What do pizza and brown dwarfs have in common?

If you brought a pizza to the surface of the sun, it would of course burn to a crisp.

But a brown dwarf could cook it perfectly, browning the edges of the crust, melting the cheese.

(Photo: Infrared image of the binary methane brown dwarfs known as 2MASS 1534-2952AB. Credit: Dr. Michael Liu, Institute for Astronomy, University of Hawaii.)

Brown dwarfs are that class in the continuum of objects that falls somewhere between stars like our sun and the gas giant planets like Jupiter.

And in a remarkable piece of work, researchers at the University of Hawai'i Institute for Astronomy and the University of Sydney have managed to calculate the mass of two pairs of brown dwarfs. (For details, see www.ifa.hawaii.edu/info/press-releases/Liu_AAS_June08.)

They did it using 17^th Century astronomy Johannes Kepler's determination that the mass of a paired, or binary, object could be determined if you knew the sized of the orbit and the precise time it takes for the objects to complete an orbit of each other.

That, plus incredibly detailed observations using both the Keck Telescope on Mauna Kea and the Hubble Space Telescope.

The team included Michael Liu and Trent J. Dupuy of the University of Hawai'i and Michael J. Ireland of the University of Sydney.

Brown dwarfs are generally bigger than planets and smaller than suns. They're hot, but not nearly as hot as the roughly 10,000-degrees of the sun. They're closer to the range of 800 degrees Fahrenheit—like a nice, hot pizza oven.

Technically, brown dwarfs are big objects smaller than 7 percent the mass of the sun. Like gas giant planets, they lack the necessary mass to launch nuclear fusion, and thus can't generate their own heat.

The Liu team studied two separate brown dwarf pairs, and was able to calculate that the mass of one pair (2MASS 1534-2952AB) is about 6 percent of the mass of the sun, and the mass of the other (HD 130948BC) is about 11 percent that of the sun.

That's still big. Jupiter is our solar system's biggest planet, and each of the planets in the smaller of the two pairs is still 30 times the mass of Jupiter.

Astronomers have long been able to calculate temperatures, distance and brightness of distant objects. A key value of this work, Liu said, is that it helps correct theoretical calculations of the mass of objects in space.

"Mass is the fundamental parameter that governs the life-history of a free-floating object...After weighing these tiny, dim, cold objects, we have confirmed that the theoretical predictions are mostly correct, but not entirely so,” he said.

One of the things that made the calculations possible is the adaptive optics on the Keck II telescope, which allows astronomers to correct for distortions of the Earth's atmosphere, and to obtain amazingly clear images of very distant objects.

"These are very challenging measurements, because brown dwarf binaries have tiny separations on the sky and orbit each other very slowly. We needed to obtain the sharpest measurements that are possible with current telescopes to precisely monitor their motion," Dupuy said.

The researchers unearthed a couple of new mysteries. Among them: temperature and energy output calculations for the two binaries don't match the theories of what they should be.

"These findings will be a challenge for the theorists, and we are inspired to measure the masses of more brown dwarfs in the coming years to better understand the problem."

The team's research was supported by the National Science Foundation and the Alfred P. Sloan Foundation.

© 2008 Jan W. TenBruggencate

Mikulina: Solar power sensible, disruptive

What's the role for residential solar power—photovoltaics or PV—in Hawai'i?

Substantial, writes Sierra Club Hawai'i chief Jeff Mikulina, on the Microsoft Environment website.

(Photo: Some of the cells on elderly photovoltaic panel. For Mikulina's article, see www.microsoft.com/environment/perspectives/articles/sierra_club_hawaii.aspx)

There remain some problems. It's still not cheap. And it's intermittent—it only makes power when the sun shines.

But you might be even more put off if today someone suggested this as a new technology: You could put in a fossil fuel generator and that it would require you hauling toxic, explosive gasoline to it several times monthly.

Viewed together, you might be less dismayed by a technology that only required batteries or a link to the power grid.

Indeed, Mikulina cites the ready “local” availability of solar power as a key benefit.

