The Cyanometer Is a 225-Year-Old Tool for Measuring the Blueness of the Sky

This simple device was invented in 1789 by Swiss physicist Horace-Bénédict de Saussure and German naturalist Alexander von Humboldt who used the circular array of 53 shaded sections in experiments above the skies over Geneva, Chamonix and Mont Blanc. The Cyanometer helped lead to a successful conclusion that the blueness of the sky is a measure of transparency caused by the amount of water vapor in the atmosphere. You can learn more at the Royal Society of Chemistry

Source: thisiscolossal

4 months ago 531 notes

Create a Dancing Oobleck! (GIF)


Chemists usually classify things as a solid, a liquid, or a gas. But when you mix cornstarch and water, you get a non-Newtonian fluid that seems to be a solid and a liquid at the same time! Make this substance dance using a subwoofer, a thin metal cookie sheet, and an MP3 of an audio test tone. This project solves a challenge under the Chemist Skill.

1 year ago 7 notes

Challenge of the Day: Write a Chemical Message

Need to pass along an important message on paper without having it accidentally discovered by your archenemy? Using very common household products, you can easily whip up an invisible ink recipe and write out your secret message with the solution. All the recipient needs to do is heat up the paper using a stovetop of light bulb, or brush the surface of the paper with a simple iodine mixture to read the message.

1 year ago 59 notes

Non-Newtonian Fluid on a Speaker Cone

Corn starch is a shear thickening non-Newtonian fluid meaning that it becomes more viscous when it is disturbed. When it’s hit repeatedly by something like a speaker cone, it forms weird tendrils. The video was shot at 30 fps and the speaker cone was vibrating at 30 Hz which is why there is no blur. This is the original video with the actual sound of the speaker.

Create your own dancing oobleck using a mixture of cornstarch and water and you’ll get a non-Newtonian fluid that seems to be a solid and a liquid at the same time!  This project solves a Challenge for the Chemist Skill.

1 year ago 38 notes

Chemist is now a Skill.

Chemists want to understand how and why the materials around us behave. They examine how atoms attach, break apart, and reconnect to create different molecules. Then they use their knowledge to create everything from cleaners to medicines to explosions!

Thanks to Meagan Moore for building this Skill!

2 years ago 4 notes