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.
- Why does a nuclear bomb create so much energy with such a small amount of mass? Why is there so much nuclear fallout with such a small amount of nuclear material in the bomb?
- If an object passes in front of a projector/point-source of light that illuminates a screen far away, it will cast a shadow on the screen. Now, if the object moves fast enough, and/or if the screen is far enough, the shadow will move much faster than the object, and at a certain speed of the object, the shadow will move faster than the speed of light. What would a bystander, or a camera, see?
- Why does the earth behave like a magnet?
- How come ice skates slide over ice so easily when hydrogen bonds usually make things stick?
- How do microwave ovens work?
- When I place a straw in a glass of soda, the part of the straw in the water appears bigger and also seems bent as I look down into the cup. Why does it look bigger and why does it appear to bend upon entering the water?
- How are the colors in a rainbow made?
- Why is the full moon bigger in some places than in others?
- If plastic is made to be biodegradable, then won't the plastic forks and spoons we use dissolve in our mouth?
- How does a microphone work?