Astronomy and Physics News - University of Sharjahscass.sharjah.ac.ae/en/Documents/Astronomy_Physics_News_Vol_4... · Astronomy and Physics News ... Light-gathering macromolecules

The field of metamaterials has produced structures with unprecedented abilities, including flat lenses, invisibility cloaks and even optical "metatronic" devices that can manipulate light in the way elec-tronic circuitry manipulates the flow of electrons. Now, the birthplace of the digital computer, ENI-AC, is using this technology in the rebirth of analog computing. A study by researchers at the University of Pennsylvania, The University of Texas at Austin and University of Sannio in Italy, shows that met-amaterials can be designed to do "photonic calcu-lus" as a light wave goes through them. A light wave, when described in terms of space and time, has a profile in space that can be thought of as a curve on a Cartesian plane. The researchers' theo-retical material can perform a specific mathematical operation on that wave's profile, such as finding its first or second derivative, as the light wave passes through the material. Essentially, shining a light wave on one side of such a material would result in that wave profile's deriva-tive exiting the other side. Metamaterials capable of other calculus operations, such as integration and convolution, could also be produced.

Researchers lay out theory for metamaterials that act as an analog

computer

An enormous sunspot, labeled

AR1944, slipped into view over

the sun's left horizon late on Jan.

1, 2014. The sunspot steadily

moved toward the right, along

with the rotation of the sun, and

now sits almost dead center, as

seen in the image above from

NASA's Solar Dynamics Observa-

tory.

Sunspots are dark areas on the

sun's surface that contain complex

arrangements of strong magnetic

fields that are constantly shifting.

The largest dark spot in this

configuration is approximately

two Earths wide, and the entire

sunspot group is some seven

Earths across.

For comparison, another giant

sunspot, five to six Earths

across, is shown below from

2005. The image was captured by

the European Space Agency and

NASA's Solar and Heliospheric

Observatory.

Sunspots are part of what's

known as active regions,

which also include regions of

the sun's atmosphere, the

corona, hovering above the

sunspots.

Active regions can be the

source of some of the sun's

great explosions: solar flares

that send out giant bursts of

light and radiation due to the

release of magnetic energy,

or coronal ...Read more...

NASA's SDO Sees Giant January Sunspots

Department of Physics—United Arab Emirates University Jan. 11, 2014 Volume 4, Issue 2

Credit: NASA

Viewing and manipulating this type of light wave

"profile" is an everyday occurrence for applications

like image processing, though it is typically done

after the light wave has been converted to electronic

signals in the form of digital information. The re-

searchers' proposed computational ...Read more...

A study by researchers at the University of Pennsylvania, The Univer-

sity of Texas at Austin and University of Sannio in Italy, shows that

metamaterials can be designed to do "photonic calculus" as a light wave

goes through them. A light wave, when described in terms of space and

time, has a profile that can be thought of as a curve on a Cartesian

plane. The researchers' theoretical material can perform a specific

mathematical operation on that wave's profile as the light wave passes

through the material. Working like an analog computer, the theoretical

metamaterial illustrated here produces the derivative of the incoming

wave's profile. Credit: Alexandre Silva, University of Pennsylvania

Weekly news from around the world compiled by Dr. Ilias Fernini

Astronomy and Physics News

Researchers lay out theory for metamaterials that act as an analog computer

1

NASA's SDO Sees Giant January Sunspots

1

Quantum mechanics explains efficiency of photosynthesis

2

CeCoIn5 reveals new secrets about how superconductivity and mag-netism can be related

2

Millisecond Pulsar Discovered In Rare Triple Star System

2

Researchers use sound waves to levitate objects in three dimensions

3

Stopping molecules with a centri-fuge

3

Chandra’s Verdict on the Demise

of a Star: “Death by Black Hole”

3

Kilimanjaro at Night 4

Engineers create light-activated

'curtains'

4

Inside this issue:

Light-gathering macromolecules in plant cells

transfer energy by taking advantage of molec-

ular vibrations whose physical descriptions

have no equivalents in classical physics, ac-

cording to the first unambiguous theoretical

evidence of quantum effects in photosynthe-

sis published today in the journal Nature

Communications.

The majority of light-gathering macromole-

cules are composed of chromophores

(responsible for the color of molecules) at-

tached to proteins, which carry out the first

step of photosynthesis, capturing sunlight and

transferring the associated energy highly effi-

ciently. Previous experiments suggest that

energy is transferred in a wave-like manner,

exploiting quantum phenomena, but crucially,

a non-classical explanation could not be con-

clusively proved as the phenomena identified

could equally be described using classical

physics.

Often, to observe or exploit quantum me-

chanical phenomena systems need to be

cooled to very low temperatures. This howev-

er does not seem to be the case in some bio-

logical systems, which display quantum prop-

erties even at ambient temperatures.

Now, a team at UCL have attempted to iden-

tify features in these biological systems which

can only be predicted by quantum physics,

and for which no classical analogues exist.

