Mysterious Dark Energy detected

There are mysteries in the universe—troubling behaviors of the stars that make no sense unless you assume forces you can't see.

Enter Dark Matter and Dark Energy. Can't see them. Can't measure them. But the most accepted models of the universe only make sense if they exist.

(Image: A University of Hawai'i team compared the strength of the Cosmic Microwave Background with sections of the sky where they located superclusters (red circles) and supervoids (blue circles). Microwaves tended to be stronger in the red and orange areas, and weaker in the blue areas. Credit: UH Institute for Astronomy.)

Now, for the first time, researchers at the University of Hawai'i's Institute for Astronomy may have actually measured the effects of one of them: Dark Energy.

A team led by Dr. István Szapudi believes it has been able to find direct evidence for the existence of Dark Energy, by measuring changes in microwaves that have moved through superclusters and supervoids.

(Okay. Some definitions:

(The universe has unimaginably vast areas that are dense with galaxies and also has areas that have comparatively few galaxies. The first are called superclusters and the second supervoids.

(Dark Matter: Based on theoretical calculations of the universe and how it works, there ought to be far more matter than we can actually find and measure. Astronomers assume it's there, but we just can't detect it. The missing stuff is called Dark Matter.

(Dark Energy: The universe is expanding, and something appears to be accelerating the expansion. What's causing the acceleration? The experts don't know, but some of them have a name for it. Astronomers call this mysterious—and until now theoretical—force Dark Energy.)

“We were able to image dark energy in action, as it stretches huge supervoids and superclusters of galaxies,” Szapudi said, in a press release from the Institute for Astronomy. His co-authors were Benjamin Granett and Mark Neyrinck. Their paper will be published within the next two months in the Astrophysical Journal Letters.

How it works is this, as Szapudi's team explains: If a microwave enters a supercluster, it gains energy. When it leaves the supercluster, it should lose that energy again. But if the supercluster is being affected by Dark Energy, being flattened in the 500 million years it takes for the microwave to cross it, then the microwave will actually retain some of the supercluster's energy.

“Dark energy sort of gives microwaves a memory of where they’ve been recently,” Neyrinck said.

The team looked at the 50 largest superclusters and at the 50 biggest supervoids in a region representing galaxies across about a quarter of the sky.

The team found that microwaves that had passed through superclusters appeared to have gained energy, while ones that had passed through supervoids lost energy. The distinctions were extremely small, but detectable.

See the Institute for Astronomy release on the paper here: http://www.ifa.hawaii.edu/info/press-releases/szapudi-7-08/.

© 2008 Jan W. TenBruggencate

Polynesian chickens in Chile? New furor, but they still look Polynesian.

A towering scientific furor has arisen over...chickens.

Specifically, whether Polynesian voyagers introduced chickens to South America before the first Europeans showed up...carrying their own chickens.

(Image: Red jungle fowl, the chicken of the Polynesians--in this case, a rooster. Credit: U.S. Fish and Wildlife Service.)

We'll get into some detail later, but the short version is this:

It still looks clear that voyaging canoes from the Polynesian culture of the Pacific carried chickens to the Americas well before Christopher Columbus, despite a great deal of rancorous comment and competing scientific papers in the esteemed journal, Proceedings of the National Academy of Scientists (PNAS).

Here's the longer version.

In 2007, researchers led by Alice Storey of New Zealand published a paper on the dating and DNA analysis of chicken bones found at the El Arenal archaeological site in southern Chile.

They found that 1) the bones dated to before Europeans first arrived in the Americas, and 2) the chickens were closely related genetically to early chickens found in Hawai'i and elsewhere in the Polynesian Pacific.

The inescapable conclusion was that the El Arenal chickens came from Polynesia, and since Polynesians, not South Americans, were a voyaging culture, that those chickens arrived on Polynesian voyaging canoes.

This helps resolve a couple of great anthropological mysteries.

1. How could the amazing Polynesian voyaging culture have populated virtually every isolated island in the vast Pacific and missed the Americas? Answer, of course: It didn't. The Polynesians simply failed to settle in the Americas, perhaps because there were
   already people there.

