Science & TechnologyS


Question

Past Due? On an Average of Every One Million Years, Earth Absorbs a Major Asteroid or Comet Impact


Daily Galaxy
Tue, 28 Jun 2011 12:26 UTC
Object In Sky
© Daily Galaxy

A house-sized asteroid zipped apst Earth yesteday closer than the moon. Stephen Hawking believes that one of the major factors in the possible scarcity of intelligent life in our galaxy is the high probability of an asteroid or comet colliding with inhabited planets. Through Earth's history such collisions occur, on the average every one million years. If this figure is correct, it would mean that intelligent life on Earth has developed only because of the lucky chance that there have been no major collisions in the last 70 million years. Other planets in the galaxy, Hawking believes, on which life has developed, may not have had a long enough collision free period to evolve intelligent beings.

We have observed, Hawking points out in Life in the Universe, the collision of a comet, Schumacher-Levi, with Jupiter, which produced a series of enormous fireballs, plumes many thousands of kilometers high, hot "bubbles" of gas in the atmosphere, and large dark "scars" on the atmosphere which had lifetimes on the order of weeks.

It is thought the collision of a rather smaller body with the Earth, about 70 million years ago, was responsible for the extinction of the dinosaurs. A few small early mammals survived, but anything as large as a human, would have almost certainly been wiped out.

"The threat of the Earth being hit by an asteroid is increasingly being accepted as the single greatest natural disaster hazard faced by humanity," according to Nick Bailey of the University of Southampton's School of Engineering Sciences team, who has developed a threat identifying program.
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Camera

Underwater wonderland: Divers take the plunge to reveal stunning images of beautiful crystal cave in depths of Russia


The Daily Mail
Tue, 28 Jun 2011 04:54 UTC
It looks like the set of a Hollywood action movie but these images were taken by a team of expert cave divers in the depths of Russia.

A team of daring cave divers have produced an incredible photo-reportage of the longest underwater gypsum crystal cave in the world.

The Orda Cave in the western Urals region is three miles of eerily dramatic natural channels created by water so clear divers can see over 50 yards ahead of them.

Over a period of six months the intrepid team led by photographer and journalist, Victor Lyagushkin, 40, from Russia explored the water filled cave tunnels at temperatures barely above freezing.

Image
© Victor Lyagushk/ Barcroft MediaCrystal clear: Cave divers explore the beautifully transparent Orda Cave in Russia's western Urals region
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Info

San Andrea Quake Lull Possibly Caused by Flood Control

Charles Q. Choi
OurAmazingPlanet
Mon, 27 Jun 2011 12:44 UTC
Salton Sea
© NASAThe Salton Sea, and the Imperial, Coachella and Mexicali Valleys in the California and Mexico desert. The Salton Sea formed by accident in 1905 when an irrigation canal ruptured, allowing the Colorado River to flood the Salton Basin.
The San Andreas Fault is overdue for "the big one," and the efforts by humans to control flooding in the area could be the reason for the recent lull in temblors, a new study suggests.

Ancient floods once helped unleash earthquakes on the San Andreas, a group of researchers has found. The southern portion of the fault has not experienced a large earthquake for about 300 years, though, which makes one long overdue - the previous five major earthquakes in the region occurred at approximately 180-year intervals.

Over the past century, humans have put in place measures to control floods in the region to protect property and infrastructure, which the researchers say might explain the quake lull.
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Magic Wand

Missing the Mark: Scientists Prove Existence of 'Magnetic Ropes' that Cause Solar Storms

Tara Laskowski
George Mason University
Wed, 15 Jun 2011 06:36 UTC
Image
© NASA and George Mason University
George Mason University scientists discovered recently that a phenomenon called a giant magnetic rope is the cause of solar storms. Confirming the existence of this formation is a key first step in helping to mitigate the adverse effects that solar storm eruptions can have on satellite communications on Earth.

The discovery was made by associate professor Jie Zhang and his graduate student Xin Cheng using images from the NASA Solar Dynamic Observatory (SDO) spacecraft.

Though the magnetic rope was believed to be the cause of these giant eruptions on the Sun, scientists had previously not been able to prove this phenomenon existed because of how quickly the rope moves.

However, through close examination of images taken by the Atmospheric Imaging Assembly (AIA) telescope on board the SDO, Zhang was able to pinpoint an area of the sun where a magnetic rope was forming. The AIA telescope suite is able to capture images of the Sun every 10 seconds, 24 hours a day. This unprecedented cadence in time helped the discovery.

"The magnetic rope triggers a solar eruption. Scientists have been debating whether or not this magnetic rope exists before a solar eruption. I believe that the result of this excellent observation helps finally solve this controversial issue," says Zhang.

Comment: As prevalent in Astronomy circles nowadays, George Mason University scientists stumbled upon a somewhat correct concept, but since it is based on an erroneous premise, missed the mark, and reached the wrong conclusions.

