Scientists Manage to Cloak a Three-dimensional Object

Posted on January 30, 2012 by | 1 comment

Researchers at the University of Texas have managed to cloak a three-dimensional object, essentially rendering the object invisible from all angles. This feat represents a major breakthrough in cloaking research, with previous studies having been either limited to two dimensions, or merely theoretical.

So, does this mean that Harry Potter’s invisibility cloak has become a reality? Not quite. This study was limited to working with waves at microwave frequencies, meaning that waves falling within the visible region of the electromagnetic spectrum would still render the object detectable.

Left: Microwaves being blocked and scattered by object. Right: Microwaves being reconstructed by cloak. (Source: http://www.bbc.co.uk/news/science-environment-16726609)

The researchers employed the use of plasmonic metamaterials—manmade materials with special light-bending properties. These metamaterials interact with light in a way that is opposite to that of ordinary materials. Our ability to see an object relies entirely on the process of light waves striking its surface and then reflecting back into our eyes. In the case of plasmonic metamaterials, waves striking their surface are scattered and reflected in a manner such that a “photo negative” is produced. This, in turn, results in the original waves being cancelled out, and it is this cancellation effect that renders the object invisible.

The process is similar to the way in which noise-cancelling headphones work. The headphones reduce outside noises by receiving them through a microphone, inverting them, and then playing the inverted signal back through the headphones. Since the inverted audio waves are completely out of phase with the audio waves coming from the listener’s environment, the two waves cancel each other out, significantly reducing the sound levels heard.

In essence, this study relates to the effectiveness of plasmonic metamaterials in cloaking real, three-dimensional objects in space. Although this study was limited to microwaves, the researchers hope to eventually extend their studies to work with waves in the visible light spectrum.

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DNA Computing

Posted on January 30, 2012 by | Leave a comment

There are limits to desktop and supercomputers as eventually there will come a point when electronic miniaturization can go no further as components become smaller and more transistors are embedded onto silicon chips. DNA computing is just one of many new computing techniques already in development. Because DNA is so ubiquitous, it is convenient as well; the four constituent bases  of DNA act as “bits” of information comparable to 0 and 1 in binary.

First demonstrated in principle in 1994, DNA techniques were used to solve a Hamiltonian directed-path graph, an important type of problem in mathematics and computer science.  Those who haven’t heard of this problem need only to think back to elementary school, where teachers might have presented a puzzle challenge to draw a continuous set of lines through several points on paper without retracing any lines.  The logic behind this is that any solution attempts are carried out simultaneously, breaking down larger problems into smaller ones, which can then be solved at the same time.

In the initial demonstrations, each point on the was represented as a 20-unit oligonucleotide (a short segment of the DNA molecule), and allowed moves between any two points were represented as 10 unit complements. Whenever a grand total of oligonucleotides was linked to DNA polymerase (an enzyme that copies DNA), then all possible paths were produced.

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Gluten-freedom?

Posted on January 30, 2012 by | 1 comment

   Image: jefferyyw  Image from flicker by jefferyw

     Diet trends come and go. (Anyone remember the Atkins’s diet?) The newest fad that has seemed to appear is the gluten-free lifestyle, claiming to help you lose weight, increase energy, and decrease that bloated feeling. However, there have been increasing cases of gluten sensitivity that have emerged  due to various external factors. So is gluten sensitivity really becoming more common? Or is being gluten-free another diet fad?

Gluten is a protein found in wheat, barley, and rye. It is what gives our breads the texture we love. It gives pizza dough its stretchy consistency. It gives soups and stews viscosity.

However, gluten proves problematic for people with celiac disease, which affects around 1 in 133 Canadians.  Celiac disease is a disorder where a person is not able to digest gluten protein as the body sees it as an invader and attacks it with antibodies and at the same time injuring the small intestine. This damage causes nutrients not be absorbed properly through the villi in the intestine, consequently causing the individual to be malnourished and feel sickly. Other symptoms include fatigue, skin problems, and even depression.

Brown, from the John A. Burns School of Medicine at the University of Hawaii, believes that gluten sensitivity is emerging as a separate condition from celiac disease. The increase in cases of gluten intolerance may involve plant genetic modifications, gluten as a food additive, environmental toxins, and human genetics.

Gluten intolerance is now starting to be seen as a spectrum where at one end is celiac disease, and at the other end is a person who seems to be digesting gluten fine. However, gluten is generally a protein that is not easily digested by humans. Everyone has a limit to the amount of gluten that the body will digest with ease.

