Chemical & Physical Science Phenomena

This collection showcases puzzling chemical and physical science phenomena. These are observable events, like videos or images, that can be used as a springboard for scientific questions.

Can you walk on water? A women tries to run across a pool of water and falls in. A big machine pours another liquid into the pool. Not only are people able to run across this fluid, but they are able to dance on it, carry other people across it, ride a bike across it, and play soccer on it... and they don't sink!

This phenomenon relates to the study of the states of matter, specifically the properties of liquids and solids. It is interesting because the material appears to be a liquid as it is poured into the container. Yet it behaves like a solid when people run, jump, and bike on it! Solids have a definite volume and shape, while liquids have a definite volume but not a definite shape.

Questions about this phenomenon include: What is this material? Is it a liquid or is it a solid? How are people able to stand on it without sinking? Why did the bike sink, but the person didn't? Why doesn't water act like this fluid?

This is an image of the world's largest rubber ducky at the Tall Ships Challenge on in Philadelphia in 2015. This giant yellow rubber duck is 61 feet tall and weighs 11 tons. It floats besides tall ships, fishing boats, and tug boats.

This phenomenon relates to the concept of density and what determines whether something floats or sinks. It is interesting because little things like pebbles sink to the bottom of a cup of water, but giant things like boats can float! So it is not how big something is or how much it weighs that determines floating, but rather it is the relationship between mass and volume or size.

Questions about this phenomenon include: Is the rubber duck lighter than the boat? How can the rubber duck be made to sink? What is filling up the duck? How much more weight can the duck be before it sinks?