Researchers At Duke University Have Developed A Light-emitting Device That Can Be Switched On And Off

Measuring Distances To Stars Just Got A Whole Lot Easier Thanks To This “Stellar Twin” Trick

Scientists have developed a novel method to calculate the distances to stars, and it could be useful in helping map the size of galaxies. The study is published in the Monthly Notices of the Royal Astronomical Society.

The researchers from the University of Cambridge examined what are known as “stellar twins.” These are stars that are identical, with exactly the same chemical composition, which can be worked out from their spectra – the type of light they emit. If they were both placed at the same distance from Earth, they would shine with equal brightness.

So the team realized that if the distance to just one of the stars was known, the other could be calculated relatively easily based on how brightly it was shining. The dimmer it is, the further away it is, and vice versa. The method can be used to accurately measure the distance.

“It’s a remarkably simple idea – so simple that it’s hard to believe no one thought of it before,” said lead author Dr Paula Jofre Pfeil, from Cambridge’s Institute of Astronomy, in a statement. “The further away a star is, the fainter it appears in the sky, and so if two stars have identical spectra, we can use the difference in brightness to calculate the distance.”

Read more ~ IFL Science

Photo credit: RealCG Animation Studio. Shutterstock.

The liquid oxygen/liquid methane engine, developed by Armadillo Aerospace with help from NASA, is tested in the vacuum chamber at NASA’s White Sands Test Facility, August 2009. (NASA)

Youngster Galaxy Magnified by Abell 383

Hubble was first to spot this galaxy, one of the youngest in the distant universe. Its stars formed 13.5 billion years ago, a mere 200 million years after the Big Bang. The galaxy’s image is magnified by the gravity of a massive cluster of galaxies (Abell 383) parked in front of it, making it appear eleven times brighter. This phenomenon is called gravitational lensing.

Image Credit: NASA, ESA, J. Richard (Centre for Astronomical Research/Observatory of Lyon, France), and J.-P Kneib (Astrophysical Laboratory of Marseille, France).

Possible expansion/revision on QED theory needed? …

“Observations made with NIST’s Electron Beam Ion Trap indicate that, in ions with a strongly positive charge, electrons can behave in ways inconsistent with quantum electrodynamics (QED) theory, which describes electromagnetism. While more experiments are needed,the data could imply that some aspects of QED theory require revision. ”

…read more

This seemed like a good day to post some rainbow laser modes!

Light in a circular cavity makes a variety of standing wave patterns, some of which look like flowers, wagon wheels, or even tie-fighter spaceships. These images are from my simulations of the light in the cavities of nanolasers - each pattern is called a mode, and the smaller the laser, the simpler the mode tends to be.

In our lasers, the modes that tend to do the best are the whispering gallery modes - for example, the mode at the upper center.  Whispering gallery modes get their name from the whispering gallery phenomenon first noticed with sound waves in cathedral domes. People noticed that if they stood along the perimeter of some cathedral domes, the sound waves from a whisper would bounce along the walls of the dome, and could be clearly heard at certain other places along the dome’s perimeter.  In the case of our lasers, it’s light that bounces around the laser cavity - wavelengths that make an integer number of oscillations in one round trip end up forming a sort of circular standing wave.  Whispering gallery modes appear not just for light and sound, but for other kinds of waves as well, like matter waves and gravitational waves.

Storing electricity in paper

One sheet, 15 centimetres in diameter and a few tenths of a millimetre thick can store as much as 1 F, which is similar to the supercapacitors currently on the market. The material can be recharged hundreds of times and each charge only takes a few seconds.

It’s a dream product in a world where the increased use of renewable energy requires new methods for energy storage – from summer to winter, from a windy day to a calm one, from a sunny day to one with heavy cloud cover.

”Thin films that function as capacitors have existed for some time. What we have done is to produce the material in three dimensions. We can produce thick sheets,” says Xavier Crispin, professor of organic electronics and co-author to the article just published in Advanced Science.

Other co-authors are researchers from KTH Royal Institute of Technology, Innventia, Technical University of Denmark and the University of Kentucky.

The material, power paper, looks and feels like a slightly plasticky paper and the researchers have amused themselves by using one piece to make an origami swan – which gives an indication of its strength.