2. Throughout Polynesia, there are sweet potatoes. Sweet potatoes come from the Americas. How did they get into the Pacific? There have been suggestions, such as Thor Heyerdahl's drift raft theory, that somehow South Americans carried the potato through the Pacific. But it seems much more likely that voyaging canoes from the Pacific touched on the coast of South America and either did some swapping or some inspired botanical exploration.

Storey's paper was published in the PNAS in mid-2007. The same journal this week (July 28, 2008) published another chicken paper that challenges the Storey results. It is: “Indo-European and Asian origins for Chilean and Pacific chickens revealed by mtDNA,” by Jaime Gongora, Nicolas J. Rawlence, Victor A. Mobegi, Han Jianlin, Jose A. Alcalde
, Jose T. Matus
, Olivier Hanotte, Chris Moran, Jeremy J. Austin, Sean Ulm, Atholl J. Anderson, Greger Larson, and Alan Cooper.

In this one, Australian researcher Jaime Gongora argued that it might be premature to attribute those El Arenal chickens to a Polynesian voyager's introduction, in part because Gongora's team can't find Polynesian chicken DNA in modern South American chickens. Also because they argue it's possible the pre-European dates for the chicken bones were wrong.

Before we proceed further, a little chicken background. Chickens originated in Southeast Asia, and were so wildly popular as domestic fowl that they were carried around the world. Some went west to Europe, and some went east into Polynesia. They certainly got to the Americas from Europe, and the Storey work shows they may also have reached the Americas from Polynesia.

Gongora, in an emailed statement on his paper, said this:

“European chickens were introduced into the American continents by the Spanish after their arrival in the 15th century. However, there is ongoing debate about the presence of pre-Columbian chickens among Amerindians in South America, particularly in relation to Chilean breeds. This debate includes controversial claims that Polynesians introduced chickens into South America before the arrival of Europeans.”

Gongora said he conducted extensive surveys of the genetics of modern South American chickens, and found that they appear to be exclusively European in origin.

“This DNA study shows that modern Chilean chickens originated from European breeds, and the apparently pre-Columbian specimen provides no support for a Polynesian introduction of chickens to South America,” Gongora wrote.

He goes on to challenge the radiocarbon dates of the El Arenal site, suggesting that marine sediments might have contaminated them and made them seem older than they are.

“Definitive proof of Polynesian chicken introductions into the Americas will require further analyses of ancient DNA sequences and radiocarbon and stable isotope data from archaeological excavations within both Chile and Polynesia,” he wrote.

Anthropologist Elizabeth Matisoo-Smith, a co-author with Storey on the original paper, said their continued research has confirmed the original dates. They have already published work that shows that the diet of the El Arenal chickens was a land-based, not a marine-based diet.

“The Carbon and Nitrogen values show that the diet of the El Arenal chicken was terrestrial,” Matisoo-Smith said in an email.

“All the dates we have are consistent,” she said. The Storey and Matisoo-Smith team is in the process of getting its latest findings published.

The upshot of all this seems to be that, on balance, there is now more rather than less evidence of Polynesian chickens in Chile, and therefore Polynesian voyaging to the Americas.

© 2008 Jan W. TenBruggencate

Making cars seXy efficient

A car is a car is a car.

Clearly, that statement ain't true.

Sometimes a car is a sportster, and sometimes an SUV. Sometimes a van, sometimes a sedan.

But what counts is under the hood, you might hear.

Even that isn't necessarily a true statement these days.

Sometimes you'll find the power source for a car under the hood, but it might just as easily be in the trunk, or in the case of big battery packs, under the seats.

The world is in the heady process of redefining the family passenger vehicle.

In the liquid fuel category, there are gasoline cars, diesel cars and biodiesel cars, propane and liquefied petroleum gas (LPG) cars, cars that run on various combinations of gasoline and ethanol, hydrogen cars and so forth.

There's the compressed air car.

There are electric cars, and hybrids. But there are such variations, that you really need to pay attention.

There, for example, are plug-in hybrids, and extended range electrics, both of which have blends of traditional fuel engines and electric car capabilities. Like hybrids, but not like most hybrids.

Each new blend of transportation technologies seems to be getting its own name.