People with even just a low level of gluten sensitivity may live a gluten-free lifestyle simply because it makes them feel better. However, switching to gluten-free is not an easy step and requires planning. Although gluten-free foods are now easier to find at your local grocery store, they are not necessarily healthy. Many of these pre-packaged foods are loaded with extra sugar or fat in order to make the food taste better. So skip the gluten-free brownies.  A gluten-free diet is only a healthy one if you consume adequate fruits and vegetables, lean high quality meats, and substitute your usual carbohydrates with rice and grain-like crops like quinoa.

Gluten sensitivity has been found to be more common than it has been previously, especially affecting those with an eastern European background. Along with this increase has been a rising trend in individuals who choose to eat foods without gluten even though they do not need to, and claim to feel much better living that lifestyle. Ultimately,eating gluten-free is not a dangerous fad diet, but  is rather a very healthy lifestyle if done properly.

 

References:

http://www.cbc.ca/news/background/health/gluten-free.html

http://www.expert-reviews.com/doi/abs/10.1586/egh.11.79?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001280/

http://www.cnn.com/2011/HEALTH/04/12/gluten.free.diet.improve/index.html

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First Earth-like planet in habitable zone discovered by NASA Kepler team

Posted on January 30, 2012 by | 3 comments

Earth is one unique planet among the rest of the planets scattering across the universe. It is the only known planet which liquid water is abundant and numerous living organisms inhabit. However, Earth may no longer be as unique as we think it is.

The Kepler mission‘s science team has found a planet that is similar to Earth which locates in the “habitable zone” of its solar system. A habitable zone is a region around a sun where water can maintain its liquid state on a planet with sufficient atmospheric pressure. 600 light years from Earth, Kepler-22b, a planet which orbits in Kepler-22 system, has a radius 2.4 times the radius of Earth and an orbit period about 290 days. Its star, Kepler-22, is slightly smaller and cooler than our Sun. The composition of Kepler-22b is not yet determined by the Kepler Science team. However, judging from the size of Kepler-22b, the team estimated that the composition of Kepler-22b is most likely to be similar to earth composition with abundant amount of water.

(Artist’s concept of Kepler-22b from Kepler: Home Page)

How did Kepler science team find Kepler-22b which is 600 light years from Earth? The science team used Kepler telescope, which can monitors the slight decrease in brightness of stars when a planet orbits across the star. Kepler telescope can detect the change in brightness up to one ten-thousandth difference. Based on the amount of brightness decreased, the team can determine the size of the planet. In order to confirm the change in the brightness of a star is caused by a planet orbiting across the star, the team has to find 3 dips of brightness. These dips are separated with a set period of time to confirm the orbital period of the planet.

Although Kepler-22b is the first confirmed Earth-like planet which orbits in the “habitable zone” of its system, there are total of 48 possible planet candidates that are being observed by the Kepler mission’s science team. There is little doubt that more Earth-like planets will be discovered by the Kepler mission. Perhaps, within these planet candidates, there may be life living on one of these Earth-like planets.

YouTube Preview Image

References:

Media announcement of NASA’s Kepler mission’s science team on December 5th,2011:

https://www.youtube.com/watch?v=en5OObU0ryU

Article of discovery of Kepler from NASA website:

http://www.jpl.nasa.gov/news/news.cfm?release=2011-373

Kepler Mission: Home Page

http://kepler.nasa.gov/

Kelper-22b From NASA Kepler website:

http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=165

Artist’s concept of Kepler-22b

http://kepler.nasa.gov/images/Kepler22bArtwork.jpg

 

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Go exercise!…to be smarter?

Posted on January 23, 2012 by | 11 comments

Image from Men's Health - "How to lace your running shoe"

Want to improve your memory and study more efficiently? Then drop your pen and lace up your sneakers! Recent studies show that exercising not only builds muscles, but it also boosts memory.

Researchers from University of Dublin  investigated the correlation between exercise and memory where they asked group of sedentary students to take part in a simple memory test. After the initial baseline test,  half of the students went through vigorous exercise and the other half just sat quietly. Then both groups took the test again. (specific procedures can be found in Physiology & Behavior Journal). Remarkably,  the exercised students performed significantly better on the memory test scores (compared to their baseline test), while the students who had rested showed no improvement.

Image of BDNF - from Wikipedia provided by Protein Data Bank

Interestingly, the researchers have collected the students’ blood samples throughout the experiment to give a biological explanation to their results. They have found that the students had significantly higher levels of a protein called  brain-derived neurotrophic factor, or BDNF, immediately after the strenuous activity, whereas the student who had sat quietly showed no change in BDNF levels. Thus these finding suggest that increases in BDNF prompted by exercise may play a particular role in improving our ability to memorize and recall on something.

