Why do our tongues stick to metal in the winter?

This question addresses a dare—or to remain true to the movie, a "triple dog dare"—popularized in A Christmas Story: to stick your tongue to a pole in the winter. A tongue can stick to metal if the metal is below the freezing point of water, 32° Fahrenheit. This phenomenon occurs because the water on a tongue freezes when it touches a sub-32°F metal. Of course, if a metal is very cold, then a tongue will freeze to it more quickly.

The property which allows this rapid freezing to occur is thermal conductivity, or the ability of a material to conduct heat. Metal has considerably high thermal conductivity which means, in the case of the tongue-to-metal dare, it is able to absorb the heat of the tongue at a faster rate than the body is able to supply heat to the tongue. This high thermal conductivity is responsible for quickly cooling the water on a tongue to a temperature where it can freeze. Aside from metals, other materials of high thermal conductivity, like ice, can cause a similar freezing effect. In contrast, materials of low thermal conductivity would not be able to overcome the heat being supplied to the tongue, so the freezing effect would not occur.

Do fish sleep?

Fish do sleep, but not by human standards. Specifically, they enter into a state of rest which serves a similar purpose as sleep. Instead of going unconscious and entering into various stages of sleep like humans, fish usually float in one place or rest on a stable surface (e.g. coral, sea bottom, etc.) and enter an energy-saving, restorative state. In this state, fish will become less aware of their surroundings and their metabolism will slow. Interestingly, research has shown that fish exhibit symptoms of sleep-deprivation if they do not get enough rest.

Is the sea level the same around the world?

Intuition seems to suggest that the ocean should even itself out around the world. Interestingly, this is not the case. The sea is not the same height around the world; rather, local sea levels vary for a number of reasons. These reasons include the presence of ice sheets, changes in prevailing winds, differing ocean currents, the presence of coastal mountain ranges, and more. The global sea level measure is an average of the local sea levels around the world. The National Oceanic and Atmospheric Administration (NOAA) tracks the latest trends in sea levels. These trends are available for viewing via the NOAA website here.

Where do barber poles come from?

Barber poles date back to medieval times when barbers not only performed hair cutting services but tooth extraction and bloodletting as well. In the process of bloodletting, a patient would hold and squeeze a red pole to increase blood circulation (and to hide blood stains). After bloodletting, the patient would receive bandages to heal. The white on the barber pole represents these bandages. In order to advertise their services to the public, barbers would wrap a red bloodletting pole with white bandages and put it outside of their shop.

In some places, like England, legislation dictated that surgeons needed to be distinguished from one-trade barbers, so barbers were required to advertise with blue on their pole while surgeons would use red. Some barber poles in the United States have red, white, and blue colors rather than the traditional red and white. This phenomenon is thought to be an expression of the country's national colors. Alternatively and in conjunction with the bloodletting theme, the blue could represent deoxygenated venous blood while the red represents oxygenated arterial blood. Today, barbers shops around the world continue to place barber poles (although commercialized and plastic) outside of their shops to advertise their services.