Star dust! By Lisa Boissy & Laura Malroux

The Pleiades

“My thoughts are stars I cannot fathom into constellations” said John Green in The fault in Our Stars. 

A constellation is a group of stars in the celestial sphere which make up a particular form that humans have named. Scientists and astrologers are fond of watching and studying them because they are spectacular, majestic and magical!  Because they are inaccessible, people find them intriguing. There is a mystery about them that inspires not just scientists but artists too…

The constellations have inspired an innovative art project using light and dance: The Pleiades by the dance company Enra.

The choreographer and dancer Yasuku Mochizuki was inspired by the story of the Pleiades. Orion decided to hunt the Pleiades: seven sisters and their mother. To save their lives, the girls implored the Gods who made them first into doves and then into constellations. In the show, we recognize the story.

Mochizuki uses light in all his shows: Torque Starter, Primitive, etc. Light is the Enra trademark.

Primitive

In The Pleiades, combining elements of dance, performance art, music, technology, light and more, the versatile Japanese troupe has made magic. The show tells us an incredible story. Thanks to the stage’s emptiness and simplicity the spectator is flabbergasted by the dancers’ performances. The two graceful dancers, Saya Watatani and Maki Yokoyami, are perfectly coordinated with the light. Light becomes a partner, a friend. During the show, we are always wondering if it is it the dancer who leads the light or the light which leads the dancer.

It is a really original performance. Different constellations are included and are in perfect harmony with the reality. The stage is plunged into darkness, and the only light source is the constellation. So, we are impressed: we can see all the dance figures because the light follows the dancers. Furthermore, Saya and Maki perform in unison and with the light. Everyone has his own interpretation and his own feelings. There dancers make it spectacular, just like the constellations! There is also curiosity: the spectator wants to see more after each move! In fact, all the emotions can be felt: pleasure, satisfaction, excitement...

Here, the light doesn’t only represent the different constellations of the Pleiades, but also the Northern Lights and water splashing. So light is diverted from its principal function. That’s the major characteristic of art, to make us see things differently. The movements are simple, but perfectly done. It’s a delight to the eyes. Moreover, the chief attraction of this show is surely the fact that the dancers seem to control all this light power and, suddenly, it’s dark and we just see the shining constellations.

Torque Starter

Even the people who are not very interested by constellations learn a lot about them, while being happy to learn. Even those not very fond of dance find it interesting because it shows them a new generation of dancers and performances.

“Wow!” is what everyone says after having seen the show. If you have not seen it yet, go!

Li-Fi. By Paul de la Gravière & Arthur Geneix

Have you ever got frustrated at the slow speed of the Wi-Fi when more than one device is tapped into the network? Have you already tried to use wireless internet in a coffee shop or to steal it from your neighbour? Nowadays, more and more people and their many devices have access to wireless internet; clogged airwaves are going to make it increasingly difficult to latch onto a reliable signal. But many people don’t know that radio waves are just one part of the spectrum that can carry our data. What if we could use other waves to surf the internet and transmit or receive data?

Li-Fi is a technology promised since 2011; Light Fidelity offers the perspective of a replacement, at least partially, of Wi-Fi; with more flow and without the waves feared by many people because of their harmfulness.

What is Li-Fi?

Like Wi-Fi, it’s a method of transmitting data from one point to another wirelessly. Whereas Wi-Fi uses radio waves, Li-Fi uses light to communicate data.

The operation of Li-Fi is quite easy to understand. It works with the transmission of a binary message due to the lighting and the extinction of a light. Therefore, it’s not difficult at all and that’s exactly what we need to end and receive data: light off is equivalent to 0 and light on is equivalent to 1.

In fact, we can say that Li-Fi is a sort of light-based Wi-Fi. The difference between them is that Li-Fi uses light instead of radio waves to transmit information. And instead of Wi-Fi modems, Li-Fi would use transceiver-fitted LED lamps that can light a room as well as transmit and receive information. Moreover, Li-Fi use simple bulbs. That’s the reason why there can be any number of access points.

This new technology uses a part of the electromagnetic spectrum (The Visible Spectrum). Nevertheless, it’s still not greatly utilized. As you know, light is a very important part of our lives and it does not have any major negative effects. It is possible to encode data in the light by varying the rate at which the LEDs flicker on and off to give different strings of 1s and 0s. The LED intensity is modulated very quickly so that human eyes cannot notice. Therefore the output appears constant. It is the fast and cheap Wireless communication system which is an optical version of Wi-Fi.

