Daily Science Brief
 

http://www.newscientist.com/article.ns?id=dn7186

Glow of alien planets glimpsed at last

* 20:00 22 March 2005
* NewScientist.com news service
* Jenny Hogan

For the first time, astronomers have seen the glow of alien planets circling sun-like stars. "This is a new era," says the leader of one of the teams, Drake Deming from NASA's Goddard Space Flight Center in Greenbelt, Maryland, US. "This is the first time we have actually seen light."

Although planet hunters have bagged almost 150 extrasolar planets since the first one was spotted 10 years ago, until now they have only inferred the planets' presence by measuring the wobble in the host star's orbit or the dimming of the starlight as the planet passes in front of it. No one had yet seen the light from a planet directly.

Earlier this year, Glenn Schneider of the University of Arizona in Tucson, US, and his colleagues directly saw an object that was hailed by many as an extrasolar planet. But Schneider's object, visible in infrared light, is five times as massive as Jupiter and is in orbit around a small, failed star known as a brown dwarf.

Schneider himself refuses to use the "P-word", preferring instead to call the thing a "planetary-mass object". "Everyone was calling this a planet in the press," says Schneider. "But this wouldn't form as planets do."
"Hot Jupiters"

By contrast, Deming's team and another led by David Charbonneau at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, US, have each studied a planet of the class called "hot Jupiters", which orbit Sun-like stars. These gas giants probably evolved in a manner similar to those in our solar system.

The orbits of both planets, as observed from Earth, take them behind their host stars. The teams took advantage of this to tease out the planets' radiation from infrared images captured by NASA's Spitzer space telescope.

First they measured the radiation from each star-planet system when the planet was to one side of its star as viewed from Earth. Then they measured the radiation when the planet was behind the star. The difference between the two readings showed the radiation coming from the planet.

"From the first moment we saw the data, we were ecstatic," says Charbonneau. "We could see the signal of the planet passing behind the sun and coming back again."
Surface temperatures

Based on these measurements, the teams estimated the temperature of the planets. Both gas giants have surface temperatures of at least 700°C.

"It is clearly a direct measurement of the flux from the planet," says Didier Queloz from the Geneva Observatory in Sauverny, Switzerland, who was behind the discovery of the first extrasolar planet 10 years ago. "It is very impressive."

Deming's planet, HD 209458b, has a mass two-thirds that of Jupiter and orbits a sun-like star in the constellation of Pegasus about 140 light years from Earth (Nature, DOI: 10.1038/nature03507).

Charbonneau studied a more distant planet called TrES-1, which has a similar mass and zips around its star in just three days. He reports these calculations in a forthcoming issue of The Astrophysical Journal.

http://www.newscientist.com/article.ns?id=dn7187

Daily Science Brief I suppose...New Fuel Cells "Membraneless" should lower costs...

The first membraneless alkaline fuel cell has been built by exploiting the way liquids do not mix in ultra-narrow channels. It could offer cheaper and more efficient fuel cells.

Doing away with membranes not only simplifies a fuel cell's design, it has also enabled the first alkaline fuel cells to be built. These could potentially be 40% more efficient than the acidic units used today, says Paul Kenis of the University of Illinois at Urbana Champaign, Illinois, US, who has developed the system.

His system exploits a phenomenon known as "laminar flow", where tiny streams of liquid become so viscous they do not mix when squeezed past one another.

"The concept of a membraneless fuel cell is a great idea, because between 20% and 40% of the cost of a fuel cell is the membrane," says chemist Shelley Minteer at the University of St Louis in Missouri, US.

She has also built a membraneless fuel cell, but her system uses two different, selective enzymes to stop the two liquids in the cell mixing, and has not yet been harnessed for an alkaline fuel cell. "This is the only other way to do it," she says, but admits that her method introduces new lifetime and power density problems.
Ten times more

Fuel cells work by breaking down a fuel such as methanol into protons and electrons, combining them with oxygen from the air and using the energy liberated to create an electric current.

Scientists hope they could be an environmentally friendly, longer-lasting replacement for the lithium-ion batteries that currently power cell phones and laptops. Fuel cells produce water as their main by-product and they could potentially be made to produce at least ten times more power for the same volume of fuel.

