Tag: change (page 18 of 102)

We’re About To Learn A Lot More About Area 51

Excerpt from huffingtonpost.comWhen the National Atomic Testing Museum of Las Vegas opened its "Area 51: Myth or Reality" exhibit two years ago, it became an instant hit. It wasn't just the only place that had a comprehensive knowledge of Area 51 -...

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A Complete Guide to the March 20th Total Solar Eclipse

Totality! The 2012 total solar eclipse as seen from Australia. Credit and copyright: www.hughca.com.

Excerpt from universetoday.com

The first of two eclipse seasons for the year is upon us this month, and kicks off with the only total solar eclipse for 2015 on Friday, March 20th.

And what a bizarre eclipse it is. Not only does this eclipse begin just 15 hours prior to the March equinox marking the beginning of astronomical spring in the northern hemisphere, but the shadow of totality also beats path through the high Arctic and ends over the North Pole.

An animation of the March 20th eclipse. Credit: NASA/GSFC/AT Sinclair.

Already, umbraphiles — those who chase eclipses — are converging on the two small tracts of terra firma where the umbra of the Moon makes landfall: the Faroe and Svalbard islands. All of Europe, the northern swath of the African continent, north-central Asia and the Middle East will see a partial solar eclipse, and the eclipse will be deeper percentage-wise the farther north you are .
2015 features four eclipses in all: two total lunars and two solars, with one total solar and one partial solar eclipse. Four is the minimum number of eclipses that can occur in a calendar year, and although North America misses out on the solar eclipse action this time ’round, most of the continent gets a front row seat to the two final total lunar eclipses of the ongoing tetrad on April 4th and September 28th.

How rare is a total solar eclipse on the vernal equinox? Well, the last total solar eclipse on the March equinox occurred back in 1662 on March 20th. There was also a hybrid eclipse — an eclipse which was annular along a portion of the track, and total along another — on March 20th, 1681. But you won’t have to wait that long for the next, as another eclipse falls on the northward equinox on March 20th, 2034.

The path of the March 20th eclipse across Europe, including start times for the partial phases, and the path of totality, click to enlarge. For more maps showing the percentage of occlusion, elevation, and more, click here. Credit: Michael Zeiler/GreatAmercianEclipse.com.

Note that in the 21st century, the March equinox falls on March 20th, and will start occasionally falling on March 19th in 2044. We’re also in that wacky time of year where North America has shifted back to ye ‘ole Daylight Saving (or Summer) Time, while Europe makes the change after the eclipse on March 29th. It really can wreak havoc with those cross-time zone plans, we know…
The March 20th eclipse also occurs only a day after lunar perigee, which falls on March 19th at 19:39 UT. This is also one of the closer lunar perigees for 2015 at 357,583 kilometres distant, though the maximum duration of totality for this eclipse is only 2 minutes and 47 seconds just northeast of the Faroe Islands.

Views from selected locales in Europe and Africa. Credit: Stellarium.

This eclipse is number 61 of 71 in solar saros series 120, which runs from 933 to 2754 AD. It’s also the second to last total in the series, with the final total solar eclipse for the saros cycle occurring one saros later on March 30th, 2033.

What would it look like to sit at the North Pole and watch a total solar eclipse on the first day of Spring? It would be a remarkable sight, as the disk of the Sun skims just above the horizon for the first time since the September 2014 equinox. Does this eclipse occur at sunrise or sunset as seen from the pole? It would be a rare spectacle indeed!

An equinoctal eclipse as simulated from the North Pole. Credit: Stellarium.

Practicing eclipse safety in Africa. Credit: Michael Zeiler/GreatAmericanEclipse.com

Safety is paramount when observing the Sun and a solar eclipse. Eye protection is mandatory during all partial phases across Europe, northern Asia, North Africa and the Middle East. A proper solar filter mask constructed of Baader safety film is easy to construct, and should fit snugly over the front aperture of a telescope. No. 14 welder’s goggles are also dense enough to look at the Sun, as are safety glasses specifically designed for eclipse viewing. Observing the Sun via projection or by using a pinhole projector is safe and easy to do.

A solar filtered scope ready to go in Tucson, Arizona. Credit: photo by author.

Weather is always the big variable in the days leading up to any eclipse. Unfortunately, March in the North Atlantic typically hosts stormy skies, and the low elevation of the eclipse in the sky may hamper observations as well. From the Faroe Islands, the Sun sits 18 degrees above the horizon during totality, while from the Svalbard Islands it’s even lower at 12 degrees in elevation. Much of Svalbard is also mountainous, making for sunless pockets of terrain that will be masked in shadow on eclipse day. Mean cloud amounts for both locales run in the 70% range, and the Eclipser website hosts a great in-depth climatology discussion for this and every eclipse.

The view of totality and the planets as seen from the Faroe Islands. Credit: Starry Night.

But don’t despair: you only need a clear view of the Sun to witness an eclipse!