The structural foundation of the material is nanocellulose, which is cellulose fibres which, using high-pressure water, are broken down into fibres as thin as 20 nm in diameter. With the cellulose fibres in a solution of water, an electrically charged polymer (PEDOT:PSS), also in a water solution, is added. The polymer then forms a thin coating around the fibres.

”The covered fibres are in tangles, where the liquid in the spaces between them functions as an electrolyte,” explains Jesper Edberg, doctoral student, who conducted the experiments together with Abdellah Malti, who recently completed his doctorate.

The new cellulose-polymer material has set a new world record in simultaneous conductivity for ions and electrons, which explains its exceptional capacity for energy storage. It also opens the door to continued development toward even higher capacity. Unlike the batteries and capacitors currently on the market, power paper is produced from simple materials – renewable cellulose and an easily available polymer. It is light in weight, it requires no dangerous chemicals or heavy metals and it is waterproof.

The Power Papers project has been financed by the Knut and Alice Wallenberg Foundation since 2012.

”They leave us to our research, without demanding lengthy reports, and they trust us. We have a lot of pressure on us to deliver, but it’s ok if it takes time, and we’re grateful for that,” says Professor Magnus Berggren, director of the Laboratory of Organic Electronics at Linköping University.

The new power paper is just like regular pulp, which has to be dehydrated when making paper. The challenge is to develop an industrial-scale process for this.

”Together with KTH, Acreo and Innventia we just received SEK 34 million from the Swedish Foundation for Strategic Research to continue our efforts to develop a rational production method, a paper machine for power paper,” says Professor Berggren.

Power paper – Four world records

Highest charge and capacitance in organic electronics, 1 C and 2 F (Coulomb and Farad).

Highest measured current in an organic conductor, 1 A (Ampere).

Highest capacity to simultaneously conduct ions and electrons.

Highest transconductance in a transistor, 1 S (Siemens)

Publication:

An Organic Mixed Ion-Electron Conductor for Power Electronics, Abdellah Malti, Jesper Edberg, Hjalmar Granberg, Zia Ullah Khan, Jens W Andreasen, Xianjie Liu, Dan Zhao, Hao Zhang, Yulong Yao, Joseph W Brill, Isak Engquist, Mats Fahlman, Lars Wågberg, Xavier Crispin and Magnus Berggren.  Advanced Science, DOI 10.1002/advs.201500305

Linköping University

By  NASA

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet Mars is today.

(excerpt - click the link for the complete article and cool video animation)

Curiosity, Sojourner and Opportunity size comparisons to people.

via reddit

Hubble Finds That the Nearest Quasar Is Powered by a Double Black Hole

The finding suggests that quasars—the brilliant cores of active galaxies – may commonly host two central supermassive black holes, which fall into orbit about one another as a result of the merger between two galaxies. Like a pair of whirling skaters, the black-hole duo generates tremendous amounts of energy that makes the core of the host galaxy outshine the glow of its population of billions of stars, which scientists then identify as quasars.

Scientists looked at Hubble archival observations of ultraviolet radiation emitted from the center of Mrk 231 to discover what they describe as “extreme and surprising properties.”

If only one black hole were present in the center of the quasar, the whole accretion disk made of surrounding hot gas would glow in ultraviolet rays. Instead, the ultraviolet glow of the dusty disk abruptly drops off toward the center. This provides observational evidence that the disk has a big donut hole encircling the central black hole. The best explanation for the donut hole in the disk, based on dynamical models, is that the center of the disk is carved out by the action of two black holes orbiting each other. The second, smaller black hole orbits in the inner edge of the accretion disk, and has its own mini-disk with an ultraviolet glow.

Read more ~ NASA.gov

Image: This artistic illustration is of a binary black hole found in the center of the nearest quasar to Earth, Markarian 231.    Credits: NASA, ESA, and G. Bacon (STScI)

Looks like they could kill you but is actually a cinnamon roll: W Boson

Looks like a cinnamon roll but could actually kill you: Photon

Looks like they could kill you and can actually kill you: Z Boson

Looks like a cinnamon roll and is actually a cinnamon roll: Gluon

Spinnamon Roll: Higgs Boson