Image of Hippocampus - from Wikipedia by user Looei496

In supporting this idea, other studies also reached similar conclusion even with animals. In one particular experiment from Universidade Federal de Santa Catarina (Federal University of Santa Catarina), Brazil, the researchers made sedentary elderly rats ran for 4-6 minutes, 4-5 days per week for five weeks (specific procedures can be found in Mechanisms of Ageing and Development Journal). This physical activity seemed to ignite some biochemical process in the memory center (hippocampus) of their brains, resulting in increased production of BDNF molecules there. As a result, these exercised elderly rats performed as well as much younger rats on rodent memory tests.

Although more needs to be studied on this topic and BDNF, these studies do indicate that exercising does help in improving memorization. So it would be a good idea to go for a walk or get any sort of physical activity in between study breaks, not only to get some fresh air, but to get some BDNF in our brains to study more efficiently. This may sound a bit bizarre but, we should go exercise to become smarter! It’s just too bad that I cannot make “studying” as an excuse for not getting any exercise anymore.

References:

Aerobic exercise improves hippocampal function and increases BDNF in the serum of yong adult male:
http://www.sciencedirect.com/science/article/pii/S0031938411003088

Brain-derived neurotrophic factor (BDNF) :
http://en.wikipedia.org/wiki/Brain-derived_neurotrophic_factor

Short bouts of mild-intensity physical exercise improve spatial learning and memory in aging rats: Involvement of hippocampal plasticity via AKT, CREB and BDNF signaling:
http://www.sciencedirect.com/science/article/pii/S0047637411001564

Hippocampus:
http://en.wikipedia.org/wiki/Hippocampus

 

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How fireworks produce various colors in the sky?

Posted on January 23, 2012 by | 5 comments

 (Image from Daily Disney by Joe Penniston)

Have you ever wondered how fireworks produce various colors in the sky? It sounds easy to produce; however, there is a lot of physics and chemistry involved in making fireworks. Colors in fireworks are generated by pyrotechnic stars usually just called stars, and the stars generally require an oxidizing agent, fuel, binder (which holds pellets together), and color producing chemicals to produce color effects.

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            Video from YouTube: Basic compositions of fireworks

Color production in fireworks involves two main mechanisms Incandescence, and Luminescence.

Incandescence from fireworks

Incandescence is one of the processes by which fireworks emit light produced from heat.

•The light emitted through Incandescence is produced through extreme heat, which when applied to another chemical compound can cause a bright glow that changes colors (initially emitting infrared, then red, orange, yellow, and white light) as the temperature intensifies.   When the temperature of a firework is controlled, the glow of components, such as charcoal can be manipulated to be the desired color (temperature) at the proper time. Metals, such as aluminum, and titanium, burn very brightly, and are useful for increasing the temperature of the firework.

 Luminescence from Fireworks

Luminescence is light produced using energy sources other than heat.

• Sometimes luminescence is called “cold light”, because it can occur at room temperature and cooler temperatures, thus it is the low temperatures involved in the process of luminescence that gives fireworks cooler shades of light, emitting instead blue, and green.  Luminescence is produced when energy is absorbed by electrons resulting in the electrons going into an unstable state of excitement. As the energy is absorbed by the molecule, the electrons in the atoms rearrange from their lowest energy rate to a higher energy state. When the electron returns to a lower energy state the energy is released in the form of a photon (light). The energy of the photon determines its wavelength or color.

 

Visible light of different wavelengths is detected by our eyes as a range of colors. Of the light that we can see, red has the longest, and violet has the shortest wavelength.

Image from hueconsultingblogspot

 

Color producing compounds (Careful formulation is required)

To make fireworks colorful, various metal salts are added to the basic oxidizing agent fuel.

Image (list of fireworks metal salts) from allsparkfireworks blog

(If you would like to see some colorful fireworks, watch this video.) Thank you

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          Video from YouTube:London Fireworks 2012  presented by BBC.

References:

http://www.pyrouniverse.com/consumer/howtheywork.htm

http://answers.yourdictionary.com/science/how-do-fireworks-work.html

http://www.elmhurst.edu/~ksagarin/color/discussion3-F07.html

http://chemistry.about.com/od/fireworkspyrotechnics/a/fireworkcolors.htm

http://en.wikipedia.org/wiki/Fireworks

http://hueconsulting.blogspot.com/2010/07/how-fireworks-produce-color.html

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2012 will be even longer than you thought

Posted on January 23, 2012 by | 2 comments

This year is special for many reasons.  One reason being that it has an extra day. But did you know that it will actually be 366 days plus one second longer? We have all heard of leap years, but have you heard of the leap second?

