Insect Eyes Inspire Improved Solar Cells

(PhysOrg.com) — The eyes of moths, which allow them to see well at night, are also covered with a water-repellent, antireflective coating that makes their eyes among the least reflective surfaces in nature and helps them hide from predators in the dark. Mimicking the moth eye’s microstructure, a team of researchers in Japan has created a new film, suitable for mass-production, for covering solar cells that can cut down on the amount of reflected light and help capture more power from the sun.

In a paper appearing in Energy Express, a bi-monthly supplement to Optics Express, the open-access journal published by the Optical Society (OSA), the team describes how this film improves the performance of photovoltaic modules in laboratory and field experiments, and they calculate how the anti-reflection film would improve the yearly performance of solar cells deployed over large areas in either Tokyo, Japan or Phoenix, Ariz.

“Surface reflections are an essential loss for any type of photovoltaic module, and ultimately low reflections are desired,” says Noboru Yamada, a scientist at Nagaoka University of Technology Japan, who led the research with colleagues at Mitsubishi Rayon Co. Ltd. and Tokyo Metropolitan University.

The team chose to look at the effect of deploying this antireflective moth-eye film on solar cells in Phoenix and Tokyo because Phoenix is a “sunbelt” city, with high annual amount of direct sunlight, while Tokyo is well outside the sunbelt region with a high fraction of diffuse solar radiation.

They estimate that the films would improve the annual efficiency of solar cells by 6 percent in Phoenix and by 5 percent in Tokyo.

“People may think this improvement is very small, but the efficiency of photovoltaics is just like fuel consumption rates of road vehicles,” says Yamada. “Every little bit helps.”

Yamada and his colleagues found the inspiration for this new technology a few years ago after they began looking for a broad-wavelength and omnidirectional antireflective structure in nature. The eyes of the moth were the best they found.

The difficulty in making the film, says Yamada, was designing a seamless, high-throughput roll-to-roll process for nanoimprinting the film. This was ultimately solved by Hideki Masuda, one of the authors on the Energy Express paper, and his colleagues at Mitsubishi Rayon Co. Ltd.

The team is now working on improving the durability of the film and optimizing it for many different types of solar cells. They also believe the film could be applied as an anti-reflection coating to windows and computer displays.

More information: Paper: “Characterization of antireflection moth-eye film on crystalline silicon photovoltaic module,” Noboru Yamada, Toshikazu Ijiro, Eiko Okamoto, Kentaro Hayashi, and Hideki Masuda, Optics Express, Vol. 19, Issue S2, pp. A118-A125. Available at: http://www.opticsi … -19-102-A118

 

“Cartoon Physics, part 1″ by Nick Flynn

Children under, say, ten, shouldn’t know
that the universe is ever-expanding,
inexorably pushing into the vacuum, galaxies

swallowed by galaxies, whole

solar systems collapsing, all of it
acted out in silence. At ten we are still learning

the rules of cartoon animation,

that if a man draws a door on a rock
only he can pass through it.
Anyone else who tries

will crash into the rock. Ten-year-olds
should stick with burning houses, car wrecks,
ships going down—earthbound, tangible

disasters, arenas

where they can be heroes. You can run
back into a burning house, sinking ships

have lifeboats, the trucks will come
with their ladders, if you jump

you will be saved. A child

places her hand on the roof of a schoolbus,
& drives across a city of sand. She knows

the exact spot it will skid, at which point
the bridge will give, who will swim to safety
& who will be pulled under by sharks. She will learn

that if a man runs off the edge of a cliff
he will not fall

until he notices his mistake.

 

Fate Of The Universe

Fate of Universe revealed by galactic lens
By Howard Falcon-Lang
Science reporter

The huge galactic cluster known as Abell 1689 acted as a cosmic magnifying glass. A “galactic lens” has revealed that the Universe will probably expand forever.

