{"id":13142,"date":"2022-05-16T16:47:19","date_gmt":"2022-05-16T20:47:19","guid":{"rendered":"https:\/\/cap.ca\/?page_id=13142\/"},"modified":"2024-11-06T14:36:16","modified_gmt":"2024-11-06T19:36:16","slug":"lart-de-la-physique-2018","status":"publish","type":"page","link":"https:\/\/cap.ca\/fr\/lart-de-physique\/lart-de-la-physique-2018\/","title":{"rendered":"L\u2019Art de la physique – 2018"},"content":{"rendered":"

Note : Nous avons le regret d’annoncer que nous avons suspendu le concours L’art de la physique pour une dur\u00e9e ind\u00e9termin\u00e9e. Le dernier concours a eu lieu en 2019.<\/p><\/blockquote>\n

[vc_row][vc_column][vc_column_text]L’Association canadienne des physiciens et physiciennes a lanc\u00e9 son premier concours, l’Art de la physique, lors de leur congr\u00e8s annuel de 1992, \u00e0 Windsor, Ontario. Ce concours cherche \u00e0 int\u00e9resser les gens, sp\u00e9cialement les profanes, \u00e0 la fascinante imagerie de la physique.<\/p>\n

Concours l\u2019Art de la Physique 2019<\/a>[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_separator][\/vc_column][\/vc_row][vc_row][vc_column][vc_custom_heading text=”2018 gagnants” font_container=”tag:h3|text_align:left” use_theme_fonts=”yes” link=”url:https%3A%2F%2Fcap.ca%2Fprograms%2Fart-physics%2Fpast-winners%2F|||”][vc_tta_pageable no_fill_content_area=”1″ autoplay=”5″ active_section=”1″ pagination_color=”black”][vc_tta_section title=”Section 1″ tab_id=”1489419557222-62d1dbfb-db45″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10507″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Total Internal Reflection and Colour Theory<\/h4>\n

When light is coming from a dense medium strikes the surface, part of the light will be reflected, and part will be refracted. The normal line perpendicular to the surface, reflects light coming off at an angle equal to that at which it entered, while the angle for the refracted light is larger than the incident angle. Thus, increasing the angle of incidence, will eventually reach a point where the refracted angle is 90o<\/sup>, light will appear to emerge along the surface between media. If the angle is increased further, it will cause the light to totally internally reflect (TIR), where 100% of the light gets reflected into the denser medium and cannot leave.<\/p>\n

Eduard Radut<\/strong>
\nVictoria Park Collegiate Institute
\nNorth York, ON
\n2018 Art of Physics Competition<\/strong>
\nHigh School\/CEGEP Individual Category, First Place<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section 2″ tab_id=”1489419557296-c2fa5c83-5b40″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10506″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Glucom\u00e8tre en lumi\u00e8re polaris\u00e9e<\/h4>\n

Lorsqu\u2019on observe certains affichages \u00e0 cristaux liquides (ACL) avec des lunettes de soleil polarisantes, on peut parfois observer des patrons color\u00e9s. Les ACL classiques sont constitu\u00e9s d’une fine couche de cristaux liquides entre deux filtres polarisants crois\u00e9s. Quand les cristaux subissent une tension \u00e9lectrique dans l\u2019axe de vision, ils ne polarisent plus la lumi\u00e8re, alors les filtres crois\u00e9s bloquent la lumi\u00e8re et produisent donc une zone sombre. Par contre, sans cette tension, les cristaux se placent en h\u00e9lice, deviennent bir\u00e9fringents et permettent le passage de la lumi\u00e8re entre les deux filtres. Ceci est per\u00e7u dans les secteurs gris p\u00e2le \u00e0 c\u00f4t\u00e9 des caract\u00e8res ou sur tout l\u2019\u00e9cran quand l\u2019appareil n\u2019est pas en fonction. En photographiant l\u2019ACL de ce glucom\u00e8tre avec un filtre polarisant sur l’objectif, on se trouve en fait \u00e0 observer la photo\u00e9lasticit\u00e9 de la petite plaque protectrice de plastique qui recouvre l\u2019\u00e9cran. Cette plaque se retrouve entre deux polariseurs qui permettent de visualiser le stress m\u00e9canique qu\u2019elle subit. Ce stress change les propri\u00e9t\u00e9s r\u00e9fractives et de polarisation de la plaque, d\u2019o\u00f9 cet arc-en-ciel. Ce ph\u00e9nom\u00e8ne est la raison principale derri\u00e8re l\u2019interdiction pour les pilotes d\u2019avion de porter des lunettes polarisantes.<\/p>\n