Prague Astronomical Clock. Photo from Flickr by simpologist

For about the past 1000 years, the rotation rate of the Earth has been slowing down. This has made our day of 24 hours, or 86 400 seconds, about 0.002 seconds longer.  Over the course of a year, this adds about 1 second.  Therefore, a second (the leap second) is added to the Coordinated Universal Time approximately every year.  This maintains its time within 0.9 seconds of the timescale of the rotation of the Earth, also known as Universal Time.  The rotation of the Earth can vary, which means that the leap second it not added at the same time every year, nor is it added every single year.  The last leap second was added in 2008, the next one will be added June 30th this year.

Controversy

The United Nations Headquarters in Geneva. Photo from Flickr by calistan

Thursday, January 19, 2012, a United Nations meeting was held on international telecommunications.  At this meeting a recommendation was supposed to be made to keep or abolish the leap second.  However, with the delegates not being able to come to a consensus, the subject was put on hold until 2015.

The United States is the main advocate for eliminating the leap second, concerned about the cost and the potential havoc it could wreak.  Satellite navigation systems rely on the precise synchronization of time for communications.  When the leap second is added, these communications could be disrupted. Computer networks could also have a hard time adding an extra second to their clock.  If the second is added inconsistently across the world, potential disasters could occur in air traffic, financial trading markets, and cell phone networks.

On the other hand, countries like Britain, China, and Canada want to keep the leap second.  They argue that in the 40 years that leap seconds have been added, there have been no problems or disasters.  The elimination of the leap second would stop our day from being in sync with the rotation of the Earth and the Sun.  Also, thousands of years from now it could be noon on the clock, but the sun indicates that it is dawn.  The advocates for the leap second propose that the elimination of the leap second could cause even more difficulties.  One hundred or so years down the line, a leap minute may have to be introduced and this could cause more problems than the leap second.

For now, we will continue to introduce the leap second every year or so.  With the rotation of the Earth and Sun always changing we do not know what the future holds.  Will we keep the leap second?  Only time will tell.

References:

http://www.bbc.co.uk/news/science-environment-15563170

http://www.nature.com.ezproxy.library.ubc.ca/news/2011/111108/full/479158a.html

http://www.nytimes.com/2012/01/19/science/to-keep-or-kill-lowly-leap-second-focus-of-world-debate.html?_r=2&ref=science

http://www.nytimes.com/2012/01/20/science/the-leap-seconds-reprieve.html?ref=science

http://iopscience.iop.org.ezproxy.library.ubc.ca/0026-1394/38/6/6/pdf/0026-1394_38_6_6.pdf

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The FUTURE is here! Skin-cell Gun

Posted on January 22, 2012 by | 8 comments

skin-cell-gunThe skin is our body’s first protective barrier from germs and viruses. Every year, thousands of victims from major effects of skin burns survive but some die while waiting for the skin to fully recover.In the past, burns have been treated with skin grafts which take skin sections from uninjured parts of the patient’s body, or grow sheets of skin artificially, and graft them over the burn. During the recovery period, the exposed flesh gives a greater chance for harmful pathogens to invade the human body.

Professor Jorg C. Gerlach and colleagues of the Department of Surgery at the University of Pittsburg’s McGowan Institute for Regenerative Medicine have been working on a way to minimize the healing time for burn victims, so that the chance of infection is reduced. The concept was first introduced shown in 2008. The good news is that they devised a tool to cut recovery time drastically and save lives. This method is called the Skin-Cell Gun.

The Skin-cell Gun is more like an airbrush gun that holds healthy stem cells that were isolated from a burn victim’s healthy part of skin. Using the device, these healthy stem cells are sprayed onto the burned area of a patient’s body. The surprising thing is the next part which is the recovery time. Instead of a burn wound in the past that normally takes weeks or months to heal, the same wound can be cured a lot faster. Dr Gerlach said the device takes only an hour and a half in total.

At the moment the technique can only be used on second-degree burns, but Dr Gerlach hopes it will later be able to tackle third-degree burns as well.

This video contains scenes that some viewers may find disturbing. This clip will also air on National Geographic‘s Explorer: How to Build a Beating Heart. The skin cell gun is a wonderful work!
References:
Spray-on Skin Is a Reality:
“Skin cell gun” regenerates cells in days

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Make your dreams come true… in your dreams

Posted on January 19, 2012 by | 2 comments

The November/December 2011 issue of the Scientific American Mind has an interesting cover story about sleep and dreaming. I was especially intrigued by its article about lucid dreaming.

