Dezember 24, 2017

Please use several different pencils and leave them stuck in the bad. Do not pull them out.

December 23, 2017

Please hold the postcard approximately 20-30 cm in front of the wall. The lamp should be a bit bigger (no point source) and be placed approximately 3 m away from the wall. Instead of one bigger lamp, you can also use several lamps next to each other. The one or two finger(s) move approximately 20-30 cm away from the postcard between the postcard and the lamp from top to bottom as shown in the movie.

December 21, 2017

Today's experiment only works with a peach, as far as we know. As many of you have difficulties to find a peach today, here a few more hint (But you should really do this experiment yourself in the spring or the summer. It is really wonderful!) You can figure out if a peach swims in water by trying with different types of fruit. Can it stick out by half its height? A peach has a soft, velvet like skin with many little hairs. They point all in the same direction just like a compass needle on the surface of the earth. What happens to the sparkling water at those hairs? What could that do to the peach? If you have any more questions, please ask them via the contact form on the web page. PS: We receive reports that today's experiments also work with a kiwi, a grape or a tomato. Try it out!

December 16, 2017

The balloon does not need to float on top of the water. It is sufficient if it floats somewhere in the water without touching the ground.

December 14, 2017

The PET bottle is completely full with water. The vial is empty.

December 12, 2017

The name of the app used today is "Phyphox". In the movie it is mis-typed.

December 9, 2017

After you pull out the plastic card, watch the water for about half a minute or a minute and submit your answer. You do not need to watch for several minutes or an hour in order to observe the effect.

December 4, 2017

Until 7:50 AM this morning, answers C and D were swapped between the movie and the web page. This is corrected now. Answers submitted earlier than this will be corrected automatically.

December 1, 2017

As question number 1 (cutting chocolate) lead to several misunderstandings, we regard answers "C" and "D" as correct.


In case of questions or obscurities regarding the current PiA-task, we publish hints and advices here. Hence, it’s worth it to read the “Advice of the day” before giving your answer. If there are still questions left, you are welcome to contact us.

You can download the current shopping list for PiA - Physics in Advent 2017 here.

Have fun and enjoy!
Your PiA-team