Richard Germain<\/strong>
\nPointe-des-Cascades (QC)
\nConcours L’Art de la Physique 2018<\/strong>
\nCat\u00e9gorie Ouvert \u00e0 tous, Mention honorable<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1491576811417-af1b6697-0ea1″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10498″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Trails of Light<\/h4>\n

This is a picture of a tram taken on a rainy night in Vienna during my spring break vacation. It encapsulates how light is captured by a camera over a five-second exposure. There are several streaks of colored light that were created by the tram\u2019s sidelights and brake lights, along with the reflection of the streetlight above. In addition, each source of light is reflected by the wet pavement creating slightly distorted reflections. In this photo, one can also see how long exposure is able to blur out the body of the tram as photons from different positions reach the camera during the five-second interval. As the sensor of the camera is more sensitive to brighter light, the dark body of the tram appears transparent, while the light trails stay solid. This photo showcases both the physics concept of reflection and refraction while also demonstrating the movement of light photons over a period of time.<\/p>\n

Edwin Tang<\/strong>
\nVancouver, BC
\n2018 Art of Physics Competition<\/strong>
\nHigh School\/CEGEP Individual Category, Third Place<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1491576893106-e4fca1ae-612b”][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10497″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Lightning Patterns on Wood<\/h4>\n

This photograph shows a Lichtenburg Figure forming on a piece of wood. This repeating pattern is usually seen in lightening and electric sparks. In this photo, a baking soda and water solution was applied onto the surface of a piece of wood. Two iron nails were hammered into opposite ends of the wood, and connected to a high voltage microwave oven transformer. When the transformer was switched on, electricity passed between the nails via the baking soda solution. This was possible because the ions in the baking soda dissociated in the water, allowing the solution to conduct electricity. Although wood is generally an insulator, the high voltage caused it to experience an electrical breakdown, allowing for current to flow through the surface of the wood. This sudden flow of electricity, known as an electrical discharge, caused the wood to heat up and to burn, since electricity passing through resistance generates heat. Once the wood started to burn, carbonized tree-like paths were created, which spread out and moved towards the opposite iron nail. The bright orange lines in the photo are paths of conduction for the electricity. The final result was a magnificent fractal pattern, known as Lichtenburg Figure.<\/p>\n

Ching Ho Leung<\/strong>
\nMarkville Secondary School
\nMarkham, ON
\n2018 Art of Physics Competition<\/strong>
\nHigh School\/CEGEP Individual Category, Second Place<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1491576954216-1ddbcb1c-a0f1″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10499″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

The Magnetic Pick-pocketing of Electricity<\/h4>\n

The picture depicts two identical plasma balls which are turned on. The globe on the left is unaltered whereas the globe on the right has a powerful neodymium magnet on top of its mechanical switch. As we can see, the magnet has caused the plasma ball to lose its intensity and also cause a change in colour of the discharge currents. The change can be attributed to the interaction between a magnetic field and an electrical current. The current in the plasma ball induces a magnetic field due to electromagnetic induction which interacts with the magnetic field of the neodymium magnet. The two magnetic fields are either the same or opposite polarity which results in the flow of electrons being attracted to, or repelled by the magnet. As the neodymium magnet has a much stronger magnetic field than the current, the majority of the current falls off the circuit, thus only a fraction of the current is able to be discharged into the globe. Lastly, the plasma filament changes colour as it does not have enough energy to completely ionize the noble gas, resulting in a low energy\/different colour discharge.<\/p>\n

Prabhav Desai<\/strong>
\nSir Winston Churchill H.S.
\nCalgary, AB
\n2018 Art of Physics Competition<\/strong>
\n High School\/CEGEP Individual Category,\u00a0Honourable Mention<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1491577057478-86d535ca-46b8″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10501″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Nature’s Snow Globe<\/h4>\n