Solar activity is also another big variable. Witnesses to the October 23rd, 2014 partial solar eclipse over the U.S. southwest will recall that we had a massive and very photogenic sunspot turned Earthward at the time. The Sun has been remarkably calm as of late, though active sunspot region 2297 is developing nicely. It will have rotated to the solar limb come eclipse day, and we should have a good grasp on what solar activity during the eclipse will look like come early next week.

And speaking of which: could an auroral display be in the cards for those brief few minutes of totality? It’s not out of the question, assuming the Sun cooperates.  Of course, the pearly white corona of the Sun still gives off a considerable amount of light during totality, equal to about half the brightness of a Full Moon. Still, witnessing two of nature’s grandest spectacles — a total solar eclipse and the aurora borealis — simultaneously would be an unforgettable sight, and to our knowledge, has never been documented!

We also put together some simulations of the eclipse as seen from Earth and space:

Note that an area of southern Spain may witness a transit of the International Space Station during the partial phase of the eclipse. This projection is tentative, as the orbit of the ISS evolves over time. Be sure to check CALSky for accurate predictions in the days leading up to the eclipse.

The ISS transits the Sun during the eclipse around 9:05 UT as seen from southern Spain. Credit: Starry Night.

Can’t make it to the eclipse? Live in the wrong hemisphere? There are already a few planned webcasts for the March 20th eclipse:

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When did humans first begin to wear clothes?

Excerpt from todayifoundout.com

Determining exactly when humans began wearing clothes is a challenge, largely because early clothes would have been things like animal hides, which degrade rapidly. Therefore, there’s very little archaeological evidence that can be used to determine the date that clothing started being worn. 

There have been several different theories based on what archaeologists have been able to find. For instance, based on genetic skin-coloration research, humans lost body hair around one million years ago—an ideal time to start wearing clothes for warmth. The first tools used to scrape hides date back to 780,000 years ago, but animal hides served other uses, such as providing shelter, and it’s thought that those tools were used to prepare hides for that, rather than clothing. Eyed needles started appearing around 40,000 years ago, but those tools point to more complex clothing, meaning clothes had probably already been around for a while.
All that being said, scientists have started gathering alternative data that might help solve the mystery of when we humans started covering our bits.

A recent University of Florida study concluded that humans started wearing clothes some 170,000 years ago, lining up with the end of the second-to-last ice age. How did they figure that date out? By studying the evolution of lice.

Scientists observed that clothing lice are, well, extremely well-adapted to clothing. They hypothesized that body lice must have evolved to live in clothing, which meant that they weren’t around before humans started wearing clothes. The study used DNA sequencing of lice to calculate when clothing lice started to genetically split from head lice.

The findings of the study are significant because they show that clothes appeared some 70,000 years before humans started to migrate north from Africa into cooler climates. The invention of clothing was probably one factor that made migration possible.
This timing also makes sense due to known climate factors in that era.  As Ian Gilligan, a lecturer at the Australian National University, said that the study gave “an unexpectedly early date for clothing, much earlier than the earliest solid archaeological evidence, but it makes sense. It means modern humans probably started wearing clothes on a regular basis to keep warm when they were first exposed to Ice Age conditions.”

As to when humans moved on from animal hides and into textiles, the first fabric is thought to have been an early ancestor of felt. From there, early humans took up weaving some 27,000 years ago, based on impressions of baskets and textiles on clay. Around 25,000 years ago, the first Venus figurines—little statues of women—appeared wearing a variety of different clothes that pointed to weaving technology being in place by this time.
From there, more recent ancient civilizations discovered many materials they could fashion into clothing. For instance, Ancient Egyptians produced linen around 5500 BC, while the Chinese likely started producing silk around 4000 B.C.

As for clothing for fashion, instead of just keeping warm, it is thought that this occurred relatively early on. The first example of dyed flax fibers were found in a cave in the Republic of Georgia and date back to 36,000 years ago. That being said, while they may have added colour, early clothes seem to have been much simpler than the clothing we wear today—mostly cloth draped over the shoulder and pinned at the waist.

Around the mid-1300s in certain regions of the world, with some technological advances in previous century, clothing fashion began to change drastically from what it was before. For instance, clothing started to be made to form fit the human body, with curved seams, laces, and buttons. Contrasting colours and fabrics also became popular in England. From this time, fashion in the West began to change at an alarming rate, largely based on aesthetics, whereas in other cultures fashion typically changed only with great political upheaval, meaning changes came more slowly in most other cultures.

The Industrial Revolution, of course, had a huge impact on the clothing industry. Clothes could now be made en mass in factories rather than just in the home and could be transported from factory to market in record time. As a result, clothes became drastically cheaper, leading to people having significantly larger wardrobes and contributing to the constant change in fashion that we still see today.