‘Lucid dreaming‘ is a term coined by the Dutch psychiatrist Frederik Willem van Eeden in 1913. It happens when the dreamer is aware that he or she is dreaming. Most people (8 out of 10) can recall having at least one lucid dream in their life, but sleepers who frequently experience lucid dreaming (once or twice a week) are rare. There are different degrees of lucidity in a lucid dream: from the realization that one is dreaming to having volitional control over the course of the dream.

Benzene molecule

In 2009, Dr. Ursula Voss and her team investigated sleepers’ brain activity using electroencephalography (EGG). The researchers found that the frontal lobes seem to perform very similarly in a lucid dream and in the waking state. On the other hand, the patterns of activity in the parietal and temporal lobes have more resemblance to those of REM (rapid eye movement) sleep. These results allowed them to conclude that lucid dreaming is a hybrid state of consciousness in between waking and REM sleep.

It has been shown experimentally that sleeping can lead to insights. Many scientific discoveries were made based on an insight that happened during a dream, such as Loewi’s theory of chemical neurotransmission, Mendeleyev’s periodic table of chemical elements, and Kekule’s discovery of the structure of benzene. Recent studies have shown that lucid dreams can have practical uses as well. People can learn to increase their chance of having a lucid dream to decrease their frequency of nightmares. Athletes have been found to learn complex motor sequences more quickly after targeted lucid-dream training. Finally, lucid dreams can also boost creativity, such as finding metaphors.

Below is a video with tips on how to increase your likelihood of having a lucid dream.

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A lot more needs to be found about lucid dreaming still, but we can already imagine many other potential applications. Who knows, maybe one day university students will be able to get more sleep while still learning everything they need. But for now, I am just dreaming.

References:

Consciousness in Dreams

How Can You Control Your Dreams?

Unlocking the Lucid Dream

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The God Particle Under the Looking Glass

Posted on January 17, 2012 by | 1 comment

After many decades of searching, CERN– the European Organization for Nuclear Research- may have just caught their first glimpse of the Higgs Boson. Also known as the God Particle for its elusiveness and significance, the Higgs particle is one of the final pieces of the subatomic puzzle that physicists worldwide are trying to solve in order to fully-understand the laws of our Universe.

 YouTube Preview Image CERN’s official statement on the LHC’s recent results and plans of further testing. 13 Dec 2011

But what exactly is this particle, and how has it eluded us for so long? First, The Standard Model of Physics predicts that the origins of mass must come down to a large field- one which surrounds us and pulls on us to supply the known masses in the Universe. In order for such a field to exist, a particle must exist at its core to provide this property, which has been named the Higgs Boson after Dr. Peter Higgs: a theoretical physicist at Edinburgh University. Until December though, most information about this mysterious particle was presented as theory rather than measurable evidence.

It was then that CERN’s Large Hadron Collider (LHC)- the largest particle accelerator in the world- had found signs of a possible Higgs Boson. This was done by colliding two protons at near-light speeds to observe what new matter may be created; this same technique may also discover the sources of dark matter, dark energy, and even the evidence of extra dimensions among other wonders in the Universe. As stated by Sir Martin Rees, the current Astronomer Royal of Britain:

“The LHC will generate, in a microscopic region where beams of particles collide, a concentration of energy that has never been achieved before – a concentration that mimics, in microcosm, the conditions that prevailed in the universe during the first trillionth of a second after the big bang.”

After these protons were destroyed by this massive amount of energy created in the collision, large detectors scoured the site to detect whether any anomalies had occurred. Through these detectors, signal spikes arose in areas where it is deemed likely this Higgs Boson is located; however, there is still an estimated 1% chance that these fluctuations in December were caused by random events. As a result, previous plans to shut down the LHC until 2014 to increase power output have been disregarded, and testing will continue onward well into 2012 to ensure consistently in data. If the accelerator continues to run smoothly, CERN plans to have the God particle isolated by the end of the year. However, this deadline seems rather ambitious considering the LHC’s recent history of shutdowns, including causes from electrical issues, coolant leaks, animal interventions and helium leakages among others since 2008. The magnitude of the discovery further adds to the scepticism that the particle could be isolated so quickly. Nevertheless, the scientific community will wait patiently to hear the results of the world’s largest accelerator.

Dark matter and dark energy will have to wait, it seems.

References

http://www.guardian.co.uk/science/2011/dec/13/higgs-boson-lhc-explained?intcmp=239

http://www.popsci.com/science/article/2011-01/cern-decides-keep-lhc-running-through-2012-hoping-find-elusive-higgs-particle

http://www.popsci.com/science/article/2011-12/tantalizing-glimpse-no-definitive-higgs-sighting-yet-%E2%80%94-wait-2012

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