview with writer Diana deRegnier of American Chronicle, Mitchell explains how the event changed his life and his entire perspective on the world and how each of us fits into the grand scale of the cosmos.

“Four hundred years ago. the philosopher Rene Descartes came to the conclusion that physicality, spirituality, mind and body belonged to different realms of reality that didn't interact. Now, that served the purpose to get the Inquisition off the backs of the intellectuals so they could disagree on material things with the church and without the fear of being burned at the stake. So that ended that, but it did cause, for four hundred years, science to consider consciousness and mind a subject for philosophy and religion and not a subject for science.

Now, one of the things that happened, in the 1940s, was the mathematician, physicist, Norbert Wiener (MIT, Massachusetts Institute of Technology) for the first time really defined information as the negative of entropy, and entropy as the idea of the universe is running down and wastes energy. But, Wiener defined information as the negative of entropy, and that's wonderful but it didn't go far enough.”

Mitchell says that in an attempt to fill in some of the missing gap, the 2008 revised edition of his book The Way of the Explorer explores the largely ignored science of human consciousness. Using what he calls the “dyadic model” he outlines the “two faces” of energy. “Instead of being two separate things, it's the energy as the basis of our existence in matter. And, it’s the basis of our knowing and information,” Mitchell explains.

“We had not had, in science, a definition of consciousness. The only definition of consciousness from the dictionary is that at its basic level it is awareness. Consciousness means to be aware, and then we have different levels of consciousness depending upon how complex the substance is. It has been demonstrated many times over in laboratories that basic awareness is demonstrable at the level of plants, at simple bacteria, at simple life forms.

This is done with Faraday cages. It's shown that this information at this deep level, at the quantum level, can transcend electromagnetic theory. And, now we're getting into quantum physics and we don´t want to go there at this point. But it's a very fundamental notion that awareness is at the very basis of things.”

Mitchell believes that perhaps both the theologians and scientists have missed the mark.

“All I can suggest to the mystic and the theologian is that our gods have been too small; they fill the universe. And to the scientist all I can say is that the gods do exist; they are the eternal, connected, and aware Self experienced by all intelligent beings.'

In response to DeRegnier questioning whether or not Mitchell believes in the idea of God, he responds that while he does not believe in the traditional “grandfather figure” version of God, “we do have great mystery about what is the origin of the universe, how it came to be. There's a great deal of question as to whether the big bang is the correct answer to the way the universe arose, and under what auspices and conditions. I don't think we have the full answers to that yet. Hopefully in due course we'll be able to find a much better way to describe all this.”

But while Mitchell does not claim to know how to perfectly interpret his experience, he is certain that it was a glimpse into a largely ignored reality: People, places and things are all more closely connected than they sometimes appear. He also mentions the need for better stewardship of our precious planet.

“The great thinker Buckminster Fuller, philosopher, now deceased but for a goodly portion of the twentieth century, pointed out at the beginning of our space exploration that we are the crew of ‘space ship earth’. But we 're a crew of mutiny and how can you run a space ship with a mutinous crew?”

Original here

In a Landfill, How Long Does Trash Really Last?

We’ve all been there—at the beach, empty beer bottle in hand, a trash can, but no recycling bin in sight. So we dump the bottle in the normal trash, perhaps feeling guilty we weren’t able to recycle it, perhaps not. Most likely, we rapidly forget about it—out of sight, out of mind, and onto the next beer.

The bottle, like the rest of our trash, may slip easily from our hands and minds, but it doesn’t leave our collective refuse piles so quickly. Landfills, which are lined with clay and plastic, layered with soil, and capped, are not extremely hospitable when it comes to microbial degradation. The three necessary components for decomposition—sunlight, moisture, oxygen—are hard to come by in a landfill; items are more likely to mummify than to break down.

But how long do things last? These rough estimates, compiled from U.S. National Park Service, United States Composting Council, New Hampshire Department of Environmental Sciences, and the New York City government, give an idea of how long our consumables remain after we’ve kissed them goodbye.