We found that the properties of some of the

chromophore vibrations that ..Read more...

tional interactions. “This is a truly remarkable system with three degenerate objects. It has survived three phases of mass transfer and a supernova explo-sion, and yet it remained dynami-cally stable”, says Thomas Tauris, first author of the present study. “Pulsars have previously been found with planets and in recent years a number of peculiar binary pulsars were discovered which seem to require a triple system origin. But this new millisecond

If you’re looking for something truly unique, then check out the cosmic menage aux trois ferreted out by a team of international astronomers using the Green Bank Telescope (GBT). This unusual group located in the constellation of Taurus includes a pulsar which is orbited by a pair of white dwarf stars. It’s the first time researchers have identified a triple star system containing a pulsar and the team has already employed the clock-like precision of the pulsar’s beat to observe the effects of gravita-

pulsar is the first to be detected with two white dwarfs.” This wasn’t just a chance discovery. The observations of 4,200 light year distant J0337+1715 came from an intensive study program involving several of the world’s largest radio telescopes including the GBT, the Arecibo radio tele-scope in Puerto Rico, and AS-TRON’s ...Read more...

Quantum mechanics explains efficiency of photosynthesis

Page 2 Volume 4, I ssue 2

Millisecond Pulsar Discovered In Rare Triple Star System

CeCoIn5 reveals new secrets about how superconductivity and magnetism can be related

Superconducting materials exhibit unex-

pected behaviors when subjected to magnetic

fields or high pressures –discoveries that have

implications for controlling electrons in those

special materials. According to two studies,

one conducted at the Paul Scherrer Institute

in Switzerland with collaborators at Los Ala-

mos National Laboratory and a second at Los

Alamos in collaboration with the Sungkyunk-

wan University in South Korea, the supercon-

ducting material Cerium-Colbalt-Indium5

reveals new secrets about how superconduc-

tivity and magnetism can be related.

Superconductivity and magnetism are nor-

mally seen as rivals – superconducting and

magnetic electrons order themselves in very

An illustration of the triple millisecond pulsar

with its two white dwarf companions. Accord-

ing to the new model, this remarkable system

has survived three phases of mass transfer and

a supernova explosion, and yet it remained

dynamically stable. Credit: Thomas Tauris

Clover leaf. Image: Scott Robinson

different ways. Like spinning tops, electrons

in superconductors form pairs of tops, one

spinning counterclockwise and one spinning

clockwise. Together, these pairs move freely

to conduct electrical current with zero re-

sistance. Magnetic electrons, in contrast, lock

themselves into a rigid arrangement that does

not move. Two papers recently published in

the journal Nature Physics show that elec-

trons in Cerium-Colbalt-Indium5 are both

superconducting and magnetic at the same

time.

In an experiment conducted at the Paul

Scherrer Institute, researchers observed an

entirely new form of ...Read more...

Simon Gerber, first author of the publication on the

superconducting properties of CeCoIn5 at the Morpheus

instrument of the Spallation Neutron Source SINQ in

Switzerland. Credit: Paul Scherrer Institute/Markus

Fischer

Researchers use sound waves to levitate objects in three dimensions

A trio of researchers with the

University of Tokyo in Japan has

expanded the science of sound

wave levitation by adding more

speakers and controlling the focal

point of the waves that are creat-

ed. In so doing, as they describe in

their paper they've uploaded to the

preprint server arXiv, they have

created a means for levitating and

moving objects in three dimen-

sional space.

Scientists have come up with sev-

eral ways to levitate objects—

using compressed air, or magnet-

ics, are just two examples—most

such efforts have left a lot to be

desired, however, when the goal

has been clean (no noise, simple

ways to move an object, etc.) levi-

tation. That has led researches to

investigate using ultrasonic waves.

Up till now, researchers have been

able to use the energy of sound

waves to push an object from a

surface up into the air, and then to

hold it there. Because the object

isn't moved in any other direction,

this type of levitation is considered

two dimensional. In this new ef-

fort, the research team has taken

the idea further by adding more

speakers and a control mecha-

nism that allows for moving

the focal point of the sound

waves generated. Objects are cap-

tured in the focal point and are

then moved around by caus-

ing the focal point to be

moved.

In their experiments, the

researchers first levitated

and moved around very tiny

Styrofoam balls. They

demonstrated an ability to

move the balls at will in

virtually any direction—in

tandem. Subsequent tests re-

vealed that their apparatus was

capable of levitating and moving

tiny electric parts, a piece of

wood and a metal nut. The nut

was perhaps most impressive as

it represented a ...Read more...

molecules is the deceleration of molecular

beams. This has been achieved so far only in

the pulsed mode, with a very low duty cycle.

Thus the hitherto-implemented techniques

cannot make use of the intrinsically high flux

delivered by the available continuous molecular

sources. To utilize the full potential of such

sources, a continuous deceleration is warranted.

Towards this end, a team of scientists in the

Quantum Dynamics Division of Professor Ger-

hard Rempe at the Max-Planck-Institute of

Quantum Optics has now developed a versa-

tile deceleration technique ...Read more...

