Archives of Ask A Scientist!
About "Ask A Scientist!"
On September 17th, 1998 the Ithaca Journal ran its first "Ask A Scientist!" article in which Professor Neil Ashcroft , who was then the director of CCMR, answered the question "What is Jupiter made of?" Since then, we have received over 1,000 questions from students and adults from all over the world. Select questions are answered weekly and published in the Ithaca Journal and on our web site. "Ask A Scientist!" reaches more than 21,000 Central New York residents through the Ithaca Journal and countless others around the world throught the "Ask a Scientist!" web site.
Across disciplines and across the state, from Nobel Prize winning scientist David Lee to notable science education advocate Bill Nye, researchers and scientists have been called on to respond to these questions. For more than seven years, kids - and a few adults - have been submitting their queries to find out the answer to life's everyday questions.
In your experiment, you are separating casein from milk. Casein is found naturally in cow's milk: however, the amount of casein in a typical glass of milk would only fill a couple of thimbles! To get this sticky stuff away from the rest of the milk, which isn't very sticky, you add vinegar. Vinegar contains an acid, and it causes the casein to precipitate (in other words, it turns the casein into a solid). Now, the casein can be easily separated from the rest of the milk, which is a liquid. The problem now is that casein isn't very sticky after being reacted with acid. Plus, these curds are kind of like cottage cheese - you wouldn't want to stick paper together with this, would you? (yuck!). To make it into a glue, you must add a base. A base is the chemical opposite of an acid. In your experiment, the base is sodium bicarbonate (commonly known as 'baking soda'). When you add it to the curds, it reacts to make the casein soluble again (no longer chunky!), and it is now sticky like a glue.
- How many types of rocks are there throughout the world?
- Why do scuba divers wear rubber?
- How long does it take for the so-called biodegradable plastic cutlery that is now on the market to decompose? What is the energy cost to produce it in the first place? Are they truly an environmentally responsible product?
- How do microwave ovens work?
- Can particle accelerators accurately simulate conditions that occured during the Big Bang?
- How do underwater flares and torches work, when water puts out fires?
- Does energy have mass? Does light have mass?
- Why does the light from a sodium lamp appear orange?
- What would happen if I dyed water green with food coloring, then put it in a humidifier? I was going to do it but my mom made me stop at the last second.
- How are plastics made into useful products?