Glass Bottle—One Million Years
Okay, we don’t really know whether a glass bottle takes a million years, two million years, or a million years and one day to degrade since no one has been monitoring them for that long. But suffice it to say, when a glass bottle isn’t recycled, it sticks around for a really, really long time. Glass is primarily of composed of silica—the same material as sand—and doesn’t break down even under the harshest environments. Given the relatively inert conditions of a landfill, it’s likely the bottle of beer our forefathers sipped is still at large.

Plastic Bags—Unknown, Possibly 500+ Years
Plastic bags also have a hard time decomposing; estimates range from ten to twenty years when exposed to air to 500–1,000 years in a landfill. Since microbes don’t recognize polyethylene—the major component of plastic bags—as food, breakdown rates by this means in landfills is virtually nil. Though plastic bags can photodegrade, sunlight in landfills is scarce. Made with petroleum and rarely recycled, many cities have banned them in order to curb consumption and prevent their long-lasting presence in litter (e.g., the Great Pacific Garbage Patch—an island you don’t want to visit).

Plastic Beverage Bottles—Unknown, Possible 500+ years
Bottles face the same problem as plastic bags. Most soda and water bottles are composed of polyethylene terephthalate (PET), a petroleum-based product that tends to last a long time in a landfill. Even newer bottles that claim to be biodegradable or photodegradable may take much longer than advertised. According to the Air and Waste Association, biodegradable plastics made with the addition of starch may just simply disintegrate into smaller non-degradable pieces: they don’t break down; they break up.

Aluminum Can—Eighty to 200 Years
According to the Container Recycling Institute, we sent 55 billion aluminum cans to the landfills in 2004, an amount that has increased by 760 percent since 1972.

Cigarette Butt—One to Five Years
The Ocean Conservancy found that during coastal cleanups, cigarette filters and butts were the number one source of litter. While certainly they’re better off in a landfill than underfoot at the shore, their composition makes them particularly resistant to breakdown both in nature and in a landfill. Though the filters look like cotton, almost all are made of cellulose acetate, which is slow to degrade.

Newspaper—Two to Four Weeks or Longer
Paper, including newspaper, seems like one of those items that although recyclable, would also break down quite nicely when mixed in a landfill. Theoretically it can, but because microbial decomposition is so stifled in landfills, paper takes much longer to decompose there than under normal conditions. Or so discovered William Rathje, a professor of archeology at the University of Arizona, who started the Garbage Project—digging through landfills to find clues about consumer behavior. While there, his team found legible newspapers more than fifteen years old, indicating decomposition in landfills doesn’t occur as it would in a compost heap. They also discovered that newspapers made up the largest single item by weight and volume in the landfills studied.

Apple Core—One to Two Months or Longer
If tossed in a composting bin or outside, an apple core might take weeks or months to break down. However, the Garbage Project discovered easily identifiable food and yard waste that were years old. They estimate that food in landfills does degrade, but at a very slow rate—about 50 percent every twenty years. Even yard waste, by definition biodegradable, was found intact years later.

So what does it all matter if stuff stays in landfills indefinitely? Limited space, for one thing—finding a suitable spot for a landfill can be difficult, especially since they are a classic case of NIMBY (Not in My Backyard). Though they can be covered and made into something else—both John F. Kennedy and La Guardia Airports were built on landfills—the process is long and fairly expensive. Perhaps most importantly, reducing the amount of stuff we consume, reusing what we already have, and of course, recycling, doesn’t just mean less trash, it also means less primary resources—oil, trees, water, etc.—that have to be used in the first place. But while most of us are familiar with recycling programs, the EPA estimates that the bulk of our garbage is made up of items that can be recycled or composted—40 percent of it is paper, 17 percent is yard waste, 8 percent is plastics, and 7 percent is food waste. Seems like something ain’t working. Perhaps to be truly effective, recycling won’t just mean more places to put your beer bottles, it’ll mean making the trash can the alternative, rather than the norm.

