LOOKING FOR ALIEN 'BUBBLES' IN OTHER GALAXIES

When I was under the velvet black skies of western Texas a few months ago I had a magnificent view of the star-studded bulge of our galaxy, in the direction of the summer constellation Sagittarius.

How many advanced civilizations might be in this hub of the Milky Way? I pondered. After all, this is the direction where the mysterious "WOW" radio signal that was detected three decades ago came from.

The problem is that we are embedded in a thick forest of stars, and identifying the location of an extraterrestrial civilization -- one that's attempting to contact us -- is the proverbial needle-in-haystack search as the SETI scientists always say.

Therefore, it would make sense to go looking at a neighboring "forest," or rather nearby galaxy, for evidence of extraterrestrial intelligence.

The image above from NASA's Wide-field Infrared Survey Explorer is an example. The red object at upper left is an aging star shrouded in dust. Nevertheless, in a survey of 250,000 infrared sky sources cataloged in the 1970s, 17 "quasi-plausible" Dyson sphere signatures came up, according to Richard Carrigan of Fermilab.

It’s imaginable that a super-civilization would begin a wave of colonization that spread out to neighboring solar type stars from its home base. Each offshoot would "astro-form" the colonized planetary system by constructing a Dyson sphere around the host star.

Carrigan envisions seeing "Dyson bubbles" in nearby galaxies. These would be clusters of Dyson spheres that enclosed a grouping of stars colonized by a Type II Kardashev civilization. The logic is that after you've built a backyard fence you can start to conceptualize building the Great Wall of China and still hope to gain perspective on the process, Carrigan writes.

These would be detected as anomalous dark voids in a galaxy's disk. When these voids were observed in infrared light they would glow brightly with the heat radiation from the surfaces of Dyson spheres. This would show that they are not that simply voids where solar-type stars are conspicuously missing.

NASA's Hubble Space Telescope is conducting a multi-year survey across a swath of the neighboring Andromeda galaxy (M31). The images are filled with so many resolved stars that they resemble at grains of sand on a beach. This could make an excellent citizen science project, to scour the Andromeda fields for anomalous-looking regions.

Gigantic elliptical galaxies (shown above), which are completely devoid of light-blocking dust, would look very odd indeed if dark voids were detected. However the nearest ellipticals are 60 million light-years away and so would require a space telescope much larger that Hubble to yield enough resolution.

An apparent lack of any evidence for large-scale artifacts in galaxies as old as ours would begin to set an upper limit on just how technologically advanced alien civilizations can evolve to become.

Kardeschev hypothesized about Type III civilizations that would harness the energy of an entire galaxy. The observational evidence of astro-engineering a complete galaxy is lacking, and so it's fair to say that Type III civilizations either don't exist at all, or at least not yet.

The universe has had 12 billion years to evolve Type II or Type III civilizations. If there's not obvious archeological evidence, then maybe intelligent beings don't evolve all that far beyond mega-engineering to the scale of a single planetary system.

Maybe extraterrestrials simply don't have the motivation, know-how, or the budget.

NEW DISCOVERY ON HIGGS BOSON

On Wednesday (July 4), scientists heading two major experiments at the LHC plan to announce their most recent findings at a physics conference in Australia with accompanying meetings in Geneva, Switzerland. What's more, senior scientists at European Organization for Nuclear Research (CERN) are hinting that there is strong evidence in their data that suggests the Higgs boson exists.

For the last year or so there have been "hints" of a Higgs detection, then those hints turned into "potential evidence." Now, will we finally get word of a bona fide discovery?

"I agree that any reasonable outside observer would say, 'It looks like a discovery,'" CERN physicist John Ellis told The Associated Press. "We've discovered something which is consistent with being a Higgs."

The Higgs boson is the last piece of the physics Standard Model, a collection of theories that underpin all modern physics. The Higgs particle is theorized to mediate mass -- like a photon (also a boson) mediates the electromagnetic force, i.e., light -- and creates the "Higgs field" that must pervade the entire Universe, endowing matter with mass.

If the LHC didn't detect signs of the Higgs particle, its non-discovery would turn modern physics on its head. But physicists are an inquisitive bunch, so a non-discovery would be just as exciting (if not more so) than a discovery. But for all the Higgs doubters out there, it's looking more and more likely the Higgs does exist and the Standard Model is as robust as physicists always thought.

So when the announcement comes from ATLAS and CMS physicists on Wednesday, will we get the definitive proof we've been (not-so-)patiently waiting for?

In the world of high-energy physics, it's not a question of slamming particles together and then photographing a Higgs boson screaming away from the carnage. Countless billions of collisions need to be recorded and the resulting spray of particles tracked. Like a photograph, more photons are needed to make the image appear defined and bright. If just a few photons hit the photographic paper, a very vague and fuzzy image is the result. The longer you leave the photograph under the light, more photons are collected and the better the image becomes.

