Dear Mr. Scientist: How come every time I take a shower the curtain attacks me? —Jessie P.
Traditionally people thought that while taking a shower, the warm water heats up the air inside the shower, and as we all know warm air rises. As the air rises, cold air is pulled in from outside the shower and pulls the shower curtain in as well. A professor at the University of Massachusetts used a computer simulation to show this theory is incorrect. What really happens is that spray from the showerhead creates a sideways vortex inside the shower. At the center of the vortex is a low-pressure zone (just like the eye of a hurricane) which, much to the dismay of the person inside the shower, sucks the shower curtain in.
Dear Mr. Scientist: Hand sanitizers claim to kill 99% of bacteria, but doesn’t that encourage the spread of the 1% of bacteria that hand sanitizer can’t kill? —Emily B.
The active ingredient in most hand sanitizers is alcohol which kills bacteria by breaking down their cell membranes and denaturing the proteins within the cell. The 1% that survive aren’t resistant to the effects of alcohol, they’re just lucky. Skin is full of cracks and crevices for bacteria to hide in so it never comes into contact with the alcohol. There is no known mechanism for bacteria to develop a resistance to alcohol, and no studies have shown any potential for resistance, so if the alcohol came into contact with these lucky germs, they’d be dead too.
Dear Mr. Scientist: How do those fancy and expensive induction stoves work? —Nicholas G.
It all comes down to the wonderful and mysterious world of electromagnetism. Simply put, placing a conductor in the magnetic field surrounding a current generates a second current within the conductor. Coils under the cooktop carry an alternating current which creates a magnetic field. When a pot or pan made of a magnetic material is placed in this field, a second current is induced within the cookware. Since the heat is generated from within the cookware, there are no open flames or heating elements to burn yourself on, and less energy is lost to radiant heat.
Mr. Scientist is Michael Leitch. If you have a burning science question you want him to answer, e-mail it to email@example.com