LEDs:

Light-emitting diodes are the next big thing in the lighting world. Efficient and long-lasting, they’re already replacing filament and halogen lighting.

Working process:

Frequency changes which are very fast are not visible to the human eye. Li-Fi is a system of wireless transmission of data using light as a medium of communication. A Li-Fi router feeds the lighting system. The LED bulb turns on and off at very High speed. An integrated sensor receives data. Photodetector registers a binary ‘1’ for on else its’0’ for off. The operational procedure is very simple, if the LED is on, you transmit a digital 1, if it’s off you transmit a 0. The LEDs can be switched on and off very quickly, which gives nice opportunities for transmitting data. Binary information is made up of strings of 1’s and 0’s. Any light source can transmit this ON and OFF information but LEDs are capable of the highest flickering speed. Light receivers interpret the flickering LED as 1’s and 0’s, and thus we have our Li-Fi.

Light off = 0    Light on = 1

Why is Li-Fi so much faster?

Visible light is far denser than radio waves; 10,000 times denser in fact, meaning much more data can be transferred.

Some figures:

3,4 billion internet users

19 billion global networks connections (mobile and fixed)

The global mobile data traffic will weigh 10,8 Exabytes per month.

A powerful technology:

With Li-Fi, a LED light can transmit multimedia content (video, sound, information, games, etc.) to a tablet or a smartphone.

No interference:

Increased security of communication

Wireless communication at very high speed

Multi-user communication

What’s so special about Li-Fi?

The speed! The highest speed yet recorded with a Li-Fi connection is 10 Gbit/s which is 250 times faster than the average Broadband speed. But commercial Li-Fi being produced in China is at about 150Mbps which is still 10 times higher than the average French connection speed.

Advantages:

New ultra-fast and secure communication network without cable, without radio waves, simply by the light! Also: smart lighting network, wireless, internet access, media access.

Transport:

During your travels, you have access to the Internet. Li-Fi can be used safely on planes because it does not interfere with radio equipment.

Hospitals:

Connections are possible in a place hostile to radio waves.

Traffic:

Allows vehicles (car headlights) to transmit information to secure the traffic and make it more fluid. Measuring distances between vehicles.

Security:

Sending and receiving data via the LED light. Very high speed communication within military vehicles: cars, planes, boats, submarines.

Hazardous environments:

Access your communications in a difficult or dangerous environment: tunnel, factory, petrochemical, refinery, etc.

However, this new technology has some drawbacks :

Presence of light is one of the keys for the good working of Li-Fi.

Fluorescent light and LEDs are optimal to use Li-Fi but these lights possess a low lightning.

Li-Fi & Wi-Fi…

We can say that Wi-Fi is perfect for wireless coverage within buildings; Li-Fi is great for high density wireless data coverage in restricted areas and for abating radio interference problems. To conclude Li-Fi and Wi-Fi can be considered complimentary.

Conclusion

Li-Fi is an amazing technology. It’s also in its early days. It’s hard to predict how a technology will develop over time, but it’s safe to say that a combination of Li-Fi and Wi-Fi will bring the best of both worlds to the internet.

Shady art... By Ines Petit & Liz Gorsen

Light is the opposite of shadow, isn’t it? But Diet Wiegman, an artist from The Netherland, disagrees. This multidisciplinary visual artist uses light to create perfect shadows out of second-hand objects.

                                                                                                      

Wiegman was born on the 24^th January 1944 and grew up in an artistic environment as his father and grandfather were artists too. He studied at the Rotterdam Academy of Arts for four years.

Diet Wiegman in 2012

In his early twenties, he acquired fame as a progressive ceramist because of his truly realistic pieces that could not be distinguished from real objects.

A bulging bag (made of clay) which should go on a "diet"!

Diet Wiegman in 1984, Berlin

           

Because of his work in a multitude of disciplines, he's referred to as an "art omnivore" and launched an art movement which is named after him. His international breakthrough came about because of his ingenious shadow and light sculptures also known as shadow art.

The concept is about illuminating waste objects to create a contrasting image in the form of a highly detailed shadow.

Trashed!

Wiegman was a pioneer. By working with light and shadows for almost forty years, he has inspired a lot of artists through the years.

Deadly night shade...

When people ask him about his work, he simply replies: "I did not invent the phenomenon of shadow; I just make holes in the light!”

Moon(light)walk!

