Dear Mr. Scientist,
What causes things like old newspapers and books to become yellow over time?
—Jon C.
As you know, most of the paper we use is made by chopping up a tree into small chips and treating those chips with chemicals to break them down into pulp. An unfortunate side effect of the pulping process is that it leaves the paper slightly acidic. This, combined with exposure to light and oxygen, causes long polymers like cellulose and lignin (they give wood cells their structure) to breakdown and oxidize resulting in a paper that darkens and yellows over time.
Dear Mr. Scientist,
How do sea monkeys work? When you buy them they’re all dried up, but when you add them to water they come to life.
—Sarah L.
When you buy sea monkeys, which, despite their name, are not primates but brine shrimp, you are buying eggs in a state of suspended animation called diapause. In the wild, the lakes and ponds that brine shrimp live in often dry up and disappear in the summer, but by producing eggs this way their young are able to survive until their watery homes reappear. Diapause isn’t unique to brine shrimp either. Most insects and many types of fish also go into this dormant state to survive adverse environmental conditions.
Ask Mr. Scientist is written by Michael Leitch. If you have a burning science question you want him to answer, tweet @DC_Science or email it to science@dailycardinal.com.