This is basically what the LHC scientists are doing. They repeat the same experiment again and again and collect the huge quantities of data to gradually build an "image" of the kinds of particles produced inside the LHC as it smashes protons together at near the speed of light. Over time, statistical spikes start to appear in the data, suggesting particles of a certain energy (or mass) are being detected.

One statistical spike, at around the energy of one predicted variety of Higgs boson, has been growing stronger and more defined over the months, but at what point does that "spike" become a discovery and not just background noise? As this is a lesson in statistics of huge numbers, physicists have a way of categorizing how strong the signal is.

EARTH SUFFERS FROM CO2 ALLERGY

About 12 million years ago, Earth wasn't sensitive to carbon dioxide ups and downs. But like seasonal allergies that develop when one gets older, the planet's climate has started responding to changing CO2 concentrations relatively recently, according to new findings from paleoclimate researchers.

The prevailing understanding in climate science is that there's been a persistent connection between CO2 levels and the Earth's climate: Long ago when the Earth was frozen, CO2 concentrations were low; when it was hotter, the level of CO2 was higher. Research published this week in the journal Nature just might have burst that thought bubble.

University of California Santa Cruz ocean sciences professor Ana Christina Ravelo and grad student Jonathan LaRiviere led a team of scientists in reconstructing the climate conditions during the late Miocene epoch, which was a period about 12 million years ago when the planet was warmer than it is now. To achieve this, they used cores collected from the ocean bottom by scientists aboard the research vessel

Deep-sea cores held microfossils of microscopic plankton that date from the Miocene, and the scientists reported that they made new stable isotopic measurements of those samples. Their analysis showed that ocean temperatures across much of the North Pacific were 9 to 14 degrees Fahrenheit warmer than they are today, while the CO2 concentration was so low it was comparable to just before the Industrial Revolution.

Comparing that with ocean temperatures and CO2 levels over the past five million years, the paleoclimate researchers demonstrated that changing climate conditions became increasingly tied to changing CO2 levels. In other words, the climate and carbon dioxide have become strongly coupled.

This study demonstrates that Earth's climate sensitivity could be at an all-time high today, Ravelo told the university. "This means that the ocean and climate systems are poised to readily respond to even small changes in carbon dioxide," she said. We're going to need more than nasal spray to deal with that.

A CHEMICAL THAT CAN TURN YOUR ORGANS TRANSPARENT

                       Researchers in Japan recently developed a chemical reagent that turns biological tissue transparent, opening doors to optical imaging techniques and avenues of research that scientists have long only dreamed of. And speaking of dreaming — if you're going to start turning body parts transparent, where better to start than the brain?

               What if you could dissect an organism without so much as picking up a scalpel? For years, researchers have used animals like zebrafish — which are naturally transparent at the embryological stage of development, and were recently genetically engineered to remain transparent through adulthood — to do just that. But for other model organisms, like mice and rats, scientists have always had to get at their insides the old fashioned way: by cutting them up.


Slicing and dicing is necessary because modern techniques for looking at the insides of an organism can't see deep enough to be of any real use; the tendency for tissue to scatter light, for instance, keeps modern optical methods of observation from probing deeper than 1mm into biological matter.

But all that is about to change. Take a look at the image pictured above. The object on the right may look like a pineapple gummi bear, but it's actually a mouse embryo that's been treated with a new chemical reagent that turns biological tissue transparent. Compare it to the embryo on the left, and you'll get a sense of why scientists are heralding this discovery as a revolution in the field of optical imaging.

The reagent, known as Scale, was developed by a group of scientists from Japan's RIKEN Brain Science Institute, and the team has already used it to study neurons in the brains of mice at unprecedented levels of detail. See, what's really impressive about Scale is that it not only renders tissue transparent, it manages to do so without interfering with fluorescent labels and signaling. (Fluorescent labeling is a well-establish imaging technique that allows scientists to genetically alter proteins of interest so that they light up with a specific color when exposed to certain wavelengths of light.)

The researchers' findings, which are documented in the latest issue of Nature Neuroscience, demonstrate their ability to visualize in three dimensions the intricate networks of neurons and blood vessels in the brains of embryonic mice at sub-cellular resolution, like the neural stem cells (green) and blood vessels (red) pictured above.   

This latest research uses Scale to visualize fluorescently-labeled brain samples, but the researchers say that their reagent will prove invaluable in the study of other tissues, as well. Dr. Atsushi Miyawaki, who led the RIKEN research team, says they envision using Scale on organs like the heart, muscles, and kidneys, and even on tissues from other organisms, including primates and humans.

And while the reagent in its current form is too powerful to use on living organisms, Miyawaki says that could change: HOPE FOR A NEW BEGINNING...

ANTARCTIC IMAGES REVEAL CHANGES IN CONTINENT'S ICE

Photographs snapped last week of the Antarctic Peninsula reveal a glittering landscape of ice and snow, crowned by rugged mountains rising majestically in the distance. Yet no human captured the stunning view — it was the work of machines.