He loves to create art which goes against clichés, laughs at his own seriousness, and makes contradictions in his art. Sometimes it's physical: he destroys his own work to recreate new sculptures made out of the fragments.

Beastly beauty...

You don't need expensive materials to create a beautiful art project... Why not try doing a Wiegman-type work of art yourself?!

Firework displays are an art! By Claire Jourdet & Florine Charachon

People who create firework displays (spending many hours and much money in the process!) give huge performances to the delight of spectators. But, they are not considered artists. And why is a firework display not considered an art form in itself?

Fireworks are a class of explosive pyrotechnic devices used for aesthetic, cultural, and religious purposes. Fireworks competitions are regularly held everywhere. Fireworks take many forms to produce the four primary effects: noise, light, smoke and floating materials (confetti for example.) They may be designed to burn with flames and sparks of many colours, like red, orange, yellow, green, blue, purple, silver and gold.

The earliest documentation of fireworks is dated back to the 7^th century in China, where they were invented. They were used in many festivities. It is a part of the culture of China and many legends include fireworks. Important events and festivities such as the Spring Festival (Chinese New Year) and the Mid-Autumn Festival were and still are times when fireworks are at the heart of celebrations. China is the largest manufacturer and exporter of fireworks in the world.

Fireworks play a key role in the most popular events of our modern world: an obvious example is the Olympic Games. In the opening ceremonies, fireworks are set off across the stadium when an athlete declares the games open. In the closing ceremonies, fireworks appear once again when the Olympic flame is put out. Fireworks are an unforgettable part of the event for hundreds of millions of people. They are artistic masterpieces surely?

Art is a diverse range of human activities and the products of those activities, usually involving imaginative or technical skill. According to this definition, fireworks and firework displays can be described as a real art form, and their creators as artists!

Some critics say fireworks are a way to burn money... But the pyrotechnic display that took place in broad daylight in Doha, Qatar, recently impressed all art lovers: Black Ceremony is the work of Cai Guo-Qiang, a Chinese national based in New York City and the world’s foremost fireworks artist. It kicked off his exhibition at the Arab Museum of Modern Art in the Qatari capital. He showed off his undeniable talent even though a daytime fireworks display might be considered by sceptics as an odd choice. The use of pastel-colours and black smoke made it an original performance. Cai also impressed millions of people with his fireworks display at the opening ceremony of the Beijing Olympics, and with his magnificent 4^th of July fireworks in New York City. And, as the fastest growing economy in the world, spending money on a daytime fireworks exhibit was no gamble for Qatar. Mayassa Bint Hamad al Thani, from the museum, said: “I thought it was spectacular. We are talking about doing a second show!”

Fireworks are at the heart of so many shows, paintings, photographs, and songs (like Katy Perry’s ‘Fireworks’ music video), it is about time firework “entertainers” were recognized as genuine artists!

Optical illusions! By Marion Nairabeze, Maëlle Rivalier & Camille Simonet

Click on this! http://www.michaelbach.de/ot/

First, look at these optical illusions:

 Who do you see? Monroe or Einstein?

Is it Gala or Lincoln?

An old couple or a guitarist and a woman?

What do you see?

In what direction is the train going? Difficult to guess, right?

Second, a short explanation of how vision works for curious people:

Click on this! http://www.acnr.co.uk/pdfs/volume6issue2/v6i2visual.pdf

Optical illusions are misperceptions of form, color, size or movement of objects. They are, for the eye, an altered perception of reality.

The eyes behave more or less like a camera. The eye has a diaphragm, an iris which lets in more or less light as it opens or closes. Behind the iris, a deformable lens, called the crystalline, allows the images to be formed on a sensitive membrane: the retina

The retina consists of rods and cones. Cones allow diurnal vision (color). There are three types of cones, receptive to red, green, blue. Rods allow night vision.

Under the influence of the light that enters through the iris, the rods and cones produce small amounts of energy and nerve impulses which are passed on up to the brain by the optical nerve. The brain then analyzes the information.

Optical illusions are errors of interpretation of our brain which tries to give meaning to all the information which is received even if there is none. This results in amplification of contrasts, creating contours, colors, perspectives, reliefs, etc.

Third, an explanation of an illusion:

1) Primary or geometric illusions

These illusions occur when the eye stops only on certain parts of the image (angles, symmetry axes, breaks lines). Then, these areas become more important than others, such as in the Titchener illusion.