This is a picture of a soap bubble experiencing the extremely cold weather in Toronto. The very low temperature causes crystals to form on the soapy film of the bubble and expand until the bubble itself is frozen. As the crystals grow and spread across the surface, they swirl across the soapy film, making it look like a snow globe! This phenomenon is caused by the imbalance in thermal energy across the soapy film. The process starts at the bottom of the bubble, where the soapy film goes through a rapid phase change from liquid to solid, creating the crystals that we see in the picture. The phase change releases latent heat which remains at the bottom of the bubble since the film is too thin for the heat to travel elsewhere. Due to this event, the liquid at the base of the bubble is warmer than the liquid at the top, creating currents with the soapy film. As a result of the Marangoni effect, liquid flows from warm to cold to transfer thermal energy. The crystals are dragged away from the bottom of the bubble and are carried along the currents, creating the snow globe effect.<\/p>\n

Faizah Islam<\/strong>
\nVictoria Park Collegiate Institute
\nToronto, ON
\n2018 Art of Physics Competition<\/strong>
\nHigh School\/C\u00c9GEP Class Project Category, 1st Place<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1491577107742-521b7d35-2e29″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10503″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Aile de Lycaenidae Polyommatinae Thersite<\/h4>\n

Certains papillons utilisent des techniques autres que la pigmentation pour obtenir les couleurs que nous voyons, soit l\u2019iridescence. Sur la photo, nous pouvons observer que les ailes sont recouvertes de petites \u00e9cailles stri\u00e9es de plis et enchevauch\u00e9es comme des ardoises. Leur configuration structurelle peut uniquement renvoyer certaines longueurs d\u2019onde dans une direction donn\u00e9e, on obtient alors une couleur structurelle.\u00a0 Des interf\u00e9rences se produisent gr\u00e2ce \u00e0 un empilement de couches nanom\u00e9triques, alternant chitine et air, produisant des r\u00e9flexions multiples. Ceci permet la superposition de certaines longueurs d\u2019onde en renfor\u00e7ant leur amplitude et pour d\u2019autres longueurs d\u2019ondes, en s\u2019opposant, elles finissent par s’annuler et dispara\u00eetre. L’agencement de ces nanostructures sur ces ailes rend possible le ph\u00e9nom\u00e8ne d\u2019iridescence: ph\u00e9nom\u00e8ne optique du changement de couleurs d\u2019une surface selon l\u2019angle de l\u2019observateur. En d\u2019autres mots, un renvoi de la lumi\u00e8re dans toutes les directions avec une longueur d\u2019onde diff\u00e9rente. La couleur iris\u00e9e, une nuance de l\u2019arc-en-ciel, ici nous appara\u00eet violette gr\u00e2ce au r\u00e9seau de diffraction de la lumi\u00e8re qui est r\u00e9fl\u00e9chie par les nanostructures des \u00e9cailles et de l\u2019angle d\u2019observation.<\/p>\n

Yoan Beaulieu<\/strong>
\n\u00c9cole Secondaire Cit\u00e9 des Jeunes
\nSaint-Lazare (QC)
\nConcours L\u2019Art de la Physique 2018<\/strong>
\nCat\u00e9gorie projet individuel au niveau secondaire ou c\u00e9gep,<\/strong>
\nMention honorable<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1491577240803-3b6ecef3-7f34″][vc_row_inner][vc_column_inner width=”1\/3″][vc_single_image image=”10504″ img_size=”full” style=”vc_box_rounded”][\/vc_column_inner][vc_column_inner width=”2\/3″][vc_column_text]<\/p>\n