Astronomers used the way that light from distant stars was distorted by a huge galactic cluster known as Abell 1689 to work out the amount of dark energy in the cosmos.

Understanding the distribution of this force revealed that the likely fate of the Universe was to keep on expanding.

It will eventually become a cold, dead wasteland, researchers say.

The study, conducted by an international team led by Professor Eric Jullo of Nasa’s Jet Propulsion Laboratory in California, is published in the journal Science.

Dark energy makes up three-quarters of our Universe but is totally invisible. We only know it exists because of its effect on the expansion of the Universe.

To work out how dark energy is spread through space, astronomers used the Hubble Space Telescope to observe the way that light from distant stars was distorted around Abell 1689, a nearby cluster of galaxies.

Abell 1689, found in the constellation of Virgo, is one of the biggest galactic clusters known to science.

Light bends around massive galaxy clusters, allowing distant objects to be seen

Because of its huge mass, the cluster acts as a cosmic magnifying glass, causing light to bend around it.

The way in which light is distorted by this cosmic lens depends on three factors: how far away the distant object is; the mass of Abell 1689; and the distribution of dark energy.

The astronomers were able to measure the first two variables using the European Southern Observatory’s Very Large Telescope, enabling them to calculate this crucial third factor.

Cold comfort

Knowing the distribution of dark energy tells astronomers that the Universe will continue to get bigger indefinitely.

Eventually it will become a cold, dead wasteland with a temperature approaching what scientists term “absolute zero”.

My take on the above:

I am shivering already! (not)

> Professor Priyamvada Natarajan of Yale University, a leading cosmologist and
> co-author of this study, said that the findings finally proved “exactly what
> the fate of the Universe will be”.

LOL, At least the fate of the Universe until Vishnu stops exhaling and starts inhaling. :-)

Jagad-anda-nathah means… Jagad-anda means universe. In each universe there is a natha, or the supervisor, or the manager, or the supreme person. Just like for management we are. Similarly, in each universe there is Lord Brahma. He is the supreme creature, manager. So these managers live only to that period when Maha-Visnu exhales. When the nisvasita-kalam. Just like we exhale and inhale, so… But exhaling the all these universes are created, and at His inhale they go into the Maha-Visnu, in the… The coming and going.

Srimad-Bhagavatam 3.25.37 — Bombay, December 6, 1974

> Dark energy is a mysterious force that speeds up the expansion of the
> Universe.

Oooh! So mysterious!  Although Europeans often misinterpreted the Lakota word “Wakan Tanka” as “Great Spirit” it is more properly translated as “Great Mystery”.

“O supreme great one! O Supreme Personality of Godhead! O Supersoul, master of all mystic power! Your pastimes are taking place continuously in these three worlds, but who can estimate where, how and when You are employing Your spiritual energy and performing these innumerable pastimes? No one can understand the mystery of how Your spiritual energy acts.”

SB 10.14.21

 

The Birthday Paradox

Written by Alan Bellows on 09 February 2006

I have never had a very good relationship with Mathematics. I used to think it was me… I thought that perhaps I was just a bit put off by Math’s confident demeanor and superior attitude, and by its tendency to micromanage every tiny detail of my universe. But over time I have come to the realization that I’m not the source of the problem. Math, as it turns out, is out of its bloody mind.

Consider the following example: Assuming for a moment that birthdays are evenly distributed throughout the year, if you’re sitting in a room with forty people in it, what are the chances that two of those people have the same birthday? For simplicity’s sake, we’ll ignore leap years. A reasonable, intelligent person might point out that the odds don’t reach 100% until there are 366 people in the room (the number of days in a year + 1)… and forty is about 11% of 366… so such a person might conclude that the odds of two people in forty sharing a birthday are about 11%. In reality, due to Math’s convoluted reasoning, the odds are about 90%. This phenomenon is known as the Birthday Paradox.