From Planetary Alignments and the Solar Capacitor - Things are heatin' up! by Ryan X:
As Michael Goodspeed of thunderbolts.info points out, you can't have a magnetic field without an electric current. The term "magnetic rope" reveals a deep confusion on the part of astronomers. Magnetic fields by themselves cannot have a beginning and end, but those induced from electric current can. In other words, "magnetic ropes" don't just form out of nothing; they suggest a vortex of moving electric charge - in this case between the Earth and the Sun.

Now McCanney discusses the sunward spike of comets in a similar way and posits that these visible spikes are due to electric charge moving from the Sun towards the comet. This sounds like another example of "magnetic ropes" to me, but McCanney refers to it as "discharging the Solar Capacitor." And likely all planets discharge the Solar Capacitor or remain connected via magnetic ropes (pick your favorite), but comets appear to be a much more visible display of this process.

It's not just magnetic ropes connecting the planets, comets, and other large objects to the Sun, there's also what occurs in the opposite direction too. Comets have an obvious plasma 'tail', and planets have a plasma 'tail' too, it's just that in the planet's case the 'tail' is invisible. Every planet has what is referred to as a magnetotail. According to Wikipedia:
A magnetic tail or magnetotail is formed by pressure from the solar wind on a planet's magnetosphere. The magnetotail can extend great distances away from its originating planet. Earth's magnetic tail extends at least 200 Earth radii in the anti-sunward direction well beyond the orbit of the Moon at about 60 Earth radii, while Jupiter's magnetic tail extends beyond the orbit of Saturn. On occasion Saturn is immersed inside the Jovian magnetosphere.
So these magnetotails have the potential to extend from planet to planet, and perhaps with more sensitive detection abilities we'd see them extend even further.

Scientists studying Jupiter's magnetotail made some surprising discoveries during their research. They discovered plasmoid bubbles traveling through Jupiter's magnetotail in the direction of the solar wind. They also discovered that unlike Earth's magnetotail, Jupiter's is surprisingly structured with clear boundaries consisting of differing plasma density. They also noted intermittent extensions of Earth's magnetotail where it would suddenly jump out to around 1000 Earth radii, extending much further than what the above Wikipedia quote describes. There's clearly some interesting things going on behind the planets as they travel around the Sun.

Jupiter magnetotail
© ScienceShows a cross section of plasmoid bubbles traveling down Jupiter's magnetotail.
So if we combine the magnetic ropes with the magnetotail, it appears that planets and comets are like electrical conduits for moving charge from the Sun to the outer-reaches of the Solar System - an electrical pathway, or wire, of sorts. Remember, according to the NASA article, these magnetic ropes are responsible for delivering the energy displayed during geomagnetic activity, which can sometimes equal the power of an earthquake. (Note to readers: this may be more than an analogy.)


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Better Earth

Discovery Adds Mystery to the Origins of Earth

Mike Wall
MSNBC
Thu, 23 Jun 2011 02:50 UTC
Image
© NASAAn artist's conception of our solar system's solar nebula, the cloud of gas and dust from which the planets formed.
Solar particles from Genesis probe studied, and we are of a different material

Earth and the other rocky planets aren't made out of the solar system's original starting material, two new studies reveal.

Scientists examined solar particles snagged in space by NASA's Genesis probe, whose return capsule crash-landed on Earth in 2004. These salvaged samples show that the sun's basic building blocks differ significantly from those of Earth, the moon and other denizens of the inner solar system, researchers said.

Nearly 4.6 billion years ago, the results suggest, some process altered many of the tiny pieces that eventually coalesced into the rocky planets, after the sun had already formed.

"From any kind of consensus view, or longer historical view, this is a surprising result," said Kevin McKeegan of UCLA, lead author of one of the studies. "And it's just one more example of how the Earth is not the center of everything."
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Sun

Best of the Web: Electric Universe: Which Came First?

Donald Scott
thunderbolts.info
Fri, 24 Jun 2011 19:14 UTC
sun
© Jo DahlmansA coronal mass ejection erupts from the Sun.

Electric currents create magnetic fields in the Sun.

"Which came first, the chicken or the egg?" Asking this question always gets a chuckle from a group of kids who haven't been asked that before. For adults, it confirms their conviction that unanswerable questions must be laughably ignored. For a farmer who gets into the egg business by purchasing a group of laying hens the answer is easy. "My chickens came first; that's how I got my eggs."

Solar astrophysicists who try to explain what causes coronal mass ejections (CMEs) have a similar conundrum: "Which came first, the change in electric current, or the change in the solar magnetic field?" Until the present day there has been no mention of electric currents in space by solar astronomers. There has been no acknowledgement whatever that electric current is needed to create magnetic fields or that it even exists.

In 1908 Kristian Birkeland suggested that electrical flows from the Sun caused the auroral displays that we see. Astronomers such as Sidney Chapman ridiculed him. When it came to descriptions of solar coronal mass ejections and similar phenomena, all we have heard about for decades was that magnetic fields move around and twist - their "magnetic lines of force" come together, touch, and then fly apart carrying matter with them. This is called "Magnetic Reconnection." Solar astronomers never mention electric currents. We are to believe that magnetic fields do it all by themselves, without help.
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Better Earth

Lynch: Much going on in the direction of Vega

Mike Lynch
Times Record News
Fri, 24 Jun 2011 18:30 UTC
Image
© WikipediaVega
As soon as it is dark enough in the evening - and that is past a lot of bedtimes this time of year - you can see a really bright star in the eastern skies. It's the star Vega. Most people pronounce it like the ill-fated Chevrolet car of the 1970s, but others insist that you pronounce it VEE-ga. However you pronounce it, Vega is a significant star, not so much because of the star itself but because of where it is in our night sky.

