Dear Mr. Scientist: When I went to get ice today, all of the ice cubes had spikes in the center. There wasn't anything above the tray so nothing dripped onto them. What's going on? –Trey P.
This phenomenon, known as ice spikes, is fairly common. As you know, water expands when it freezes. If there is already a thin sheet of ice on top, the water below the surface will begin to push up and break through the ice. This water will then freeze forming a small bump.
Liquid water beneath the frozen surface continues pushing up, breaking through, and freezing changing the small bump into a tall spike. With a cold enough freezer, good air circulation, and clean water, there's a good chance a few of the ice cubes in your tray will develop spikes.
Dear Mr. Scientist: I heard the moon is supposed the closest it's been in decades. Did this have anything to do with the earthquake, tsunami and volcano in Japan? –Shannon M.
Not at all. Although the moon appeared much larger on the 19th, it was really only 1/4000 of a percent closer than last year and has no major impact on the Earth.
Furthermore, earthquakes are caused by shifting tectonic plates which the moon has no effect on. The tsunami that followed was created as a result of the earthquake, not the moon.
As for the volcano that erupted in Kyushu after the quake, volcanologists aren't sure. It erupted earlier in January so the earthquake may have triggered it, but you can rest assured knowing that it wasn't the moon's doing.
Dear Mr. Scientist: Growing up my mother always told me that I'd ruin my eyes if I sat too close to the television, I'd ruin my eyesight. I thought she was full of it, but I ended up needing to wear glasses. Was she telling the truth? –Shane B.
Chalk this one up in the old wives tales category. Sitting close to the TV may be a sign of nearsightedness, but it is not the cause. According to the American Academy of Ophthalmology there is no evidence supporting the notion that sitting right in front of the TV can damage a child's vision.
The AAO also says that unlike adults, kids can focus on close objects without straining their eyes, which may be why children tend to sit inches from the TV.
To send your question to Mr. Scientist, email Michael at mleitch@wisc.edu.