2) Effect of angles

We underestimate obtuse angles and overestimate sharp corners because the eye has a tendency to bring the angles to a right angle. In a Zöllner illusion, the lines appear to us deformed because of small lines which are on the big ones. The oblique lines do not seem parallel though they actually are.

The same goes for the Müller-Lyer illusion. The eye does not pay attention to segments but sees first the angles at their end. It appears that one is larger than the other.

 3) Movement  illusion

It turns! It will make us dizzy. Don’t be afraid, you are not hallucinating, you are suffering from an movement illusion. The human eye gets tired fast when it stares at an object for a long time. If, however, we look next to the object, it avoids staring too intensely and the image strikes other segments of the retina which have their full capacity.

4) Artistic illusions

There are three types of artistic illusions. A group that shows illusion drawings gives rise to visual interpretations that are very different from the properties of the elements shown.

Our brain is used to seeing a real head. But here, the head consists of many animals: an elephant, a kangaroo, a bear... So the brain has trouble analyzing this image.

In the following picture we see a tree and the sea, but aren’t they something else? A baby, no?

Each drawing may result in at least two visual mutually exclusive interpretations. The observer can normally voluntarily move from one interpretation to another, once the different interpretations have been identified and given us some clues about the different interpretations.

This cartoon, created by Willian Hill in 1915, is entitled "My mother / My young woman." The image has two possible interpretations: you see the young woman or the old witch. It is sometimes difficult to switch from one to the other!

Impossible groups: different parts of each of the drawings give rise to conflicting interpretations. All items in this category cannot exist, or it would be highly unlikely that they exist in reality.

The Penrose triangle is an impossible object designed by the mathematician Roger Penrose in the 1950s. By the paradox between logic and reality, which extends to other spheres (cultural impossibility), impossible objects thus give rise to mathematical curiosities and artistic inspirations.

Optical illusions and cultures

"The influence of the culture and  of the environment on our visual perception ", this theory was explored for the first time by Robert Laws, a Scottish missionary, working at Malawi in Africa during the 19th century.

Look at this picture:

What do you see? What is the woman carrying on her head? When researchers put this question to African people, they answered “a box”. Then they asked “where does the scene take place?” This person with a culture with few “corners” naturally said that the family was sitting under a tree. We westerners, accustomed to comfort, see a scene which takes place in a room with a window with a view outside.

Finally, optical illusions show that our vision is always a matter of personal interpretation!

If you enjoyed our article, please send us a comment!

Aurora Borealis. By Matthieu Hollaender & Pierre Caillet

Igor is small. He is a member of an Inuit community. One evening, he was playing by himself not far from the family home. Suddenly he rushed home to talk to his grandfather.

“Grandpa, I think the Gods are sending us a message!”

“What are you saying my little boy? What did you see?”

“I saw a big spot of color spreading in the sky! What was it grandpa?

“Come and sit beside me, next to the fire, I'll tell you the story of this mystery. You are now old enough to understand.”

They huddle together under the caribou skin.

“There are a lot of stories about this extraordinary thing you have seen; each country has its explanation, different from ours, but they are all wrong! Look at our neighbors, they are real poets! They think that a fox wanders through the Arctic snow and lights up the sky thanks to its tail sowing sparks of snow, giving off colors. And the fishermen of the Ice Lakes believe that it is the reflection of herring scales on the water! For the Inuit from the south of Alaska, those of the Yukon River, this special light in the sky simply represents the souls of deer, salmon, seal or beluga dancing. But this light also represents a threat. That is why they hunt it with their knives. To discourage their children from playing outside too late, their parents tell them that this special light will catch them, cut off their heads and play soccer with their heads! Of course it’s not true, don’t worry, it’s a silly superstition!”

“So, what’s the real reason, Grandad?”

“As you know, the sun is guarded by the God Odor and the moon is protected by Elanore. They fight each other because they both want to rule the world. That is why there is a period of darkness followed by a period of light. We have been in darkness for 4 months now. It’s the same every year. It’s because of a trick played by Elanore on Odor. She hides Odor’s light. The colored spots that you saw are stardust from Odor’s torch; he is looking in all the nooks and crannies for his sun. These spots do not last forever in the sky because the sun god is careful not to get caught by Elanore. That is why it changes place quite very often.”

“I am going out to help Odor find his sun, Grandad!”

“Oh, no you're not! You go to bed now. You can help him tomorrow find his sun…”

Igor went to bed, and he dreamt of stars...

A heated debate on the nature of fire... By Simon Amado, Joachim Huon De Kermadec & Hugo Madebène