Vega is the brightest star in what's called the "Summer Triangle" that was featured last week in this column, and it's also the brightest star in Lyra - the Lyre or Harp - a small constellation that I'll talk more about next month in Starwatch. It's one of the brighter stars in our sky, the third brightest we see from North Texas.
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2 + 2 = 4

SOTT Focus: Is the Sun Part of a Binary Star System? - Six Reasons to Consider

Ryan X
Sott.net
Fri, 24 Jun 2011 09:51 UTC
Lost Star and Myth of Time
© Binary Research Institute
Just what is the real cause behind the precession of the equinoxes and why did the ancients believe this cycle was so important? Walter Cruttenden asks this question in his latest book Lost Star of Myth and Time and comes to some provocative conclusions.

To the layman, the precession of the equinoxes is the observed motion of the night sky shifting backwards by a small amount every year. Of course, the night sky continuously shifts throughout the year as the Earth orbits around the Sun, but if one were to take a fixed point in time (like the Vernal Equinox, for instance) and take a snapshot of the sky on that day every year, one would notice the sky slowly shifting backwards with each progressing year. This is what is meant by the precession of the zodiac, or precessional movement. Astrologers would say we are in a different 'age' or zodiac sign depending on which constellations are visible in the sky on the Vernal Equinox of a particular year. This precessional movement of the sky amounts to about 50 arc seconds per year and takes about 24,000-26,000 years to complete a full cycle; the "great year" or "great world cycle" as it is often called.

Sir Isaac Newton was the first to put forth the idea that this precession is due to a wobbly motion of the Earth's axis, and few scientists have challenged this assumption since Newton's time. Cruttenden dares to ask the most basic question about this in his book bringing together a number of clues to form a hypothesis for precession being the result of the Sun moving in a binary orbit about a companion star. Could Cruttenden's speculations really lead to data that could overturn the ideas of Newton - a man treated like a deity in the world of physics and astronomy? As we'll see below, there's actually a large body of evidence to support Cruttenden's ideas.
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Beaker

Should we clone Neanderthals?

Andrew Brown
Guardian.co.uk
Fri, 24 Jun 2011 02:22 UTC
Given reliable technology, could it ever be ethical to bring our prehistoric relatives back from the dead?
Image
© Action Press /Rex FeaturesCloning Neanderthals ... 'No one would want to be the only member of their species'.

I am at a conference in Dubai on science, religion and modernity, and the best question to come up was "should we clone Neanderthals?" Let's assume the kind of technical progress which would make this look like a possibly ethical thing to do: the failure rate with mammalian cloning has been so high that it really would be rather dodgy to inflict the process on a human being. But for the sake of argument assume a reliable technology and a sufficiency of DNA to work with.

Of course, the first difficulty from the strictly utilitarian point of view is that we don't know what the consequences would be. Neanderthal brains were physically different from ours and we have no idea how that impacted their consciousness. We assume they had speech, but this is obviously something that does not fossilise. So it's hard to judge the consequences inflicted on a sentient being when we have no clear idea of what kind of sentience is involved.

So a straightforward calculation of the likely consequences can't be done in the way that it can at least be attempted in bioethical questions as they affect homo sapiens. That doesn't mean that religion can provide answers, either. I haven't asked a Roman Catholic but assume that they would apply the same kind of precautionary principle as is applied in the case of abortion: that something which might be a human being should always be given the benefit of the doubt. But other religions, and other forms of Christianity, are not opposed to human cloning. They might not be opposed to cloning Neanderthals.
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Info

The Flames of Betelgeuse - New Image Reveals Vast Nebula Around Famous Supergiant star


European Southern Observatory
Fri, 24 Jun 2011 14:05 UTC
Betelgeuse
© ESO

Using the VISIR instrument on ESO's Very Large Telescope (VLT), astronomers have imaged a complex and bright nebula around the supergiant star Betelgeuse in greater detail than ever before. This structure, which resembles flames emanating from the star, is formed as the behemoth sheds its material into space.

Betelgeuse, a red supergiant in the constellation of Orion, is one of the brightest stars in the night sky. It is also one of the biggest, being almost the size of the orbit of Jupiter -- about four and half times the diameter of the Earth's orbit. The VLT image shows the surrounding nebula, which is much bigger than the supergiant itself, stretching 60 billion kilometres away from the star's surface -- about 400 times the distance of the Earth from the Sun.

Red supergiants like Betelgeuse represent one of the last stages in the life of a massive star. In this short-lived phase, the star increases in size, and expels material into space at a tremendous rate -- it sheds immense quantities of material (about the mass of the Sun) in just 10 000 years.
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