In the past, fuel cells have been made up of two chambers, one housing the liquid fuel that produces protons and supplies electrons to the anode, the other containing an oxygen-water mixture, which absorbs electrons.

The polymer membrane separating the chambers is punctured by tiny pores that allow protons through but are small enough to stop the larger methanol and oxygen molecules from diffusing across.
Limiting chemistry

The problem is that using these membranes means that all fuel cells must be based on the exchange of acidic protons. Because alkaline hydroxide ions are much bigger than protons, there are no membranes that can allow the hydroxide ions through without also causing mixing between the two chambers, explains Kenis. "The membrane limits the chemistry of the fuel cell," he says. But he insists that alkaline fuel cells are nevertheless more efficient.

So he decided to do away with the membrane altogether. Kenis realised that if he shrank the chambers down to about 0.25 millimetres and ensured that the liquids were always moving, the two could flow past each other and would not mix, even with no separating a membrane. And they would still allow the diffusion of protons or hydroxide ions from one side of the cell to the other.
Thin streams

The reason that two liquids normally mix - as with cream poured into coffee, for example - is a physical effect known as turbulence. But turbulence disappears when streams of liquid become thinner than about 1 centimetre, explains Kenis.

Kenis has patented the concept of his membraneless fuel cell system and presented a demonstration of the first membraneless alkaline fuel cell at the American Physical Society meeting in Los Angeles on Tuesday.

The cell is a cuboid of 3cm by 1mm by 1mm and produces 0.25 watts of power. He has already used it to power a miniature fan in the lab, but to power laptops or battery chargers in future, hundreds of tiny cells would have to be arranged in parallel.

However, this prototype model has not yet shown the high efficiency that might be expected from an alkaline fuel cell because the oxygen does not dissolve well in water. Kenis claims to have a solution, but will not divulge it until he has patented the idea.

http://www.newscientist.com/article.ns?id=dn7190

Remains of ancient Egyptian seafaring ships discovered

The first remains of ancient Egyptian seagoing ships ever to be recovered have been found in two caves on Egypt's Red Sea coast, according to a team at Boston University in the US.

The team also found fragments of pottery at the site, which could help resolve controversies about the extent of ancient Egyptian trade voyages. But details of the newly disclosed finds remain sketchy.

Kathryn Bard, who co-led the dig with Italian archaeologists in December 2004, has revealed to the Boston University weekly community newsletter that the team found a range of items - including timbers and riggings - inside the man-made caves, located at the coastal Pharaonic site of Wadi Gawasis.

According to the report, pottery in the caves could date at least some of the artefacts to a famous 15th century BC naval expedition by Queen Hatshepsut to the mysterious, incense-producing land of Punt. This voyage is depicted in detailed reliefs on Queen Hatshepsut's temple on the west bank of the Nile, near modern-day Luxor.

Bard declined to speak to New Scientist. But the find is exciting, says John Baines, professor of Egyptology at the University of Oxford, UK, who has been in contact with Bard. "These finds put flesh on what we might have imagined," he says.
Gold and ebony

The pottery finds include items the Italian researchers think could be from Yemen - a potential candidate for the modern identity of Punt. The ancient Egyptians sourced a variety of exotic wares in Punt, including gold, ebony and incense.

"The Yemeni pottery is very interesting because it was suspected that there were contacts across the Red Sea - and this proves that there were," Baines says.

The naval artefacts included two curved cedar planks which might have been parts of steering oars. But linking these to Queen Hatshepsut's famous voyage might be a little too specific, he says.

"Kathryn [Bard] has told me the pottery is early New Kingdom, and we know of no other expedition to Punt in that period, so it is a reasonable guess. But we also have to bear in mind that almost everything from antiquity is lost, so there could well have been other voyages."

It is not clear exactly why the artefacts were sealed up inside the caves. But it is possible that they were offerings to the Egyptian gods. "That sounds very plausible to me, not least because previous excavations found a structure made of stone anchors that could again be some sort of thanks-offering," says Baines.