If the set of people is increased to sixty, the odds climb to above 99%. This means that with only sixty people in a room, even though there are 365 possible birthdays, it is almost certain that two people have a birthday on the same day. After making these preposterous assertions, Math then goes on to rationalize its claims by recruiting its bastard offspring: numbers and formulas.

It’s tricky to explain the phenomenon in a way that feels intuitive. You can consider the fact that forty people can be paired up in 780 unique ways, and it follows that there would be a good chance that at least one of those pairs would share a birthday. But that doesn’t really satisfy the question for me, it just feels marginally less screwy. So I did something quite out of character: I crunched the numbers. The values rapidly become unmanageable, but the trend is clear:

# of people	Possible combinations of birthdays	# of those combinations where at least two birthdays fall on the same day	% of combinations where two people have same birthday
1	365	0	0.0%
2	133,225	365	0.2%
3	48,627,125	398,945	0.8%
4	17,748,900,625	290,299,465	1.6%
5	6,478,348,728,125	175,793,709,365	2.7%
6	2,364,597,285,765,625	95,677,479,012,025	4.0%
7	863,078,009,304,453,125	48,535,798,679,910,725	5.6%
8	315,023,473,396,125,390,625	23,417,361,992,539,211,425	7.4%
9	IF YOU PUSH THAT EQUALS BUTTON I WILL MAKE YOU BLEED. SINCERELY, YOUR CALCULATOR. END OF LINE.	5318008	—

Only calculating up to eight people, we see that of the three hundred fifteen quintillion possible combinations of birthdays the group has, 7.4% of cases– or about one in thirteen– result in two of them having the same birthday. As each person is added, the odds do not increase linearly, but rather they curve upwards rapidly. This trend continues up to around twenty-three people, where the curve hits 50% odds, and the rate of increase starts going down. It practically flattens out when fifty-seven people are considered, and the odds rest at about 99%. Though it may not be intuitive, the numbers follow the pattern quite faithfully.

So does this mean that you can walk into a math class of forty students, bet them that at least two people in the room share a birthday, and win 90% of the time? Not exactly. In real life, where Math is not particularly welcome, birthdays are not distributed perfectly throughout the year. More people are born in the springtime, which throws the numbers off. Also, as a result of the way that hospitals operate, more babies are born on Mondays and Tuesdays than on weekends, which further complicates the problem. Depending on the group of people and how evenly distributed their birthdays are, the results can vary widely. But most of the time, you’ll still have some very good odds.

But there is at least one highly practical application for this numerical phenomenon: computer hacking. There is a classic cryptographic computer attack known as the “birthday attack” which exploits the math of the birthday paradox. Using this method, a programmer can store the results of the birthday math in memory to decrease overall processing time when doing certain computationally useful things, such as attempting to crack a digital signature.

Another thing that I discovered in my research is that a one followed by fifty-one zeros is called one sexdecillion. I knew those mathematician guys were hiding something in those big numbers.

As much as Math would like us to think that it is an advocate for structure and intuition, every once in a while it churns up something dastardly and unintuitive like the Birthday Paradox, the Monty Hall problem or Benford’s Law. And we have no choice but to obey these fickle whims of the great control freak. But every once in a while, I like to divide by zero, just to show Math that I’m not powerless to retaliate.

To those who would claim that only a fool would fall prey to the Birthday Paradox, and that the true nature of the odds is perfectly intuitive, I ask this of your Rainman-like grasp of numbers… why is it that all of the totals in this article’s first chart (aside from zero) end in the digit five? That outcome surprised me, but I currently lack the conviction to pursue the matter. I now see that numbers represent all that is soulless and wrong.

Further reading:
Wikipedia article on the Birthday Attack
MathWorld description of the Birthday Problem

 

What is Higgs boson – and will CERN scientists find the ‘God particle’?

From The Christian Science Monitor

Like followers of God, followers of the Higgs boson act on faith. The Higgs boson has never been observed, and some physicists doubt it even exists.

