Задачи IYNT 2025
1. Squawking cup
A long thread is attached to the bottom of a plastic cup. Wrap tightly a piece of wet paper towel
around the thread and pull it down. Investigate and explain the squawking sound created in this
experiment.
2. Saliva
What amount of human saliva is sufficient to break down a fixed amount of starch into sugars? Is
it possible to detect differences in enzymatic activity and other properties of saliva for each
member of your team?
3. Blue bottle
A solution of methylene blue and an alkaline solution of a reducing agent are mixed. Under
certain conditions, the resulting solution may repeatedly change color from blue to colorless and
back. How many cycles of color change can be observed depending on the ratio of components
and other parameters?
4. Wobbly bridge
A horizontal metal ruler extends into the air and is supported just at one end, like a cantilever
bridge. A plastic cup is attached to the other end of the ruler. Water droplets fall into the cup from
a dropper at regular time intervals. Motionless at first, the bridge starts oscillating up and down,
and then again comes to rest. Investigate and explain this effect.
5. Euglena
Species of the genus Euglena are sensitive to light. How does the color of a water sample
containing Euglena depend on light levels and presence of nutrients?
6. Explosive precipitate
Ammonia and iodine can be used to produce a dark precipitate which is stable when wet but
explosive when dry. Demonstrate how this precipitate detonates in safe conditions and estimate
what energy is released in the detonation.
7. Vacuum flasks
Measure experimentally how fast the hot water in a vacuum flask cools down to room
temperature. What parameters of vacuum flasks influence their efficacy?
8. Germination rate
If several dry seeds are exposed to the suitable conditions, some seeds germinate much sooner
than others. What factors are essential for one particular seed to germinate? Investigate how the
fraction of germinated seeds increases with time.
9. Film development
The amount of time required to develop a sample of black-and-white photographic film depends
on various factors and may be unknown if the film is expired. Try various methods to measure
the optimum development time for such a film using a developer of your choice. What methods
are fast enough to test a film sample provided by your opponent in the Science Fight?
10. Precise time
Mechanical watches are notorious for losing or gaining time depending on conditions in which
they are used. Compare the accuracy of several watches and find the factors which affect the rate
of any mechanical watch.
11. Drying hair
It is sometimes said that drying hair with hot air damages hair. Use a microscope to put this
statement to a test.
12. Reed diffusers
One or several reeds are inserted into a bottle containing an alcohol-water-oil mixture.
Investigate and explain how evaporation rate depends on the number of reeds and other relevant
parameters.
13. Invent Yourself: Mathematical artwork
Suggest a problem on methods or functions that can be used to describe a 2D drawing with a
minimum amount of numerical data. What changes in the data are sufficient to make a depicted
real-life object unrecognizable by humans?
14. Invent Yourself: Seriation
Seriation is a method in archaeology that allows to chronologically order several similar finds by
comparing gradual changes in contents and style of each find. Seriation is useful if absolute
dating is impossible. Design experiments or suggest cases in which undated real-life finds may
be chronologically ordered with seriation.
15. Invent Yourself: Light scattering
Formulate a problem that links the visible color of a real-life object to the effect of light
scattering.
16. Invent Yourself: Large microscopic organisms
A majority of unicellular organisms are too small to be seen with naked eye, but some of them
are larger than others. Propose a problem to demonstrate and investigate the largest unicellular
organism that can be found in the natural habitat of your area.
17. Invent Yourself: Sixth sense
Sensory organs of various animals may allow them detecting the stimuli inaccessible to human
perception. Suggest a problem that requires studying the sensitivity of a receptor in animals of
your choice.
21. Fruits
Various fruit trees grow in the garden of Bobek Center. Measure the pH of these fruits and determine the exact biological species of the plants.
22. Sunspots
Use a telescope to identify sunspots on the surface of the Sun. What is the number, location, and size of spots today? Estimate the total sunspot area and discuss how significantly these parameters may vary in the upcoming days, months and years.
23. Crystal
Using available chemicals and tools, grow a salt crystal of the largest possible size.
24. Density of an egg
Measure the average density of a chicken egg. How accurate your method is?
25. Homemade compass
A needle is magnetized with a magnet and can rotate freely. Under what conditions the needle can show direction to the North?
26. Rocket pendulum
A deflating air balloon can fly as a rocket, however its motion can be constrained if attached to a long thread and if additional weights are attached to the balloon. Investigate the behavior and stability of the resulting rocket pendulum.