Many people love to eat popsicles in the summer, if the popsicles are covered with a thin layer of ice sand, you stick your lips to suck, accidentally mouth will be stuck.

With a pull, it may also tear the skin of the lips, resulting in bleeding. The reason for this phenomenon.

In fact, the need to use the phenomenon of solidification of water in physics to explain.

The phenomenon of water solidification refers to the liquid water cooled to zero degrees Celsius continue to exothermic, will become solid ice.

When the ice stick just into the mouth, the temperature difference between the surface temperature and the surface temperature of people's lips is too large.

The popsicle will absorb heat and the person's lips will release heat.

At this time, the water on the surface of the lips will quickly release heat to zero degrees Celsius due to contact with the popsicle.

The phenomenon of solidification becomes ice, and then with the ice and water mixture on the surface of the popsicle after coagulation, people feel that the mouth is stuck by the popsicle.

In addition, just bought the hands of the popsicle its surface will be visible to the naked eye "white smoke".

These "white smoke" is actually some tiny water droplets.

The air is filled with a lot of tiny water vapor invisible to our naked eye, which contains a large number of water molecules.

In summer, the air temperature is very high, and the temperature of the popsicle is very low.

The water molecules will condense into small water droplets when cold, many tiny little water droplets suspended in the air, converging to form the "white smoke" that we see.

In physics, we call this phenomenon "liquefaction".

In summer, when the weather is hot, eating a cool popsicle is the happiest time for people.

But when eating cold food, the palate will be cooled rapidly, and there is a nerve center at the back of the palate.

At this time, the nerve group of the nerve center will send signals to the brain to change the body temperature.

When the rate of exposure to cold is too fast, these nerve groups are overstimulated and send the wrong signals to the brain indicating that the temperature has dropped too much, which in turn leads to a rapid constriction of the blood vessels in the brain.

After a short period of time, the temperature of the palate returns to normal, the nerve clusters send signals that everything is normal again, and the blood vessels in the brain expand rapidly.

This process lasts only a few seconds, but the consequence of the rapid constriction and expansion of the blood vessels is that the person feels severe pain in the head, usually in the temples, forehead, and sometimes in the face.

In fact, low temperature is also a major cause of migraine.

Therefore, eating popsicles regularly can cause headaches, and most of these induced headaches are relatively short in duration, usually 10 to 30 seconds.

A popsicle before a meal can cause a reduced intake of staple foods or no appetite at all.

The gastrointestinal sterilization function is weakened after a cold spell, and if you eat, you are more vulnerable to bacteria in food.

After a meal a popsicle, the stomach contraction, reduce gastric acid secretion, will cause indigestion, serious intestinal cramps and other serious gastrointestinal injury.

Therefore, it is better to eat a little less popsicles in summer.