Click on the “efficient transportation” category in the right hand column of this blog for a number of stories on these issues. One is found at http://raisingislands.blogspot.com/2008/05/hot-new-car-class-extended-range.html.

The key to modern vehicle technology, in an age of astronomic liquid fuel prices, is efficiency. And one of the things expected to help move efficiency along is the Automotive X Prize, a $10 million contest to develop the most energy efficient automobile possible—and they need to be fast.

“The technology-neutral competition, a project of the X PRIZE Foundation, is open to teams from around the world that can design and build production-capable, 100 MPGe (miles per gallon energy equivalent) vehicles that people will want to buy and that meet market needs for price, size, capability, safety and performance. Winners of the $10 million prize purse will need to exceed 100 MPG equivalent fuel economy, fall under strict emissions caps and finish in the fastest time,” says the X Prize website, http://www.xprize.org/.

The latest news on the prize is that there are 94 teams that have signed letters of intent to participate. They come from 14 countries and 24 states. They'll close the entry list sometime in the next few months.

To win the prize, car makers not only have to come up with an efficient car. They have to prove that the thing works. For that, there will be racing, and U.S. cities are now competing for their own piece of the prize—to be the site where the races are held.

“The cross country stage race will begin in New York City in September 2009, and will continue in up to nine other major markets throughout the U.S. Each stage race will feature a driving competition over city, suburban and rural roads between 30 and 200 miles in length. The Progressive Automotive X PRIZE is interested in offering diverse geographic and driving “real world” conditions, including the potential for slick and snowy roads, mountainous conditions and downtown city streets,” the X-folks say.

So far, there's been a lot of interest.

“Cities representing a diverse geographic and demographic mix – such as Albuquerque, Boston, Cleveland, Dallas, Detroit, Denver, Indianapolis, New York, Las Vegas, Long Beach, Pasadena, Portland, San Francisco, Seattle, and St. Louis – have all expressed interest in the competition,” says X.

With the average American car getting mileage in the 20-30 mile per gallon range, the X Prize pushes the envelope with a minimum requirement that achieves four times that efficiency.

It's gotta help.

© 2008 Jan W. TenBruggencate

The lasagne forests of Hawai'i

The key value to forests is their ability, according to a new federal report, is to manage water, and the native lasagne forests of Hawai'i are a key example.

That's lasagne in the sense of layered, not food, since much of the Hawaiian forest is not particularly edible.

(Image: The native Kaua'i forest shrub, mokihana, whose berries are collected and woven into lei that have a distinct anise scent. But you wouldn't want to eat them.)

A new federal study is saying that water is perhaps the most product of a forest. The online journal Science Daily today (July 21) issued a report under the title “Greatest Value Of Forests Is Sustainable Water Supply.”

"Historically, forest managers have not focused much of their attention on water, and water managers have not focused on forests. But today's water problems demand that these groups work together closely," said Oregon State geosciencies professor Julia Jones, vice chair of a committee of the National Research Council, which released the report. She was quoted in Science Daily.

Hawai'i resarchers have figured this out, and water departments work alongside wildlife managers and conservation groups on watershed management teams across the state, to protect native forests.

What's special about Hawaiian native forests as opposed to, for instance, woodlands of non-native species?

One way to determine this is to walk through a woodland in Hawai'i. The planted loblolly pine forests of Kōke'e on Kaua'i have very little other growth under them. Eucaluptus stands in Maui's Upcountry area prevent other species from coming up in their shade. Miconia forests on the Big Island are often nearly entirely miconia, with very little other vegetation able to survive.

When a heavy rain pounds these woodlands, muddy water can flow from them, as the rain erodes the unprotected soil below.

By contrast, a healthy native Hawaiian forest can be layered like a dish of lasagne.

As a raindrop is driven by gravity toward the ground, it first encounters an upper layer of canopy trees, like koa and 'ōhi'a. And then it encounters the shorter trees growing below, the mehame and 'āla'a. And then the ferns like hāpu'u and shrubs like 'a'ali'i. And then the ground ferns, mosses and the dense layers of roots, leaves, rotting branches and the rest.