Does the electron possess an electric dipole

moment? Will it be possible to achieve per-

fect control over chemical reactions between

polyatomic molecules, or can one envisage

quantum simulations and quantum compu-

tation with cold polar molecules? The fast-

growing investigation of cold polar mole-

cules holds promise for delivering answers

to these long-standing questions that con-

cern fundamental physics as well as future

applications. Producing abundant samples of

cold polyatomic molecules from thermal

ensembles, however, is a formidable chal-

lenge. A key method for obtaining cold

hole at the heart of a dwarf galaxy

“in the act”.

The results span observations

carried out by the space-based

Chandra X-ray observatory over a

period spanning 1999 to 2005. The

search is part of an archival study

of observations, and revealed no

further outbursts after 2005.

“We can’t see the star being torn

apart by the black hole, but we can

track what happens to the star’s

remains,” said University of Ala-

bama’s Peter Maksym in a re-

cent press release. A comparison

of with similar events seen in larg-

This week, astronomers an-

nounced the detection of a rare

event, a star being torn to shreds

by a massive black hole in the

heart of a distant dwarf galaxy.

The evidence was presented

Wednesday January 8th at the

ongoing 223rd meeting of the

American Astronomical Society

being held this week in Washing-

ton D.C.

Although other instances of the

death of stars at the hands of black

holes have been witnessed before,

Chandra may have been the first

to document an intermediate black

er galaxies backs up the ruling of

“death by black hole.” A compet-

ing team led by Davide Donato also

looked at archival data from Chan-

dra and the Extreme Ultraviolet

Explorer (EUVE), along with sup-

plementary observations from the

Canada-France-Hawaii Telescope

to determine the brightness of the

host galaxy, and gained similar

results.

The dwarf galaxy in the Abell 1795

cluster that was observed has the

name WINGS J134849.88+

263557.5, or WINGS J1348 for

short. The Abell ...Read more...

Page 3 Volume 4, I ssue 2

Stopping molecules with a centrifuge

Fig. left: Photo of the 'centrifuge' / Fig. right: On a fast

rotating disc, an electric quadrupole guide forces the molecules

to move towards the rotation axis. As the molecules have to

fight against the centrifugal force on their way, they lose

kinetic energy and are slowed down to almost a complete

halt. Credit: MPQ, Quantum Dynamics Division.

Chandra’s Verdict on the Demise of a Star: “Death by Black Hole”

(left) Levitation and manipulation of particles. (right) Scooping up and holding particles. Credit: arXiv:1312.4006 [physics.class-ph]

A composite x-ray and optical image of a dwarf

galaxy showing the x-ray transcient in the inset.

Credit-CFHT (Optical), NASA/CXC/

University of Alabama/GSCF/UMD/W.P.

Maksym, D.Donato et al.

College of Science - United Arab Emirates University

POB 15551

Al-Ain

United Arab Emirates

http://fos.uaeu.ac.ae/department/physics

nal Nature Communications. They were able to tweak the size and chirality – referring to the left or right direction of twist – of the nanotubes to make the material react to dif-ferent wavelengths of light. The swaths of material they created, dubbed "smart cur-tains," could bend or straighten in response to the flick of a light switch.

"We envision these in future smart, energy-efficient buildings," said Javey. "Curtains made of this material could automatically open or close during the day."

Other potential applications include light-driven motors and robotics that move toward or away from light, the researchers said. Read more….

Forget remote-controlled curtains. A new development by researchers at the Universi-ty of California, Berkeley, could lead to curtains and other materials that move in response to light, no batteries needed.

A research team led by Ali Javey, associate professor of electrical engineering and com-puter sciences, layered carbon nanotubes – atom-thick rolls of carbon – onto a plastic polycarbonate membrane to create a materi-al that moves quickly in response to light. Within fractions of a second, the nanotubes absorb light, convert it into heat and trans-fer the heat to the polycarbonate mem-brane's surface. The plastic expands in re-sponse to the heat, while the nanotube layer does not, causing the two-layered material to bend.

"The advantages of this new class of photo-reactive actuator is that it is very easy to make, and it is very sensitive to low-intensity light," said Javey, who is also a faculty scientist at the Lawrence Berkeley National Lab. "The light from a flashlight is enough to generate a response."

The researchers described their experiments in a paper published this week in the jour-

Engineers create light-activated 'curtains'

Phone: 00-971-3-7136336

Fax: 00-971-3-767-1291

E-mail: [email protected]

Physics Department

At the break of dawn the southern Milky Way is photographed over Mount Kilimanjaro, as

seen from Amboseli National Park, Kenya. The Great Carina Nebula is the red cloud at

top. Constellation Crux or the Southern Cross appear on the left. On the Earth is the

second peak of Mount Kilimanjaro reaching 5149 m high, known as Mawenzi (meaning

the moon in Swahili). Credit and copyright: Babak A. Tafreshi. Read more...