In an attempt to prove the particle’s existence, physicists at the European Organization for Nuclear Research (CERN) rammed protons together today at an energy level of about 7 trillion electron volts at the Large Hadron Collider (LHC), which straddles the border of Switzerland and France.

Type Higgs boson into Google and you get the search option ‘Higgs boson for dummies’ as well as ‘Higgs boson time travel’ and ‘Higgs boson doesn’t want to be found.’

Here’s a run-down about the so-called ‘God particle.’

What is a boson?

A boson is a sub-atomic particle. The atomic particles are protons, neutrons, and electrons. While the Greek word atom means indivisible, modern scientists found atomic particles divisible into sub-atomic particles. These include quarks, leptons, and bosons. They were only hypothesized and observed in the last century.

This is according to the Standard Model of physics, the most accepted universal theory of everything. (The string theory is a strong contender.)

What is the Higgs boson?

But scientists aren’t entirely sure how these subatomic particles gained mass. They speculate that another boson (or bosons), named after scientist Peter Higgs who helped come up with the idea, imparts mass on other bosons and all quarks and leptons.

Observing the Higgs boson would give credence to the Standard Model and help explain the origin of mass and the four forces of nature – (1) electromagnetism, (2) the strong force (which binds atomic nuclei), (3) the weak force (which governs radioactive decay and some fusion reactions), and (4) gravity. Observing the Higgs boson may also unleash a black hole or anti-matter that will annihilate us all, say a few.

What does this have to do with the Large Hadron Collider?

Scientists at CERN hope to observe the Higgs boson.

The LHC accelerates two particle beams, called hadrons, around a 17-mile ring in opposite directions. The goal is to get the two beams to collide at nearly the speed of light. But that’s hard because the beams are so small, and the scientists don’t expect a collision every time.

If a collision does occur, it could create smaller pieces of matter –particles – a scenario similar to that at the beginning of the universe, giving scientists a unique look at the universe’s origins and at particles never before observed. Particles such as the Higgs boson.

Why is the Higgs boson to hard to detect?

The Higgs boson, however, only exists at high energies – and only lasts for fractions of a second, then decays into other particles. Scientists will be looking for trace patterns of decay that indicate the Higgs has made an appearance.

Einstein famously said E = mc2. If CERN scientists can accelerate particles to the speed of light, they will observe the highest recorded energies, which should allow a look at the Higgs boson.

Back in 2001, CERN’s Large Electron Positron (LEP), the precursor to the LHC, found what it believed to be evidence of the elusive particle. Without conclusive data, however, CERN scientists worried the Fermilab collider in the US, just outside Chicago, would observe the particle first. Fermilab got close, but no quantum cigar.

Will the Higgs boson allow time travel?

The Higgs boson itself won’t allow time travel. But the LHC may, say some scientists.

Remember String Theory, the contending grand theory of the universe? It claims that the world is made of tiny vibrating strings. It also claims that there exist 10 dimensions to space time (we currently observe only four: think of a point, a square, a box, and time).

If true, then the LHC may create the high-energy environments that enable particles to jump in and out of these six hidden dimensions.

A recent essay in The New York Times suggests that the Higgs boson itself may be using time travel to prevent itself from being discovered: hence all the delays at Fermilab and CERN.

A pair of otherwise distinguished physicists have suggested that the hypothesized Higgs boson, which physicists hope to produce with the collider, might be so abhorrent to nature that its creation would ripple backward through time and stop the collider before it could make one, like a time traveler who goes back in time to kill his grandfather.

What does this have to do with God?

Leon Lederman, the 1988 Nobel prize winner in physics and former director of Fermilab, coined the phrase “the God particle” for the Higgs boson because it would explain what gives nature’s fundamental particles mass. But Mr. Lederman wasn’t religious. He also famously joked: “Physics isn’t a religion. If it were, we’d have a much easier time raising money.”