“An average household in Hawaii can decrease their carbon emissions by about seven tons annually when compared with conventional fossil fuel grid. Power from PV is generated locally, so PV users are no longer tethered to oil wells located thousands of miles away,” he writes.

In fact, the sun is dumping all that power on your rooftop right now, and it's going to waste.

“With hundreds of thousands of empty rooftops facing the sun in Hawaii, distributed PV is perfectly positioned to be game-changing technology that overturns the current model of producing electricity,” he writes.

Some folks are converting to solar now, either storing the energy in their own battery banks or hooking up to the grid through a net metering system. Net metering is where you supply power to the grid when you're producing more energy than you use, and then pull power off the grid when (in the case of solar) the sun isn't shining.

To most efficiently use a system in which many residents both produce and consume power, the grid itself needs an upgrade—so it is smart enough to sense what's going on, to send and receive messages from its customers, to better manage its ebb and flow of energy.

“Electric utilities would transform their business model from power producing to power distributing, much like the telecommunication sector. This distributed model of community-scaled power generation and storage would also fulfill Thomas Edison’s original vision for electricity—in the 1880s he forecast a power plant in every community,” Mikulina writes.

Mikulina has long been a proponent of solar power. In fact, he wrote his master's degree thesis on the subject last year.

He surveyed Hawai'i residents about their views on solar power.

Among the other key indicators of potential solar adopters: pro-environmental views, participation in environmental activities, a desire for self-sufficiency, and holding the belief that electricity costs are going to keep going up.

Writes Mikulina in his thesis: “Clearly, there are many ways to foster interest in (grid-tied photovoltaic) adoption. But the strongest drivers appear to be perceived economic relative advantage and the belief that (grid-tied photovoltaic) is effective in satisfying environmental concern.”

In his thesis, he argues that residential photovoltaic systems, hooked up to the community electricity grid, is a key component of Hawai'i's energy future.

“Grid-tied residential photovoltaic's minimal environmental impact, rapidly decreasing cost, and renewable fuel source may position it as the disruptive energy technology of the 21^st century,” Mikulina writes.

“With its high electricity prices, near-complete dependence on imported oil for energy, and abundant sunlight, Hawai'i is poised to be a leader in adopting this ancient source of power, hastening the day when 'alternative energy' is simply 'energy.'”

© 2008 Jan W. TenBruggencate

Rats redate Aotearoa (New Zealand) occupation

Rats are helping scientists rethink the first appearance of humans in New Zealand, and that work is causing them to rethink Polynesian migrations.

The new work looks at evidence of Polynesian rats—radiocarbon dating both rat bones and gnawed seeds. It suggests that the first population—at least by rats—of both North Island and South Island New Zealand occurred from 1280 to 1300 AD.

(Photo: A rat-gnawed seed--in this case a macadamia nut eaten by a black rat.)

New Zealand has long been considered the most recently inhabited major island group of Polynesia, but most dates have placed that initial habitation several hundred years earlier.

One problem with those earliest estimates for human habitation has been that there was little archaeological evidence for them. The assumption of archaeologists was that this was because it took a few hundred years for human populations to build up to the point at which they would be “visible” to archaeological investigation.

It has long been known that Polynesian voyaging canoes carried rats. Theories differ as to whether they were carried accidentally, for food or for some other purpose, but it is clear that everywhere Polynesians arrived, rats arrived as well. Furthermore, rats reproduce must faster than humans, and quickly make impacts on the environment.

The new work was published today (June 2, 2008) in the Proceedings of the National Academy of Sciences, researchers Janet Wilmshurst of Landcare Research in New Zealand, Atholl Anderson of Australian National University, Thomas Higham of Oxford University in the United Kingdom and Trevor Worthy of the University of Adelaide in Australia.

They note that many early dates—of rat bones and other evidence of human activity—have been based on flawed radiocarbon dates. In the latest work, the researchers redated previous rat bone samples, and also compared their results with other evidence—notably seed cases that contain the clear imprints of rat teeth in gnawing patterns.

And the new rat information coincides well with other evidence of human presence.

“There is now excellent agreement between the ages of the earliest archaeological sites and the earliest-dated evidence for widespread deforestation, massive megafaunal extinctions,the decline of marine mammal populations and rat predation of seeds and invertebrates,” the paper says.

