Review: Curved Mirrors Reporter: China Qing Dao Opponent: Russia 12 FM Reviewer: Switzerland IYNT 2017-Team Switzerland

IYNT 2017-Team Switzerland Problem 3. Invent Yourself: Curved mirrors Suggest and demonstrate interesting experiments in which large concave mirrors can be used to heat up or cool down various objects. We built a sun oven in order to prove that large concave mirrors can be used to heat up various objects and that light which parallels the principle axis all converges at the focus. We also did some experiences to determine the position of the focus and prove that the temperature of the focus is the highest.  A) Apples Why do apple slices turn brown after being cut? Investigate the speed of this process and test methods to prevent browning of apple slices. B) Growing through asphalt Can a little plant grow straight up through concrete or asphalt? C) Tonic water in UV light Tonic water glows brightly when exposed to an ultraviolet black light bulb. It is however easy to quench the glow of tonic water by adding salt. Investigate this effect. What other common substances glow under UV light and how can one influence their glow? D) Salt production Solar evaporation of seawater or salt mining are common methods to produce common salt (NaCl). Propose a method to extract salt from a natural source and determine both productive capacity of your method and purity of the product. Demonstrate an amount of salt produced by your method. E) Rijke's tube If air inside a vertical cylindrical tube open at both ends is heated, the tube produces sound. Study this effect. F) Grow light Investigate how different types of artificial lights affect plant growth. What is the role of light spectrum? G) Milk Develop simple methods allowing determination of some of the important properties of milk. Suggest an investigation requiring comparison of various milk samples. H) Allometry How do length and thickness of bones scale with overall size and weight of animal? I) Routers and garden cress In 2013, five young students claimed a sensational discovery that garden cress (Lepidium sativum) won't germinate when placed near two Wi-Fi routers. Reproduce their experiments under controlled conditions to support or dismiss their conclusions. J) Water from the air Design and construct a device allowing collection of water by condensing moisture from air. Determine if the water obtained with your device is suitable for drinking. What amount of water is possible to collect during one Science Fight? K) Paper wrinkles When a piece of paper dries after being wet, it can get wrinkled. Investigate and explain this phenomenon. L) Tornado machine Build a machine to produce an indoor air tornado. Investigate the properties and stability of the tornado. Is the machine portative enough to be demonstrated at a Science Fight room of the 1st SYNT? Task partially fulfilled IYNT 2017-Team Switzerland

Problem & Interpretation Outline of Report Problem & Interpretation Cooling Theory: Parabolas Theory: Focus Theory: Light Setup Experiments: Heating Analysis: Heating Experiments: Focus Analysis: Focus Conclusion ▪ Good ▪ Ok ▪ Needs Improvement

Strengths and Weaknesses Reporter Large amount of theory on parabolas Went in depth about the ability of parabolas to focus light Determined the actual focus of the parabolic mirror Visuals included in slides to try and show data Controlled variables such as weather conditions Irrelevant information on parabolas (e.g. formulas) Slides unorganized and chaotic (formulas) Cooling not mentioned at all Name of concave curve used (parabola/paraboloid for 3D) not mentioned Reason why parabolas focus light Graphs not used to represent data Did not specifically mention what concave means Visuals not perfect (e.g. mistake in parabola visual) IYNT 2017-Team Switzerland

Strengths and Weaknesses Opponent Clarifying questions not used well Superficial weaknesses used instead of specific weaknesses Incorrect weaknesses and strengths (e.g. dimensions of mirror) Time was not used well Read directly off of slide for strengths and weakness Irrelevant questions asked to reporter (e.g. questions about focus) Asked some questions during the discussion and clarifying questions Was able to point out certain flaws in the reporters experiments IYNT 2017-Team Switzerland

IYNT 2017-Team Switzerland Discussion Burning of paper Focus point Environmental factors A) Apples Why do apple slices turn brown after being cut? Investigate the speed of this process and test methods to prevent browning of apple slices. B) Growing through asphalt Can a little plant grow straight up through concrete or asphalt? C) Tonic water in UV light Tonic water glows brightly when exposed to an ultraviolet black light bulb. It is however easy to quench the glow of tonic water by adding salt. Investigate this effect. What other common substances glow under UV light and how can one influence their glow? D) Salt production Solar evaporation of seawater or salt mining are common methods to produce common salt (NaCl). Propose a method to extract salt from a natural source and determine both productive capacity of your method and purity of the product. Demonstrate an amount of salt produced by your method. E) Rijke's tube If air inside a vertical cylindrical tube open at both ends is heated, the tube produces sound. Study this effect. F) Grow light Investigate how different types of artificial lights affect plant growth. What is the role of light spectrum? G) Milk Develop simple methods allowing determination of some of the important properties of milk. Suggest an investigation requiring comparison of various milk samples. H) Allometry How do length and thickness of bones scale with overall size and weight of animal? I) Routers and garden cress In 2013, five young students claimed a sensational discovery that garden cress (Lepidium sativum) won't germinate when placed near two Wi-Fi routers. Reproduce their experiments under controlled conditions to support or dismiss their conclusions. J) Water from the air Design and construct a device allowing collection of water by condensing moisture from air. Determine if the water obtained with your device is suitable for drinking. What amount of water is possible to collect during one Science Fight? K) Paper wrinkles When a piece of paper dries after being wet, it can get wrinkled. Investigate and explain this phenomenon. L) Tornado machine Build a machine to produce an indoor air tornado. Investigate the properties and stability of the tornado. Is the machine portative enough to be demonstrated at a Science Fight room of the 1st SYNT? IYNT 2017-Team Switzerland

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