When Moses saw God, according to the Bible’s Book of Numbers, his face was radiant for days. Scientists at CERN eagerly await their own sighting of the so-called God particle.

“Imagine a house with a lot of children on Christmas Eve, and you’ve pretty much captured the mood,” Thomas LeCompte told the Monitor in an email exchange from the lab in Geneva.

 

Antikythera Mechanism

The Antikythera mechanism is an ancient mechanical calculator (also described as the first known mechanical computer) designed to calculate astronomical positions. It was recovered in 1901 from the Antikythera wreck, but its complexity and significance were not understood until decades later. It is now thought to have been built about 150 BC. Technological artifacts of similar complexity did not reappear until the 14th century, when mechanical astronomical clocks appeared in Europe.

Professor Michael Edmunds of Cardiff University who led the most recent study of the mechanism said: “This device is just extraordinary, the only thing of its kind. The design is beautiful, the astronomy is exactly right. The way the mechanics are designed just makes your jaw drop. Whoever has done this has done it extremely carefully…in terms of historic and scarcity value, I have to regard this mechanism as being more valuable than the Mona Lisa.”

The device is displayed in the Bronze Collection of the National Archaeological Museum of Athens, accompanied by a reconstruction made and offered to the museum by Derek de Solla Price.

The most recent findings of The Antikythera Mechanism Research Project were
published in the July 30, 2008, edition of Nature.

Read another article here.

As you might expect, some believe it came from ancient India.

 

Purity

http://xkcd.com/435/

 

Why Good Samaritans Should Avoid Virtual Carnage

From Short Sharp Science

by Ewen Callaway, reporter

I was shocked the first time I watched my 12-year old cousin play Grand Theft Auto Vice City, an ultra-violent video game where the protagonist roams around a city, stealing cars and wreaking bodily havoc. I also averted my eyes through much of 300, a visually stunning yet exceedingly gruesome film about the battle of Thermopylae.

So it was with a certain measure of self-interest that I picked up a new paper claiming that watching horror films and playing violent video games makes college students less inclined to help those in need.

Other researchers have documented other negative effects of violent media, but none applied methods quite this… theatrical

Psychologist Brad Bushman, of the University of Michigan, and Craig Anderson, of Iowa State University, staged two scenarios to see whether on-screen violence has a desensitising effect on people.

In the first experiment, 320 students – half men, half women – played either a violent game or a non-violent game. Violent games included Carmageddon, Duke Nukem, and Future Cop. I’ve never heard of any of the non-violent games, but they certainly sounded the part: Glider Pro, 3D Pinball, Austin Powers and Tetra Madness.

After playing the game for 20 minutes, students filled out a survey assessing their experience. At this point, researchers played an audio recording of a simulated fight in the corridor outside.

The transcript of the faux fight tells the story:

First Actor: “You stole her from me. I’m right and you know it, loser.”

Second Actor: “Loser? If I’m a loser, why am I dating your ex-girlfriend?”

First Actor: “OK, that’s it, I don’t have to put up with this shit any longer.”

A chair-flinging tussle ensues, and Second Actor gets pummelled – “It’s my ankle, you bastard. It’s twisted or something.” And to make the ruse more convincing, the researchers kicked on the door a couple times.

Three minutes after the final groan – giving test subjects ample time to offer help – a researcher returned to the testing room and asked if everything was OK. If the volunteer mentioned a fight – only a handful did not – the researcher asked them to rate it on a scale of 1 to 10.

Students who played a violent game took nearly five times longer to help (73 vs 16 seconds), were slightly less likely to mention the mêlée (94 vs 99%), and rated it as less serious (5.9 vs 6.4 out of 10), compared with volunteers who played a non-violent game, the researchers found. The results are published in Psychological Science (DOI: 10.1111/j.1467-9280.2009.02287.x).

Their movie experiment was only slightly less bizarre…

Read complete article here