Rat evidence in the past couple of years has also been used to redate other islands' habitation—notably Rapa Nui or Easter Island. University of Hawai'i archaeologist Terry Hunt found that gnawed seeds and other data suggest the initial occupation of Rapa Nui was about 1200 AD—also several hundred years later than was earlier believed.

“Everything is turning out later than we thought,” Hunt said.

He said both Rapa Nui and Aotearoa (New Zealand) were at the margins of Polynesia and appear to have been occupied near the end of the period of active Polynesian migration. Hunt said there appears to have been a very active period of open-ocean voyaging and discovery starting around about a millenium ago.

“Around 1000 AD people are moving rapidly through eastern Polynesia and out to the margins,” he said. The islands of Rapa and Mangareva appear to have been populated about 1100, and may have been springboard to the occupation of Rapa Nui.

New Zealand's later population appears also to have come from somewhere in eastern Polynesia, but it is difficult to say exactly whence its settlers came. Perhaps Tahiti or the southern Cook Islands, Hunt said.

By contrast with these areas, Hawai'i, although it is extremely isolated, appears to have been populated quite early in the eastern Polynesian migrations.

“Hawai'i is actively settled quite early—as if it was in the locale of Tahiti” rather than more than 2,000 miles away, Hunt said. Modern occupation dates for Hawai'i fall in the neighborhood of 800 or 900 AD.

© 2008 Jan W. TenBruggencate

Honolulu's energy use: what the media missed in Brookings report

The Brookings Institution announced that Honolulu residents use less energy any other major U.S. city and Hawai'i's news media cheerily announced the results, without inspection.

(Image: Brookings Institution's map of city energy use.)

But there is a very dark side to the Brookings data that both daily newspapers missed entirely.

There is also a huge transportation fuel use flaw in the Brookings study.

And the Hawai'i media failed to explain clearly the key reason Honolulu's residential energy use numbers are low.

The Dark Side: Honolulu's use of energy and its carbon footprint grew at nearly 10 times the national average for major cities, up 10.24 percent from 2000 to 2005, according to the Brookings Institution study.

The Missing Side: If you want to go 100 miles out of town and you live in San Francisco, you generally drive, and your gasoline use is counted by Brookings. If you want to go 100 miles out of town in Honolulu (say, to Līhu'e or Kahului), you fly, and Brookings doesn't count that at all.

One Key Difference: Honolulu does so well in these calculations not because we are such good stewards of our energy use, but because of our subtropical climate. We don't use heating oil. Brookings ranked Honolulu first in the nation for its low use of residential fuels.

What it all means is that this study isn't comparing apples with apples, but you only got a hint of that in major news media coverage.

There are certainly worse records than Honolulu's 10.24 percent overall five-year increase in combined residential and transportation energy use for residential and ground transportation, like Dallas-Fort Worth's 11.05 percent and Chattanooga's amazing 48 percent.

But the majority of America's 100 top cites did far better than Honolulu, many of them cutting their emissions. Bakersfield cut its emissions by nearly 11 percent. Portland cut by almost 5 percent. San Francisco by 3 percent.

That's not the news you saw in the major Hawai'i media this morning. The Star-Bulletin declared Honolulu the nation's greenest city. The Advertiser called it the “best U.S. city” for its carbon dioxide production. The Advertiser's account did include a little useful perspective in the form of quotes from Sierra Club's Jeff Mikulina and the Department of Health's Laurence Lau.

Beyond the city-by-city comparisons, the Brookings report says that, nationwide, the picture is not good:

“America’s carbon footprint is expanding. With a growing population and an expanding economy, America’s settlement area is widening, and as it does, Americans are driving more, building more, consuming more energy, and emitting more carbon. Rising energy prices, growing dependence on imported fuels, and accelerating global climate change make the nation’s growth patterns unsustainable,” the organization says.

The Brookings city-by-city statistics are available here: www.brookings.edu/papers/2008/~/media/Files/rc/papers/2008/05_carbon_footprint_sarzynski/metroprofiles.pdf.