Papier d’emballage iridescent<\/h4>\n

Certains papiers d’emballage cadeaux ont une surface argent\u00e9e qui pr\u00e9sente des reflets multicolores iris\u00e9s variant selon les angles d’\u00e9clairage et d’observation. Fr\u00e9quemment, ces papiers sont faussement qualifi\u00e9s d’holographiques. Cette image montre une section d’environ 2mm x 3mm d’un tel papier photographi\u00e9 au microscope. Le disque central entour\u00e9 d’un anneau sont tous les deux faits d’une mince couche m\u00e9tallique appos\u00e9e sur du papier ou sur une pellicule de plastique. Bien que le disque et l’anneau soient \u00e9clair\u00e9s de la m\u00eame fa\u00e7on, on per\u00e7oit des couleurs tr\u00e8s diff\u00e9rentes. L’observation au microscope permet de voir des structures rainur\u00e9es sur leur surface, mais dans des axes diff\u00e9rents pour le disque et l’anneau. Ces rayures tr\u00e8s fines transforment les surfaces m\u00e9talliques en r\u00e9seaux de diffraction. En pr\u00e9sence de lumi\u00e8re blanche, polychromatique, l’angle d’incidence de l’\u00e9clairage et la position de l’observateur (dans ce cas, le microscope muni de l’appareil photo), d\u00e9termineront si les ondes d’une couleur donn\u00e9e, r\u00e9fl\u00e9chies sur les r\u00e9seaux, s’additionneront pour produire une interf\u00e9rence constructive ou s’annuleront pour produire une interf\u00e9rence destructive. Alors diff\u00e9rentes couleurs apparaitront selon l’orientation du papier et ces couleurs structurelles seront distinctes sur les cercles et les anneaux.<\/p>\n

Richard Germain<\/strong>
\nPointe-des-Cascades (QC)
\nConcours L’Art de la Physique 2018<\/strong>
\nCat\u00e9gorie Ouvert \u00e0 tous, 1e Prix<\/strong>[\/vc_column_text][\/vc_column_inner][\/vc_row_inner][\/vc_tta_section][vc_tta_section title=”Section” tab_id=”1527608250640-88c4b56d-9bea”][vc_single_image image=”10505″][vc_column_text]<\/p>\n

“A birch curtain”<\/strong><\/span><\/h4>\n

One would think that the photography displays a tree’s trunk, a birch, with some growth rings on the side. In reality, this image taken in the middle of summer season shows the passage of the rays of light through a red translucent curtain behind a window. The series of curves on the side, characterised by a variable light intensity, is the consequence of the physics interference phenomenon, that is, the superposition of light waves through the complex network of weaving that characterises the fabric.<\/p>\n

“Le rideau bouleau”<\/strong><\/span><\/h4>\n

On pourrait croire que la photographie montre le profile d’un arbre, un bouleau, avec, \u00e0 son c\u00f4t\u00e9, des cernes de croissance sur la section d’un arbre. En r\u00e9alit\u00e9, l’image prise en pleine saison estivale repr\u00e9sente le passage de la lumi\u00e8re solaire \u00e0 travers des rideaux translucides rouges derri\u00e8re une fen\u00eatre. La s\u00e9rie de courbes visibles sur le c\u00f4t\u00e9, caract\u00e9ris\u00e9es par une intensit\u00e9 lumineuse variable, est le r\u00e9sultat d’un ph\u00e9nom\u00e8ne physique de l’interf\u00e9rence, c’est \u00e0 dire, la superposition des ondes lumineuses \u00e0 travers le complexe r\u00e9seau de la trame constituant la texture du tissu.<\/p>\n

Francesco Barletta<\/strong>
\nSaint-Tharcisius (QC)
\nConcours L’Art de la physique 2018<\/strong>
\nCat\u00e9gorie Ouvert \u00e0 tous, Mention honorable<\/strong><\/p>\n

[\/vc_column_text][\/vc_tta_section][\/vc_tta_pageable][\/vc_column][\/vc_row]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

Note : Nous avons le regret d’annoncer que nous avons suspendu le concours L’art de la physique pour une dur\u00e9e ind\u00e9termin\u00e9e. Le dernier concours a eu lieu en 2019. [vc_row][vc_column][vc_column_text]L’Association canadienne des physiciens et physiciennes a lanc\u00e9 son premier concours, l’Art de la physique, lors de leur congr\u00e8s annuel de 1992, \u00e0 Windsor, Ontario. Ce… Lire la suite »<\/a><\/p>\n","protected":false},"author":8,"featured_media":0,"parent":3362,"menu_order":7,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-13142","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/pages\/13142","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/comments?post=13142"}],"version-history":[{"count":8,"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/pages\/13142\/revisions"}],"predecessor-version":[{"id":25975,"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/pages\/13142\/revisions\/25975"}],"up":[{"embeddable":true,"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/pages\/3362"}],"wp:attachment":[{"href":"https:\/\/cap.ca\/fr\/wp-json\/wp\/v2\/media?parent=13142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}