Thanks to the combined technological powers of satellites and weather stations scattered around the Antarctic Peninsula, researchers can now keep tabs on the region's shifting ice — which in recent years has undergone dramatic changes — from the comfort of their offices.  

AMIGOS 6, one of many specialized weather stations staked around the region, took the above image on April 24 and relayed it to a satellite the same day.

First deployed during the 2010-2011 Antarctic field season, each AMIGOS (Automated Met-Ice-Geophysics Observation System) station is equipped with a thermometer, instruments to measure wind speed and direction and a camera to photograph its surroundings. Stations set out on the ice itself are equipped with GPS to monitor changes in the flow speed of Antarctic glaciers, which are essentially huge rivers of ice.

The AMIGOS are congregated near a spot that has been home to sudden, catastrophic changes in Antarctica's ice. In 2002, the Larsen B ice shelf — a vast, floating plain of ice larger than Rhode Island — broke off from Antarctica's coastline, disintegrated into an army of icebergs and floated away in the course of 35 days. (Ice shelves are enormous plates of ice that float on polar seas, but are connected to the shoreline by the land-bound glaciers that feed into them.)

WHAT'S THE DEAL WITH 'SUPER-EARTH' EXOPLANETS?

The big news in the universe this week is that NASA’s Spitzer Space Telescope has managed to capture light from an exoplanet. An alien "super-Earth" to be exact, which makes this the first time astronomers have managed to detect light from a small, rocky body.


But don't let the name fool you. Super-Earths have very little in common with our own planet. That's not to say the discovery isn't fascinating, but it's more science as usual than the discovery of our next home.



There are many parts to this story, like the part about 55 Cancri e. It isn't a new find. Astronomers discovered it in 2005 and have since determined that it's one of five planets in a solar system orbiting the star 55 Cancri about 41 lightyears away in the constellation Cancer. They also know that 55 Cancri e orbits extremely close to its parent star and its star-facing side is heated and emits a thermal glow -- that's the infrared emission Spitzer picked up.


This isn't the first planet Spitzer has observed directly either -- usually astronomers "see" planets by a telltale dip in the brightness of the parent star as they pass in front of it (i.e. the "transit method"), or the "wobble" of a star as an exoplanet orbits it (i.e. the "radial velocity method"). But the $770 million telescope, which was launched in 2003, is searching for exoplanets directly by detecting their glow in the infrared spectrum.



Hot Jupiters are gas giants that orbit their parent stars closer than Mercury orbits our Sun. These are big planets with big surfaces that reflect a lot of light and generate a lot of heat making them easier for telescopes to find. That Spitzer measured 55 Cancri e directly is impressive since as a super-Earth, it's much smaller than a hot-Jupiter and gives off a lot less light.


It's 55 Cancri e's classification as a super-Earth that's a little problematic. The term may be intuitive to astronomers, but to the rest of us it's incredibly misleading.


With the familiar name "Earth," it's easy to see why people read "super Earth" and get really excited. Our home planet Earth is pretty super. We have a temperate climate, fresh water, ample sunlight, a protective magnetic field, and a balanced atmosphere. Earth has everything that makes life possible. By extension, and by linguistic convention, a super-Earth should be better -- a bigger Earth with more fresh water, beach weather year round, a thicker or richer atmosphere, and anything else that could improve our own planet.


In actuality, super Earths are quite different from our Earth. Super Earths have masses roughly 10 times greater than Earth's, but 55 Cancri e shares its rocky nature with Earth -- that’s where the similarities end, however. But that isn't to say it’s not a really neat planet.



55 Cancri e stood out to astronomers in 2005 because of how close it is to its star; about 26 times closer than Mercury is to the sun, which gives it an 18 hour day. At that distance, the temperature on the star-facing side reaches up to a staggering 3,140 degrees Fahrenheit. Measurements of the planet tell astronomers that its likely a dark world without the substantial atmosphere needed to warm its nighttime side. It's also oozing. The extreme heat keeps material on its surface, which includes some amount of water, in a supercritical fluid state meaning the liquid is likely topped with a layer of steam from the heat.


So 55 Cancri e isn’t at all like Earth -- so what should we take away from this latest development from Spitzer? That very cool science happens all the time, and that "firsts" are exciting. And that we still haven’t found a true outstanding Earth other than our own.

FAST-TRAVELING SAND DUNES INDICATE THE RED PLANET'S SURFACE IS MORE ACTIVE THAN PREVIOUSLY THOUGHT.

Mars has an atmosphere 100 times less dense than Earth's, scientists figured hurricane-force winds are needed to move sand around in the thin Martian air, and winds that high are rare.


But this turns out to be only half the story.


New analysis of high-resolution images, taken by NASA's Mars Reconnaissance Orbiter, show sand dunes in an area known as Nili Patera are shifting as fast as some dunes on Earth -- despite a dearth of high-speed winds.


Scientists suspect it takes a big wind to get sand particles airborne, but once launched from the surface, they bounce around with ease, thanks to the planet's thin atmosphere and low gravity.