Original here

5 Giant Holes That Devoured Everything Around Them

Guatemala Sinkhole. Image via AP

Imagine walking down the street, minding your own business, when suddenly the earth begins to shake and fold in. Imagine that the very ground you stand on is disintegrating beneath your feet, being devoured by a giant hole. No - this isn’t some lewd joke about Paris Hilton or something from Return of the Jedi. No, today we’re going to explore the phenomenon of sinkholes and some of the most incredible and destructive examples.

Before we go into them however, you’ll probably need a bit of amateur scientific background from me. In short, sinkholes form when the bedrock or soil underneath subsides, forcing the topsoil (or in many cases concrete) to collapse. They can be exceptionally large (several hundred meters in diameter and depth) and can swallow everything directly above. So, without further ado, here are five giant holes that devoured everything around them.

5. Montrose Avenue sinkhole

80 feet in diameter and 15 feet deep, a huge sinkhole opened up in the middle of Montrose Avenue after a water main break flooded the tarmac. The avenue remained closed for a couple weeks and helped shut down roughly 8 businesses, right after Christmas, in January this year. Fortunately, no one was killed.

Want to know what the flood that caused this sinkhole looked like?

4. Macungie, Lehigh County, Pennsylvania 1986

At over 75 feet wide and 35 feet deep, the Macungie sinkhole formed in June, 1986. Stabilization and repair costs totaled $450,000.

Image via DCNR

3. Bowling Green KY

A 200 ft wide and 35 deep, this sinkhole collapsed in Bowling Green Kentucky, due to water runoff, underneath the soil. The site was right next to the proposed TriModal Transpark. I bet they’re glad they didn’t build there!

2. Sarisariñama Plateau

Located in the Jaua-Sarisariñama National Park in Venezuela are some of the biggest sinkholes in the world. The sinkholes are 350 meters wide and 350 meters deep and are a geological mystery. The huge vertical walls have created an isolated ecosystem, with completely unique species of both flora and fauna. They’re so isolated in fact, that the sinkholes were only discovered in 1974. The scientific expedition was documented in David Nott’s book “into the lost world.”

1. Guatemala City

On the 23rd of February 2007, a 330 foot deep sinkhole swallowed up over a dozen homes in a crowded neighbourhood in Guatemala City. Over 1000 people were evacuated and two people were killed.

The giant hole emitted a foul stench, tremors and loud noises. The authorities blamed the sinkhole on a ruptured underground sewage flow.

Images from AP, orignally found from deputy dog

and if you understand Spanish, there’s a news report here, which just shows how large the hole is:

Original here

Inconvenient Truths: Get Ready to Rethink What It Means to Be Green

Photo: Yann Arthus-Bertrand/Altitude

The environmental movement has never been short on noble goals. Preserving wild spaces, cleaning up the oceans, protecting watersheds, neutralizing acid rain, saving endangered species — all laudable. But today, one ecological problem outweighs all others: global warming. Restoring the Everglades, protecting the Headwaters redwoods, or saving the Illinois mud turtle won't matter if climate change plunges the planet into chaos. It's high time for greens to unite around the urgent need to reduce emissions of greenhouse gases.

Just one problem. Winning the war on global warming requires slaughtering some of environmentalism's sacred cows. We can afford to ignore neither the carbon-free electricity supplied by nuclear energy nor the transformational potential of genetic engineering. We need to take advantage of the energy efficiencies offered by urban density. We must accept that the world's fastest-growing economies won't forgo a higher standard of living in the name of climate science — and that, on the way up, countries like India and China might actually help devise the solutions the planet so desperately needs.

Some will reject this approach as dangerously single-minded: The environment is threatened on many fronts, and all of them need attention. So argues Alex Steffen. That may be true, but global warming threatens to overwhelm any progress made on other issues. The planet is already heating up, and the point of no return may be only decades away. So combating greenhouse gases must be our top priority, even if that means embracing the unthinkable. Here, then, are 10 tenets of the new environmental apostasy.

Original here