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Surface of Venus revealed by new radio telescope data


Excerpt from smnweekly.com
By David M. DeMar

New radio telescope data from the National Radio Astronomy Observatory has revealed for the first time ever just what Venus has under its thick veil of clouds that otherwise occlude its surface from view.
25 million miles distant from us, Venus looks to the naked eye – or through a light telescope – much like a cloudy marble, thanks to the thick cloudbanks of carbon dioxide ringing the planet. However, the surface underneath, long a mystery to planetary scientists, has been laid bare thanks to the work of Puerto Rico’s Arecibo Observatory radio transmitter and the Green Bank Telescope, a radio telescope located in West Virginia and operated by the National Science Foundation.
The two facilities worked together with the NRAO in order to uncover the hidden surface of Mars. Arecibo sent radar signals to Venus, where they penetrated the thick atmosphere and bounced off the ground. The returning radio signals were picked up by the GBT in West Virginia in a process known as bistatic radar; the result is a radar image that shows craters and mountains strewn across the surface of Venus at a surprisingly high resolution.
The image is bisected by a dark line, representing areas where it’s particularly difficult to receive useful image data through the use of bistatic radar. However, scientists are intending to compare multiple images as time goes by in order to identify any active geologic processes on the surface of Venus such as volcanic activity.
It’s no particularly easy task to compare radar images in search of evidence of any change in this manner says Smithsonian senior scientist Bruce Campbell, but the work will continue. Campbell, who works at the National Air and Space Museum in the nation’s capital and is associated with the center for Earth and Planetary Studies, added that combining images from the latest NRAO endeavor and others will yield large amounts of data on how the surface of Venus might be altered by other processes.
The radar data, and a scientific paper based on it, will be published in April in Icarus, the scientific journal dedicated to studies of the solar system.

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Let There Be Light! Photo Shows Light As Wave And Particle For First Time

Light as a particle and a wave

Excerpt from escapistmagazine.com

According to quantum mechanics light acts as both a particle and a wave, but now we can finally see what that looks like.

Quantum mechanics is an incredibly complex field for a simple reason: So much of what it studies can be two different things at the exact same time. Light is a great example since it behaves like both a particle and a wave, but only appears in one state during experiments. Mathematically speaking, we have to treat light as both ways for the universe to make sense but actually confirming it visually has been impossible. Or at least that was the case until scientists from Switzerland's École polytechnique fédérale de Lausanne developed their own unique photography method.
The image was created by shooting a pulse of laser light at a metallic nanowire to make its charged particles vibrate. Next the scientists fired a stream of electrons past the wire holding the trapped light. When the two collided, it created an energy exchange that could be photographed from the electron microscope.

So what does this mean when looking at the photograph? When the photons and electrons collide, they either slow down or speed up, which creates a visualization of a light wave. At the same time the speed change appears as a quanta - packets of energy - transferred between the electrons and photons as particles. In other words, it's the first case of observing light particles and waves simultaneously.

"This experiment demonstrates that, for the first time ever, we can film quantum mechanics - and its paradoxical nature - directly," research leader Fabrizio Carbone explained. This has enormous implications not only for quantum research, but also quantum-based technologies still in development. "Being able to image and control quantum phenomena at the nanometer scale like this opens up a new route towards quantum computing," he continued.

The experiment results were posted in today's Nature Communications, which will help other scientists build on this research with further studies. After all, it's not like we've unlocked all of light's secrets yet - we can barely even tell what color a dress is sometimes.

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Galactic Federation of Light Arcturian Group March 01 2015

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Galactic Federation of Light SaLuSa February 28 2015

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Skywatch: Venus and Jupiter continue to accentuate the night heavens

Venus (right) & Jupiter

Excerpt from washingtonpost.com
By Blaine Friedlander Jr. 
In winter’s waning weeks, Venus and Jupiter continue to accentuate the night heavens, we change our clocks forward and we grab spring with no intention of letting go.

Check the west-southwestern heavens at dusk to spy the vivacious Venus and the dim Mars. In late February, the two planets met for a sweet cosmic waltz, but in March, they appear to separate. Venus approaches negative fourth magnitude (very bright) while Mars makes do at magnitude 1.3 (dim, hard to find in urban light pollution). With a clear sky, Mars looks like a red pinpoint. 

A young, waxing crescent moon visits Mars on the evening of March 21, and on the next evening the crescent flirts with Venus.
Robust Jupiter ascends the evening’s eastern sky. Find this gas giant at a -2.5 magnitude, very bright, in the constellation Cancer. The lion in the constellation Leo appears to stare at the planet. By the Ides of March, find it south around 10:30 p.m. 

The waxing gibbous moon drops by the dazzling Jupiter on March 2, days before the moon itself becomes full on March 5. 

Catch the ringed Saturn rising after midnight in the east-southeast now, hanging out near a gang of constellations, Scorpius, Ophiuchus and Libra. It’s a zero magnitude object, bright enough that it can be seen under urban skies. The waning moon loiters near Saturn before dawn on March 12. On that morning, the reddish star below them is Antares.
We adjust our clocks to Daylight Saving Time at 2 a.m. March 8. Spring forward, moving the clock ahead one hour. 

Winter is almost over. Spring is weeks away. The vernal equinox brings spring’s official arrival on March 20 at 6:45 p.m. 

Also on March 20 — the day a new moon — the North Atlantic and the Arctic waters get a short total eclipse. We won’t see it here, but Slooh.com will carry it live. Totality will start seconds after 5:44 a.m. and end at 5:47 a.m., according to Geoff Chester of the U.S. Naval Observatory. 

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