The Brookings report policy brief is here: www.brookings.edu/papers/2008/05_carbon_footprint_sarzynski.aspx.

A Brookings table of energy use and emissons is here:

www.brookings.edu/reports/2008/~/media/Files/rc/papers/2008/05_carbon_footprint_sarzynski/tables.pdf.

© 2008 Jan W. TenBruggencate

Massive conservation partnership covers 25% of Hawai'i land area

Partnering is the new paradigm in conservation in Hawai'i, and a group of Big Island partners have announced a stupendous new camaraderie.

It will join together for conservation a quarter of all the land in the state—a million acres that sweeps across the Big Island, covering 40 percent of that island's land area.

(Images: photo of Ka'ū Forest Reserve by Christine Ogura, Map of the new Three Mountain Alliance region .)

The new Three Mountain Alliance watershed partnership covers the slopes of much of Mauna Loa, Kīlauea and Hualālai.

Nine landowners have signed on on a memorandum of understanding. They include: The Kamehameha Schools and The Nature Conservancy of Hawai'i; the state's Department of Land and Natural Resources and Department of Public Safety; and the federal government's U.S. National Park
Service (Hawai‘i Volcanoes National Park), U.S. Fish and Wildlife Service, U.S. Geological Survey Pacific Island Ecosystems Research Center, USDA Forest Service and USDA Natural Resources Conservation Service.

A management plan for the region covers the joint efforts they propose to protect the watersheds.

“The Three Mountain Alliance will focus on protection of native habitat and species and will benefit the community by managing upland, forested portions of the watershed that provide essential groundwater, water filtration, and flood reduction,” said a press release announcing the partnership.

The new organization brings to nine the number of watershed partnerships across the state.

The Three Mountain Alliance is one of nine such partnerships throughout the State. And they have their own partnership, the Hawai‘i Association of Watershed Partnerships. The management plan for the Three Mountain Alliance as well as other watershed partnership information is available at www.hawp.org.

One of the early projects for the alliance is to involve students and teachers in an education and restoration project at the national park and adjacent Keauhou Ranch, using native plants grown by inmates at Kūlani Correctional Facility. The alliance also plans to control wild cattle in several state-owned forest reserves in the region, to fence dry forests of upland Kona to protect them, to conduct joint invasive weed control work and to develop a watershed management plan for the high country forests of Ka'ū and Kapāpala.

Here are some quotes from the various partners:

Cindy Orlando, Hawai'i Volcanoes National Park superintendent: “Partnerships such as the Three Mountain Alliance are the most effective way to address threats to the landscape such as invasive weed species that occur across land ownership boundaries,. The Park is able to accomplish much more with partners than we could on our own by sharing scarce staff and resources to accomplish joint objectives.”

Laura Thielen, chairperson of the Department of Land and Natural Resources : “DLNR is pleased to participate in this latest multi-partner cooperative agreement. Land-based activities have a direct effect on nearshore waters and corals and fisheries. For this reason, partnerships are critical to support healthy ecosystems, on land and in the ocean.”

Roger Imoto, Division of Forestry and Wildlife Branch Manager for Hawai‘i Island: “Coordinated on-the-ground management of threats such as invasive animals, weeds and fire is critically needed to maintain healthy watersheds on the slopes of Kîlauea, Mauna Loa and Hualâlai to sustain the future quality and quantity of fresh water and benefit Hawaii’s people as well as native plants and animals.”

Peter Simmons, Kamehameha Schools regional assets manager: “Large landowners such as Kamehameha Schools have a responsibility to show leadership in caring for their lands because these areas are critically important to the life, health and well being of the native Hawaiian
ecosystems and human communities that inhabit them.”

Beryl Iramina, warden at Kūlani Correctional Facility, whose inmtes will do some of the conservation work: “The Department of Public Safety and Kūlani Correctional Facility are very excited to participate with this innovative partnership through our inmate programs such as the conservation workline and the native plant horticulture program. By participating in the partnership, our inmates receive education and work training opportunities. Inmates can also give back to the community through our community service programs helping Three Mountain Alliance partners protect and restore important watershed lands.”

© 2008 Jan W. TenBruggencate