The upshot, according to botanists, is that all the gravity-fed power of that raindrop to slam into the ground and break up soil particles is gone. Instead of muddy water seeping into streams, the water drips clear from springs and saturated mosses. Those dense forests also inhibit the ground-level winds that suck moisture out of the landscape, and block the evaporative powers of the sunshine.

Here is a list of findings from the report cited in Science Daily:

• Forests provide natural filtration and storage systems that process nearly two-thirds of the water supply in the U.S.

• Demand for water continues to rise due to population growth, while forest acreage is declining and remaining forest lands are threatened by climate change, disease epidemics, fire and global climate change.

• Forest vegetation and soils, if healthy and intact, can benefit human water supplies by controlling water yield, peak flows, low flows, sediment levels, water chemistry and quality.

• Increases in water yield after forest harvesting are transitory; they decrease over time as forests re-grow, and in the meantime water quality may be reduced.

• Impervious surfaces such as roads and road drainage systems increase overland flow, deliver water directly to stream channels, and can increase surface erosion.

• Forest chemicals, including those used to fight fire, can adversely affect aquatic ecosystems, especially if they are applied directly to water bodies or wet soil.

• One of the biggest threats to forests, and the water that derives from them, is the permanent conversion of forested land to residential, industrial and commercial uses.

The Science Daily report is found at http://www.sciencedaily.com/releases/2008/07/080714162600.htm.

© 2008 Jan W. TenBruggencate

Symbionts starve reef corals

Some corals may carry within them the seeds of their own destruction.

Reef-building corals are understood to be a combined biological creature, made up of coral animals that contain plants known as dinoflagellates. The coral can feed off the waste products of its symbiotic tenant, while the plant gains a range of benefits, including protection, from the coral.

(Image:Disease spreading across a coral. Credit: Michael Stat, HIMB/SOEST.)

But researchers have found that not all the symbionts—the plants contained within reef corals—are created equal.

“Symbioses are widespread in nature and occur along a continuum from parasitism to mutualism,” write Michael Stat, Emily Morris and Ruth Gates, of the University of Hawai'i's Hawai'i Institute of Marine Biology in the School of Ocean and Earth Science and Technology.

Their report, Functional diversity in coral-dinoflagellate symbiosis, was published in the Proceedings of the National Academy of Sciences.

In essence, they found that some of the single-celled plants that live within corals are excellent tenants and great partners.

But others are not, and can in fact are so dangerous to their hosts that they can be used to identify corals that will soon be in trouble from disease. It appears that by not providing nearly as much food to the corals as other such plants, they may weaken the corals and make them susceptible to diseases that healthy corals can avoid.

“The relationship between these dinoflagellates and corals has long been considered mutually beneficial, with the dinoflagellates supplying the coral with food via photosynthesis in return for recycled nutrients and shelter. Over the last 20 years it has been made clear that there are many different types of dinoflagellates in corals and that the unions or symbiosis between a given coral and their dinoflagellates can be very specific,” Stat said in a press release.

In work on the coral reefs of the Northwestern Hawaiian Islands at French Frigate Shoals, the researchers found that healthy corals often had a different variety, or clade, of dinoflagellate than diseased corals.

When they conducted laboratory tests, they found that the type found on diseased corals produced far fewer nutrients than the ones found in healthy corals.

“We have discovered that a group of diseased corals in the Northwestern Hawaiian Islands associate with a type of endosymbiotic algae that has never been found in Hawaiian corals before. Our analyses suggest that these endosymbiotic algae are not providing the coral with nutrition and that the corals may be starving, making them more susceptible to disease,” Gates said.

“This work shows for the first time that different types of coral dinoflagellates are not equally beneficial, and that there is a link between the type of dinoflagellate and coral disease,” Stat said.

The work suggests that reef researchers may be able to recognize a reef's susceptibility to disease by looking at the microscopic plantlife in its corals.

“Just as we have tests for human diseases such as cancer and tuberculosis, we now have the ability to screen corals for disease susceptibility. This discovery is a key finding that will contribute to the conservation and protection of ecologically important corals in Hawaii and elsewhere, Gates said.

© 2008 Jan W. TenBruggencate