The team plans to return to the caves in December 2005 to continue their excavations.

http://www.newscientist.com/article.ns?id=dn7191

Exotic black holes spawn new universal law

holes may define the perfect fluid, suggests a study of black holes that only exist in a theoretical 10-dimensional space. The finding may have spawned a new universal law in physics, which puts constraints on the way fluids behave in the real world.

Dam Thanh Son from the University of Washington, US, and his colleagues used string theory to model a 10-dimensional black hole as a liquid. String theory tries to explain fundamental properties of the universe by predicting that seven more spatial dimensions exist on top of the known three. While the concept is currently unproven as a cosmological model, the tools of string theory can sometimes provide answers to real quantum problems.

That means that while the "black holes" modelled by Son are not astrophysical black holes, but mathematical objects that exist in string theory, their findings may have relevance to the real world.

The fluid has two properties that relate to the black hole's surface area: viscosity, which describes how thick the liquid is, and entropy density, which is a measure of the internal disorder. Son's team found that the ratio of these two properties is a constant which can be expressed as a mixture of fundamental constants from the quantum world.
Super-cooled atoms

They suggest this constant acts as a universal lower limit for the ratio of the viscosity to entropy in real fluids. This backs an argument based on Heisenberg's famed uncertainty principle suggesting that such a limit should exist.

"That is what we hypothesise. We couldn't prove that it's the case, but we couldn't find anything that is less viscous," says Son. For example, the value of this ratio for water is 400 times greater than for black hole fluid. Even liquid helium is nine times more viscous.

Fluids that could approach the limit include super-cooled clouds of atoms, or the plasmas created in particle colliders, suggests Son.

Physicists have already drawn comparisons between the fireball produced at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, New York, US, and string-theory black holes. "I've started taking it seriously," says Peter Steinberg from Brookhaven National Laboratory, who works with one of the teams collecting data at the RHIC.

Although RHIC have not yet measured the viscosity of their fireball, this would allow an experimental test of Son's prediction. "The final word will come from the experimentalists," Son says.

http://www.newscientist.com/channel/...mg18524926.500

Snooze button addicts defeated by runaway clock

If you have an unhealthy addiction to the snooze button on your alarm clock, you may appreciate the latest invention from MIT's Media Lab. Clocky is an alarm with an ingenious method for rousing even the most dedicated morning dozer. After you hit the snooze button, the contraption rolls off the bedside table and zooms away on a set of wheels to some other part of the room, finding a new hiding place every day. When the alarm sounds again, simply finding Clocky ought to be strenuous enough to prevent even the doziest owner from going back to sleep.

Very cool stuff! The one thing I dig about 10 dimensional black hole theories is the displacement of the entire fabric of the galaxy that it shreds. Warping the inverse energy from the black hole into an unknown mass is mind-boggling to say the least. I've always felt that if we could theorize a fifth dimension into an understandable reality that it could very well lead to the understanding of some of the possibilities of this universe.

But then again, a runaway clock will just have to do for now ROFL!

Geek


Correction...old geek.

ha-ha

I bet if I titled this thread "Naked b****es here!" It would have 100 replies by now.

This sucks! I typed "Naked b****es" in the search engine, and got this lame thread!

Hmmmmmmmmmm Naked b****es aooaoaollllalalal

Fascinating stuff, good read, it's like Carl Sagan, Clive Cussler, and Dr. Fad wrapped up in one thread.

The land of Punt?

I think Marty Schottenheimer was born there.

Being a Chemistry dork... That is absolutely awesome. I know their are alot of "Fuel Cell" detractors, but this technology could absolutely revolutionize the world we live in.... Great Find.

Thats the funniest thing I've read all day

damn Alec ..... Interesting stuff ..... hard to imagine Planets bigger then Jupiter , but then it is hard to imagine the size of Jupiter , from earth here .......

Spide are you going to start talking about Uranus again?

only if you promise not to jerk off again .........

I love the string theorists...the base theory itself toys with known physics & it's fascinating to watch people who work 'out of the box' anyway...work out of the entire known universe...as it's understood now anyway

I say we turn it all over to SG-1 & visit one of these places...eh