Dear Ms. Scientist,
Why do our noses run when we eat spicy foods? —Tia D.
Chemicals, such as capsaicin in chili peppers and allyl isothiocyanate in wasabi and mustard, are responsible for the hot sensation when eating spicy foods. However, they don’t only irritate your tongue. They also irritate your mucus membranes, which line your nose, throat, sinuses and lungs. Your mucus membranes function to keep dust, pollen and infectious agents out of your lungs by producing snot and tears when they are irritated. Even though spicy foods are not infectious agents, the irritation still causes mucus and tears to be produced, resulting in a runny nose. The spicy chemicals produced by the plants evolved as defense mechanisms to prevent herbivores from eating them.
Dear Ms. Scientist,
I can’t even remember the directions between my home in Illinois and Madison. So, how does a bird know where to fly when migrating greater distances? —Tasher L.
There have been many studies about this. However there is still controversy as to how this phenomenon occurs. It depends on the species, but here are some hypotheses. Often, diurnal birds create “mental maps” during their first migration with their parents and remember where to go for the rest of their life. Birds may also create an olfactory “mental map” from gradients of environmental smells, which allows them to navigate even if they have never seen a place before. Some birds are able to sense changes in the magnetic field, allowing them to differentiate between north and south. And other birds learn to navigate from the different positions of the sun and stars and different times of year.
Ask Ms. Scientist is written by Corinne Thornton. If you have a burning science question you want her to answer, tweet @DC_Science or email it to science@dailycardinal.com.
